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This is to resolve an issue with ArchLinux where it expects sd_mod to be a module while building bootloader.

If this would break anything at your side I wont be upset if it's rejected - just trying to fix upstream instead of patching downstream.

Cheers!

This is to resolve an issue with ArchLinux where it expects sd_mod to be a module while building bootloader.

If this would break anything at your side I wont be upset if it's rejected - just trying to fix upstream instead of patching downstream.

Cheers!
@jwrdegoede
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Hi,

I'm sorry but I'm trying to keep my ,config as close as possible to the Fedora kernel .config, so I don't want to change this. You could try asking the arch people to fix their scripts to deal with this instead.

Regards,

Hans

@jwrdegoede jwrdegoede closed this Aug 20, 2017
@cawilliamson
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No worries - I understand. 👍

@cawilliamson cawilliamson deleted the patch-1 branch August 20, 2017 08:58
jwrdegoede pushed a commit that referenced this pull request Aug 22, 2017
c70c473 "ARCv2: SLC: Make sure busy bit is set properly on SLC flushing"
fixes problem for entire SLC operation where the problem was initially
caught. But given a nature of the issue it is perfectly possible for
busy bit to be read incorrectly even when region operation was started.

So extending initial fix for regional operation as well.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: stable@vger.kernel.org   #4.10
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
jwrdegoede pushed a commit that referenced this pull request Aug 22, 2017
It is necessary to explicitly set both SLC_AUX_RGN_START1 and SLC_AUX_RGN_END1
which hold MSB bits of the physical address correspondingly of region start
and end otherwise SLC region operation is executed in unpredictable manner

Without this patch, SLC flushes on HSDK (IOC disabled) were taking
seconds.

Cc: stable@vger.kernel.org   #4.4+
Reported-by: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: PAR40 regs only written if PAE40 exist]
jwrdegoede pushed a commit that referenced this pull request Aug 22, 2017
… SoC

PAE40 confiuration in hardware extends some of the address registers
for TLB/cache ops to 2 words.

So far kernel was NOT setting the higher word if feature was not enabled
in software which is wrong. Those need to be set to 0 in such case.

Normally this would be done in the cache flush / tlb ops, however since
these registers only exist conditionally, this would have to be
conditional to a flag being set on boot which is expensive/ugly -
specially for the more common case of PAE exists but not in use.
Optimize that by zero'ing them once at boot - nobody will write to
them afterwards

Cc: stable@vger.kernel.org   #4.4+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
jwrdegoede pushed a commit that referenced this pull request Aug 26, 2017
…buffer

Since we split the scsi_request out of struct request bsg fails to
provide a reply-buffer for the drivers. This was done via the pointer
for sense-data, that is not preallocated anymore.

Failing to allocate/assign it results in illegal dereferences because
LLDs use this pointer unquestioned.

An example panic on s390x, using the zFCP driver, looks like this (I had
debugging on, otherwise NULL-pointer dereferences wouldn't even panic on
s390x):

Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6403
Fault in home space mode while using kernel ASCE.
AS:0000000001590007 R3:0000000000000024
Oops: 0038 ilc:2 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: <Long List>
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.12.0-bsg-regression+ #3
Hardware name: IBM 2964 N96 702 (z/VM 6.4.0)
task: 0000000065cb0100 task.stack: 0000000065cb4000
Krnl PSW : 0704e00180000000 000003ff801e4156 (zfcp_fc_ct_els_job_handler+0x16/0x58 [zfcp])
           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000001 000000005fa9d0d0 000000005fa9d078 0000000000e16866
           000003ff00000290 6b6b6b6b6b6b6b6b 0000000059f78f00 000000000000000f
           00000000593a0958 00000000593a0958 0000000060d88800 000000005ddd4c38
           0000000058b50100 07000000659cba08 000003ff801e8556 00000000659cb9a8
Krnl Code: 000003ff801e4146: e31020500004        lg      %r1,80(%r2)
           000003ff801e414c: 58402040           l       %r4,64(%r2)
          #000003ff801e4150: e35020200004       lg      %r5,32(%r2)
          >000003ff801e4156: 50405004           st      %r4,4(%r5)
           000003ff801e415a: e54c50080000       mvhi    8(%r5),0
           000003ff801e4160: e33010280012       lt      %r3,40(%r1)
           000003ff801e4166: a718fffb           lhi     %r1,-5
           000003ff801e416a: 1803               lr      %r0,%r3
Call Trace:
([<000003ff801e8556>] zfcp_fsf_req_complete+0x726/0x768 [zfcp])
 [<000003ff801ea82a>] zfcp_fsf_reqid_check+0x102/0x180 [zfcp]
 [<000003ff801eb980>] zfcp_qdio_int_resp+0x230/0x278 [zfcp]
 [<00000000009b91b6>] qdio_kick_handler+0x2ae/0x2c8
 [<00000000009b9e3e>] __tiqdio_inbound_processing+0x406/0xc10
 [<00000000001684c2>] tasklet_action+0x15a/0x1d8
 [<0000000000bd28ec>] __do_softirq+0x3ec/0x848
 [<00000000001675a4>] irq_exit+0x74/0xf8
 [<000000000010dd6a>] do_IRQ+0xba/0xf0
 [<0000000000bd19e8>] io_int_handler+0x104/0x2d4
 [<00000000001033b6>] enabled_wait+0xb6/0x188
([<000000000010339e>] enabled_wait+0x9e/0x188)
 [<000000000010396a>] arch_cpu_idle+0x32/0x50
 [<0000000000bd0112>] default_idle_call+0x52/0x68
 [<00000000001cd0fa>] do_idle+0x102/0x188
 [<00000000001cd41e>] cpu_startup_entry+0x3e/0x48
 [<0000000000118c64>] smp_start_secondary+0x11c/0x130
 [<0000000000bd2016>] restart_int_handler+0x62/0x78
 [<0000000000000000>]           (null)
INFO: lockdep is turned off.
Last Breaking-Event-Address:
 [<000003ff801e41d6>] zfcp_fc_ct_job_handler+0x3e/0x48 [zfcp]

Kernel panic - not syncing: Fatal exception in interrupt

This patch moves bsg-lib to allocate and setup struct bsg_job ahead of
time, including the allocation of a buffer for the reply-data.

This means, struct bsg_job is not allocated separately anymore, but as part
of struct request allocation - similar to struct scsi_cmd. Reflect this in
the function names that used to handle creation/destruction of struct
bsg_job.

Reported-by: Steffen Maier <maier@linux.vnet.ibm.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Fixes: 82ed4db ("block: split scsi_request out of struct request")
Cc: <stable@vger.kernel.org> #4.11+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
jwrdegoede pushed a commit that referenced this pull request Oct 1, 2017
If the gpu submit fails, bail out to avoid accessing a potentially
unititalized fence.

CC: stable@vger.kernel.org #4.12+
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
jwrdegoede pushed a commit that referenced this pull request Oct 4, 2017
Commit 4c39d4b ("usb: xhci: use bus->sysdev for DMA configuration")
updated the method determining DMA for XHCI from sysdev. However, this
patch broke the ability to enumerate the FWNODE from parent ACPI devices
from the child plat XHCI device.

Currently, xhci_plat is not set up properly when the parent device is an
ACPI node. The conditions that xhci_plat_probe should satisfy are

1. xhci_plat comes from firmware
2. xhci_plat is child of a device from firmware (dwc3-plat)
3. xhci_plat is grandchild of a pci device (dwc3-pci)

Case 2 is covered when the child is an OF node (by checking
sysdev->parent->of_node), however, an ACPI parent will return NULL in
the of_node check and will thus not result in sysdev being set to
sysdev->parent

[   17.591549] xhci-hcd: probe of xhci-hcd.6.auto failed with error -5

This change adds a check for ACPI to completely allow for condition 2.
This is done by first checking if the parent node is of type ACPI (e.g.,
dwc3-plat) and set sysdev to sysdev->parent if either of the two
following conditions are met:

1: If fwnode is empty (in the case that platform_device_add_properties
was not called on the allocated platform device)
2: fwnode exists but is not of type ACPI (this would happen if
platform_device_add_properties was called on the allocated device.
Instead of type FWNODE_ACPI, you would end up with FWNODE_PDATA)

Cc: stable@vger.kernel.org #4.12.x
Cc: stable@vger.kernel.org #4.13.x

Fixes: 4c39d4b ("usb: xhci: use bus->sysdev for DMA configuration")
Tested-by: Thang Q. Nguyen <tqnguyen@apm.com>
Signed-off-by: Adam Wallis <awallis@codeaurora.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jwrdegoede pushed a commit that referenced this pull request Oct 4, 2017
The flow control workaround for ASM1042A xHC hosts sleeps between
register polling. The workaround gets called in several places, among
them with spin_lock_irq() held when xHC host is resumed or hoplug removed.

This was noticed as kernel panics at resume on a Dell XPS15 9550 with
TB16 thunderbolt dock.

Avoid sleeping with spin_lock_irq() held, use udelay() instead

The original workaround was added to 4.9 and 4.12 stable releases,
this patch needs to be applied to those as well.

Fixes: 9da5a10 ("xhci: Bad Ethernet performance plugged in ASM1042A host")
Cc: <stable@vger.kernel.org> #4.9+
Reported-by: Jose Marino <marinoj@nso.edu>
Tested-by: Jose Marino <marinoj@nso.edu>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jwrdegoede pushed a commit that referenced this pull request Oct 13, 2017
ppp_release() tries to ensure that netdevices are unregistered before
decrementing the unit refcount and running ppp_destroy_interface().

This is all fine as long as the the device is unregistered by
ppp_release(): the unregister_netdevice() call, followed by
rtnl_unlock(), guarantee that the unregistration process completes
before rtnl_unlock() returns.

However, the device may be unregistered by other means (like
ppp_nl_dellink()). If this happens right before ppp_release() calling
rtnl_lock(), then ppp_release() has to wait for the concurrent
unregistration code to release the lock.
But rtnl_unlock() releases the lock before completing the device
unregistration process. This allows ppp_release() to proceed and
eventually call ppp_destroy_interface() before the unregistration
process completes. Calling free_netdev() on this partially unregistered
device will BUG():

 ------------[ cut here ]------------
 kernel BUG at net/core/dev.c:8141!
 invalid opcode: 0000 [#1] SMP

 CPU: 1 PID: 1557 Comm: pppd Not tainted 4.14.0-rc2+ #4
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014

 Call Trace:
  ppp_destroy_interface+0xd8/0xe0 [ppp_generic]
  ppp_disconnect_channel+0xda/0x110 [ppp_generic]
  ppp_unregister_channel+0x5e/0x110 [ppp_generic]
  pppox_unbind_sock+0x23/0x30 [pppox]
  pppoe_connect+0x130/0x440 [pppoe]
  SYSC_connect+0x98/0x110
  ? do_fcntl+0x2c0/0x5d0
  SyS_connect+0xe/0x10
  entry_SYSCALL_64_fastpath+0x1a/0xa5

 RIP: free_netdev+0x107/0x110 RSP: ffffc28a40573d88
 ---[ end trace ed294ff0cc40eeff ]---

We could set the ->needs_free_netdev flag on PPP devices and move the
ppp_destroy_interface() logic in the ->priv_destructor() callback. But
that'd be quite intrusive as we'd first need to unlink from the other
channels and units that depend on the device (the ones that used the
PPPIOCCONNECT and PPPIOCATTACH ioctls).

Instead, we can just let the netdevice hold a reference on its
ppp_file. This reference is dropped in ->priv_destructor(), at the very
end of the unregistration process, so that neither ppp_release() nor
ppp_disconnect_channel() can call ppp_destroy_interface() in the interim.

Reported-by: Beniamino Galvani <bgalvani@redhat.com>
Fixes: 8cb775b ("ppp: fix device unregistration upon netns deletion")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
jwrdegoede pushed a commit that referenced this pull request Oct 13, 2017
Since we switched to upstream IOSF MBI API the custom code become not in
use anymore.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
jwrdegoede pushed a commit that referenced this pull request Oct 18, 2017
This patch fixes a regression caused by the new changes
in the "run wake" handlers.

The mei devices that support D0i3 are no longer receiving an interrupt
after entering runtime suspend state and will stall.

pci_dev_run_wake function now returns "true" for some devices
(including mei) for which it used to return "false",
arguably incorrectly as "run wake" used to mean that
wakeup signals can be generated for a device in
the working state of the system, so it could not be enabled
or disabled before too.

MEI maps runtime suspend/resume to its own defined
power gating (PG) states, (D0i3 or other depending on generation),
hence we need to go around the native PCI runtime service which
eventually brings the device into D3cold/hot state,
but the mei devices cannot wake up from D3 unlike from D0i3/PG state,
which keeps irq running.
To get around PCI device native runtime pm,
MEI uses runtime pm domain handlers which take precedence.

Cc: <stable@vger.kernel.org> #4.13+
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jwrdegoede pushed a commit that referenced this pull request Oct 18, 2017
Since we switched to upstream IOSF MBI API the custom code become not in
use anymore.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
jwrdegoede pushed a commit that referenced this pull request Nov 20, 2017
v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN
recovery") extended accessing parent pointer fields of struct
zfcp_erp_action for tracing.  If an erp_action has never been enqueued
before, these parent pointer fields are uninitialized and NULL. Examples
are zfcp objects freshly added to the parent object's children list,
before enqueueing their first recovery subsequently. In
zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action
fields can cause a NULL pointer dereference.  Since the kernel can read
from lowcore on s390, it does not immediately cause a kernel page
fault. Instead it can cause hangs on trying to acquire the wrong
erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl()
                      ^bogus^
while holding already other locks with IRQs disabled.

Real life example from attaching lots of LUNs in parallel on many CPUs:

crash> bt 17723
PID: 17723  TASK: ...               CPU: 25  COMMAND: "zfcperp0.0.1800"
 LOWCORE INFO:
  -psw      : 0x0404300180000000 0x000000000038e424
  -function : _raw_spin_lock_wait_flags at 38e424
...
 #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp]
 #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp]
 #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp]
 #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp]
 #4 [fdde8fe60] kthread at 173550
 #5 [fdde8feb8] kernel_thread_starter at 10add2

zfcp_adapter
 zfcp_port
  zfcp_unit <address>, 0x404040d600000000
  scsi_device NULL, returning early!
zfcp_scsi_dev.status = 0x40000000
0x40000000 ZFCP_STATUS_COMMON_RUNNING

crash> zfcp_unit <address>
struct zfcp_unit {
  erp_action = {
    adapter = 0x0,
    port = 0x0,
    unit = 0x0,
  },
}

zfcp_erp_action is always fully embedded into its container object. Such
container object is never moved in its object tree (only add or delete).
Hence, erp_action parent pointers can never change.

To fix the issue, initialize the erp_action parent pointers before
adding the erp_action container to any list and thus before it becomes
accessible from outside of its initializing function.

In order to also close the time window between zfcp_erp_setup_act()
memsetting the entire erp_action to zero and setting the parent pointers
again, drop the memset and instead explicitly initialize individually
all erp_action fields except for parent pointers. To be extra careful
not to introduce any other unintended side effect, even keep zeroing the
erp_action fields for list and timer. Also double-check with
WARN_ON_ONCE that erp_action parent pointers never change, so we get to
know when we would deviate from previous behavior.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery")
Cc: <stable@vger.kernel.org> #2.6.32+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
jwrdegoede pushed a commit that referenced this pull request Nov 20, 2017
Thomas reported that 'perf buildid-list' gets a SEGFAULT due to NULL
pointer deref when he ran it on a data with namespace events.  It was
because the buildid_id__mark_dso_hit_ops lacks the namespace event
handler and perf_too__fill_default() didn't set it.

  Program received signal SIGSEGV, Segmentation fault.
  0x0000000000000000 in ?? ()
  Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x
  +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x
  +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x
  (gdb) where
  #0  0x0000000000000000 in ?? ()
  #1  0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18,
      evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888,
      tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287
  #2  0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>,
      sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340
  #3  perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470,
      file_offset=file_offset@entry=1136) at util/session.c:1522
  #4  0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>,
      data_offset=<optimized out>, session=0x0) at util/session.c:1899
  #5  perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953
  #6  0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>)
      at builtin-buildid-list.c:83
  #7  cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115
  #8  0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0)
      at perf.c:296
  #9  0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348
  #10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392
  #11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536
  (gdb)

Fix it by adding a stub event handler for namespace event.

Committer testing:

Further clarifying, plain using 'perf buildid-list' will not end up in a
SEGFAULT when processing a perf.data file with namespace info:

  # perf record -a --namespaces sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 2.024 MB perf.data (1058 samples) ]
  # perf buildid-list | wc -l
  38
  # perf buildid-list | head -5
  e2a171c7b905826fc8494f0711ba76ab6abbd604 /lib/modules/4.14.0-rc3+/build/vmlinux
  874840a02d8f8a31cedd605d0b8653145472ced3 /lib/modules/4.14.0-rc3+/kernel/arch/x86/kvm/kvm-intel.ko
  ea7223776730cd8a22f320040aae4d54312984bc /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/i915/i915.ko
  5961535e6732a8edb7f22b3f148bb2fa2e0be4b9 /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/drm.ko
  f045f54aa78cf1931cc893f78b6cbc52c72a8cb1 /usr/lib64/libc-2.25.so
  #

It is only when one asks for checking what of those entries actually had
samples, i.e. when we use either -H or --with-hits, that we will process
all the PERF_RECORD_ events, and since tools/perf/builtin-buildid-list.c
neither explicitely set a perf_tool.namespaces() callback nor the
default stub was set that we end up, when processing a
PERF_RECORD_NAMESPACE record, causing a SEGFAULT:

  # perf buildid-list -H
  Segmentation fault (core dumped)
  ^C
  #

Reported-and-Tested-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Fixes: f3b3614 ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info")
Link: http://lkml.kernel.org/r/20171017132900.11043-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
jwrdegoede pushed a commit that referenced this pull request Nov 20, 2017
When an EMAD is transmitted, a timeout work item is scheduled with a
delay of 200ms, so that another EMAD will be retried until a maximum of
five retries.

In certain situations, it's possible for the function waiting on the
EMAD to be associated with a work item that is queued on the same
workqueue (`mlxsw_core`) as the timeout work item. This results in
flushing a work item on the same workqueue.

According to commit e159489 ("workqueue: relax lockdep annotation
on flush_work()") the above may lead to a deadlock in case the workqueue
has only one worker active or if the system in under memory pressure and
the rescue worker is in use. The latter explains the very rare and
random nature of the lockdep splats we have been seeing:

[   52.730240] ============================================
[   52.736179] WARNING: possible recursive locking detected
[   52.742119] 4.14.0-rc3jiri+ #4 Not tainted
[   52.746697] --------------------------------------------
[   52.752635] kworker/1:3/599 is trying to acquire lock:
[   52.758378]  (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c4fa4>] flush_work+0x3a4/0x5e0
[   52.767837]
               but task is already holding lock:
[   52.774360]  (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0
[   52.784495]
               other info that might help us debug this:
[   52.791794]  Possible unsafe locking scenario:
[   52.798413]        CPU0
[   52.801144]        ----
[   52.803875]   lock(mlxsw_core_driver_name);
[   52.808556]   lock(mlxsw_core_driver_name);
[   52.813236]
                *** DEADLOCK ***
[   52.819857]  May be due to missing lock nesting notation
[   52.827450] 3 locks held by kworker/1:3/599:
[   52.832221]  #0:  (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0
[   52.842846]  #1:  ((&(&bridge->fdb_notify.dw)->work)){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0
[   52.854537]  #2:  (rtnl_mutex){+.+.}, at: [<ffffffff822ad8e7>] rtnl_lock+0x17/0x20
[   52.863021]
               stack backtrace:
[   52.867890] CPU: 1 PID: 599 Comm: kworker/1:3 Not tainted 4.14.0-rc3jiri+ #4
[   52.875773] Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016
[   52.886267] Workqueue: mlxsw_core mlxsw_sp_fdb_notify_work [mlxsw_spectrum]
[   52.894060] Call Trace:
[   52.909122]  __lock_acquire+0xf6f/0x2a10
[   53.025412]  lock_acquire+0x158/0x440
[   53.047557]  flush_work+0x3c4/0x5e0
[   53.087571]  __cancel_work_timer+0x3ca/0x5e0
[   53.177051]  cancel_delayed_work_sync+0x13/0x20
[   53.182142]  mlxsw_reg_trans_bulk_wait+0x12d/0x7a0 [mlxsw_core]
[   53.194571]  mlxsw_core_reg_access+0x586/0x990 [mlxsw_core]
[   53.225365]  mlxsw_reg_query+0x10/0x20 [mlxsw_core]
[   53.230882]  mlxsw_sp_fdb_notify_work+0x2a3/0x9d0 [mlxsw_spectrum]
[   53.237801]  process_one_work+0x8f1/0x12f0
[   53.321804]  worker_thread+0x1fd/0x10c0
[   53.435158]  kthread+0x28e/0x370
[   53.448703]  ret_from_fork+0x2a/0x40
[   53.453017] mlxsw_spectrum 0000:01:00.0: EMAD retries (2/5) (tid=bf4549b100000774)
[   53.453119] mlxsw_spectrum 0000:01:00.0: EMAD retries (5/5) (tid=bf4549b100000770)
[   53.453132] mlxsw_spectrum 0000:01:00.0: EMAD reg access failed (tid=bf4549b100000770,reg_id=200b(sfn),type=query,status=0(operation performed))
[   53.453143] mlxsw_spectrum 0000:01:00.0: Failed to get FDB notifications

Fix this by creating another workqueue for EMAD timeouts, thereby
preventing the situation of a work item trying to flush a work item
queued on the same workqueue.

Fixes: caf7297 ("mlxsw: core: Introduce support for asynchronous EMAD register access")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
jwrdegoede pushed a commit that referenced this pull request Nov 20, 2017
The warning below says it all:

  BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1
  caller is __this_cpu_preempt_check
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc8 #4
  Call Trace:
   dump_stack
   check_preemption_disabled
   ? do_early_param
   __this_cpu_preempt_check
   arch_perfmon_init
   op_nmi_init
   ? alloc_pci_root_info
   oprofile_arch_init
   oprofile_init
   do_one_initcall
   ...

These accessors should not have been used in the first place: it is PPro so
no mixed silicon revisions and thus it can simply use boot_cpu_data.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Fix-creation-mandated-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Robert Richter <rric@kernel.org>
Cc: x86@kernel.org
Cc: stable@vger.kernel.org
jwrdegoede pushed a commit that referenced this pull request Nov 25, 2017
We don't need struct_mutex to initialise userptr (it just allocates a
workqueue for itself etc), but we do need struct_mutex later on in
i915_gem_init() in order to feed requests onto the HW.

This should break the chain

[  385.697902] ======================================================
[  385.697907] WARNING: possible circular locking dependency detected
[  385.697913] 4.14.0-CI-Patchwork_7234+ #1 Tainted: G     U
[  385.697917] ------------------------------------------------------
[  385.697922] perf_pmu/2631 is trying to acquire lock:
[  385.697927]  (&mm->mmap_sem){++++}, at: [<ffffffff811bfe1e>] __might_fault+0x3e/0x90
[  385.697941]
               but task is already holding lock:
[  385.697946]  (&cpuctx_mutex){+.+.}, at: [<ffffffff8116fe8c>] perf_event_ctx_lock_nested+0xbc/0x1d0
[  385.697957]
               which lock already depends on the new lock.

[  385.697963]
               the existing dependency chain (in reverse order) is:
[  385.697970]
               -> #4 (&cpuctx_mutex){+.+.}:
[  385.697980]        __mutex_lock+0x86/0x9b0
[  385.697985]        perf_event_init_cpu+0x5a/0x90
[  385.697991]        perf_event_init+0x178/0x1a4
[  385.697997]        start_kernel+0x27f/0x3f1
[  385.698003]        verify_cpu+0x0/0xfb
[  385.698006]
               -> #3 (pmus_lock){+.+.}:
[  385.698015]        __mutex_lock+0x86/0x9b0
[  385.698020]        perf_event_init_cpu+0x21/0x90
[  385.698025]        cpuhp_invoke_callback+0xca/0xc00
[  385.698030]        _cpu_up+0xa7/0x170
[  385.698035]        do_cpu_up+0x57/0x70
[  385.698039]        smp_init+0x62/0xa6
[  385.698044]        kernel_init_freeable+0x97/0x193
[  385.698050]        kernel_init+0xa/0x100
[  385.698055]        ret_from_fork+0x27/0x40
[  385.698058]
               -> #2 (cpu_hotplug_lock.rw_sem){++++}:
[  385.698068]        cpus_read_lock+0x39/0xa0
[  385.698073]        apply_workqueue_attrs+0x12/0x50
[  385.698078]        __alloc_workqueue_key+0x1d8/0x4d8
[  385.698134]        i915_gem_init_userptr+0x5f/0x80 [i915]
[  385.698176]        i915_gem_init+0x7c/0x390 [i915]
[  385.698213]        i915_driver_load+0x99e/0x15c0 [i915]
[  385.698250]        i915_pci_probe+0x33/0x90 [i915]
[  385.698256]        pci_device_probe+0xa1/0x130
[  385.698262]        driver_probe_device+0x293/0x440
[  385.698267]        __driver_attach+0xde/0xe0
[  385.698272]        bus_for_each_dev+0x5c/0x90
[  385.698277]        bus_add_driver+0x16d/0x260
[  385.698282]        driver_register+0x57/0xc0
[  385.698287]        do_one_initcall+0x3e/0x160
[  385.698292]        do_init_module+0x5b/0x1fa
[  385.698297]        load_module+0x2374/0x2dc0
[  385.698302]        SyS_finit_module+0xaa/0xe0
[  385.698307]        entry_SYSCALL_64_fastpath+0x1c/0xb1
[  385.698311]
               -> #1 (&dev->struct_mutex){+.+.}:
[  385.698320]        __mutex_lock+0x86/0x9b0
[  385.698361]        i915_mutex_lock_interruptible+0x4c/0x130 [i915]
[  385.698403]        i915_gem_fault+0x206/0x760 [i915]
[  385.698409]        __do_fault+0x1a/0x70
[  385.698413]        __handle_mm_fault+0x7c4/0xdb0
[  385.698417]        handle_mm_fault+0x154/0x300
[  385.698440]        __do_page_fault+0x2d6/0x570
[  385.698445]        page_fault+0x22/0x30
[  385.698449]
               -> #0 (&mm->mmap_sem){++++}:
[  385.698459]        lock_acquire+0xaf/0x200
[  385.698464]        __might_fault+0x68/0x90
[  385.698470]        _copy_to_user+0x1e/0x70
[  385.698475]        perf_read+0x1aa/0x290
[  385.698480]        __vfs_read+0x23/0x120
[  385.698484]        vfs_read+0xa3/0x150
[  385.698488]        SyS_read+0x45/0xb0
[  385.698493]        entry_SYSCALL_64_fastpath+0x1c/0xb1
[  385.698497]
               other info that might help us debug this:

[  385.698505] Chain exists of:
                 &mm->mmap_sem --> pmus_lock --> &cpuctx_mutex

[  385.698517]  Possible unsafe locking scenario:

[  385.698522]        CPU0                    CPU1
[  385.698526]        ----                    ----
[  385.698529]   lock(&cpuctx_mutex);
[  385.698553]                                lock(pmus_lock);
[  385.698558]                                lock(&cpuctx_mutex);
[  385.698564]   lock(&mm->mmap_sem);
[  385.698568]
                *** DEADLOCK ***

[  385.698574] 1 lock held by perf_pmu/2631:
[  385.698578]  #0:  (&cpuctx_mutex){+.+.}, at: [<ffffffff8116fe8c>] perf_event_ctx_lock_nested+0xbc/0x1d0
[  385.698589]
               stack backtrace:
[  385.698595] CPU: 3 PID: 2631 Comm: perf_pmu Tainted: G     U          4.14.0-CI-Patchwork_7234+ #1
[  385.698602] Hardware name:                  /NUC6CAYB, BIOS AYAPLCEL.86A.0040.2017.0619.1722 06/19/2017
[  385.698609] Call Trace:
[  385.698615]  dump_stack+0x5f/0x86
[  385.698621]  print_circular_bug.isra.18+0x1d0/0x2c0
[  385.698627]  __lock_acquire+0x19c3/0x1b60
[  385.698634]  ? generic_exec_single+0x77/0xe0
[  385.698640]  ? lock_acquire+0xaf/0x200
[  385.698644]  lock_acquire+0xaf/0x200
[  385.698650]  ? __might_fault+0x3e/0x90
[  385.698655]  __might_fault+0x68/0x90
[  385.698660]  ? __might_fault+0x3e/0x90
[  385.698665]  _copy_to_user+0x1e/0x70
[  385.698670]  perf_read+0x1aa/0x290
[  385.698675]  __vfs_read+0x23/0x120
[  385.698682]  ? __fget+0x101/0x1f0
[  385.698686]  vfs_read+0xa3/0x150
[  385.698691]  SyS_read+0x45/0xb0
[  385.698696]  entry_SYSCALL_64_fastpath+0x1c/0xb1
[  385.698701] RIP: 0033:0x7ff1c46876ed
[  385.698705] RSP: 002b:00007fff13552f90 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
[  385.698712] RAX: ffffffffffffffda RBX: ffffc90000647ff0 RCX: 00007ff1c46876ed
[  385.698718] RDX: 0000000000000010 RSI: 00007fff13552fa0 RDI: 0000000000000005
[  385.698723] RBP: 000056063d300580 R08: 0000000000000000 R09: 0000000000000060
[  385.698729] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000046
[  385.698734] R13: 00007fff13552c6f R14: 00007ff1c6279d00 R15: 00007ff1c6279a40

Testcase: igt/perf_pmu
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171122172621.16158-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
jwrdegoede pushed a commit that referenced this pull request Nov 28, 2017
…el/git/maz/arm-platforms into irq/urgent

Pull irqchip updates for 4.15, take #4 from Marc Zyngier

 - A core irq fix for legacy cases where the irq trigger is not reported
   by firmware

 - A couple of GICv3/4 fixes (Kconfig, of-node refcount, error handling)

 - Trivial pr_err fixes
jwrdegoede pushed a commit that referenced this pull request Dec 4, 2017
 watchdog: BUG: soft lockup - CPU#6 stuck for 22s! [qemu-system-x86:10185]
 CPU: 6 PID: 10185 Comm: qemu-system-x86 Tainted: G           OE   4.14.0-rc4+ #4
 RIP: 0010:kvm_get_time_scale+0x4e/0xa0 [kvm]
 Call Trace:
  get_time_ref_counter+0x5a/0x80 [kvm]
  kvm_hv_process_stimers+0x120/0x5f0 [kvm]
  kvm_arch_vcpu_ioctl_run+0x4b4/0x1690 [kvm]
  kvm_vcpu_ioctl+0x33a/0x620 [kvm]
  do_vfs_ioctl+0xa1/0x5d0
  SyS_ioctl+0x79/0x90
  entry_SYSCALL_64_fastpath+0x1e/0xa9

This can be reproduced when running kvm-unit-tests/hyperv_stimer.flat and
cpu-hotplug stress simultaneously. __this_cpu_read(cpu_tsc_khz) returns 0
(set in kvmclock_cpu_down_prep()) when the pCPU is unhotplug which results
in kvm_get_time_scale() gets into an infinite loop.

This patch fixes it by treating the unhotplug pCPU as not using master clock.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
jwrdegoede pushed a commit that referenced this pull request Dec 4, 2017
Jiri Pirko says:

====================
mlxsw: GRE offloading fixes

Petr says:

This patchset fixes a couple bugs in offloading GRE tunnels in mlxsw
driver.

Patch #1 fixes a problem that local routes pointing at a GRE tunnel
device are offloaded even if that netdevice is down.

Patch #2 detects that as a result of moving a GRE netdevice to a
different VRF, two tunnels now have a conflict of local addresses,
something that the mlxsw driver can't offload.

Patch #3 fixes a FIB abort caused by forming a route pointing at a
GRE tunnel that is eligible for offloading but already onloaded.

Patch #4 fixes a problem that next hops migrated to a new RIF kept the
old RIF reference, which went dangling shortly afterwards.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
jwrdegoede pushed a commit that referenced this pull request Dec 10, 2017
Hendrik Brueckner says:

====================
Perf tool bpf selftests revealed a broken uapi for s390 and arm64.
With the BPF_PROG_TYPE_PERF_EVENT program type the bpf_perf_event
structure exports the pt_regs structure for all architectures.

This fails for s390 and arm64 because pt_regs are not part of the
user api and kept in-kernel only.  To mitigate the broken uapi,
introduce a wrapper that exports pt_regs in an asm-generic way.
For arm64, export the exising user_pt_regs structure.  For s390,
introduce a user_pt_regs structure that exports the beginning of
pt_regs.

Note that user_pt_regs must export from the beginning of pt_regs
as BPF_PROG_TYPE_PERF_EVENT program type is not the only type for
running BPF programs.

Some more background:

  For the bpf_perf_event, there is a uapi definition that is
  passed to the BPF program.  For other "probe" points like
  trace points, kprobes, and uprobes, there is no uapi and the
  BPF program is always passed pt_regs (which is OK as the BPF
  program runs in the kernel context).  The perf tool can attach
  BPF programs to all of these "probe" points and, optionally,
  can create a BPF prologue to access particular arguments
  (passed as registers).  For this, it uses DWARF/CFI
  information to obtain the register and calls a perf-arch
  backend function, regs_query_register_offset().  This function
  returns the index into (user_)pt_regs for a particular
  register.  Then, perf creates a BPF prologue that accesses
  this register based on the passed stucture from the "probe"
  point.

Part of this series, are also updates to the testing and bpf selftest
to deal with asm-specifics.  To complete the bpf support in perf, the
the regs_query_register_offset function is added for s390 to support
BPF prologue creation.

Changelog v1 -> v2:
- Correct kbuild test bot issues by including
  asm-generic/bpf_perf_event.h for archictectures that do not have
  their own asm version.
- Added patch to clean-up whitespace and coding style issues in s390
  asm/ptrace.h (#4/6) as suggested by Alexei.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
jwrdegoede pushed a commit that referenced this pull request Dec 10, 2017
We don't need struct_mutex to initialise userptr (it just allocates a
workqueue for itself etc), but we do need struct_mutex later on in
i915_gem_init() in order to feed requests onto the HW.

This should break the chain

[  385.697902] ======================================================
[  385.697907] WARNING: possible circular locking dependency detected
[  385.697913] 4.14.0-CI-Patchwork_7234+ #1 Tainted: G     U
[  385.697917] ------------------------------------------------------
[  385.697922] perf_pmu/2631 is trying to acquire lock:
[  385.697927]  (&mm->mmap_sem){++++}, at: [<ffffffff811bfe1e>] __might_fault+0x3e/0x90
[  385.697941]
               but task is already holding lock:
[  385.697946]  (&cpuctx_mutex){+.+.}, at: [<ffffffff8116fe8c>] perf_event_ctx_lock_nested+0xbc/0x1d0
[  385.697957]
               which lock already depends on the new lock.

[  385.697963]
               the existing dependency chain (in reverse order) is:
[  385.697970]
               -> #4 (&cpuctx_mutex){+.+.}:
[  385.697980]        __mutex_lock+0x86/0x9b0
[  385.697985]        perf_event_init_cpu+0x5a/0x90
[  385.697991]        perf_event_init+0x178/0x1a4
[  385.697997]        start_kernel+0x27f/0x3f1
[  385.698003]        verify_cpu+0x0/0xfb
[  385.698006]
               -> #3 (pmus_lock){+.+.}:
[  385.698015]        __mutex_lock+0x86/0x9b0
[  385.698020]        perf_event_init_cpu+0x21/0x90
[  385.698025]        cpuhp_invoke_callback+0xca/0xc00
[  385.698030]        _cpu_up+0xa7/0x170
[  385.698035]        do_cpu_up+0x57/0x70
[  385.698039]        smp_init+0x62/0xa6
[  385.698044]        kernel_init_freeable+0x97/0x193
[  385.698050]        kernel_init+0xa/0x100
[  385.698055]        ret_from_fork+0x27/0x40
[  385.698058]
               -> #2 (cpu_hotplug_lock.rw_sem){++++}:
[  385.698068]        cpus_read_lock+0x39/0xa0
[  385.698073]        apply_workqueue_attrs+0x12/0x50
[  385.698078]        __alloc_workqueue_key+0x1d8/0x4d8
[  385.698134]        i915_gem_init_userptr+0x5f/0x80 [i915]
[  385.698176]        i915_gem_init+0x7c/0x390 [i915]
[  385.698213]        i915_driver_load+0x99e/0x15c0 [i915]
[  385.698250]        i915_pci_probe+0x33/0x90 [i915]
[  385.698256]        pci_device_probe+0xa1/0x130
[  385.698262]        driver_probe_device+0x293/0x440
[  385.698267]        __driver_attach+0xde/0xe0
[  385.698272]        bus_for_each_dev+0x5c/0x90
[  385.698277]        bus_add_driver+0x16d/0x260
[  385.698282]        driver_register+0x57/0xc0
[  385.698287]        do_one_initcall+0x3e/0x160
[  385.698292]        do_init_module+0x5b/0x1fa
[  385.698297]        load_module+0x2374/0x2dc0
[  385.698302]        SyS_finit_module+0xaa/0xe0
[  385.698307]        entry_SYSCALL_64_fastpath+0x1c/0xb1
[  385.698311]
               -> #1 (&dev->struct_mutex){+.+.}:
[  385.698320]        __mutex_lock+0x86/0x9b0
[  385.698361]        i915_mutex_lock_interruptible+0x4c/0x130 [i915]
[  385.698403]        i915_gem_fault+0x206/0x760 [i915]
[  385.698409]        __do_fault+0x1a/0x70
[  385.698413]        __handle_mm_fault+0x7c4/0xdb0
[  385.698417]        handle_mm_fault+0x154/0x300
[  385.698440]        __do_page_fault+0x2d6/0x570
[  385.698445]        page_fault+0x22/0x30
[  385.698449]
               -> #0 (&mm->mmap_sem){++++}:
[  385.698459]        lock_acquire+0xaf/0x200
[  385.698464]        __might_fault+0x68/0x90
[  385.698470]        _copy_to_user+0x1e/0x70
[  385.698475]        perf_read+0x1aa/0x290
[  385.698480]        __vfs_read+0x23/0x120
[  385.698484]        vfs_read+0xa3/0x150
[  385.698488]        SyS_read+0x45/0xb0
[  385.698493]        entry_SYSCALL_64_fastpath+0x1c/0xb1
[  385.698497]
               other info that might help us debug this:

[  385.698505] Chain exists of:
                 &mm->mmap_sem --> pmus_lock --> &cpuctx_mutex

[  385.698517]  Possible unsafe locking scenario:

[  385.698522]        CPU0                    CPU1
[  385.698526]        ----                    ----
[  385.698529]   lock(&cpuctx_mutex);
[  385.698553]                                lock(pmus_lock);
[  385.698558]                                lock(&cpuctx_mutex);
[  385.698564]   lock(&mm->mmap_sem);
[  385.698568]
                *** DEADLOCK ***

[  385.698574] 1 lock held by perf_pmu/2631:
[  385.698578]  #0:  (&cpuctx_mutex){+.+.}, at: [<ffffffff8116fe8c>] perf_event_ctx_lock_nested+0xbc/0x1d0
[  385.698589]
               stack backtrace:
[  385.698595] CPU: 3 PID: 2631 Comm: perf_pmu Tainted: G     U          4.14.0-CI-Patchwork_7234+ #1
[  385.698602] Hardware name:                  /NUC6CAYB, BIOS AYAPLCEL.86A.0040.2017.0619.1722 06/19/2017
[  385.698609] Call Trace:
[  385.698615]  dump_stack+0x5f/0x86
[  385.698621]  print_circular_bug.isra.18+0x1d0/0x2c0
[  385.698627]  __lock_acquire+0x19c3/0x1b60
[  385.698634]  ? generic_exec_single+0x77/0xe0
[  385.698640]  ? lock_acquire+0xaf/0x200
[  385.698644]  lock_acquire+0xaf/0x200
[  385.698650]  ? __might_fault+0x3e/0x90
[  385.698655]  __might_fault+0x68/0x90
[  385.698660]  ? __might_fault+0x3e/0x90
[  385.698665]  _copy_to_user+0x1e/0x70
[  385.698670]  perf_read+0x1aa/0x290
[  385.698675]  __vfs_read+0x23/0x120
[  385.698682]  ? __fget+0x101/0x1f0
[  385.698686]  vfs_read+0xa3/0x150
[  385.698691]  SyS_read+0x45/0xb0
[  385.698696]  entry_SYSCALL_64_fastpath+0x1c/0xb1
[  385.698701] RIP: 0033:0x7ff1c46876ed
[  385.698705] RSP: 002b:00007fff13552f90 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
[  385.698712] RAX: ffffffffffffffda RBX: ffffc90000647ff0 RCX: 00007ff1c46876ed
[  385.698718] RDX: 0000000000000010 RSI: 00007fff13552fa0 RDI: 0000000000000005
[  385.698723] RBP: 000056063d300580 R08: 0000000000000000 R09: 0000000000000060
[  385.698729] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000046
[  385.698734] R13: 00007fff13552c6f R14: 00007ff1c6279d00 R15: 00007ff1c6279a40

Testcase: igt/perf_pmu
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171122172621.16158-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
(cherry picked from commit ee48700)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
jwrdegoede pushed a commit that referenced this pull request Dec 13, 2017
This reverts commit 5b72505.

The rtc block on i.MX53 is a completely different hardware than the
one found on i.MX25.

Cc: <stable@vger.kernel.org> #4.14
Reported-by: Noel Vellemans <Noel.Vellemans@visionbms.com>
Suggested-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
jwrdegoede pushed a commit that referenced this pull request Dec 20, 2017
The RDMA netlink core code checks validity of messages by ensuring
that type and operand are in range. It works well for almost all
clients except NLDEV, which has cb_table less than number of operands.

Request to access such operand will trigger the following kernel panic.

This patch updates all places where cb_table is declared for the
consistency, but only NLDEV is actually need it.

general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
Modules linked in:
CPU: 0 PID: 522 Comm: syz-executor6 Not tainted 4.13.0+ #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
task: ffff8800657799c0 task.stack: ffff8800695d000
RIP: 0010:rdma_nl_rcv_msg+0x13a/0x4c0
RSP: 0018:ffff8800695d7838 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: 1ffff1000d2baf0b RCX: 00000000704ff4d7
RDX: 0000000000000000 RSI: ffffffff81ddb03c RDI: 00000003827fa6bc
RBP: ffff8800695d7900 R08: ffffffff82ec0578 R09: 0000000000000000
R10: ffff8800695d7900 R11: 0000000000000001 R12: 000000000000001c
R13: ffff880069d31e00 R14: 00000000ffffffff R15: ffff880069d357c0
FS:  00007fee6acb8700(0000) GS:ffff88006ca00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000201a9000 CR3: 0000000059766000 CR4: 00000000000006b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ? rdma_nl_multicast+0x80/0x80
 rdma_nl_rcv+0x36b/0x4d0
 ? ibnl_put_attr+0xc0/0xc0
 netlink_unicast+0x4bd/0x6d0
 ? netlink_sendskb+0x50/0x50
 ? drop_futex_key_refs.isra.4+0x68/0xb0
 netlink_sendmsg+0x9ab/0xbd0
 ? nlmsg_notify+0x140/0x140
 ? wake_up_q+0xa1/0xf0
 ? drop_futex_key_refs.isra.4+0x68/0xb0
 sock_sendmsg+0x88/0xd0
 sock_write_iter+0x228/0x3c0
 ? sock_sendmsg+0xd0/0xd0
 ? do_futex+0x3e5/0xb20
 ? iov_iter_init+0xaf/0x1d0
 __vfs_write+0x46e/0x640
 ? sched_clock_cpu+0x1b/0x190
 ? __vfs_read+0x620/0x620
 ? __fget+0x23a/0x390
 ? rw_verify_area+0xca/0x290
 vfs_write+0x192/0x490
 SyS_write+0xde/0x1c0
 ? SyS_read+0x1c0/0x1c0
 ? trace_hardirqs_on_thunk+0x1a/0x1c
 entry_SYSCALL_64_fastpath+0x18/0xad
RIP: 0033:0x7fee6a74a219
RSP: 002b:00007fee6acb7d58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000638000 RCX: 00007fee6a74a219
RDX: 0000000000000078 RSI: 0000000020141000 RDI: 0000000000000006
RBP: 0000000000000046 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: ffff8800695d7f98
R13: 0000000020141000 R14: 0000000000000006 R15: 00000000ffffffff
Code: d6 48 b8 00 00 00 00 00 fc ff df 66 41 81 e4 ff 03 44 8d 72 ff 4a 8d 3c b5 c0 a6 7f 82 44 89 b5 4c ff ff ff 48 89 f9 48 c1 e9 03 <0f> b6 0c 01 48 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85
RIP: rdma_nl_rcv_msg+0x13a/0x4c0 RSP: ffff8800695d7838
---[ end trace ba085d123959c8ec ]---
Kernel panic - not syncing: Fatal exception

Cc: syzkaller <syzkaller@googlegroups.com>
Fixes: b4c598a ("RDMA/netlink: Implement nldev device dumpit calback")
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

Signed-off-by: Doug Ledford <dledford@redhat.com>
jwrdegoede pushed a commit that referenced this pull request Nov 6, 2024
Petr Machata says:

====================
mlxsw: Fixes

In this patchset:

- Tx header should be pushed for each packet which is transmitted via
  Spectrum ASICs. Patch #1 adds a missing call to skb_cow_head() to make
  sure that there is both enough room to push the Tx header and that the
  SKB header is not cloned and can be modified.

- Commit b5b60bb ("mlxsw: pci: Use page pool for Rx buffers
  allocation") converted mlxsw to use page pool for Rx buffers allocation.
  Sync for CPU and for device should be done for Rx pages. In patches #2
  and #3, add the missing calls to sync pages for, respectively, CPU and
  the device.

- Patch #4 then fixes a bug to IPv6 GRE forwarding offload. Patch #5 adds
  a generic forwarding test that fails with mlxsw ports prior to the fix.
====================

Link: https://patch.msgid.link/cover.1729866134.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
jwrdegoede pushed a commit that referenced this pull request Nov 18, 2024
When CONFIG_KASAN_SW_TAGS and CONFIG_KASAN_STACK are enabled, the
object_is_on_stack() function may produce incorrect results due to the
presence of tags in the obj pointer, while the stack pointer does not have
tags.  This discrepancy can lead to incorrect stack object detection and
subsequently trigger warnings if CONFIG_DEBUG_OBJECTS is also enabled.

Example of the warning:

ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at lib/debugobjects.c:557 __debug_object_init+0x330/0x364
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc5 #4
Hardware name: linux,dummy-virt (DT)
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __debug_object_init+0x330/0x364
lr : __debug_object_init+0x330/0x364
sp : ffff800082ea7b40
x29: ffff800082ea7b40 x28: 98ff0000c0164518 x27: 98ff0000c0164534
x26: ffff800082d93ec8 x25: 0000000000000001 x24: 1cff0000c00172a0
x23: 0000000000000000 x22: ffff800082d93ed0 x21: ffff800081a24418
x20: 3eff800082ea7bb0 x19: efff800000000000 x18: 0000000000000000
x17: 00000000000000ff x16: 0000000000000047 x15: 206b63617473206e
x14: 0000000000000018 x13: ffff800082ea7780 x12: 0ffff800082ea78e
x11: 0ffff800082ea790 x10: 0ffff800082ea79d x9 : 34d77febe173e800
x8 : 34d77febe173e800 x7 : 0000000000000001 x6 : 0000000000000001
x5 : feff800082ea74b8 x4 : ffff800082870a90 x3 : ffff80008018d3c4
x2 : 0000000000000001 x1 : ffff800082858810 x0 : 0000000000000050
Call trace:
 __debug_object_init+0x330/0x364
 debug_object_init_on_stack+0x30/0x3c
 schedule_hrtimeout_range_clock+0xac/0x26c
 schedule_hrtimeout+0x1c/0x30
 wait_task_inactive+0x1d4/0x25c
 kthread_bind_mask+0x28/0x98
 init_rescuer+0x1e8/0x280
 workqueue_init+0x1a0/0x3cc
 kernel_init_freeable+0x118/0x200
 kernel_init+0x28/0x1f0
 ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---
ODEBUG: object 3eff800082ea7bb0 is NOT on stack ffff800082ea0000, but annotated.
------------[ cut here ]------------

Link: https://lkml.kernel.org/r/20241113042544.19095-1-qun-wei.lin@mediatek.com
Signed-off-by: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Cc: Andrew Yang <andrew.yang@mediatek.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Casper Li <casper.li@mediatek.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
jwrdegoede pushed a commit that referenced this pull request Dec 15, 2024
Its used from trace__run(), for the 'perf trace' live mode, i.e. its
strace-like, non-perf.data file processing mode, the most common one.

The trace__run() function will set trace->host using machine__new_host()
that is supposed to give a machine instance representing the running
machine, and since we'll use perf_env__arch_strerrno() to get the right
errno -> string table, we need to use machine->env, so initialize it in
machine__new_host().

Before the patch:

  (gdb) run trace --errno-summary -a sleep 1
  <SNIP>
   Summary of events:

   gvfs-afc-volume (3187), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     pselect6               1      0     0.000     0.000     0.000     0.000      0.00%

   GUsbEventThread (3519), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                   1      0     0.000     0.000     0.000     0.000      0.00%
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  478		if (env->arch_strerrno == NULL)
  (gdb) bt
  #0  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  #1  0x00000000004b75d2 in thread__dump_stats (ttrace=0x14f58f0, trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4673
  #2  0x00000000004b78bf in trace__fprintf_thread (fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>, thread=0x10fa0b0, trace=0x7fffffffa5b0) at builtin-trace.c:4708
  #3  0x00000000004b7ad9 in trace__fprintf_thread_summary (trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4747
  #4  0x00000000004b656e in trace__run (trace=0x7fffffffa5b0, argc=2, argv=0x7fffffffde60) at builtin-trace.c:4456
  #5  0x00000000004ba43e in cmd_trace (argc=2, argv=0x7fffffffde60) at builtin-trace.c:5487
  #6  0x00000000004c0414 in run_builtin (p=0xec3068 <commands+648>, argc=5, argv=0x7fffffffde60) at perf.c:351
  #7  0x00000000004c06bb in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:404
  #8  0x00000000004c0814 in run_argv (argcp=0x7fffffffdc4c, argv=0x7fffffffdc40) at perf.c:448
  #9  0x00000000004c0b5d in main (argc=5, argv=0x7fffffffde60) at perf.c:560
  (gdb)

After:

  root@number:~# perf trace -a --errno-summary sleep 1
  <SNIP>
     pw-data-loop (2685), 1410 events, 16.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     epoll_wait           188      0   983.428     0.000     5.231    15.595      8.68%
     ioctl                 94      0     0.811     0.004     0.009     0.016      2.82%
     read                 188      0     0.322     0.001     0.002     0.006      5.15%
     write                141      0     0.280     0.001     0.002     0.018      8.39%
     timerfd_settime       94      0     0.138     0.001     0.001     0.007      6.47%

   gnome-control-c (179406), 1848 events, 20.9%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                 222      0   959.577     0.000     4.322    21.414     11.40%
     recvmsg              150      0     0.539     0.001     0.004     0.013      5.12%
     write                300      0     0.442     0.001     0.001     0.007      3.29%
     read                 150      0     0.183     0.001     0.001     0.009      5.53%
     getpid               102      0     0.101     0.000     0.001     0.008      7.82%

  root@number:~#

Fixes: 54373b5 ("perf env: Introduce perf_env__arch_strerrno()")
Reported-by: Veronika Molnarova <vmolnaro@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Veronika Molnarova <vmolnaro@redhat.com>
Acked-by: Michael Petlan <mpetlan@redhat.com>
Tested-by: Michael Petlan <mpetlan@redhat.com>
Link: https://lore.kernel.org/r/Z0XffUgNSv_9OjOi@x1
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
jwrdegoede pushed a commit that referenced this pull request Dec 15, 2024
…s_lock

For storing a value to a queue attribute, the queue_attr_store function
first freezes the queue (->q_usage_counter(io)) and then acquire
->sysfs_lock. This seems not correct as the usual ordering should be to
acquire ->sysfs_lock before freezing the queue. This incorrect ordering
causes the following lockdep splat which we are able to reproduce always
simply by accessing /sys/kernel/debug file using ls command:

[   57.597146] WARNING: possible circular locking dependency detected
[   57.597154] 6.12.0-10553-gb86545e02e8c linux-sunxi#20 Tainted: G        W
[   57.597162] ------------------------------------------------------
[   57.597168] ls/4605 is trying to acquire lock:
[   57.597176] c00000003eb56710 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0x58/0xc0
[   57.597200]
               but task is already holding lock:
[   57.597207] c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4
[   57.597226]
               which lock already depends on the new lock.

[   57.597233]
               the existing dependency chain (in reverse order) is:
[   57.597241]
               -> #5 (&sb->s_type->i_mutex_key#3){++++}-{4:4}:
[   57.597255]        down_write+0x6c/0x18c
[   57.597264]        start_creating+0xb4/0x24c
[   57.597274]        debugfs_create_dir+0x2c/0x1e8
[   57.597283]        blk_register_queue+0xec/0x294
[   57.597292]        add_disk_fwnode+0x2e4/0x548
[   57.597302]        brd_alloc+0x2c8/0x338
[   57.597309]        brd_init+0x100/0x178
[   57.597317]        do_one_initcall+0x88/0x3e4
[   57.597326]        kernel_init_freeable+0x3cc/0x6e0
[   57.597334]        kernel_init+0x34/0x1cc
[   57.597342]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597350]
               -> #4 (&q->debugfs_mutex){+.+.}-{4:4}:
[   57.597362]        __mutex_lock+0xfc/0x12a0
[   57.597370]        blk_register_queue+0xd4/0x294
[   57.597379]        add_disk_fwnode+0x2e4/0x548
[   57.597388]        brd_alloc+0x2c8/0x338
[   57.597395]        brd_init+0x100/0x178
[   57.597402]        do_one_initcall+0x88/0x3e4
[   57.597410]        kernel_init_freeable+0x3cc/0x6e0
[   57.597418]        kernel_init+0x34/0x1cc
[   57.597426]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597434]
               -> #3 (&q->sysfs_lock){+.+.}-{4:4}:
[   57.597446]        __mutex_lock+0xfc/0x12a0
[   57.597454]        queue_attr_store+0x9c/0x110
[   57.597462]        sysfs_kf_write+0x70/0xb0
[   57.597471]        kernfs_fop_write_iter+0x1b0/0x2ac
[   57.597480]        vfs_write+0x3dc/0x6e8
[   57.597488]        ksys_write+0x84/0x140
[   57.597495]        system_call_exception+0x130/0x360
[   57.597504]        system_call_common+0x160/0x2c4
[   57.597516]
               -> #2 (&q->q_usage_counter(io)linux-sunxi#21){++++}-{0:0}:
[   57.597530]        __submit_bio+0x5ec/0x828
[   57.597538]        submit_bio_noacct_nocheck+0x1e4/0x4f0
[   57.597547]        iomap_readahead+0x2a0/0x448
[   57.597556]        xfs_vm_readahead+0x28/0x3c
[   57.597564]        read_pages+0x88/0x41c
[   57.597571]        page_cache_ra_unbounded+0x1ac/0x2d8
[   57.597580]        filemap_get_pages+0x188/0x984
[   57.597588]        filemap_read+0x13c/0x4bc
[   57.597596]        xfs_file_buffered_read+0x88/0x17c
[   57.597605]        xfs_file_read_iter+0xac/0x158
[   57.597614]        vfs_read+0x2d4/0x3b4
[   57.597622]        ksys_read+0x84/0x144
[   57.597629]        system_call_exception+0x130/0x360
[   57.597637]        system_call_common+0x160/0x2c4
[   57.597647]
               -> #1 (mapping.invalidate_lock#2){++++}-{4:4}:
[   57.597661]        down_read+0x6c/0x220
[   57.597669]        filemap_fault+0x870/0x100c
[   57.597677]        xfs_filemap_fault+0xc4/0x18c
[   57.597684]        __do_fault+0x64/0x164
[   57.597693]        __handle_mm_fault+0x1274/0x1dac
[   57.597702]        handle_mm_fault+0x248/0x484
[   57.597711]        ___do_page_fault+0x428/0xc0c
[   57.597719]        hash__do_page_fault+0x30/0x68
[   57.597727]        do_hash_fault+0x90/0x35c
[   57.597736]        data_access_common_virt+0x210/0x220
[   57.597745]        _copy_from_user+0xf8/0x19c
[   57.597754]        sel_write_load+0x178/0xd54
[   57.597762]        vfs_write+0x108/0x6e8
[   57.597769]        ksys_write+0x84/0x140
[   57.597777]        system_call_exception+0x130/0x360
[   57.597785]        system_call_common+0x160/0x2c4
[   57.597794]
               -> #0 (&mm->mmap_lock){++++}-{4:4}:
[   57.597806]        __lock_acquire+0x17cc/0x2330
[   57.597814]        lock_acquire+0x138/0x400
[   57.597822]        __might_fault+0x7c/0xc0
[   57.597830]        filldir64+0xe8/0x390
[   57.597839]        dcache_readdir+0x80/0x2d4
[   57.597846]        iterate_dir+0xd8/0x1d4
[   57.597855]        sys_getdents64+0x88/0x2d4
[   57.597864]        system_call_exception+0x130/0x360
[   57.597872]        system_call_common+0x160/0x2c4
[   57.597881]
               other info that might help us debug this:

[   57.597888] Chain exists of:
                 &mm->mmap_lock --> &q->debugfs_mutex --> &sb->s_type->i_mutex_key#3

[   57.597905]  Possible unsafe locking scenario:

[   57.597911]        CPU0                    CPU1
[   57.597917]        ----                    ----
[   57.597922]   rlock(&sb->s_type->i_mutex_key#3);
[   57.597932]                                lock(&q->debugfs_mutex);
[   57.597940]                                lock(&sb->s_type->i_mutex_key#3);
[   57.597950]   rlock(&mm->mmap_lock);
[   57.597958]
                *** DEADLOCK ***

[   57.597965] 2 locks held by ls/4605:
[   57.597971]  #0: c0000000137c12f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0xcc/0x154
[   57.597989]  #1: c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4

Prevent the above lockdep warning by acquiring ->sysfs_lock before
freezing the queue while storing a queue attribute in queue_attr_store
function. Later, we also found[1] another function __blk_mq_update_nr_
hw_queues where we first freeze queue and then acquire the ->sysfs_lock.
So we've also updated lock ordering in __blk_mq_update_nr_hw_queues
function and ensured that in all code paths we follow the correct lock
ordering i.e. acquire ->sysfs_lock before freezing the queue.

[1] https://lore.kernel.org/all/CAFj5m9Ke8+EHKQBs_Nk6hqd=LGXtk4mUxZUN5==ZcCjnZSBwHw@mail.gmail.com/

Reported-by: kjain@linux.ibm.com
Fixes: af28141 ("block: freeze the queue in queue_attr_store")
Tested-by: kjain@linux.ibm.com
Cc: hch@lst.de
Cc: axboe@kernel.dk
Cc: ritesh.list@gmail.com
Cc: ming.lei@redhat.com
Cc: gjoyce@linux.ibm.com
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241210144222.1066229-1-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
jwrdegoede pushed a commit that referenced this pull request Jan 7, 2025
syzbot reports that a recent fix causes nesting issues between the (now)
raw timeoutlock and the eventfd locking:

=============================
[ BUG: Invalid wait context ]
6.13.0-rc4-00080-g9828a4c0901f linux-sunxi#29 Not tainted
-----------------------------
kworker/u32:0/68094 is trying to lock:
ffff000014d7a520 (&ctx->wqh#2){..-.}-{3:3}, at: eventfd_signal_mask+0x64/0x180
other info that might help us debug this:
context-{5:5}
6 locks held by kworker/u32:0/68094:
 #0: ffff0000c1d98148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x4e8/0xfc0
 #1: ffff80008d927c78 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x53c/0xfc0
 #2: ffff0000c59bc3d8 (&ctx->completion_lock){+.+.}-{3:3}, at: io_kill_timeouts+0x40/0x180
 #3: ffff0000c59bc358 (&ctx->timeout_lock){-.-.}-{2:2}, at: io_kill_timeouts+0x48/0x180
 #4: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38
 #5: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38
stack backtrace:
CPU: 7 UID: 0 PID: 68094 Comm: kworker/u32:0 Not tainted 6.13.0-rc4-00080-g9828a4c0901f linux-sunxi#29
Hardware name: linux,dummy-virt (DT)
Workqueue: iou_exit io_ring_exit_work
Call trace:
 show_stack+0x1c/0x30 (C)
 __dump_stack+0x24/0x30
 dump_stack_lvl+0x60/0x80
 dump_stack+0x14/0x20
 __lock_acquire+0x19f8/0x60c8
 lock_acquire+0x1a4/0x540
 _raw_spin_lock_irqsave+0x90/0xd0
 eventfd_signal_mask+0x64/0x180
 io_eventfd_signal+0x64/0x108
 io_req_local_work_add+0x294/0x430
 __io_req_task_work_add+0x1c0/0x270
 io_kill_timeout+0x1f0/0x288
 io_kill_timeouts+0xd4/0x180
 io_uring_try_cancel_requests+0x2e8/0x388
 io_ring_exit_work+0x150/0x550
 process_one_work+0x5e8/0xfc0
 worker_thread+0x7ec/0xc80
 kthread+0x24c/0x300
 ret_from_fork+0x10/0x20

because after the preempt-rt fix for the timeout lock nesting inside
the io-wq lock, we now have the eventfd spinlock nesting inside the
raw timeout spinlock.

Rather than play whack-a-mole with other nesting on the timeout lock,
split the deletion and killing of timeouts so queueing the task_work
for the timeout cancelations can get done outside of the timeout lock.

Reported-by: syzbot+b1fc199a40b65d601b65@syzkaller.appspotmail.com
Fixes: 020b40f ("io_uring: make ctx->timeout_lock a raw spinlock")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
jwrdegoede pushed a commit that referenced this pull request Jan 7, 2025
…le_direct_reclaim()

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.  

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.  

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20241130164346.436469-1-snishika@redhat.com
Link: https://lkml.kernel.org/r/20241130161236.433747-2-snishika@redhat.com
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <snishika@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
jwrdegoede pushed a commit that referenced this pull request Jan 7, 2025
…nt message

Address a bug in the kernel that triggers a "sleeping function called from
invalid context" warning when /sys/kernel/debug/kmemleak is printed under
specific conditions:
- CONFIG_PREEMPT_RT=y
- Set SELinux as the LSM for the system
- Set kptr_restrict to 1
- kmemleak buffer contains at least one item

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 136, name: cat
preempt_count: 1, expected: 0
RCU nest depth: 2, expected: 2
6 locks held by cat/136:
 #0: ffff32e64bcbf950 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb8/0xe30
 #1: ffffafe6aaa9dea0 (scan_mutex){+.+.}-{3:3}, at: kmemleak_seq_start+0x34/0x128
 #3: ffff32e6546b1cd0 (&object->lock){....}-{2:2}, at: kmemleak_seq_show+0x3c/0x1e0
 #4: ffffafe6aa8d8560 (rcu_read_lock){....}-{1:2}, at: has_ns_capability_noaudit+0x8/0x1b0
 #5: ffffafe6aabbc0f8 (notif_lock){+.+.}-{2:2}, at: avc_compute_av+0xc4/0x3d0
irq event stamp: 136660
hardirqs last  enabled at (136659): [<ffffafe6a80fd7a0>] _raw_spin_unlock_irqrestore+0xa8/0xd8
hardirqs last disabled at (136660): [<ffffafe6a80fd85c>] _raw_spin_lock_irqsave+0x8c/0xb0
softirqs last  enabled at (0): [<ffffafe6a5d50b28>] copy_process+0x11d8/0x3df8
softirqs last disabled at (0): [<0000000000000000>] 0x0
Preemption disabled at:
[<ffffafe6a6598a4c>] kmemleak_seq_show+0x3c/0x1e0
CPU: 1 UID: 0 PID: 136 Comm: cat Tainted: G            E      6.11.0-rt7+ linux-sunxi#34
Tainted: [E]=UNSIGNED_MODULE
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0xa0/0x128
 show_stack+0x1c/0x30
 dump_stack_lvl+0xe8/0x198
 dump_stack+0x18/0x20
 rt_spin_lock+0x8c/0x1a8
 avc_perm_nonode+0xa0/0x150
 cred_has_capability.isra.0+0x118/0x218
 selinux_capable+0x50/0x80
 security_capable+0x7c/0xd0
 has_ns_capability_noaudit+0x94/0x1b0
 has_capability_noaudit+0x20/0x30
 restricted_pointer+0x21c/0x4b0
 pointer+0x298/0x760
 vsnprintf+0x330/0xf70
 seq_printf+0x178/0x218
 print_unreferenced+0x1a4/0x2d0
 kmemleak_seq_show+0xd0/0x1e0
 seq_read_iter+0x354/0xe30
 seq_read+0x250/0x378
 full_proxy_read+0xd8/0x148
 vfs_read+0x190/0x918
 ksys_read+0xf0/0x1e0
 __arm64_sys_read+0x70/0xa8
 invoke_syscall.constprop.0+0xd4/0x1d8
 el0_svc+0x50/0x158
 el0t_64_sync+0x17c/0x180

%pS and %pK, in the same back trace line, are redundant, and %pS can void
%pK service in certain contexts.

%pS alone already provides the necessary information, and if it cannot
resolve the symbol, it falls back to printing the raw address voiding
the original intent behind the %pK.

Additionally, %pK requires a privilege check CAP_SYSLOG enforced through
the LSM, which can trigger a "sleeping function called from invalid
context" warning under RT_PREEMPT kernels when the check occurs in an
atomic context. This issue may also affect other LSMs.

This change avoids the unnecessary privilege check and resolves the
sleeping function warning without any loss of information.

Link: https://lkml.kernel.org/r/20241217142032.55793-1-acarmina@redhat.com
Fixes: 3a6f33d ("mm/kmemleak: use %pK to display kernel pointers in backtrace")
Signed-off-by: Alessandro Carminati <acarmina@redhat.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Clément Léger <clement.leger@bootlin.com>
Cc: Alessandro Carminati <acarmina@redhat.com>
Cc: Eric Chanudet <echanude@redhat.com>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this pull request Jan 17, 2025
[ Upstream commit 59a931c ]

If the driver uses a page pool, it creates a page pool with
page_pool_create().
The reference count of page pool is 1 as default.
A page pool will be destroyed only when a reference count reaches 0.
page_pool_destroy() is used to destroy page pool, it decreases a
reference count.
When a page pool is destroyed, ->disconnect() is called, which is
mem_allocator_disconnect().
This function internally acquires mutex_lock().

If the driver uses XDP, it registers a memory model with
xdp_rxq_info_reg_mem_model().
The xdp_rxq_info_reg_mem_model() internally increases a page pool
reference count if a memory model is a page pool.
Now the reference count is 2.

To destroy a page pool, the driver should call both page_pool_destroy()
and xdp_unreg_mem_model().
The xdp_unreg_mem_model() internally calls page_pool_destroy().
Only page_pool_destroy() decreases a reference count.

If a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we
will face an invalid wait context warning.
Because xdp_unreg_mem_model() calls page_pool_destroy() with
rcu_read_lock().
The page_pool_destroy() internally acquires mutex_lock().

Splat looks like:
=============================
[ BUG: Invalid wait context ]
6.10.0-rc6+ jwrdegoede#4 Tainted: G W
-----------------------------
ethtool/1806 is trying to lock:
ffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150
other info that might help us debug this:
context-{5:5}
3 locks held by ethtool/1806:
stack backtrace:
CPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ jwrdegoede#4 f916f41f172891c800f2fed
Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021
Call Trace:
<TASK>
dump_stack_lvl+0x7e/0xc0
__lock_acquire+0x1681/0x4de0
? _printk+0x64/0xe0
? __pfx_mark_lock.part.0+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
lock_acquire+0x1b3/0x580
? mem_allocator_disconnect+0x73/0x150
? __wake_up_klogd.part.0+0x16/0xc0
? __pfx_lock_acquire+0x10/0x10
? dump_stack_lvl+0x91/0xc0
__mutex_lock+0x15c/0x1690
? mem_allocator_disconnect+0x73/0x150
? __pfx_prb_read_valid+0x10/0x10
? mem_allocator_disconnect+0x73/0x150
? __pfx_llist_add_batch+0x10/0x10
? console_unlock+0x193/0x1b0
? lockdep_hardirqs_on+0xbe/0x140
? __pfx___mutex_lock+0x10/0x10
? tick_nohz_tick_stopped+0x16/0x90
? __irq_work_queue_local+0x1e5/0x330
? irq_work_queue+0x39/0x50
? __wake_up_klogd.part.0+0x79/0xc0
? mem_allocator_disconnect+0x73/0x150
mem_allocator_disconnect+0x73/0x150
? __pfx_mem_allocator_disconnect+0x10/0x10
? mark_held_locks+0xa5/0xf0
? rcu_is_watching+0x11/0xb0
page_pool_release+0x36e/0x6d0
page_pool_destroy+0xd7/0x440
xdp_unreg_mem_model+0x1a7/0x2a0
? __pfx_xdp_unreg_mem_model+0x10/0x10
? kfree+0x125/0x370
? bnxt_free_ring.isra.0+0x2eb/0x500
? bnxt_free_mem+0x5ac/0x2500
xdp_rxq_info_unreg+0x4a/0xd0
bnxt_free_mem+0x1356/0x2500
bnxt_close_nic+0xf0/0x3b0
? __pfx_bnxt_close_nic+0x10/0x10
? ethnl_parse_bit+0x2c6/0x6d0
? __pfx___nla_validate_parse+0x10/0x10
? __pfx_ethnl_parse_bit+0x10/0x10
bnxt_set_features+0x2a8/0x3e0
__netdev_update_features+0x4dc/0x1370
? ethnl_parse_bitset+0x4ff/0x750
? __pfx_ethnl_parse_bitset+0x10/0x10
? __pfx___netdev_update_features+0x10/0x10
? mark_held_locks+0xa5/0xf0
? _raw_spin_unlock_irqrestore+0x42/0x70
? __pm_runtime_resume+0x7d/0x110
ethnl_set_features+0x32d/0xa20

To fix this problem, it uses rhashtable_lookup_fast() instead of
rhashtable_lookup() with rcu_read_lock().
Using xa without rcu_read_lock() here is safe.
xa is freed by __xdp_mem_allocator_rcu_free() and this is called by
call_rcu() of mem_xa_remove().
The mem_xa_remove() is called by page_pool_destroy() if a reference
count reaches 0.
The xa is already protected by the reference count mechanism well in the
control plane.
So removing rcu_read_lock() for page_pool_destroy() is safe.

Fixes: c3f812c ("page_pool: do not release pool until inflight == 0.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20240712095116.3801586-1-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this pull request Jan 17, 2025
[ Upstream commit 86a41ea ]

When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/87sfialu2n.fsf@cloudflare.com/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ linux-sunxi#34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   jwrdegoede#1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   jwrdegoede#2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   jwrdegoede#3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   jwrdegoede#4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   jwrdegoede#5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   jwrdegoede#6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   jwrdegoede#7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   jwrdegoede#8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   jwrdegoede#9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ linux-sunxi#34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+6acef9e0a4d1f46c83d4@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: gnault@redhat.com
CC: cong.wang@bytedance.com
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Link: https://patch.msgid.link/20240806160626.1248317-1-jchapman@katalix.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this pull request Jan 17, 2025
[ Upstream commit b313a8c ]

Lockdep reported a warning in Linux version 6.6:

[  414.344659] ================================
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda jwrdegoede#6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda jwrdegoede#6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.356863]   scsi_io_completion+0x177/0x1610
[  414.357379]   scsi_complete+0x12f/0x260
[  414.357856]   blk_complete_reqs+0xba/0xf0
[  414.358338]   __do_softirq+0x1b0/0x7a2
[  414.358796]   irq_exit_rcu+0x14b/0x1a0
[  414.359262]   sysvec_call_function_single+0xaf/0xc0
[  414.359828]   asm_sysvec_call_function_single+0x1a/0x20
[  414.360426]   default_idle+0x1e/0x30
[  414.360873]   default_idle_call+0x9b/0x1f0
[  414.361390]   do_idle+0x2d2/0x3e0
[  414.361819]   cpu_startup_entry+0x55/0x60
[  414.362314]   start_secondary+0x235/0x2b0
[  414.362809]   secondary_startup_64_no_verify+0x18f/0x19b
[  414.363413] irq event stamp: 428794
[  414.363825] hardirqs last  enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200
[  414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50
[  414.365629] softirqs last  enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2
[  414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0
[  414.367425]
               other info that might help us debug this:
[  414.368194]  Possible unsafe locking scenario:
[  414.368900]        CPU0
[  414.369225]        ----
[  414.369548]   lock(&sbq->ws[i].wait);
[  414.370000]   <Interrupt>
[  414.370342]     lock(&sbq->ws[i].wait);
[  414.370802]
                *** DEADLOCK ***
[  414.371569] 5 locks held by kworker/u10:3/1152:
[  414.372088]  #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0
[  414.373180]  jwrdegoede#1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0
[  414.374384]  jwrdegoede#2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00
[  414.375342]  jwrdegoede#3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.376377]  jwrdegoede#4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0
[  414.378607]
               stack backtrace:
[  414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda jwrdegoede#6
[  414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[  414.381177] Workqueue: writeback wb_workfn (flush-253:0)
[  414.381805] Call Trace:
[  414.382136]  <TASK>
[  414.382429]  dump_stack_lvl+0x91/0xf0
[  414.382884]  mark_lock_irq+0xb3b/0x1260
[  414.383367]  ? __pfx_mark_lock_irq+0x10/0x10
[  414.383889]  ? stack_trace_save+0x8e/0xc0
[  414.384373]  ? __pfx_stack_trace_save+0x10/0x10
[  414.384903]  ? graph_lock+0xcf/0x410
[  414.385350]  ? save_trace+0x3d/0xc70
[  414.385808]  mark_lock.part.20+0x56d/0xa90
[  414.386317]  mark_held_locks+0xb0/0x110
[  414.386791]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.387320]  lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.387901]  ? _raw_spin_unlock_irq+0x28/0x50
[  414.388422]  trace_hardirqs_on+0x58/0x100
[  414.388917]  _raw_spin_unlock_irq+0x28/0x50
[  414.389422]  __blk_mq_tag_busy+0x1d6/0x2a0
[  414.389920]  __blk_mq_get_driver_tag+0x761/0x9f0
[  414.390899]  blk_mq_dispatch_rq_list+0x1780/0x1ee0
[  414.391473]  ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10
[  414.392070]  ? sbitmap_get+0x2b8/0x450
[  414.392533]  ? __blk_mq_get_driver_tag+0x210/0x9f0
[  414.393095]  __blk_mq_sched_dispatch_requests+0xd99/0x1690
[  414.393730]  ? elv_attempt_insert_merge+0x1b1/0x420
[  414.394302]  ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10
[  414.394970]  ? lock_acquire+0x18d/0x460
[  414.395456]  ? blk_mq_run_hw_queue+0x637/0xa00
[  414.395986]  ? __pfx_lock_acquire+0x10/0x10
[  414.396499]  blk_mq_sched_dispatch_requests+0x109/0x190
[  414.397100]  blk_mq_run_hw_queue+0x66e/0xa00
[  414.397616]  blk_mq_flush_plug_list.part.17+0x614/0x2030
[  414.398244]  ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10
[  414.398897]  ? writeback_sb_inodes+0x241/0xcc0
[  414.399429]  blk_mq_flush_plug_list+0x65/0x80
[  414.399957]  __blk_flush_plug+0x2f1/0x530
[  414.400458]  ? __pfx___blk_flush_plug+0x10/0x10
[  414.400999]  blk_finish_plug+0x59/0xa0
[  414.401467]  wb_writeback+0x7cc/0x920
[  414.401935]  ? __pfx_wb_writeback+0x10/0x10
[  414.402442]  ? mark_held_locks+0xb0/0x110
[  414.402931]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.403462]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.404062]  wb_workfn+0x2b3/0xcf0
[  414.404500]  ? __pfx_wb_workfn+0x10/0x10
[  414.404989]  process_scheduled_works+0x432/0x13f0
[  414.405546]  ? __pfx_process_scheduled_works+0x10/0x10
[  414.406139]  ? do_raw_spin_lock+0x101/0x2a0
[  414.406641]  ? assign_work+0x19b/0x240
[  414.407106]  ? lock_is_held_type+0x9d/0x110
[  414.407604]  worker_thread+0x6f2/0x1160
[  414.408075]  ? __kthread_parkme+0x62/0x210
[  414.408572]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.409168]  ? __kthread_parkme+0x13c/0x210
[  414.409678]  ? __pfx_worker_thread+0x10/0x10
[  414.410191]  kthread+0x33c/0x440
[  414.410602]  ? __pfx_kthread+0x10/0x10
[  414.411068]  ret_from_fork+0x4d/0x80
[  414.411526]  ? __pfx_kthread+0x10/0x10
[  414.411993]  ret_from_fork_asm+0x1b/0x30
[  414.412489]  </TASK>

When interrupt is turned on while a lock holding by spin_lock_irq it
throws a warning because of potential deadlock.

blk_mq_prep_dispatch_rq
 blk_mq_get_driver_tag
  __blk_mq_get_driver_tag
   __blk_mq_alloc_driver_tag
    blk_mq_tag_busy -> tag is already busy
    // failed to get driver tag
 blk_mq_mark_tag_wait
  spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait)
  __add_wait_queue(wq, wait) -> wait queue active
  blk_mq_get_driver_tag
  __blk_mq_tag_busy
-> 1) tag must be idle, which means there can't be inflight IO
   spin_lock_irq(&tags->lock) -> lock B (hctx->tags)
   spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally
-> 2) context must be preempt by IO interrupt to trigger deadlock.

As shown above, the deadlock is not possible in theory, but the warning
still need to be fixed.

Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq.

Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240815024736.2040971-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
jwrdegoede pushed a commit that referenced this pull request Feb 3, 2025
The tcpci_irq() may meet below NULL pointer dereference issue:

[    2.641851] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
[    2.641951] status 0x1, 0x37f
[    2.650659] Mem abort info:
[    2.656490]   ESR = 0x0000000096000004
[    2.660230]   EC = 0x25: DABT (current EL), IL = 32 bits
[    2.665532]   SET = 0, FnV = 0
[    2.668579]   EA = 0, S1PTW = 0
[    2.671715]   FSC = 0x04: level 0 translation fault
[    2.676584] Data abort info:
[    2.679459]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[    2.684936]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[    2.689980]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[    2.695284] [0000000000000010] user address but active_mm is swapper
[    2.701632] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[    2.707883] Modules linked in:
[    2.710936] CPU: 1 UID: 0 PID: 87 Comm: irq/111-2-0051 Not tainted 6.12.0-rc6-06316-g7f63786ad3d1-dirty #4
[    2.720570] Hardware name: NXP i.MX93 11X11 EVK board (DT)
[    2.726040] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    2.732989] pc : tcpci_irq+0x38/0x318
[    2.736647] lr : _tcpci_irq+0x14/0x20
[    2.740295] sp : ffff80008324bd30
[    2.743597] x29: ffff80008324bd70 x28: ffff800080107894 x27: ffff800082198f70
[    2.750721] x26: ffff0000050e6680 x25: ffff000004d172ac x24: ffff0000050f0000
[    2.757845] x23: ffff000004d17200 x22: 0000000000000001 x21: ffff0000050f0000
[    2.764969] x20: ffff000004d17200 x19: 0000000000000000 x18: 0000000000000001
[    2.772093] x17: 0000000000000000 x16: ffff80008183d8a0 x15: ffff00007fbab040
[    2.779217] x14: ffff00007fb918c0 x13: 0000000000000000 x12: 000000000000017a
[    2.786341] x11: 0000000000000001 x10: 0000000000000a90 x9 : ffff80008324bd00
[    2.793465] x8 : ffff0000050f0af0 x7 : ffff00007fbaa840 x6 : 0000000000000031
[    2.800589] x5 : 000000000000017a x4 : 0000000000000002 x3 : 0000000000000002
[    2.807713] x2 : ffff80008324bd3a x1 : 0000000000000010 x0 : 0000000000000000
[    2.814838] Call trace:
[    2.817273]  tcpci_irq+0x38/0x318
[    2.820583]  _tcpci_irq+0x14/0x20
[    2.823885]  irq_thread_fn+0x2c/0xa8
[    2.827456]  irq_thread+0x16c/0x2f4
[    2.830940]  kthread+0x110/0x114
[    2.834164]  ret_from_fork+0x10/0x20
[    2.837738] Code: f9426420 f9001fe0 d2800000 52800201 (f9400a60)

This may happen on shared irq case. Such as two Type-C ports share one
irq. After the first port finished tcpci_register_port(), it may trigger
interrupt. However, if the interrupt comes by chance the 2nd port finishes
devm_request_threaded_irq(), the 2nd port interrupt handler will run at
first. Then the above issue happens due to tcpci is still a NULL pointer
in tcpci_irq() when dereference to regmap.

  devm_request_threaded_irq()
				<-- port1 irq comes
  disable_irq(client->irq);
  tcpci_register_port()

This will restore the logic to the state before commit (77e8510 "usb:
typec: tcpci: support edge irq").

However, moving tcpci_register_port() earlier creates a problem when use
edge irq because tcpci_init() will be called before
devm_request_threaded_irq(). The tcpci_init() writes the ALERT_MASK to
the hardware to tell it to start generating interrupts but we're not ready
to deal with them yet, then the ALERT events may be missed and ALERT line
will not recover to high level forever. To avoid the issue, this will also
set ALERT_MASK register after devm_request_threaded_irq() return.

Fixes: 77e8510 ("usb: typec: tcpci: support edge irq")
Cc: stable <stable@kernel.org>
Tested-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20241218095328.2604607-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jwrdegoede pushed a commit that referenced this pull request Feb 3, 2025
irq_chip functions may be called in raw spinlock context. Therefore, we
must also use a raw spinlock for our own internal locking.

This fixes the following lockdep splat:

[    5.349336] =============================
[    5.353349] [ BUG: Invalid wait context ]
[    5.357361] 6.13.0-rc5+ linux-sunxi#69 Tainted: G        W
[    5.363031] -----------------------------
[    5.367045] kworker/u17:1/44 is trying to lock:
[    5.371587] ffffff88018b02c0 (&chip->gpio_lock){....}-{3:3}, at: xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.380079] other info that might help us debug this:
[    5.385138] context-{5:5}
[    5.387762] 5 locks held by kworker/u17:1/44:
[    5.392123] #0: ffffff8800014958 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3204)
[    5.402260] #1: ffffffc082fcbdd8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3205)
[    5.411528] #2: ffffff880172c900 (&dev->mutex){....}-{4:4}, at: __device_attach (drivers/base/dd.c:1006)
[    5.419929] #3: ffffff88039c8268 (request_class#2){+.+.}-{4:4}, at: __setup_irq (kernel/irq/internals.h:156 kernel/irq/manage.c:1596)
[    5.428331] #4: ffffff88039c80c8 (lock_class#2){....}-{2:2}, at: __setup_irq (kernel/irq/manage.c:1614)
[    5.436472] stack backtrace:
[    5.439359] CPU: 2 UID: 0 PID: 44 Comm: kworker/u17:1 Tainted: G        W          6.13.0-rc5+ linux-sunxi#69
[    5.448690] Tainted: [W]=WARN
[    5.451656] Hardware name: xlnx,zynqmp (DT)
[    5.455845] Workqueue: events_unbound deferred_probe_work_func
[    5.461699] Call trace:
[    5.464147] show_stack+0x18/0x24 C
[    5.467821] dump_stack_lvl (lib/dump_stack.c:123)
[    5.471501] dump_stack (lib/dump_stack.c:130)
[    5.474824] __lock_acquire (kernel/locking/lockdep.c:4828 kernel/locking/lockdep.c:4898 kernel/locking/lockdep.c:5176)
[    5.478758] lock_acquire (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851 kernel/locking/lockdep.c:5814)
[    5.482429] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162)
[    5.486797] xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.490737] irq_enable (kernel/irq/internals.h:236 kernel/irq/chip.c:170 kernel/irq/chip.c:439 kernel/irq/chip.c:432 kernel/irq/chip.c:345)
[    5.494060] __irq_startup (kernel/irq/internals.h:241 kernel/irq/chip.c:180 kernel/irq/chip.c:250)
[    5.497645] irq_startup (kernel/irq/chip.c:270)
[    5.501143] __setup_irq (kernel/irq/manage.c:1807)
[    5.504728] request_threaded_irq (kernel/irq/manage.c:2208)

Fixes: a32c7ca ("gpio: gpio-xilinx: Add interrupt support")
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250110163354.2012654-1-sean.anderson@linux.dev
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
jwrdegoede pushed a commit that referenced this pull request Feb 3, 2025
This commit addresses a circular locking dependency issue within the GFX
isolation mechanism. The problem was identified by a warning indicating
a potential deadlock due to inconsistent lock acquisition order.

- The `amdgpu_gfx_enforce_isolation_ring_begin_use` and
  `amdgpu_gfx_enforce_isolation_ring_end_use` functions previously
  acquired `enforce_isolation_mutex` and called `amdgpu_gfx_kfd_sch_ctrl`,
  leading to potential deadlocks. ie., If `amdgpu_gfx_kfd_sch_ctrl` is
  called while `enforce_isolation_mutex` is held, and
  `amdgpu_gfx_enforce_isolation_handler` is called while `kfd_sch_mutex` is
  held, it can create a circular dependency.

By ensuring consistent lock usage, this fix resolves the issue:

[  606.297333] ======================================================
[  606.297343] WARNING: possible circular locking dependency detected
[  606.297353] 6.10.0-amd-mlkd-610-311224-lof linux-sunxi#19 Tainted: G           OE
[  606.297365] ------------------------------------------------------
[  606.297375] kworker/u96:3/3825 is trying to acquire lock:
[  606.297385] ffff9aa64e431cb8 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}, at: __flush_work+0x232/0x610
[  606.297413]
               but task is already holding lock:
[  606.297423] ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.297725]
               which lock already depends on the new lock.

[  606.297738]
               the existing dependency chain (in reverse order) is:
[  606.297749]
               -> #2 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}:
[  606.297765]        __mutex_lock+0x85/0x930
[  606.297776]        mutex_lock_nested+0x1b/0x30
[  606.297786]        amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.298007]        amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.298225]        amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.298412]        amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.298603]        amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.298866]        drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.298880]        process_one_work+0x21e/0x680
[  606.298890]        worker_thread+0x190/0x350
[  606.298899]        kthread+0xe7/0x120
[  606.298908]        ret_from_fork+0x3c/0x60
[  606.298919]        ret_from_fork_asm+0x1a/0x30
[  606.298929]
               -> #1 (&adev->enforce_isolation_mutex){+.+.}-{3:3}:
[  606.298947]        __mutex_lock+0x85/0x930
[  606.298956]        mutex_lock_nested+0x1b/0x30
[  606.298966]        amdgpu_gfx_enforce_isolation_handler+0x87/0x370 [amdgpu]
[  606.299190]        process_one_work+0x21e/0x680
[  606.299199]        worker_thread+0x190/0x350
[  606.299208]        kthread+0xe7/0x120
[  606.299217]        ret_from_fork+0x3c/0x60
[  606.299227]        ret_from_fork_asm+0x1a/0x30
[  606.299236]
               -> #0 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}:
[  606.299257]        __lock_acquire+0x16f9/0x2810
[  606.299267]        lock_acquire+0xd1/0x300
[  606.299276]        __flush_work+0x250/0x610
[  606.299286]        cancel_delayed_work_sync+0x71/0x80
[  606.299296]        amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu]
[  606.299509]        amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.299723]        amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.299909]        amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.300101]        amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.300355]        drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.300369]        process_one_work+0x21e/0x680
[  606.300378]        worker_thread+0x190/0x350
[  606.300387]        kthread+0xe7/0x120
[  606.300396]        ret_from_fork+0x3c/0x60
[  606.300406]        ret_from_fork_asm+0x1a/0x30
[  606.300416]
               other info that might help us debug this:

[  606.300428] Chain exists of:
                 (work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work) --> &adev->enforce_isolation_mutex --> &adev->gfx.kfd_sch_mutex

[  606.300458]  Possible unsafe locking scenario:

[  606.300468]        CPU0                    CPU1
[  606.300476]        ----                    ----
[  606.300484]   lock(&adev->gfx.kfd_sch_mutex);
[  606.300494]                                lock(&adev->enforce_isolation_mutex);
[  606.300508]                                lock(&adev->gfx.kfd_sch_mutex);
[  606.300521]   lock((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work));
[  606.300536]
                *** DEADLOCK ***

[  606.300546] 5 locks held by kworker/u96:3/3825:
[  606.300555]  #0: ffff9aa5aa1f5d58 ((wq_completion)comp_1.1.0){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680
[  606.300577]  #1: ffffaa53c3c97e40 ((work_completion)(&sched->work_run_job)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680
[  606.300600]  #2: ffff9aa64e463c98 (&adev->enforce_isolation_mutex){+.+.}-{3:3}, at: amdgpu_gfx_enforce_isolation_ring_begin_use+0x1c3/0x5d0 [amdgpu]
[  606.300837]  #3: ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.301062]  #4: ffffffff8c1a5660 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x70/0x610
[  606.301083]
               stack backtrace:
[  606.301092] CPU: 14 PID: 3825 Comm: kworker/u96:3 Tainted: G           OE      6.10.0-amd-mlkd-610-311224-lof linux-sunxi#19
[  606.301109] Hardware name: Gigabyte Technology Co., Ltd. X570S GAMING X/X570S GAMING X, BIOS F7 03/22/2024
[  606.301124] Workqueue: comp_1.1.0 drm_sched_run_job_work [gpu_sched]
[  606.301140] Call Trace:
[  606.301146]  <TASK>
[  606.301154]  dump_stack_lvl+0x9b/0xf0
[  606.301166]  dump_stack+0x10/0x20
[  606.301175]  print_circular_bug+0x26c/0x340
[  606.301187]  check_noncircular+0x157/0x170
[  606.301197]  ? register_lock_class+0x48/0x490
[  606.301213]  __lock_acquire+0x16f9/0x2810
[  606.301230]  lock_acquire+0xd1/0x300
[  606.301239]  ? __flush_work+0x232/0x610
[  606.301250]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.301261]  ? mark_held_locks+0x54/0x90
[  606.301274]  ? __flush_work+0x232/0x610
[  606.301284]  __flush_work+0x250/0x610
[  606.301293]  ? __flush_work+0x232/0x610
[  606.301305]  ? __pfx_wq_barrier_func+0x10/0x10
[  606.301318]  ? mark_held_locks+0x54/0x90
[  606.301331]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.301345]  cancel_delayed_work_sync+0x71/0x80
[  606.301356]  amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu]
[  606.301661]  amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.302050]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.302069]  amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.302452]  amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.302862]  ? drm_sched_entity_error+0x82/0x190 [gpu_sched]
[  606.302890]  amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.303366]  drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.303388]  process_one_work+0x21e/0x680
[  606.303409]  worker_thread+0x190/0x350
[  606.303424]  ? __pfx_worker_thread+0x10/0x10
[  606.303437]  kthread+0xe7/0x120
[  606.303449]  ? __pfx_kthread+0x10/0x10
[  606.303463]  ret_from_fork+0x3c/0x60
[  606.303476]  ? __pfx_kthread+0x10/0x10
[  606.303489]  ret_from_fork_asm+0x1a/0x30
[  606.303512]  </TASK>

v2: Refactor lock handling to resolve circular dependency (Alex)

- Introduced a `sched_work` flag to defer the call to
  `amdgpu_gfx_kfd_sch_ctrl` until after releasing
  `enforce_isolation_mutex`.
- This change ensures that `amdgpu_gfx_kfd_sch_ctrl` is called outside
  the critical section, preventing the circular dependency and deadlock.
- The `sched_work` flag is set within the mutex-protected section if
  conditions are met, and the actual function call is made afterward.
- This approach ensures consistent lock acquisition order.

Fixes: afefd6f ("drm/amdgpu: Implement Enforce Isolation Handler for KGD/KFD serialization")
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 0b6b2dd)
Cc: stable@vger.kernel.org
jwrdegoede pushed a commit that referenced this pull request Feb 3, 2025
Attempt to enable IPsec packet offload in tunnel mode in debug kernel
generates the following kernel panic, which is happening due to two
issues:
1. In SA add section, the should be _bh() variant when marking SA mode.
2. There is not needed flush_workqueue in SA delete routine. It is not
needed as at this stage as it is removed from SADB and the running work
will be canceled later in SA free.

 =====================================================
 WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
 6.12.0+ #4 Not tainted
 -----------------------------------------------------
 charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire:
 ffff88810f365020 (&xa->xa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]

 and this task is already holding:
 ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30
 which would create a new lock dependency:
  (&x->lock){+.-.}-{3:3} -> (&xa->xa_lock#24){+.+.}-{3:3}

 but this new dependency connects a SOFTIRQ-irq-safe lock:
  (&x->lock){+.-.}-{3:3}

 ... which became SOFTIRQ-irq-safe at:
   lock_acquire+0x1be/0x520
   _raw_spin_lock_bh+0x34/0x40
   xfrm_timer_handler+0x91/0xd70
   __hrtimer_run_queues+0x1dd/0xa60
   hrtimer_run_softirq+0x146/0x2e0
   handle_softirqs+0x266/0x860
   irq_exit_rcu+0x115/0x1a0
   sysvec_apic_timer_interrupt+0x6e/0x90
   asm_sysvec_apic_timer_interrupt+0x16/0x20
   default_idle+0x13/0x20
   default_idle_call+0x67/0xa0
   do_idle+0x2da/0x320
   cpu_startup_entry+0x50/0x60
   start_secondary+0x213/0x2a0
   common_startup_64+0x129/0x138

 to a SOFTIRQ-irq-unsafe lock:
  (&xa->xa_lock#24){+.+.}-{3:3}

 ... which became SOFTIRQ-irq-unsafe at:
 ...
   lock_acquire+0x1be/0x520
   _raw_spin_lock+0x2c/0x40
   xa_set_mark+0x70/0x110
   mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
   xfrm_dev_state_add+0x3bb/0xd70
   xfrm_add_sa+0x2451/0x4a90
   xfrm_user_rcv_msg+0x493/0x880
   netlink_rcv_skb+0x12e/0x380
   xfrm_netlink_rcv+0x6d/0x90
   netlink_unicast+0x42f/0x740
   netlink_sendmsg+0x745/0xbe0
   __sock_sendmsg+0xc5/0x190
   __sys_sendto+0x1fe/0x2c0
   __x64_sys_sendto+0xdc/0x1b0
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x4b/0x53

 other info that might help us debug this:

  Possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&xa->xa_lock#24);
                                local_irq_disable();
                                lock(&x->lock);
                                lock(&xa->xa_lock#24);
   <Interrupt>
     lock(&x->lock);

  *** DEADLOCK ***

 2 locks held by charon/1337:
  #0: ffffffff87f8f858 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90
  #1: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30

 the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
 -> (&x->lock){+.-.}-{3:3} ops: 29 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_alloc_spi+0xc0/0xe60
                     xfrm_alloc_userspi+0x5f6/0xbc0
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    IN-SOFTIRQ-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_timer_handler+0x91/0xd70
                     __hrtimer_run_queues+0x1dd/0xa60
                     hrtimer_run_softirq+0x146/0x2e0
                     handle_softirqs+0x266/0x860
                     irq_exit_rcu+0x115/0x1a0
                     sysvec_apic_timer_interrupt+0x6e/0x90
                     asm_sysvec_apic_timer_interrupt+0x16/0x20
                     default_idle+0x13/0x20
                     default_idle_call+0x67/0xa0
                     do_idle+0x2da/0x320
                     cpu_startup_entry+0x50/0x60
                     start_secondary+0x213/0x2a0
                     common_startup_64+0x129/0x138
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    xfrm_alloc_spi+0xc0/0xe60
                    xfrm_alloc_userspi+0x5f6/0xbc0
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffff87f9cd20>] __key.18+0x0/0x40

 the dependencies between the lock to be acquired
  and SOFTIRQ-irq-unsafe lock:
 -> (&xa->xa_lock#24){+.+.}-{3:3} ops: 9 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    SOFTIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock+0x2c/0x40
                     xa_set_mark+0x70/0x110
                     mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                    xfrm_dev_state_add+0x3bb/0xd70
                    xfrm_add_sa+0x2451/0x4a90
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffffa078ff60>] __key.48+0x0/0xfffffffffff210a0 [mlx5_core]
  ... acquired at:
    __lock_acquire+0x30a0/0x5040
    lock_acquire+0x1be/0x520
    _raw_spin_lock_bh+0x34/0x40
    mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
    xfrm_dev_state_delete+0x90/0x160
    __xfrm_state_delete+0x662/0xae0
    xfrm_state_delete+0x1e/0x30
    xfrm_del_sa+0x1c2/0x340
    xfrm_user_rcv_msg+0x493/0x880
    netlink_rcv_skb+0x12e/0x380
    xfrm_netlink_rcv+0x6d/0x90
    netlink_unicast+0x42f/0x740
    netlink_sendmsg+0x745/0xbe0
    __sock_sendmsg+0xc5/0x190
    __sys_sendto+0x1fe/0x2c0
    __x64_sys_sendto+0xdc/0x1b0
    do_syscall_64+0x6d/0x140
    entry_SYSCALL_64_after_hwframe+0x4b/0x53

 stack backtrace:
 CPU: 7 UID: 0 PID: 1337 Comm: charon Not tainted 6.12.0+ #4
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x74/0xd0
  check_irq_usage+0x12e8/0x1d90
  ? print_shortest_lock_dependencies_backwards+0x1b0/0x1b0
  ? check_chain_key+0x1bb/0x4c0
  ? __lockdep_reset_lock+0x180/0x180
  ? check_path.constprop.0+0x24/0x50
  ? mark_lock+0x108/0x2fb0
  ? print_circular_bug+0x9b0/0x9b0
  ? mark_lock+0x108/0x2fb0
  ? print_usage_bug.part.0+0x670/0x670
  ? check_prev_add+0x1c4/0x2310
  check_prev_add+0x1c4/0x2310
  __lock_acquire+0x30a0/0x5040
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  lock_acquire+0x1be/0x520
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  ? lockdep_hardirqs_on_prepare+0x400/0x400
  ? __xfrm_state_delete+0x5f0/0xae0
  ? lock_downgrade+0x6b0/0x6b0
  _raw_spin_lock_bh+0x34/0x40
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  xfrm_dev_state_delete+0x90/0x160
  __xfrm_state_delete+0x662/0xae0
  xfrm_state_delete+0x1e/0x30
  xfrm_del_sa+0x1c2/0x340
  ? xfrm_get_sa+0x250/0x250
  ? check_chain_key+0x1bb/0x4c0
  xfrm_user_rcv_msg+0x493/0x880
  ? copy_sec_ctx+0x270/0x270
  ? check_chain_key+0x1bb/0x4c0
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  netlink_rcv_skb+0x12e/0x380
  ? copy_sec_ctx+0x270/0x270
  ? netlink_ack+0xd90/0xd90
  ? netlink_deliver_tap+0xcd/0xb60
  xfrm_netlink_rcv+0x6d/0x90
  netlink_unicast+0x42f/0x740
  ? netlink_attachskb+0x730/0x730
  ? lock_acquire+0x1be/0x520
  netlink_sendmsg+0x745/0xbe0
  ? netlink_unicast+0x740/0x740
  ? __might_fault+0xbb/0x170
  ? netlink_unicast+0x740/0x740
  __sock_sendmsg+0xc5/0x190
  ? fdget+0x163/0x1d0
  __sys_sendto+0x1fe/0x2c0
  ? __x64_sys_getpeername+0xb0/0xb0
  ? do_user_addr_fault+0x856/0xe30
  ? lock_acquire+0x1be/0x520
  ? __task_pid_nr_ns+0x117/0x410
  ? lock_downgrade+0x6b0/0x6b0
  __x64_sys_sendto+0xdc/0x1b0
  ? lockdep_hardirqs_on_prepare+0x284/0x400
  do_syscall_64+0x6d/0x140
  entry_SYSCALL_64_after_hwframe+0x4b/0x53
 RIP: 0033:0x7f7d31291ba4
 Code: 7d e8 89 4d d4 e8 4c 42 f7 ff 44 8b 4d d0 4c 8b 45 c8 89 c3 44 8b 55 d4 8b 7d e8 b8 2c 00 00 00 48 8b 55 d8 48 8b 75 e0 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 45 e8 e8 99 42 f7 ff 48 8b 45
 RSP: 002b:00007f7d2ccd94f0 EFLAGS: 00000297 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f7d31291ba4
 RDX: 0000000000000028 RSI: 00007f7d2ccd96a0 RDI: 000000000000000a
 RBP: 00007f7d2ccd9530 R08: 00007f7d2ccd9598 R09: 000000000000000c
 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000028
 R13: 00007f7d2ccd9598 R14: 00007f7d2ccd96a0 R15: 00000000000000e1
  </TASK>

Fixes: 4c24272 ("net/mlx5e: Listen to ARP events to update IPsec L2 headers in tunnel mode")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
jwrdegoede pushed a commit that referenced this pull request Feb 9, 2025
When COWing a relocation tree path, at relocation.c:replace_path(), we
can trigger a lockdep splat while we are in the btrfs_search_slot() call
against the relocation root. This happens in that callchain at
ctree.c:read_block_for_search() when we happen to find a child extent
buffer already loaded through the fs tree with a lockdep class set to
the fs tree. So when we attempt to lock that extent buffer through a
relocation tree we have to reset the lockdep class to the class for a
relocation tree, since a relocation tree has extent buffers that used
to belong to a fs tree and may currently be already loaded (we swap
extent buffers between the two trees at the end of replace_path()).

However we are missing calls to btrfs_maybe_reset_lockdep_class() to reset
the lockdep class at ctree.c:read_block_for_search() before we read lock
an extent buffer, just like we did for btrfs_search_slot() in commit
b40130b ("btrfs: fix lockdep splat with reloc root extent buffers").

So add the missing btrfs_maybe_reset_lockdep_class() calls before the
attempts to read lock an extent buffer at ctree.c:read_block_for_search().

The lockdep splat was reported by syzbot and it looks like this:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Not tainted
   ------------------------------------------------------
   syz.0.0/5335 is trying to acquire lock:
   ffff8880545dbc38 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

   but task is already holding lock:
   ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #2 (btrfs-treloc-02/1){+.+.}-{4:4}:
          reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374
          __lock_release kernel/locking/lockdep.c:5563 [inline]
          lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870
          up_write+0x79/0x590 kernel/locking/rwsem.c:1629
          btrfs_force_cow_block+0x14b3/0x1fd0 fs/btrfs/ctree.c:660
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #1 (btrfs-tree-01/1){+.+.}-{4:4}:
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
          btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
          btrfs_init_new_buffer fs/btrfs/extent-tree.c:5052 [inline]
          btrfs_alloc_tree_block+0x41c/0x1440 fs/btrfs/extent-tree.c:5132
          btrfs_force_cow_block+0x526/0x1fd0 fs/btrfs/ctree.c:573
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4351
          btrfs_insert_empty_item fs/btrfs/ctree.h:688 [inline]
          btrfs_insert_inode_ref+0x2bb/0xf80 fs/btrfs/inode-item.c:330
          btrfs_rename_exchange fs/btrfs/inode.c:7990 [inline]
          btrfs_rename2+0xcb7/0x2b90 fs/btrfs/inode.c:8374
          vfs_rename+0xbdb/0xf00 fs/namei.c:5067
          do_renameat2+0xd94/0x13f0 fs/namei.c:5224
          __do_sys_renameat2 fs/namei.c:5258 [inline]
          __se_sys_renameat2 fs/namei.c:5255 [inline]
          __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5255
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #0 (btrfs-tree-01){++++}-{4:4}:
          check_prev_add kernel/locking/lockdep.c:3161 [inline]
          check_prevs_add kernel/locking/lockdep.c:3280 [inline]
          validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
          __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
          btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
          btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
          read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
          btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   other info that might help us debug this:

   Chain exists of:
     btrfs-tree-01 --> btrfs-tree-01/1 --> btrfs-treloc-02/1

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(btrfs-treloc-02/1);
                                  lock(btrfs-tree-01/1);
                                  lock(btrfs-treloc-02/1);
     rlock(btrfs-tree-01);

    *** DEADLOCK ***

   8 locks held by syz.0.0/5335:
    #0: ffff88801e3ae420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
    #1: ffff888052c760d0 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: __btrfs_balance+0x4c2/0x26b0 fs/btrfs/volumes.c:4183
    #2: ffff888052c74850 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x775/0xd90 fs/btrfs/relocation.c:4086
    #3: ffff88801e3ae610 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xf11/0x1ad0 fs/btrfs/relocation.c:1659
    #4: ffff888052c76470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #5: ffff888052c76498 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #6: ffff8880545db878 (btrfs-tree-01/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
    #7: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   stack backtrace:
   CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
    check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
    check_prev_add kernel/locking/lockdep.c:3161 [inline]
    check_prevs_add kernel/locking/lockdep.c:3280 [inline]
    validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
    __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
    down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
    btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
    btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
    read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
    btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
    replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
    merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
    merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
    relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1ac6985d29
   Code: ff ff c3 (...)
   RSP: 002b:00007f1ac63fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f1ac6b76160 RCX: 00007f1ac6985d29
   RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000007
   RBP: 00007f1ac6a01b08 R08: 0000000000000000 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000001 R14: 00007f1ac6b76160 R15: 00007fffda145a88
    </TASK>

Reported-by: syzbot+63913e558c084f7f8fdc@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/677b3014.050a0220.3b53b0.0064.GAE@google.com/
Fixes: 9978599 ("btrfs: reduce lock contention when eb cache miss for btree search")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
jwrdegoede pushed a commit that referenced this pull request Feb 17, 2025
We have several places across the kernel where we want to access another
task's syscall arguments, such as ptrace(2), seccomp(2), etc., by making
a call to syscall_get_arguments().

This works for register arguments right away by accessing the task's
`regs' member of `struct pt_regs', however for stack arguments seen with
32-bit/o32 kernels things are more complicated.  Technically they ought
to be obtained from the user stack with calls to an access_remote_vm(),
but we have an easier way available already.

So as to be able to access syscall stack arguments as regular function
arguments following the MIPS calling convention we copy them over from
the user stack to the kernel stack in arch/mips/kernel/scall32-o32.S, in
handle_sys(), to the current stack frame's outgoing argument space at
the top of the stack, which is where the handler called expects to see
its incoming arguments.  This area is also pointed at by the `pt_regs'
pointer obtained by task_pt_regs().

Make the o32 stack argument space a proper member of `struct pt_regs'
then, by renaming the existing member from `pad0' to `args' and using
generated offsets to access the space.  No functional change though.

With the change in place the o32 kernel stack frame layout at the entry
to a syscall handler invoked by handle_sys() is therefore as follows:

$sp + 68 -> |         ...         | <- pt_regs.regs[9]
            +---------------------+
$sp + 64 -> |         $t0         | <- pt_regs.regs[8]
            +---------------------+
$sp + 60 -> |   $a3/argument #4   | <- pt_regs.regs[7]
            +---------------------+
$sp + 56 -> |   $a2/argument #3   | <- pt_regs.regs[6]
            +---------------------+
$sp + 52 -> |   $a1/argument #2   | <- pt_regs.regs[5]
            +---------------------+
$sp + 48 -> |   $a0/argument #1   | <- pt_regs.regs[4]
            +---------------------+
$sp + 44 -> |         $v1         | <- pt_regs.regs[3]
            +---------------------+
$sp + 40 -> |         $v0         | <- pt_regs.regs[2]
            +---------------------+
$sp + 36 -> |         $at         | <- pt_regs.regs[1]
            +---------------------+
$sp + 32 -> |        $zero        | <- pt_regs.regs[0]
            +---------------------+
$sp + 28 -> |  stack argument #8  | <- pt_regs.args[7]
            +---------------------+
$sp + 24 -> |  stack argument #7  | <- pt_regs.args[6]
            +---------------------+
$sp + 20 -> |  stack argument #6  | <- pt_regs.args[5]
            +---------------------+
$sp + 16 -> |  stack argument #5  | <- pt_regs.args[4]
            +---------------------+
$sp + 12 -> | psABI space for $a3 | <- pt_regs.args[3]
            +---------------------+
$sp +  8 -> | psABI space for $a2 | <- pt_regs.args[2]
            +---------------------+
$sp +  4 -> | psABI space for $a1 | <- pt_regs.args[1]
            +---------------------+
$sp +  0 -> | psABI space for $a0 | <- pt_regs.args[0]
            +---------------------+

holding user data received and with the first 4 frame slots reserved by
the psABI for the compiler to spill the incoming arguments from $a0-$a3
registers (which it sometimes does according to its needs) and the next
4 frame slots designated by the psABI for any stack function arguments
that follow.  This data is also available for other tasks to peek/poke
at as reqired and where permitted.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
jwrdegoede pushed a commit that referenced this pull request Mar 12, 2025
Use raw_spinlock in order to fix spurious messages about invalid context
when spinlock debugging is enabled. The lock is only used to serialize
register access.

    [    4.239592] =============================
    [    4.239595] [ BUG: Invalid wait context ]
    [    4.239599] 6.13.0-rc7-arm64-renesas-05496-gd088502a519f linux-sunxi#35 Not tainted
    [    4.239603] -----------------------------
    [    4.239606] kworker/u8:5/76 is trying to lock:
    [    4.239609] ffff0000091898a0 (&p->lock){....}-{3:3}, at: gpio_rcar_config_interrupt_input_mode+0x34/0x164
    [    4.239641] other info that might help us debug this:
    [    4.239643] context-{5:5}
    [    4.239646] 5 locks held by kworker/u8:5/76:
    [    4.239651]  #0: ffff0000080fb148 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x190/0x62c
    [    4.250180] OF: /soc/sound@ec500000/ports/port@0/endpoint: Read of boolean property 'frame-master' with a value.
    [    4.254094]  #1: ffff80008299bd80 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1b8/0x62c
    [    4.254109]  #2: ffff00000920c8f8
    [    4.258345] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'bitclock-master' with a value.
    [    4.264803]  (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0x3c/0xdc
    [    4.264820]  #3: ffff00000a50ca40 (request_class#2){+.+.}-{4:4}, at: __setup_irq+0xa0/0x690
    [    4.264840]  #4:
    [    4.268872] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'frame-master' with a value.
    [    4.273275] ffff00000a50c8c8 (lock_class){....}-{2:2}, at: __setup_irq+0xc4/0x690
    [    4.296130] renesas_sdhi_internal_dmac ee10000.mmc: mmc1 base at 0x00000000ee100000, max clock rate 200 MHz
    [    4.304082] stack backtrace:
    [    4.304086] CPU: 1 UID: 0 PID: 76 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-arm64-renesas-05496-gd088502a519f linux-sunxi#35
    [    4.304092] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT)
    [    4.304097] Workqueue: async async_run_entry_fn
    [    4.304106] Call trace:
    [    4.304110]  show_stack+0x14/0x20 (C)
    [    4.304122]  dump_stack_lvl+0x6c/0x90
    [    4.304131]  dump_stack+0x14/0x1c
    [    4.304138]  __lock_acquire+0xdfc/0x1584
    [    4.426274]  lock_acquire+0x1c4/0x33c
    [    4.429942]  _raw_spin_lock_irqsave+0x5c/0x80
    [    4.434307]  gpio_rcar_config_interrupt_input_mode+0x34/0x164
    [    4.440061]  gpio_rcar_irq_set_type+0xd4/0xd8
    [    4.444422]  __irq_set_trigger+0x5c/0x178
    [    4.448435]  __setup_irq+0x2e4/0x690
    [    4.452012]  request_threaded_irq+0xc4/0x190
    [    4.456285]  devm_request_threaded_irq+0x7c/0xf4
    [    4.459398] ata1: link resume succeeded after 1 retries
    [    4.460902]  mmc_gpiod_request_cd_irq+0x68/0xe0
    [    4.470660]  mmc_start_host+0x50/0xac
    [    4.474327]  mmc_add_host+0x80/0xe4
    [    4.477817]  tmio_mmc_host_probe+0x2b0/0x440
    [    4.482094]  renesas_sdhi_probe+0x488/0x6f4
    [    4.486281]  renesas_sdhi_internal_dmac_probe+0x60/0x78
    [    4.491509]  platform_probe+0x64/0xd8
    [    4.495178]  really_probe+0xb8/0x2a8
    [    4.498756]  __driver_probe_device+0x74/0x118
    [    4.503116]  driver_probe_device+0x3c/0x154
    [    4.507303]  __device_attach_driver+0xd4/0x160
    [    4.511750]  bus_for_each_drv+0x84/0xe0
    [    4.515588]  __device_attach_async_helper+0xb0/0xdc
    [    4.520470]  async_run_entry_fn+0x30/0xd8
    [    4.524481]  process_one_work+0x210/0x62c
    [    4.528494]  worker_thread+0x1ac/0x340
    [    4.532245]  kthread+0x10c/0x110
    [    4.535476]  ret_from_fork+0x10/0x20

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250121135833.3769310-1-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
jwrdegoede pushed a commit that referenced this pull request Mar 12, 2025
…/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.14, take #4

- Fix a couple of bugs affecting pKVM's PSCI relay implementation
  when running in the hVHE mode, resulting in the host being entered
  with the MMU in an unknown state, and EL2 being in the wrong mode.
jwrdegoede pushed a commit that referenced this pull request Apr 2, 2025
…cal section

A circular lock dependency splat has been seen involving down_trylock():

  ======================================================
  WARNING: possible circular locking dependency detected
  6.12.0-41.el10.s390x+debug
  ------------------------------------------------------
  dd/32479 is trying to acquire lock:
  0015a20accd0d4f8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x26/0x90

  but task is already holding lock:
  000000017e461698 (&zone->lock){-.-.}-{2:2}, at: rmqueue_bulk+0xac/0x8f0

  the existing dependency chain (in reverse order) is:
  -> #4 (&zone->lock){-.-.}-{2:2}:
  -> #3 (hrtimer_bases.lock){-.-.}-{2:2}:
  -> #2 (&rq->__lock){-.-.}-{2:2}:
  -> #1 (&p->pi_lock){-.-.}-{2:2}:
  -> #0 ((console_sem).lock){-.-.}-{2:2}:

The console_sem -> pi_lock dependency is due to calling try_to_wake_up()
while holding the console_sem raw_spinlock. This dependency can be broken
by using wake_q to do the wakeup instead of calling try_to_wake_up()
under the console_sem lock. This will also make the semaphore's
raw_spinlock become a terminal lock without taking any further locks
underneath it.

The hrtimer_bases.lock is a raw_spinlock while zone->lock is a
spinlock. The hrtimer_bases.lock -> zone->lock dependency happens via
the debug_objects_fill_pool() helper function in the debugobjects code.

  -> #4 (&zone->lock){-.-.}-{2:2}:
         __lock_acquire+0xe86/0x1cc0
         lock_acquire.part.0+0x258/0x630
         lock_acquire+0xb8/0xe0
         _raw_spin_lock_irqsave+0xb4/0x120
         rmqueue_bulk+0xac/0x8f0
         __rmqueue_pcplist+0x580/0x830
         rmqueue_pcplist+0xfc/0x470
         rmqueue.isra.0+0xdec/0x11b0
         get_page_from_freelist+0x2ee/0xeb0
         __alloc_pages_noprof+0x2c2/0x520
         alloc_pages_mpol_noprof+0x1fc/0x4d0
         alloc_pages_noprof+0x8c/0xe0
         allocate_slab+0x320/0x460
         ___slab_alloc+0xa58/0x12b0
         __slab_alloc.isra.0+0x42/0x60
         kmem_cache_alloc_noprof+0x304/0x350
         fill_pool+0xf6/0x450
         debug_object_activate+0xfe/0x360
         enqueue_hrtimer+0x34/0x190
         __run_hrtimer+0x3c8/0x4c0
         __hrtimer_run_queues+0x1b2/0x260
         hrtimer_interrupt+0x316/0x760
         do_IRQ+0x9a/0xe0
         do_irq_async+0xf6/0x160

Normally a raw_spinlock to spinlock dependency is not legitimate
and will be warned if CONFIG_PROVE_RAW_LOCK_NESTING is enabled,
but debug_objects_fill_pool() is an exception as it explicitly
allows this dependency for non-PREEMPT_RT kernel without causing
PROVE_RAW_LOCK_NESTING lockdep splat. As a result, this dependency is
legitimate and not a bug.

Anyway, semaphore is the only locking primitive left that is still
using try_to_wake_up() to do wakeup inside critical section, all the
other locking primitives had been migrated to use wake_q to do wakeup
outside of the critical section. It is also possible that there are
other circular locking dependencies involving printk/console_sem or
other existing/new semaphores lurking somewhere which may show up in
the future. Let just do the migration now to wake_q to avoid headache
like this.

Reported-by: yzbot+ed801a886dfdbfe7136d@syzkaller.appspotmail.com
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250307232717.1759087-3-boqun.feng@gmail.com
jwrdegoede pushed a commit that referenced this pull request May 25, 2025
When migrating a THP, concurrent access to the PMD migration entry during
a deferred split scan can lead to an invalid address access, as
illustrated below.  To prevent this invalid access, it is necessary to
check the PMD migration entry and return early.  In this context, there is
no need to use pmd_to_swp_entry and pfn_swap_entry_to_page to verify the
equality of the target folio.  Since the PMD migration entry is locked, it
cannot be served as the target.

Mailing list discussion and explanation from Hugh Dickins: "An anon_vma
lookup points to a location which may contain the folio of interest, but
might instead contain another folio: and weeding out those other folios is
precisely what the "folio != pmd_folio((*pmd)" check (and the "risk of
replacing the wrong folio" comment a few lines above it) is for."

BUG: unable to handle page fault for address: ffffea60001db008
CPU: 0 UID: 0 PID: 2199114 Comm: tee Not tainted 6.14.0+ #4 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:split_huge_pmd_locked+0x3b5/0x2b60
Call Trace:
<TASK>
try_to_migrate_one+0x28c/0x3730
rmap_walk_anon+0x4f6/0x770
unmap_folio+0x196/0x1f0
split_huge_page_to_list_to_order+0x9f6/0x1560
deferred_split_scan+0xac5/0x12a0
shrinker_debugfs_scan_write+0x376/0x470
full_proxy_write+0x15c/0x220
vfs_write+0x2fc/0xcb0
ksys_write+0x146/0x250
do_syscall_64+0x6a/0x120
entry_SYSCALL_64_after_hwframe+0x76/0x7e

The bug is found by syzkaller on an internal kernel, then confirmed on
upstream.

Link: https://lkml.kernel.org/r/20250421113536.3682201-1-gavinguo@igalia.com
Link: https://lore.kernel.org/all/20250414072737.1698513-1-gavinguo@igalia.com/
Link: https://lore.kernel.org/all/20250418085802.2973519-1-gavinguo@igalia.com/
Fixes: 84c3fc4 ("mm: thp: check pmd migration entry in common path")
Signed-off-by: Gavin Guo <gavinguo@igalia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Cc: Florent Revest <revest@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
jwrdegoede pushed a commit that referenced this pull request May 25, 2025
A warning on driver removal started occurring after commit 9dd05df
("net: warn if NAPI instance wasn't shut down"). Disable tx napi before
deleting it in mt76_dma_cleanup().

 WARNING: CPU: 4 PID: 18828 at net/core/dev.c:7288 __netif_napi_del_locked+0xf0/0x100
 CPU: 4 UID: 0 PID: 18828 Comm: modprobe Not tainted 6.15.0-rc4 #4 PREEMPT(lazy)
 Hardware name: ASUS System Product Name/PRIME X670E-PRO WIFI, BIOS 3035 09/05/2024
 RIP: 0010:__netif_napi_del_locked+0xf0/0x100
 Call Trace:
 <TASK>
 mt76_dma_cleanup+0x54/0x2f0 [mt76]
 mt7921_pci_remove+0xd5/0x190 [mt7921e]
 pci_device_remove+0x47/0xc0
 device_release_driver_internal+0x19e/0x200
 driver_detach+0x48/0x90
 bus_remove_driver+0x6d/0xf0
 pci_unregister_driver+0x2e/0xb0
 __do_sys_delete_module.isra.0+0x197/0x2e0
 do_syscall_64+0x7b/0x160
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Tested with mt7921e but the same pattern can be actually applied to other
mt76 drivers calling mt76_dma_cleanup() during removal. Tx napi is enabled
in their *_dma_init() functions and only toggled off and on again inside
their suspend/resume/reset paths. So it should be okay to disable tx
napi in such a generic way.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 2ac515a ("mt76: mt76x02: use napi polling for tx cleanup")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Tested-by: Ming Yen Hsieh <mingyen.hsieh@mediatek.com>
Link: https://patch.msgid.link/20250506115540.19045-1-pchelkin@ispras.ru
Signed-off-by: Felix Fietkau <nbd@nbd.name>
jwrdegoede pushed a commit that referenced this pull request Jun 21, 2025
Before the commit under the Fixes tag below, bnxt_ulp_stop() and
bnxt_ulp_start() were always invoked in pairs.  After that commit,
the new bnxt_ulp_restart() can be invoked after bnxt_ulp_stop()
has been called.  This may result in the RoCE driver's aux driver
.suspend() method being invoked twice.  The 2nd bnxt_re_suspend()
call will crash when it dereferences a NULL pointer:

(NULL ib_device): Handle device suspend call
BUG: kernel NULL pointer dereference, address: 0000000000000b78
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
CPU: 20 UID: 0 PID: 181 Comm: kworker/u96:5 Tainted: G S                  6.15.0-rc1 #4 PREEMPT(voluntary)
Tainted: [S]=CPU_OUT_OF_SPEC
Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017
Workqueue: bnxt_pf_wq bnxt_sp_task [bnxt_en]
RIP: 0010:bnxt_re_suspend+0x45/0x1f0 [bnxt_re]
Code: 8b 05 a7 3c 5b f5 48 89 44 24 18 31 c0 49 8b 5c 24 08 4d 8b 2c 24 e8 ea 06 0a f4 48 c7 c6 04 60 52 c0 48 89 df e8 1b ce f9 ff <48> 8b 83 78 0b 00 00 48 8b 80 38 03 00 00 a8 40 0f 85 b5 00 00 00
RSP: 0018:ffffa2e84084fd88 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffffb4b6b934 RDI: 00000000ffffffff
RBP: ffffa1760954c9c0 R08: 0000000000000000 R09: c0000000ffffdfff
R10: 0000000000000001 R11: ffffa2e84084fb50 R12: ffffa176031ef070
R13: ffffa17609775000 R14: ffffa17603adc180 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffffa17daa397000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000b78 CR3: 00000004aaa30003 CR4: 00000000003706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
bnxt_ulp_stop+0x69/0x90 [bnxt_en]
bnxt_sp_task+0x678/0x920 [bnxt_en]
? __schedule+0x514/0xf50
process_scheduled_works+0x9d/0x400
worker_thread+0x11c/0x260
? __pfx_worker_thread+0x10/0x10
kthread+0xfe/0x1e0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2b/0x40
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30

Check the BNXT_EN_FLAG_ULP_STOPPED flag and do not proceed if the flag
is already set.  This will preserve the original symmetrical
bnxt_ulp_stop() and bnxt_ulp_start().

Also, inside bnxt_ulp_start(), clear the BNXT_EN_FLAG_ULP_STOPPED
flag after taking the mutex to avoid any race condition.  And for
symmetry, only proceed in bnxt_ulp_start() if the
BNXT_EN_FLAG_ULP_STOPPED is set.

Fixes: 3c163f3 ("bnxt_en: Optimize recovery path ULP locking in the driver")
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Co-developed-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250613231841.377988-2-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
jwrdegoede pushed a commit that referenced this pull request Jul 6, 2025
… context

The current use of a mutex to protect the notifier hashtable accesses
can lead to issues in the atomic context. It results in the below
kernel warnings:

  |  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:258
  |  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 9, name: kworker/0:0
  |  preempt_count: 1, expected: 0
  |  RCU nest depth: 0, expected: 0
  |  CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.14.0 #4
  |  Workqueue: ffa_pcpu_irq_notification notif_pcpu_irq_work_fn
  |  Call trace:
  |   show_stack+0x18/0x24 (C)
  |   dump_stack_lvl+0x78/0x90
  |   dump_stack+0x18/0x24
  |   __might_resched+0x114/0x170
  |   __might_sleep+0x48/0x98
  |   mutex_lock+0x24/0x80
  |   handle_notif_callbacks+0x54/0xe0
  |   notif_get_and_handle+0x40/0x88
  |   generic_exec_single+0x80/0xc0
  |   smp_call_function_single+0xfc/0x1a0
  |   notif_pcpu_irq_work_fn+0x2c/0x38
  |   process_one_work+0x14c/0x2b4
  |   worker_thread+0x2e4/0x3e0
  |   kthread+0x13c/0x210
  |   ret_from_fork+0x10/0x20

To address this, replace the mutex with an rwlock to protect the notifier
hashtable accesses. This ensures that read-side locking does not sleep and
multiple readers can acquire the lock concurrently, avoiding unnecessary
contention and potential deadlocks. Writer access remains exclusive,
preserving correctness.

This change resolves warnings from lockdep about potential sleep in
atomic context.

Cc: Jens Wiklander <jens.wiklander@linaro.org>
Reported-by: Jérôme Forissier <jerome.forissier@linaro.org>
Closes: OP-TEE/optee_os#7394
Fixes: e057344 ("firmware: arm_ffa: Add interfaces to request notification callbacks")
Message-Id: <20250528-ffa_notif_fix-v1-3-5ed7bc7f8437@arm.com>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
jwrdegoede pushed a commit that referenced this pull request Aug 4, 2025
…ux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.16, take #4

- Gracefully fail initialising pKVM if the interrupt controller isn't
  GICv3

- Also gracefully fail initialising pKVM if the carveout allocation
  fails

- Fix the computing of the minimum MMIO range required for the host on
  stage-2 fault

- Fix the generation of the GICv3 Maintenance Interrupt in nested mode
jwrdegoede pushed a commit that referenced this pull request Aug 31, 2025
These iterations require the read lock, otherwise RCU
lockdep will splat:

=============================
WARNING: suspicious RCU usage
6.17.0-rc3-00014-g31419c045d64 #6 Tainted: G           O
-----------------------------
drivers/base/power/main.c:1333 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
5 locks held by rtcwake/547:
 #0: 00000000643ab418 (sb_writers#6){.+.+}-{0:0}, at: file_start_write+0x2b/0x3a
 #1: 0000000067a0ca88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x181/0x24b
 #2: 00000000631eac40 (kn->active#3){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x191/0x24b
 #3: 00000000609a1308 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0xaf/0x30b
 #4: 0000000060c0fdb0 (device_links_srcu){.+.+}-{0:0}, at: device_links_read_lock+0x75/0x98

stack backtrace:
CPU: 0 UID: 0 PID: 547 Comm: rtcwake Tainted: G           O        6.17.0-rc3-00014-g31419c045d64 #6 VOLUNTARY
Tainted: [O]=OOT_MODULE
Stack:
 223721b3a80 6089eac6 00000001 00000001
 ffffff00 6089eac6 00000535 6086e528
 721b3ac0 6003c294 00000000 60031fc0
Call Trace:
 [<600407ed>] show_stack+0x10e/0x127
 [<6003c294>] dump_stack_lvl+0x77/0xc6
 [<6003c2fd>] dump_stack+0x1a/0x20
 [<600bc2f8>] lockdep_rcu_suspicious+0x116/0x13e
 [<603d8ea1>] dpm_async_suspend_superior+0x117/0x17e
 [<603d980f>] device_suspend+0x528/0x541
 [<603da24b>] dpm_suspend+0x1a2/0x267
 [<603da837>] dpm_suspend_start+0x5d/0x72
 [<600ca0c9>] suspend_devices_and_enter+0xab/0x736
 [...]

Add the fourth argument to the iteration to annotate
this and avoid the splat.

Fixes: 0679963 ("PM: sleep: Make async suspend handle suppliers like parents")
Fixes: ed18738 ("PM: sleep: Make async resume handle consumers like children")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://patch.msgid.link/20250826134348.aba79f6e6299.I9ecf55da46ccf33778f2c018a82e1819d815b348@changeid
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
jwrdegoede pushed a commit that referenced this pull request Oct 27, 2025
…ked_roots()

If fs_info->super_copy or fs_info->super_for_commit allocated failed in
btrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info().
Otherwise btrfs_check_leaked_roots() would access NULL pointer because
fs_info->allocated_roots had not been initialised.

syzkaller reported the following information:
  ------------[ cut here ]------------
  BUG: unable to handle page fault for address: fffffffffffffbb0
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0
  Oops: Oops: 0000 [#1] SMP KASAN PTI
  CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy)
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...)
  RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
  RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
  RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
  RIP: 0010:refcount_read include/linux/refcount.h:170 [inline]
  RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230
  [...]
  Call Trace:
   <TASK>
   btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280
   btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029
   btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097
   vfs_get_tree+0x98/0x320 fs/super.c:1759
   do_new_mount+0x357/0x660 fs/namespace.c:3899
   path_mount+0x716/0x19c0 fs/namespace.c:4226
   do_mount fs/namespace.c:4239 [inline]
   __do_sys_mount fs/namespace.c:4450 [inline]
   __se_sys_mount fs/namespace.c:4427 [inline]
   __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f032eaffa8d
  [...]

Fixes: 3bb17a2 ("btrfs: add get_tree callback for new mount API")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Dewei Meng <mengdewei@cqsoftware.com.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
jwrdegoede pushed a commit that referenced this pull request Oct 27, 2025
The original code causes a circular locking dependency found by lockdep.

======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 Tainted: G S   U
------------------------------------------------------
xe_fault_inject/5091 is trying to acquire lock:
ffff888156815688 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}, at: __flush_work+0x25d/0x660

but task is already holding lock:

ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&devcd->mutex){+.+.}-{3:3}:
       mutex_lock_nested+0x4e/0xc0
       devcd_data_write+0x27/0x90
       sysfs_kf_bin_write+0x80/0xf0
       kernfs_fop_write_iter+0x169/0x220
       vfs_write+0x293/0x560
       ksys_write+0x72/0xf0
       __x64_sys_write+0x19/0x30
       x64_sys_call+0x2bf/0x2660
       do_syscall_64+0x93/0xb60
       entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (kn->active#236){++++}-{0:0}:
       kernfs_drain+0x1e2/0x200
       __kernfs_remove+0xae/0x400
       kernfs_remove_by_name_ns+0x5d/0xc0
       remove_files+0x54/0x70
       sysfs_remove_group+0x3d/0xa0
       sysfs_remove_groups+0x2e/0x60
       device_remove_attrs+0xc7/0x100
       device_del+0x15d/0x3b0
       devcd_del+0x19/0x30
       process_one_work+0x22b/0x6f0
       worker_thread+0x1e8/0x3d0
       kthread+0x11c/0x250
       ret_from_fork+0x26c/0x2e0
       ret_from_fork_asm+0x1a/0x30
-> #0 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}:
       __lock_acquire+0x1661/0x2860
       lock_acquire+0xc4/0x2f0
       __flush_work+0x27a/0x660
       flush_delayed_work+0x5d/0xa0
       dev_coredump_put+0x63/0xa0
       xe_driver_devcoredump_fini+0x12/0x20 [xe]
       devm_action_release+0x12/0x30
       release_nodes+0x3a/0x120
       devres_release_all+0x8a/0xd0
       device_unbind_cleanup+0x12/0x80
       device_release_driver_internal+0x23a/0x280
       device_driver_detach+0x14/0x20
       unbind_store+0xaf/0xc0
       drv_attr_store+0x21/0x50
       sysfs_kf_write+0x4a/0x80
       kernfs_fop_write_iter+0x169/0x220
       vfs_write+0x293/0x560
       ksys_write+0x72/0xf0
       __x64_sys_write+0x19/0x30
       x64_sys_call+0x2bf/0x2660
       do_syscall_64+0x93/0xb60
       entry_SYSCALL_64_after_hwframe+0x76/0x7e
other info that might help us debug this:
Chain exists of: (work_completion)(&(&devcd->del_wk)->work) --> kn->active#236 --> &devcd->mutex
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&devcd->mutex);
                               lock(kn->active#236);
                               lock(&devcd->mutex);
  lock((work_completion)(&(&devcd->del_wk)->work));
 *** DEADLOCK ***
5 locks held by xe_fault_inject/5091:
 #0: ffff8881129f9488 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x72/0xf0
 #1: ffff88810c755078 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x123/0x220
 #2: ffff8881054811a0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x55/0x280
 #3: ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0
 #4: ffffffff8359e020 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x72/0x660
stack backtrace:
CPU: 14 UID: 0 PID: 5091 Comm: xe_fault_inject Tainted: G S   U              6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 PREEMPT_{RT,(lazy)}
Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
Hardware name: Micro-Star International Co., Ltd. MS-7D25/PRO Z690-A DDR4(MS-7D25), BIOS 1.10 12/13/2021
Call Trace:
 <TASK>
 dump_stack_lvl+0x91/0xf0
 dump_stack+0x10/0x20
 print_circular_bug+0x285/0x360
 check_noncircular+0x135/0x150
 ? register_lock_class+0x48/0x4a0
 __lock_acquire+0x1661/0x2860
 lock_acquire+0xc4/0x2f0
 ? __flush_work+0x25d/0x660
 ? mark_held_locks+0x46/0x90
 ? __flush_work+0x25d/0x660
 __flush_work+0x27a/0x660
 ? __flush_work+0x25d/0x660
 ? trace_hardirqs_on+0x1e/0xd0
 ? __pfx_wq_barrier_func+0x10/0x10
 flush_delayed_work+0x5d/0xa0
 dev_coredump_put+0x63/0xa0
 xe_driver_devcoredump_fini+0x12/0x20 [xe]
 devm_action_release+0x12/0x30
 release_nodes+0x3a/0x120
 devres_release_all+0x8a/0xd0
 device_unbind_cleanup+0x12/0x80
 device_release_driver_internal+0x23a/0x280
 ? bus_find_device+0xa8/0xe0
 device_driver_detach+0x14/0x20
 unbind_store+0xaf/0xc0
 drv_attr_store+0x21/0x50
 sysfs_kf_write+0x4a/0x80
 kernfs_fop_write_iter+0x169/0x220
 vfs_write+0x293/0x560
 ksys_write+0x72/0xf0
 __x64_sys_write+0x19/0x30
 x64_sys_call+0x2bf/0x2660
 do_syscall_64+0x93/0xb60
 ? __f_unlock_pos+0x15/0x20
 ? __x64_sys_getdents64+0x9b/0x130
 ? __pfx_filldir64+0x10/0x10
 ? do_syscall_64+0x1a2/0xb60
 ? clear_bhb_loop+0x30/0x80
 ? clear_bhb_loop+0x30/0x80
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x76e292edd574
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
RSP: 002b:00007fffe247a828 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000076e292edd574
RDX: 000000000000000c RSI: 00006267f6306063 RDI: 000000000000000b
RBP: 000000000000000c R08: 000076e292fc4b20 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00006267f6306063
R13: 000000000000000b R14: 00006267e6859c00 R15: 000076e29322a000
 </TASK>
xe 0000:03:00.0: [drm] Xe device coredump has been deleted.

Fixes: 01daccf ("devcoredump : Serialize devcd_del work")
Cc: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
Cc: Matthew Brost <matthew.brost@intel.com>
Acked-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250723142416.1020423-1-dev@lankhorst.se
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jwrdegoede pushed a commit that referenced this pull request Nov 10, 2025
Michael Chan says:

====================
bnxt_en: Bug fixes

Patches 1, 3, and 4 are bug fixes related to the FW log tracing driver
coredump feature recently added in 6.13.  Patch #1 adds the necessary
call to shutdown the FW logging DMA during PCI shutdown.  Patch #3 fixes
a possible null pointer derefernce when using early versions of the FW
with this feature.  Patch #4 adds the coredump header information
unconditionally to make it more robust.

Patch #2 fixes a possible memory leak during PTP shutdown.  Patch #5
eliminates a dmesg warning when doing devlink reload.
====================

Link: https://patch.msgid.link/20251104005700.542174-1-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
jwrdegoede pushed a commit that referenced this pull request Nov 10, 2025
On completion of i915_vma_pin_ww(), a synchronous variant of
dma_fence_work_commit() is called.  When pinning a VMA to GGTT address
space on a Cherry View family processor, or on a Broxton generation SoC
with VTD enabled, i.e., when stop_machine() is then called from
intel_ggtt_bind_vma(), that can potentially lead to lock inversion among
reservation_ww and cpu_hotplug locks.

[86.861179] ======================================================
[86.861193] WARNING: possible circular locking dependency detected
[86.861209] 6.15.0-rc5-CI_DRM_16515-gca0305cadc2d+ #1 Tainted: G     U
[86.861226] ------------------------------------------------------
[86.861238] i915_module_loa/1432 is trying to acquire lock:
[86.861252] ffffffff83489090 (cpu_hotplug_lock){++++}-{0:0}, at: stop_machine+0x1c/0x50
[86.861290]
but task is already holding lock:
[86.861303] ffffc90002e0b4c8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.862233]
which lock already depends on the new lock.
[86.862251]
the existing dependency chain (in reverse order) is:
[86.862265]
-> #5 (reservation_ww_class_mutex){+.+.}-{3:3}:
[86.862292]        dma_resv_lockdep+0x19a/0x390
[86.862315]        do_one_initcall+0x60/0x3f0
[86.862334]        kernel_init_freeable+0x3cd/0x680
[86.862353]        kernel_init+0x1b/0x200
[86.862369]        ret_from_fork+0x47/0x70
[86.862383]        ret_from_fork_asm+0x1a/0x30
[86.862399]
-> #4 (reservation_ww_class_acquire){+.+.}-{0:0}:
[86.862425]        dma_resv_lockdep+0x178/0x390
[86.862440]        do_one_initcall+0x60/0x3f0
[86.862454]        kernel_init_freeable+0x3cd/0x680
[86.862470]        kernel_init+0x1b/0x200
[86.862482]        ret_from_fork+0x47/0x70
[86.862495]        ret_from_fork_asm+0x1a/0x30
[86.862509]
-> #3 (&mm->mmap_lock){++++}-{3:3}:
[86.862531]        down_read_killable+0x46/0x1e0
[86.862546]        lock_mm_and_find_vma+0xa2/0x280
[86.862561]        do_user_addr_fault+0x266/0x8e0
[86.862578]        exc_page_fault+0x8a/0x2f0
[86.862593]        asm_exc_page_fault+0x27/0x30
[86.862607]        filldir64+0xeb/0x180
[86.862620]        kernfs_fop_readdir+0x118/0x480
[86.862635]        iterate_dir+0xcf/0x2b0
[86.862648]        __x64_sys_getdents64+0x84/0x140
[86.862661]        x64_sys_call+0x1058/0x2660
[86.862675]        do_syscall_64+0x91/0xe90
[86.862689]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.862703]
-> #2 (&root->kernfs_rwsem){++++}-{3:3}:
[86.862725]        down_write+0x3e/0xf0
[86.862738]        kernfs_add_one+0x30/0x3c0
[86.862751]        kernfs_create_dir_ns+0x53/0xb0
[86.862765]        internal_create_group+0x134/0x4c0
[86.862779]        sysfs_create_group+0x13/0x20
[86.862792]        topology_add_dev+0x1d/0x30
[86.862806]        cpuhp_invoke_callback+0x4b5/0x850
[86.862822]        cpuhp_issue_call+0xbf/0x1f0
[86.862836]        __cpuhp_setup_state_cpuslocked+0x111/0x320
[86.862852]        __cpuhp_setup_state+0xb0/0x220
[86.862866]        topology_sysfs_init+0x30/0x50
[86.862879]        do_one_initcall+0x60/0x3f0
[86.862893]        kernel_init_freeable+0x3cd/0x680
[86.862908]        kernel_init+0x1b/0x200
[86.862921]        ret_from_fork+0x47/0x70
[86.862934]        ret_from_fork_asm+0x1a/0x30
[86.862947]
-> #1 (cpuhp_state_mutex){+.+.}-{3:3}:
[86.862969]        __mutex_lock+0xaa/0xed0
[86.862982]        mutex_lock_nested+0x1b/0x30
[86.862995]        __cpuhp_setup_state_cpuslocked+0x67/0x320
[86.863012]        __cpuhp_setup_state+0xb0/0x220
[86.863026]        page_alloc_init_cpuhp+0x2d/0x60
[86.863041]        mm_core_init+0x22/0x2d0
[86.863054]        start_kernel+0x576/0xbd0
[86.863068]        x86_64_start_reservations+0x18/0x30
[86.863084]        x86_64_start_kernel+0xbf/0x110
[86.863098]        common_startup_64+0x13e/0x141
[86.863114]
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
[86.863135]        __lock_acquire+0x1635/0x2810
[86.863152]        lock_acquire+0xc4/0x2f0
[86.863166]        cpus_read_lock+0x41/0x100
[86.863180]        stop_machine+0x1c/0x50
[86.863194]        bxt_vtd_ggtt_insert_entries__BKL+0x3b/0x60 [i915]
[86.863987]        intel_ggtt_bind_vma+0x43/0x70 [i915]
[86.864735]        __vma_bind+0x55/0x70 [i915]
[86.865510]        fence_work+0x26/0xa0 [i915]
[86.866248]        fence_notify+0xa1/0x140 [i915]
[86.866983]        __i915_sw_fence_complete+0x8f/0x270 [i915]
[86.867719]        i915_sw_fence_commit+0x39/0x60 [i915]
[86.868453]        i915_vma_pin_ww+0x462/0x1360 [i915]
[86.869228]        i915_vma_pin.constprop.0+0x133/0x1d0 [i915]
[86.870001]        initial_plane_vma+0x307/0x840 [i915]
[86.870774]        intel_initial_plane_config+0x33f/0x670 [i915]
[86.871546]        intel_display_driver_probe_nogem+0x1c6/0x260 [i915]
[86.872330]        i915_driver_probe+0x7fa/0xe80 [i915]
[86.873057]        i915_pci_probe+0xe6/0x220 [i915]
[86.873782]        local_pci_probe+0x47/0xb0
[86.873802]        pci_device_probe+0xf3/0x260
[86.873817]        really_probe+0xf1/0x3c0
[86.873833]        __driver_probe_device+0x8c/0x180
[86.873848]        driver_probe_device+0x24/0xd0
[86.873862]        __driver_attach+0x10f/0x220
[86.873876]        bus_for_each_dev+0x7f/0xe0
[86.873892]        driver_attach+0x1e/0x30
[86.873904]        bus_add_driver+0x151/0x290
[86.873917]        driver_register+0x5e/0x130
[86.873931]        __pci_register_driver+0x7d/0x90
[86.873945]        i915_pci_register_driver+0x23/0x30 [i915]
[86.874678]        i915_init+0x37/0x120 [i915]
[86.875347]        do_one_initcall+0x60/0x3f0
[86.875369]        do_init_module+0x97/0x2a0
[86.875385]        load_module+0x2c54/0x2d80
[86.875398]        init_module_from_file+0x96/0xe0
[86.875413]        idempotent_init_module+0x117/0x330
[86.875426]        __x64_sys_finit_module+0x77/0x100
[86.875440]        x64_sys_call+0x24de/0x2660
[86.875454]        do_syscall_64+0x91/0xe90
[86.875470]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.875486]
other info that might help us debug this:
[86.875502] Chain exists of:
  cpu_hotplug_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex
[86.875539]  Possible unsafe locking scenario:
[86.875552]        CPU0                    CPU1
[86.875563]        ----                    ----
[86.875573]   lock(reservation_ww_class_mutex);
[86.875588]                                lock(reservation_ww_class_acquire);
[86.875606]                                lock(reservation_ww_class_mutex);
[86.875624]   rlock(cpu_hotplug_lock);
[86.875637]
 *** DEADLOCK ***
[86.875650] 3 locks held by i915_module_loa/1432:
[86.875663]  #0: ffff888101f5c1b0 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x104/0x220
[86.875699]  #1: ffffc90002e0b4a0 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.876512]  #2: ffffc90002e0b4c8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.877305]
stack backtrace:
[86.877326] CPU: 0 UID: 0 PID: 1432 Comm: i915_module_loa Tainted: G     U              6.15.0-rc5-CI_DRM_16515-gca0305cadc2d+ #1 PREEMPT(voluntary)
[86.877334] Tainted: [U]=USER
[86.877336] Hardware name:  /NUC5CPYB, BIOS PYBSWCEL.86A.0079.2020.0420.1316 04/20/2020
[86.877339] Call Trace:
[86.877344]  <TASK>
[86.877353]  dump_stack_lvl+0x91/0xf0
[86.877364]  dump_stack+0x10/0x20
[86.877369]  print_circular_bug+0x285/0x360
[86.877379]  check_noncircular+0x135/0x150
[86.877390]  __lock_acquire+0x1635/0x2810
[86.877403]  lock_acquire+0xc4/0x2f0
[86.877408]  ? stop_machine+0x1c/0x50
[86.877422]  ? __pfx_bxt_vtd_ggtt_insert_entries__cb+0x10/0x10 [i915]
[86.878173]  cpus_read_lock+0x41/0x100
[86.878182]  ? stop_machine+0x1c/0x50
[86.878191]  ? __pfx_bxt_vtd_ggtt_insert_entries__cb+0x10/0x10 [i915]
[86.878916]  stop_machine+0x1c/0x50
[86.878927]  bxt_vtd_ggtt_insert_entries__BKL+0x3b/0x60 [i915]
[86.879652]  intel_ggtt_bind_vma+0x43/0x70 [i915]
[86.880375]  __vma_bind+0x55/0x70 [i915]
[86.881133]  fence_work+0x26/0xa0 [i915]
[86.881851]  fence_notify+0xa1/0x140 [i915]
[86.882566]  __i915_sw_fence_complete+0x8f/0x270 [i915]
[86.883286]  i915_sw_fence_commit+0x39/0x60 [i915]
[86.884003]  i915_vma_pin_ww+0x462/0x1360 [i915]
[86.884756]  ? i915_vma_pin.constprop.0+0x6c/0x1d0 [i915]
[86.885513]  i915_vma_pin.constprop.0+0x133/0x1d0 [i915]
[86.886281]  initial_plane_vma+0x307/0x840 [i915]
[86.887049]  intel_initial_plane_config+0x33f/0x670 [i915]
[86.887819]  intel_display_driver_probe_nogem+0x1c6/0x260 [i915]
[86.888587]  i915_driver_probe+0x7fa/0xe80 [i915]
[86.889293]  ? mutex_unlock+0x12/0x20
[86.889301]  ? drm_privacy_screen_get+0x171/0x190
[86.889308]  ? acpi_dev_found+0x66/0x80
[86.889321]  i915_pci_probe+0xe6/0x220 [i915]
[86.890038]  local_pci_probe+0x47/0xb0
[86.890049]  pci_device_probe+0xf3/0x260
[86.890058]  really_probe+0xf1/0x3c0
[86.890067]  __driver_probe_device+0x8c/0x180
[86.890072]  driver_probe_device+0x24/0xd0
[86.890078]  __driver_attach+0x10f/0x220
[86.890083]  ? __pfx___driver_attach+0x10/0x10
[86.890088]  bus_for_each_dev+0x7f/0xe0
[86.890097]  driver_attach+0x1e/0x30
[86.890101]  bus_add_driver+0x151/0x290
[86.890107]  driver_register+0x5e/0x130
[86.890113]  __pci_register_driver+0x7d/0x90
[86.890119]  i915_pci_register_driver+0x23/0x30 [i915]
[86.890833]  i915_init+0x37/0x120 [i915]
[86.891482]  ? __pfx_i915_init+0x10/0x10 [i915]
[86.892135]  do_one_initcall+0x60/0x3f0
[86.892145]  ? __kmalloc_cache_noprof+0x33f/0x470
[86.892157]  do_init_module+0x97/0x2a0
[86.892164]  load_module+0x2c54/0x2d80
[86.892168]  ? __kernel_read+0x15c/0x300
[86.892185]  ? kernel_read_file+0x2b1/0x320
[86.892195]  init_module_from_file+0x96/0xe0
[86.892199]  ? init_module_from_file+0x96/0xe0
[86.892211]  idempotent_init_module+0x117/0x330
[86.892224]  __x64_sys_finit_module+0x77/0x100
[86.892230]  x64_sys_call+0x24de/0x2660
[86.892236]  do_syscall_64+0x91/0xe90
[86.892243]  ? irqentry_exit+0x77/0xb0
[86.892249]  ? sysvec_apic_timer_interrupt+0x57/0xc0
[86.892256]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.892261] RIP: 0033:0x7303e1b2725d
[86.892271] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48
[86.892276] RSP: 002b:00007ffddd1fdb38 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[86.892281] RAX: ffffffffffffffda RBX: 00005d771d88fd90 RCX: 00007303e1b2725d
[86.892285] RDX: 0000000000000000 RSI: 00005d771d893aa0 RDI: 000000000000000c
[86.892287] RBP: 00007ffddd1fdbf0 R08: 0000000000000040 R09: 00007ffddd1fdb80
[86.892289] R10: 00007303e1c03b20 R11: 0000000000000246 R12: 00005d771d893aa0
[86.892292] R13: 0000000000000000 R14: 00005d771d88f0d0 R15: 00005d771d895710
[86.892304]  </TASK>

Call asynchronous variant of dma_fence_work_commit() in that case.

v3: Provide more verbose in-line comment (Andi),
  - mention target environments in commit message.

Fixes: 7d1c261 ("drm/i915: Take reservation lock around i915_vma_pin.")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14985
Cc: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Sebastian Brzezinka <sebastian.brzezinka@intel.com>
Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>
Acked-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/20251023082925.351307-6-janusz.krzysztofik@linux.intel.com
(cherry picked from commit 648ef13)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
jwrdegoede pushed a commit that referenced this pull request Nov 28, 2025
On completion of i915_vma_pin_ww(), a synchronous variant of
dma_fence_work_commit() is called.  When pinning a VMA to GGTT address
space on a Cherry View family processor, or on a Broxton generation SoC
with VTD enabled, i.e., when stop_machine() is then called from
intel_ggtt_bind_vma(), that can potentially lead to lock inversion among
reservation_ww and cpu_hotplug locks.

[86.861179] ======================================================
[86.861193] WARNING: possible circular locking dependency detected
[86.861209] 6.15.0-rc5-CI_DRM_16515-gca0305cadc2d+ #1 Tainted: G     U
[86.861226] ------------------------------------------------------
[86.861238] i915_module_loa/1432 is trying to acquire lock:
[86.861252] ffffffff83489090 (cpu_hotplug_lock){++++}-{0:0}, at: stop_machine+0x1c/0x50
[86.861290]
but task is already holding lock:
[86.861303] ffffc90002e0b4c8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.862233]
which lock already depends on the new lock.
[86.862251]
the existing dependency chain (in reverse order) is:
[86.862265]
-> #5 (reservation_ww_class_mutex){+.+.}-{3:3}:
[86.862292]        dma_resv_lockdep+0x19a/0x390
[86.862315]        do_one_initcall+0x60/0x3f0
[86.862334]        kernel_init_freeable+0x3cd/0x680
[86.862353]        kernel_init+0x1b/0x200
[86.862369]        ret_from_fork+0x47/0x70
[86.862383]        ret_from_fork_asm+0x1a/0x30
[86.862399]
-> #4 (reservation_ww_class_acquire){+.+.}-{0:0}:
[86.862425]        dma_resv_lockdep+0x178/0x390
[86.862440]        do_one_initcall+0x60/0x3f0
[86.862454]        kernel_init_freeable+0x3cd/0x680
[86.862470]        kernel_init+0x1b/0x200
[86.862482]        ret_from_fork+0x47/0x70
[86.862495]        ret_from_fork_asm+0x1a/0x30
[86.862509]
-> #3 (&mm->mmap_lock){++++}-{3:3}:
[86.862531]        down_read_killable+0x46/0x1e0
[86.862546]        lock_mm_and_find_vma+0xa2/0x280
[86.862561]        do_user_addr_fault+0x266/0x8e0
[86.862578]        exc_page_fault+0x8a/0x2f0
[86.862593]        asm_exc_page_fault+0x27/0x30
[86.862607]        filldir64+0xeb/0x180
[86.862620]        kernfs_fop_readdir+0x118/0x480
[86.862635]        iterate_dir+0xcf/0x2b0
[86.862648]        __x64_sys_getdents64+0x84/0x140
[86.862661]        x64_sys_call+0x1058/0x2660
[86.862675]        do_syscall_64+0x91/0xe90
[86.862689]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.862703]
-> #2 (&root->kernfs_rwsem){++++}-{3:3}:
[86.862725]        down_write+0x3e/0xf0
[86.862738]        kernfs_add_one+0x30/0x3c0
[86.862751]        kernfs_create_dir_ns+0x53/0xb0
[86.862765]        internal_create_group+0x134/0x4c0
[86.862779]        sysfs_create_group+0x13/0x20
[86.862792]        topology_add_dev+0x1d/0x30
[86.862806]        cpuhp_invoke_callback+0x4b5/0x850
[86.862822]        cpuhp_issue_call+0xbf/0x1f0
[86.862836]        __cpuhp_setup_state_cpuslocked+0x111/0x320
[86.862852]        __cpuhp_setup_state+0xb0/0x220
[86.862866]        topology_sysfs_init+0x30/0x50
[86.862879]        do_one_initcall+0x60/0x3f0
[86.862893]        kernel_init_freeable+0x3cd/0x680
[86.862908]        kernel_init+0x1b/0x200
[86.862921]        ret_from_fork+0x47/0x70
[86.862934]        ret_from_fork_asm+0x1a/0x30
[86.862947]
-> #1 (cpuhp_state_mutex){+.+.}-{3:3}:
[86.862969]        __mutex_lock+0xaa/0xed0
[86.862982]        mutex_lock_nested+0x1b/0x30
[86.862995]        __cpuhp_setup_state_cpuslocked+0x67/0x320
[86.863012]        __cpuhp_setup_state+0xb0/0x220
[86.863026]        page_alloc_init_cpuhp+0x2d/0x60
[86.863041]        mm_core_init+0x22/0x2d0
[86.863054]        start_kernel+0x576/0xbd0
[86.863068]        x86_64_start_reservations+0x18/0x30
[86.863084]        x86_64_start_kernel+0xbf/0x110
[86.863098]        common_startup_64+0x13e/0x141
[86.863114]
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
[86.863135]        __lock_acquire+0x1635/0x2810
[86.863152]        lock_acquire+0xc4/0x2f0
[86.863166]        cpus_read_lock+0x41/0x100
[86.863180]        stop_machine+0x1c/0x50
[86.863194]        bxt_vtd_ggtt_insert_entries__BKL+0x3b/0x60 [i915]
[86.863987]        intel_ggtt_bind_vma+0x43/0x70 [i915]
[86.864735]        __vma_bind+0x55/0x70 [i915]
[86.865510]        fence_work+0x26/0xa0 [i915]
[86.866248]        fence_notify+0xa1/0x140 [i915]
[86.866983]        __i915_sw_fence_complete+0x8f/0x270 [i915]
[86.867719]        i915_sw_fence_commit+0x39/0x60 [i915]
[86.868453]        i915_vma_pin_ww+0x462/0x1360 [i915]
[86.869228]        i915_vma_pin.constprop.0+0x133/0x1d0 [i915]
[86.870001]        initial_plane_vma+0x307/0x840 [i915]
[86.870774]        intel_initial_plane_config+0x33f/0x670 [i915]
[86.871546]        intel_display_driver_probe_nogem+0x1c6/0x260 [i915]
[86.872330]        i915_driver_probe+0x7fa/0xe80 [i915]
[86.873057]        i915_pci_probe+0xe6/0x220 [i915]
[86.873782]        local_pci_probe+0x47/0xb0
[86.873802]        pci_device_probe+0xf3/0x260
[86.873817]        really_probe+0xf1/0x3c0
[86.873833]        __driver_probe_device+0x8c/0x180
[86.873848]        driver_probe_device+0x24/0xd0
[86.873862]        __driver_attach+0x10f/0x220
[86.873876]        bus_for_each_dev+0x7f/0xe0
[86.873892]        driver_attach+0x1e/0x30
[86.873904]        bus_add_driver+0x151/0x290
[86.873917]        driver_register+0x5e/0x130
[86.873931]        __pci_register_driver+0x7d/0x90
[86.873945]        i915_pci_register_driver+0x23/0x30 [i915]
[86.874678]        i915_init+0x37/0x120 [i915]
[86.875347]        do_one_initcall+0x60/0x3f0
[86.875369]        do_init_module+0x97/0x2a0
[86.875385]        load_module+0x2c54/0x2d80
[86.875398]        init_module_from_file+0x96/0xe0
[86.875413]        idempotent_init_module+0x117/0x330
[86.875426]        __x64_sys_finit_module+0x77/0x100
[86.875440]        x64_sys_call+0x24de/0x2660
[86.875454]        do_syscall_64+0x91/0xe90
[86.875470]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.875486]
other info that might help us debug this:
[86.875502] Chain exists of:
  cpu_hotplug_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex
[86.875539]  Possible unsafe locking scenario:
[86.875552]        CPU0                    CPU1
[86.875563]        ----                    ----
[86.875573]   lock(reservation_ww_class_mutex);
[86.875588]                                lock(reservation_ww_class_acquire);
[86.875606]                                lock(reservation_ww_class_mutex);
[86.875624]   rlock(cpu_hotplug_lock);
[86.875637]
 *** DEADLOCK ***
[86.875650] 3 locks held by i915_module_loa/1432:
[86.875663]  #0: ffff888101f5c1b0 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x104/0x220
[86.875699]  #1: ffffc90002e0b4a0 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.876512]  #2: ffffc90002e0b4c8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.877305]
stack backtrace:
[86.877326] CPU: 0 UID: 0 PID: 1432 Comm: i915_module_loa Tainted: G     U              6.15.0-rc5-CI_DRM_16515-gca0305cadc2d+ #1 PREEMPT(voluntary)
[86.877334] Tainted: [U]=USER
[86.877336] Hardware name:  /NUC5CPYB, BIOS PYBSWCEL.86A.0079.2020.0420.1316 04/20/2020
[86.877339] Call Trace:
[86.877344]  <TASK>
[86.877353]  dump_stack_lvl+0x91/0xf0
[86.877364]  dump_stack+0x10/0x20
[86.877369]  print_circular_bug+0x285/0x360
[86.877379]  check_noncircular+0x135/0x150
[86.877390]  __lock_acquire+0x1635/0x2810
[86.877403]  lock_acquire+0xc4/0x2f0
[86.877408]  ? stop_machine+0x1c/0x50
[86.877422]  ? __pfx_bxt_vtd_ggtt_insert_entries__cb+0x10/0x10 [i915]
[86.878173]  cpus_read_lock+0x41/0x100
[86.878182]  ? stop_machine+0x1c/0x50
[86.878191]  ? __pfx_bxt_vtd_ggtt_insert_entries__cb+0x10/0x10 [i915]
[86.878916]  stop_machine+0x1c/0x50
[86.878927]  bxt_vtd_ggtt_insert_entries__BKL+0x3b/0x60 [i915]
[86.879652]  intel_ggtt_bind_vma+0x43/0x70 [i915]
[86.880375]  __vma_bind+0x55/0x70 [i915]
[86.881133]  fence_work+0x26/0xa0 [i915]
[86.881851]  fence_notify+0xa1/0x140 [i915]
[86.882566]  __i915_sw_fence_complete+0x8f/0x270 [i915]
[86.883286]  i915_sw_fence_commit+0x39/0x60 [i915]
[86.884003]  i915_vma_pin_ww+0x462/0x1360 [i915]
[86.884756]  ? i915_vma_pin.constprop.0+0x6c/0x1d0 [i915]
[86.885513]  i915_vma_pin.constprop.0+0x133/0x1d0 [i915]
[86.886281]  initial_plane_vma+0x307/0x840 [i915]
[86.887049]  intel_initial_plane_config+0x33f/0x670 [i915]
[86.887819]  intel_display_driver_probe_nogem+0x1c6/0x260 [i915]
[86.888587]  i915_driver_probe+0x7fa/0xe80 [i915]
[86.889293]  ? mutex_unlock+0x12/0x20
[86.889301]  ? drm_privacy_screen_get+0x171/0x190
[86.889308]  ? acpi_dev_found+0x66/0x80
[86.889321]  i915_pci_probe+0xe6/0x220 [i915]
[86.890038]  local_pci_probe+0x47/0xb0
[86.890049]  pci_device_probe+0xf3/0x260
[86.890058]  really_probe+0xf1/0x3c0
[86.890067]  __driver_probe_device+0x8c/0x180
[86.890072]  driver_probe_device+0x24/0xd0
[86.890078]  __driver_attach+0x10f/0x220
[86.890083]  ? __pfx___driver_attach+0x10/0x10
[86.890088]  bus_for_each_dev+0x7f/0xe0
[86.890097]  driver_attach+0x1e/0x30
[86.890101]  bus_add_driver+0x151/0x290
[86.890107]  driver_register+0x5e/0x130
[86.890113]  __pci_register_driver+0x7d/0x90
[86.890119]  i915_pci_register_driver+0x23/0x30 [i915]
[86.890833]  i915_init+0x37/0x120 [i915]
[86.891482]  ? __pfx_i915_init+0x10/0x10 [i915]
[86.892135]  do_one_initcall+0x60/0x3f0
[86.892145]  ? __kmalloc_cache_noprof+0x33f/0x470
[86.892157]  do_init_module+0x97/0x2a0
[86.892164]  load_module+0x2c54/0x2d80
[86.892168]  ? __kernel_read+0x15c/0x300
[86.892185]  ? kernel_read_file+0x2b1/0x320
[86.892195]  init_module_from_file+0x96/0xe0
[86.892199]  ? init_module_from_file+0x96/0xe0
[86.892211]  idempotent_init_module+0x117/0x330
[86.892224]  __x64_sys_finit_module+0x77/0x100
[86.892230]  x64_sys_call+0x24de/0x2660
[86.892236]  do_syscall_64+0x91/0xe90
[86.892243]  ? irqentry_exit+0x77/0xb0
[86.892249]  ? sysvec_apic_timer_interrupt+0x57/0xc0
[86.892256]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.892261] RIP: 0033:0x7303e1b2725d
[86.892271] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48
[86.892276] RSP: 002b:00007ffddd1fdb38 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[86.892281] RAX: ffffffffffffffda RBX: 00005d771d88fd90 RCX: 00007303e1b2725d
[86.892285] RDX: 0000000000000000 RSI: 00005d771d893aa0 RDI: 000000000000000c
[86.892287] RBP: 00007ffddd1fdbf0 R08: 0000000000000040 R09: 00007ffddd1fdb80
[86.892289] R10: 00007303e1c03b20 R11: 0000000000000246 R12: 00005d771d893aa0
[86.892292] R13: 0000000000000000 R14: 00005d771d88f0d0 R15: 00005d771d895710
[86.892304]  </TASK>

Call asynchronous variant of dma_fence_work_commit() in that case.

v3: Provide more verbose in-line comment (Andi),
  - mention target environments in commit message.

Fixes: 7d1c261 ("drm/i915: Take reservation lock around i915_vma_pin.")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14985
Cc: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Sebastian Brzezinka <sebastian.brzezinka@intel.com>
Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>
Acked-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/20251023082925.351307-6-janusz.krzysztofik@linux.intel.com
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