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npiggin and others added 19 commits November 27, 2020 00:10
A typo has the R field of the instruction assigned by lucky dip a la
register allocator.

Fixes: d474827 ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126102530.691335-2-npiggin@gmail.com
tlbiel_all() can not be usable in !HVMODE when running hash presently,
remove HV privileged flushes when running in guest to make it usable.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126102530.691335-3-npiggin@gmail.com
powerpc/64s keeps a counter in the mm which counts bits set in
mm_cpumask as well as other things. This means it can't use generic code
to clear bits out of the mask and doesn't adjust the arch specific
counter.

Add an arch override that allows powerpc/64s to use
clear_tasks_mm_cpumask().

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126102530.691335-4-npiggin@gmail.com
When offlining a CPU, powerpc/64s does not flush TLBs, rather it just
leaves the CPU set in mm_cpumasks, so it continues to receive TLBIEs
to manage its TLBs.

However the exit_flush_lazy_tlbs() function expects that after
returning, all CPUs (except self) have flushed TLBs for that mm, in
which case TLBIEL can be used for this flush. This breaks for offline
CPUs because they don't get the IPI to flush their TLB. This can lead
to stale translations.

Fix this by clearing the CPU from mm_cpumasks, then flushing all TLBs
before going offline.

These offlined CPU bits stuck in the cpumask also prevents the cpumask
from being trimmed back to local mode, which means continual broadcast
IPIs or TLBIEs are needed for TLB flushing. This patch prevents that
situation too.

A cast of many were involved in working this out, but in particular
Milton, Aneesh, Paul made key discoveries.

Fixes: 0cef77c ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Debugged-by: Milton Miller <miltonm@us.ibm.com>
Debugged-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Debugged-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126102530.691335-5-npiggin@gmail.com
Commit e75130f ("powerpc/numa: Offline memoryless cpuless node 0")
offlines node 0 and expects nodes to be subsequently onlined when CPUs
or nodes are detected.

Commit 6398eaa ("powerpc/numa: Prefer node id queried from vphn")
skips onlining node 0 when CPUs are associated with node 0.

On systems with node 0 having CPUs but no memory, this causes node 0 be
marked offline. This causes issues at boot time when trying to set
memory node for online CPUs while building the zonelist.

0:mon> t
[link register   ] c000000000400354 __build_all_zonelists+0x164/0x280
[c00000000161bda0] c0000000016533c8 node_states+0x20/0xa0 (unreliable)
[c00000000161bdc0] c000000000400384 __build_all_zonelists+0x194/0x280
[c00000000161be30] c000000001041800 build_all_zonelists_init+0x4c/0x118
[c00000000161be80] c0000000004020d0 build_all_zonelists+0x190/0x1b0
[c00000000161bef0] c000000001003cf8 start_kernel+0x18c/0x6a8
[c00000000161bf90] c00000000000adb4 start_here_common+0x1c/0x3e8
0:mon> r
R00 = c000000000400354   R16 = 000000000b57a0e8
R01 = c00000000161bda0   R17 = 000000000b57a6b0
R02 = c00000000161ce00   R18 = 000000000b5afee8
R03 = 0000000000000000   R19 = 000000000b6448a0
R04 = 0000000000000000   R20 = fffffffffffffffd
R05 = 0000000000000000   R21 = 0000000001400000
R06 = 0000000000000000   R22 = 000000001ec00000
R07 = 0000000000000001   R23 = c000000001175580
R08 = 0000000000000000   R24 = c000000001651ed8
R09 = c0000000017e84d8   R25 = c000000001652480
R10 = 0000000000000000   R26 = c000000001175584
R11 = c000000c7fac0d10   R27 = c0000000019568d0
R12 = c000000000400180   R28 = 0000000000000000
R13 = c000000002200000   R29 = c00000000164dd78
R14 = 000000000b579f78   R30 = 0000000000000000
R15 = 000000000b57a2b8   R31 = c000000001175584
pc  = c000000000400194 local_memory_node+0x24/0x80
cfar= c000000000074334 mcount+0xc/0x10
lr  = c000000000400354 __build_all_zonelists+0x164/0x280
msr = 8000000002001033   cr  = 44002284
ctr = c000000000400180   xer = 0000000000000001   trap =  380
dar = 0000000000001388   dsisr = c00000000161bc90
0:mon>

Fix this by setting node to be online while onlining CPUs that belong to
node 0.

Fixes: e75130f ("powerpc/numa: Offline memoryless cpuless node 0")
Fixes: 6398eaa ("powerpc/numa: Prefer node id queried from vphn")
Reported-by: Milan Mohanty <milmohan@in.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201127053738.10085-1-srikar@linux.vnet.ibm.com
Return -ENOMEM from the error handling case instead of 0.

Link: https://lore.kernel.org/r/20201127030206.104616-1-jingxiangfeng@huawei.com
Fixes: 436ad94 ("scsi: storvsc: Allow only one remove lun work item to be issued per lun")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
…el_callback()

Check that the packet is of the expected size at least, don't copy data
past the packet.

Link: https://lore.kernel.org/r/20201118145348.109879-1-parri.andrea@gmail.com
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Reported-by: Saruhan Karademir <skarade@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Commit c1a6c5a ("scsi: mpt3sas: For NVME device, issue a protocol
level reset") modified the ioctl path 'timeout' variable type to u8 from
unsigned long, limiting the maximum timeout value that the driver can
support to 255 seconds.

If the management application is requesting a higher value the resulting
timeout will be zero. The operation times out immediately and the ioctl
request fails.

Change datatype back to unsigned long.

Link: https://lore.kernel.org/r/20201125094838.4340-1-suganath-prabu.subramani@broadcom.com
Fixes: c1a6c5a ("scsi: mpt3sas: For NVME device, issue a protocol level reset")
Cc: <stable@vger.kernel.org> #v4.18+
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently the IOCInit request message timeout is set to 10s. This is not
sufficient in some scenarios such as during HBA FW downgrade operations.

Increase the IOCInit request timeout to 30s.

Link: https://lore.kernel.org/r/20201130082733.26120-1-sreekanth.reddy@broadcom.com
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Commit 062cfab ("KVM: PPC: Book3S HV: XIVE: Make VP block size
configurable") updated kvmppc_xive_vcpu_id_valid() in a way that
allows userspace to trigger an assertion in skiboot and crash the host:

[  696.186248988,3] XIVE[ IC 08  ] eq_blk != vp_blk (0 vs. 1) for target 0x4300008c/0
[  696.186314757,0] Assert fail: hw/xive.c:2370:0
[  696.186342458,0] Aborting!
xive-kvCPU 0043 Backtrace:
 S: 0000000031e2b8f0 R: 0000000030013840   .backtrace+0x48
 S: 0000000031e2b990 R: 000000003001b2d0   ._abort+0x4c
 S: 0000000031e2ba10 R: 000000003001b34c   .assert_fail+0x34
 S: 0000000031e2ba90 R: 0000000030058984   .xive_eq_for_target.part.20+0xb0
 S: 0000000031e2bb40 R: 0000000030059fdc   .xive_setup_silent_gather+0x2c
 S: 0000000031e2bc20 R: 000000003005a334   .opal_xive_set_vp_info+0x124
 S: 0000000031e2bd20 R: 00000000300051a4   opal_entry+0x134
 --- OPAL call token: 0x8a caller R1: 0xc000001f28563850 ---

XIVE maintains the interrupt context state of non-dispatched vCPUs in
an internal VP structure. We allocate a bunch of those on startup to
accommodate all possible vCPUs. Each VP has an id, that we derive from
the vCPU id for efficiency:

static inline u32 kvmppc_xive_vp(struct kvmppc_xive *xive, u32 server)
{
	return xive->vp_base + kvmppc_pack_vcpu_id(xive->kvm, server);
}

The KVM XIVE device used to allocate KVM_MAX_VCPUS VPs. This was
limitting the number of concurrent VMs because the VP space is
limited on the HW. Since most of the time, VMs run with a lot less
vCPUs, commit 062cfab ("KVM: PPC: Book3S HV: XIVE: Make VP
block size configurable") gave the possibility for userspace to
tune the size of the VP block through the KVM_DEV_XIVE_NR_SERVERS
attribute.

The check in kvmppc_pack_vcpu_id() was changed from

	cpu < KVM_MAX_VCPUS * xive->kvm->arch.emul_smt_mode

to

	cpu < xive->nr_servers * xive->kvm->arch.emul_smt_mode

The previous check was based on the fact that the VP block had
KVM_MAX_VCPUS entries and that kvmppc_pack_vcpu_id() guarantees
that packed vCPU ids are below KVM_MAX_VCPUS. We've changed the
size of the VP block, but kvmppc_pack_vcpu_id() has nothing to
do with it and it certainly doesn't ensure that the packed vCPU
ids are below xive->nr_servers. kvmppc_xive_vcpu_id_valid() might
thus return true when the VM was configured with a non-standard
VSMT mode, even if the packed vCPU id is higher than what we
expect. We end up using an unallocated VP id, which confuses
OPAL. The assert in OPAL is probably abusive and should be
converted to a regular error that the kernel can handle, but
we shouldn't really use broken VP ids in the first place.

Fix kvmppc_xive_vcpu_id_valid() so that it checks the packed
vCPU id is below xive->nr_servers, which is explicitly what we
want.

Fixes: 062cfab ("KVM: PPC: Book3S HV: XIVE: Make VP block size configurable")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/160673876747.695514.1809676603724514920.stgit@bahia.lan
… MCE

This can be hit by an HPT guest running on an HPT host and bring down
the host, so it's quite important to fix.

Fixes: 7290f3b ("powerpc/64s/powernv: machine check dump SLB contents")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201128070728.825934-2-npiggin@gmail.com
For an operation compounded with an SMB2 CREATE request, client must set
COMPOUND_FID(0xFFFFFFFFFFFFFFFF) to FileID field of smb2 ioctl.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Fixes: 2e4564b ("smb3: add support stat of WSL reparse points for special file types")
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In some scenarios (DFS and BAD_NETWORK_NAME) set_root_set() can be
called with a NULL ses->tcon_ipc.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
When mounting with "idsfromsid" mount option, Azure
corrupted the owner SIDs due to excessive padding
caused by placing the owner fields at the end of the
security descriptor on create.  Placing owners at the
front of the security descriptor (rather than the end)
is also safer, as the number of ACEs (that follow it)
are variable.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Suggested-by: Rohith Surabattula <rohiths@microsoft.com>
CC: Stable <stable@vger.kernel.org> # v5.8
Signed-off-by: Steve French <stfrench@microsoft.com>
If non-zero 'chunk_sectors' is passed in to blk_max_size_offset() that
override will be incorrectly ignored.

Old blk_max_size_offset() branching, prior to commit 3ee16db,
must be used only if passed 'chunk_sectors' override is zero.

Fixes: 3ee16db ("dm: fix IO splitting")
Cc: stable@vger.kernel.org # 5.9
Reported-by: John Dorminy <jdorminy@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
…/kernel/git/device-mapper/linux-dm

Pull fix for device mapper fixes from Mike Snitzer:
 "Apologies for the glaring bug I introduced with my previous pull
  request!

  Fix incorrect branching at top of blk_max_size_offset()"

* tag 'for-5.10/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  block: fix incorrect branching in blk_max_size_offset()
…it/jejb/scsi

Pull SCSI fixes from James Bottomley:
 "Four small fixes in two drivers.

  The mpt3sas fixes are all problems with timeout under unusual
  conditions, and the storvsc is a missed incoming packet validation
  and a missed error return"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: mpt3sas: Increase IOCInit request timeout to 30s
  scsi: mpt3sas: Fix ioctl timeout
  scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()
  scsi: storvsc: Fix error return in storvsc_probe()
…cifs-2.6

Pull cifs fixes from Steve French:
 "Three smb3 fixes (two for stable) fixing

   - a null pointer issue in a DFS error path

   - a problem with excessive padding when mounted with "idsfromsid"
     causing owner fields to get corrupted

   - a more recent problem with compounded reparse point query found in
     testing to the Linux kernel server"

* tag '5.10-rc6-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: refactor create_sd_buf() and and avoid corrupting the buffer
  cifs: add NULL check for ses->tcon_ipc
  smb3: set COMPOUND_FID to FileID field of subsequent compound request
…el/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.10:

   - Three commits fixing possible missed TLB invalidations for
     multi-threaded processes when CPUs are hotplugged in and out.

   - A fix for a host crash triggerable by host userspace (qemu) in KVM
     on Power9.

   - A fix for a host crash in machine check handling when running HPT
     guests on a HPT host.

   - One commit fixing potential missed TLB invalidations when using the
     hash MMU on Power9 or later.

   - A regression fix for machines with CPUs on node 0 but no memory.

  Thanks to Aneesh Kumar K.V, Cédric Le Goater, Greg Kurz, Milan
  Mohanty, Milton Miller, Nicholas Piggin, Paul Mackerras, and Srikar
  Dronamraju"

* tag 'powerpc-5.10-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/powernv: Fix memory corruption when saving SLB entries on MCE
  KVM: PPC: Book3S HV: XIVE: Fix vCPU id sanity check
  powerpc/numa: Fix a regression on memoryless node 0
  powerpc/64s: Trim offlined CPUs from mm_cpumasks
  kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling
  powerpc/64s/pseries: Fix hash tlbiel_all_isa300 for guest kernels
  powerpc/64s: Fix hash ISA v3.0 TLBIEL instruction generation
@pull pull bot added the ⤵️ pull label Dec 5, 2020
@pull pull bot merged commit 32f741b into bergwolf:master Dec 5, 2020
pull bot pushed a commit that referenced this pull request Jul 13, 2024
Add a test case which replaces an active ingress qdisc while keeping the
miniq in-tact during the transition period to the new clsact qdisc.

  # ./vmtest.sh -- ./test_progs -t tc_link
  [...]
  ./test_progs -t tc_link
  [    3.412871] bpf_testmod: loading out-of-tree module taints kernel.
  [    3.413343] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
  #332     tc_links_after:OK
  #333     tc_links_append:OK
  #334     tc_links_basic:OK
  #335     tc_links_before:OK
  #336     tc_links_chain_classic:OK
  #337     tc_links_chain_mixed:OK
  #338     tc_links_dev_chain0:OK
  #339     tc_links_dev_cleanup:OK
  #340     tc_links_dev_mixed:OK
  #341     tc_links_ingress:OK
  #342     tc_links_invalid:OK
  #343     tc_links_prepend:OK
  #344     tc_links_replace:OK
  #345     tc_links_revision:OK
  Summary: 14/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240708133130.11609-2-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
pull bot pushed a commit that referenced this pull request Sep 2, 2025
While working on the lazy MMU mode enablement for s390 I hit pretty
curious issues in the kasan code.

The first is related to a custom kasan-based sanitizer aimed at catching
invalid accesses to PTEs and is inspired by [1] conversation.  The kasan
complains on valid PTE accesses, while the shadow memory is reported as
unpoisoned:

[  102.783993] ==================================================================
[  102.784008] BUG: KASAN: out-of-bounds in set_pte_range+0x36c/0x390
[  102.784016] Read of size 8 at addr 0000780084cf9608 by task vmalloc_test/0/5542
[  102.784019] 
[  102.784040] CPU: 1 UID: 0 PID: 5542 Comm: vmalloc_test/0 Kdump: loaded Tainted: G           OE       6.16.0-gcc-ipte-kasan-11657-gb2d930c4950e #340 PREEMPT 
[  102.784047] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[  102.784049] Hardware name: IBM 8561 T01 703 (LPAR)
[  102.784052] Call Trace:
[  102.784054]  [<00007fffe0147ac0>] dump_stack_lvl+0xe8/0x140 
[  102.784059]  [<00007fffe0112484>] print_address_description.constprop.0+0x34/0x2d0 
[  102.784066]  [<00007fffe011282c>] print_report+0x10c/0x1f8 
[  102.784071]  [<00007fffe090785a>] kasan_report+0xfa/0x220 
[  102.784078]  [<00007fffe01d3dec>] set_pte_range+0x36c/0x390 
[  102.784083]  [<00007fffe01d41c2>] leave_ipte_batch+0x3b2/0xb10 
[  102.784088]  [<00007fffe07d3650>] apply_to_pte_range+0x2f0/0x4e0 
[  102.784094]  [<00007fffe07e62e4>] apply_to_pmd_range+0x194/0x3e0 
[  102.784099]  [<00007fffe07e820e>] __apply_to_page_range+0x2fe/0x7a0 
[  102.784104]  [<00007fffe07e86d8>] apply_to_page_range+0x28/0x40 
[  102.784109]  [<00007fffe090a3ec>] __kasan_populate_vmalloc+0xec/0x310 
[  102.784114]  [<00007fffe090aa36>] kasan_populate_vmalloc+0x96/0x130 
[  102.784118]  [<00007fffe0833a04>] alloc_vmap_area+0x3d4/0xf30 
[  102.784123]  [<00007fffe083a8ba>] __get_vm_area_node+0x1aa/0x4c0 
[  102.784127]  [<00007fffe083c4f6>] __vmalloc_node_range_noprof+0x126/0x4e0 
[  102.784131]  [<00007fffe083c980>] __vmalloc_node_noprof+0xd0/0x110 
[  102.784135]  [<00007fffe083ca32>] vmalloc_noprof+0x32/0x40 
[  102.784139]  [<00007fff608aa336>] fix_size_alloc_test+0x66/0x150 [test_vmalloc] 
[  102.784147]  [<00007fff608aa710>] test_func+0x2f0/0x430 [test_vmalloc] 
[  102.784153]  [<00007fffe02841f8>] kthread+0x3f8/0x7a0 
[  102.784159]  [<00007fffe014d8b4>] __ret_from_fork+0xd4/0x7d0 
[  102.784164]  [<00007fffe299c00a>] ret_from_fork+0xa/0x30 
[  102.784173] no locks held by vmalloc_test/0/5542.
[  102.784176] 
[  102.784178] The buggy address belongs to the physical page:
[  102.784186] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x84cf9
[  102.784198] flags: 0x3ffff00000000000(node=0|zone=1|lastcpupid=0x1ffff)
[  102.784212] page_type: f2(table)
[  102.784225] raw: 3ffff00000000000 0000000000000000 0000000000000122 0000000000000000
[  102.784234] raw: 0000000000000000 0000000000000000 f200000000000001 0000000000000000
[  102.784248] page dumped because: kasan: bad access detected
[  102.784250] 
[  102.784252] Memory state around the buggy address:
[  102.784260]  0000780084cf9500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784274]  0000780084cf9580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784277] >0000780084cf9600: fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784290]                          ^
[  102.784293]  0000780084cf9680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784303]  0000780084cf9700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784306] ==================================================================

The second issue hits when the custom sanitizer above is not implemented,
but the kasan itself is still active:

[ 1554.438028] Unable to handle kernel pointer dereference in virtual kernel address space
[ 1554.438065] Failing address: 001c0ff0066f0000 TEID: 001c0ff0066f0403
[ 1554.438076] Fault in home space mode while using kernel ASCE.
[ 1554.438103] AS:00000000059d400b R2:0000000ffec5c00b R3:00000000c6c9c007 S:0000000314470001 P:00000000d0ab413d 
[ 1554.438158] Oops: 0011 ilc:2 [#1]SMP 
[ 1554.438175] Modules linked in: test_vmalloc(E+) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) nf_tables(E) sunrpc(E) pkey_pckmo(E) uvdevice(E) s390_trng(E) rng_core(E) eadm_sch(E) vfio_ccw(E) mdev(E) vfio_iommu_type1(E) vfio(E) sch_fq_codel(E) drm(E) loop(E) i2c_core(E) drm_panel_orientation_quirks(E) nfnetlink(E) ctcm(E) fsm(E) zfcp(E) scsi_transport_fc(E) diag288_wdt(E) watchdog(E) ghash_s390(E) prng(E) aes_s390(E) des_s390(E) libdes(E) sha3_512_s390(E) sha3_256_s390(E) sha512_s390(E) sha1_s390(E) sha_common(E) pkey(E) autofs4(E)
[ 1554.438319] Unloaded tainted modules: pkey_uv(E):1 hmac_s390(E):2
[ 1554.438354] CPU: 1 UID: 0 PID: 1715 Comm: vmalloc_test/0 Kdump: loaded Tainted: G            E       6.16.0-gcc-ipte-kasan-11657-gb2d930c4950e #350 PREEMPT 
[ 1554.438368] Tainted: [E]=UNSIGNED_MODULE
[ 1554.438374] Hardware name: IBM 8561 T01 703 (LPAR)
[ 1554.438381] Krnl PSW : 0704e00180000000 00007fffe1d3d6ae (memset+0x5e/0x98)
[ 1554.438396]            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
[ 1554.438409] Krnl GPRS: 0000000000000001 001c0ff0066f0000 001c0ff0066f0000 00000000000000f8
[ 1554.438418]            00000000000009fe 0000000000000009 0000000000000000 0000000000000002
[ 1554.438426]            0000000000005000 000078031ae655c8 00000feffdcf9f59 0000780258672a20
[ 1554.438433]            0000780243153500 00007f8033780000 00007fffe083a510 00007f7fee7cfa00
[ 1554.438452] Krnl Code: 00007fffe1d3d6a0: eb540008000c	srlg	%r5,%r4,8
           00007fffe1d3d6a6: b9020055		ltgr	%r5,%r5
          #00007fffe1d3d6aa: a784000b		brc	8,00007fffe1d3d6c0
          >00007fffe1d3d6ae: 42301000		stc	%r3,0(%r1)
           00007fffe1d3d6b2: d2fe10011000	mvc	1(255,%r1),0(%r1)
           00007fffe1d3d6b8: 41101100		la	%r1,256(%r1)
           00007fffe1d3d6bc: a757fff9		brctg	%r5,00007fffe1d3d6ae
           00007fffe1d3d6c0: 42301000		stc	%r3,0(%r1)
[ 1554.438539] Call Trace:
[ 1554.438545]  [<00007fffe1d3d6ae>] memset+0x5e/0x98 
[ 1554.438552] ([<00007fffe083a510>] remove_vm_area+0x220/0x400)
[ 1554.438562]  [<00007fffe083a9d6>] vfree.part.0+0x26/0x810 
[ 1554.438569]  [<00007fff6073bd50>] fix_align_alloc_test+0x50/0x90 [test_vmalloc] 
[ 1554.438583]  [<00007fff6073c73a>] test_func+0x46a/0x6c0 [test_vmalloc] 
[ 1554.438593]  [<00007fffe0283ac8>] kthread+0x3f8/0x7a0 
[ 1554.438603]  [<00007fffe014d8b4>] __ret_from_fork+0xd4/0x7d0 
[ 1554.438613]  [<00007fffe299ac0a>] ret_from_fork+0xa/0x30 
[ 1554.438622] INFO: lockdep is turned off.
[ 1554.438627] Last Breaking-Event-Address:
[ 1554.438632]  [<00007fffe1d3d65c>] memset+0xc/0x98
[ 1554.438644] Kernel panic - not syncing: Fatal exception: panic_on_oops

This series fixes the above issues and is a pre-requisite for the s390
lazy MMU mode implementation.

test_vmalloc was used to stress-test the fixes.


This patch (of 2):

When vmalloc shadow memory is established the modification of the
corresponding page tables is not protected by any locks.  Instead, the
locking is done per-PTE.  This scheme however has defects.

kasan_populate_vmalloc_pte() - while ptep_get() read is atomic the
sequence pte_none(ptep_get()) is not.  Doing that outside of the lock
might lead to a concurrent PTE update and what could be seen as a shadow
memory corruption as result.

kasan_depopulate_vmalloc_pte() - by the time a page whose address was
extracted from ptep_get() read and cached in a local variable outside of
the lock is attempted to get free, could actually be freed already.

To avoid these put ptep_get() itself and the code that manipulates the
result of the read under lock.  In addition, move freeing of the page out
of the atomic context.

Link: https://lkml.kernel.org/r/cover.1755528662.git.agordeev@linux.ibm.com
Link: https://lkml.kernel.org/r/adb258634194593db294c0d1fb35646e894d6ead.1755528662.git.agordeev@linux.ibm.com
Link: https://lore.kernel.org/linux-mm/5b0609c9-95ee-4e48-bb6d-98f57c5d2c31@arm.com/ [1]
Fixes: 3c5c3cf ("kasan: support backing vmalloc space with real shadow memory")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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