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Finish RISC-V support#249

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ojeda merged 2 commits intoRust-for-Linux:rustfrom
ojeda:riscv
May 3, 2021
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Finish RISC-V support#249
ojeda merged 2 commits intoRust-for-Linux:rustfrom
ojeda:riscv

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@ojeda ojeda commented May 3, 2021

Finishes #225.

There were several problems:

  • No console output. This was due to missing CONFIG_SOC_VIRT
    and CONFIG_SERIAL_OF_PLATFORM.

  • Hanging QEMU. This was due to missing CONFIG_SOC_VIRT plus
    reboot not working in older QEMU versions for RISC-V.
    We provide a custom build of the latest QEMU (6.0.0, recently
    released) in https://github.com/Rust-for-Linux/ci-bin.

  • Broken boot for debug builds. Some debugging options under
    Kernel hacking do not seem to work for RISC-V (in our
    branched kernel version, that is).

Also take the chance to clean up the .configs a bit more.

ojeda added 2 commits May 3, 2021 18:02
@ojeda
Finish RISC-V support
0b9fc04 
Completes Rust-for-Linux#225.

There were several problems:

  - No console output. This was due to missing `CONFIG_SOC_VIRT`
    and `CONFIG_SERIAL_OF_PLATFORM`.

  - Hanging QEMU. This was due to missing `CONFIG_SOC_VIRT` plus
    reboot not working in older QEMU versions for RISC-V.
    We provide a custom build of the latest QEMU (6.0.0, recently
    released) in https://github.com/Rust-for-Linux/ci-bin.

  - Broken boot for debug builds. Some debugging options under
    `Kernel hacking` do not seem to work for RISC-V (in our
    branched kernel version, that is).

Also take the chance to clean up the `.config`s a bit more.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
@ojeda
docs: rust: riscv is maintained
3cbb62f 
We run it in the CI now (`riscv64` only for the moment).

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
@ojeda ojeda merged commit 45ffe64 into Rust-for-Linux:rust May 3, 2021
@ojeda ojeda deleted the riscv branch May 3, 2021 16:36
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ojeda commented May 3, 2021

Related: #66.

ojeda pushed a commit that referenced this pull request Mar 1, 2023
@chleroy @akpm00
kasan: fix Oops due to missing calls to kasan_arch_is_ready()
55d77ba 
On powerpc64, you can build a kernel with KASAN as soon as you build it
with RADIX MMU support.  However if the CPU doesn't have RADIX MMU, KASAN
isn't enabled at init and the following Oops is encountered.

  [    0.000000][    T0] KASAN not enabled as it requires radix!

  [    4.484295][   T26] BUG: Unable to handle kernel data access at 0xc00e000000804a04
  [    4.485270][   T26] Faulting instruction address: 0xc00000000062ec6c
  [    4.485748][   T26] Oops: Kernel access of bad area, sig: 11 [#1]
  [    4.485920][   T26] BE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  [    4.486259][   T26] Modules linked in:
  [    4.486637][   T26] CPU: 0 PID: 26 Comm: kworker/u2:2 Not tainted 6.2.0-rc3-02590-gf8a023b0a805 #249
  [    4.486907][   T26] Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1200 0xf000005 of:SLOF,HEAD pSeries
  [    4.487445][   T26] Workqueue: eval_map_wq .tracer_init_tracefs_work_func
  [    4.488744][   T26] NIP:  c00000000062ec6c LR: c00000000062bb84 CTR: c0000000002ebcd0
  [    4.488867][   T26] REGS: c0000000049175c0 TRAP: 0380   Not tainted  (6.2.0-rc3-02590-gf8a023b0a805)
  [    4.489028][   T26] MSR:  8000000002009032 <SF,VEC,EE,ME,IR,DR,RI>  CR: 44002808  XER: 00000000
  [    4.489584][   T26] CFAR: c00000000062bb80 IRQMASK: 0
  [    4.489584][   T26] GPR00: c0000000005624d4 c000000004917860 c000000001cfc000 1800000000804a04
  [    4.489584][   T26] GPR04: c0000000003a2650 0000000000000cc0 c00000000000d3d8 c00000000000d3d8
  [    4.489584][   T26] GPR08: c0000000049175b0 a80e000000000000 0000000000000000 0000000017d78400
  [    4.489584][   T26] GPR12: 0000000044002204 c000000003790000 c00000000435003c c0000000043f1c40
  [    4.489584][   T26] GPR16: c0000000043f1c68 c0000000043501a0 c000000002106138 c0000000043f1c08
  [    4.489584][   T26] GPR20: c0000000043f1c10 c0000000043f1c20 c000000004146c40 c000000002fdb7f8
  [    4.489584][   T26] GPR24: c000000002fdb834 c000000003685e00 c000000004025030 c000000003522e90
  [    4.489584][   T26] GPR28: 0000000000000cc0 c0000000003a2650 c000000004025020 c000000004025020
  [    4.491201][   T26] NIP [c00000000062ec6c] .kasan_byte_accessible+0xc/0x20
  [    4.491430][   T26] LR [c00000000062bb84] .__kasan_check_byte+0x24/0x90
  [    4.491767][   T26] Call Trace:
  [    4.491941][   T26] [c000000004917860] [c00000000062ae70] .__kasan_kmalloc+0xc0/0x110 (unreliable)
  [    4.492270][   T26] [c0000000049178f0] [c0000000005624d4] .krealloc+0x54/0x1c0
  [    4.492453][   T26] [c000000004917990] [c0000000003a2650] .create_trace_option_files+0x280/0x530
  [    4.492613][   T26] [c000000004917a90] [c000000002050d90] .tracer_init_tracefs_work_func+0x274/0x2c0
  [    4.492771][   T26] [c000000004917b40] [c0000000001f9948] .process_one_work+0x578/0x9f0
  [    4.492927][   T26] [c000000004917c30] [c0000000001f9ebc] .worker_thread+0xfc/0x950
  [    4.493084][   T26] [c000000004917d60] [c00000000020be84] .kthread+0x1a4/0x1b0
  [    4.493232][   T26] [c000000004917e10] [c00000000000d3d8] .ret_from_kernel_thread+0x58/0x60
  [    4.495642][   T26] Code: 60000000 7cc802a6 38a00000 4bfffc78 60000000 7cc802a6 38a00001 4bfffc68 60000000 3d20a80e 7863e8c2 792907c6 <7c6348ae> 20630007 78630fe0 68630001
  [    4.496704][   T26] ---[ end trace 0000000000000000 ]---

The Oops is due to kasan_byte_accessible() not checking the readiness of
KASAN.  Add missing call to kasan_arch_is_ready() and bail out when not
ready.  The same problem is observed with ____kasan_kfree_large() so fix
it the same.

Also, as KASAN is not available and no shadow area is allocated for linear
memory mapping, there is no point in allocating shadow mem for vmalloc
memory as shown below in /sys/kernel/debug/kernel_page_tables

  ---[ kasan shadow mem start ]---
  0xc00f000000000000-0xc00f00000006ffff  0x00000000040f0000       448K         r  w       pte  valid  present        dirty  accessed
  0xc00f000000860000-0xc00f00000086ffff  0x000000000ac10000        64K         r  w       pte  valid  present        dirty  accessed
  0xc00f3ffffffe0000-0xc00f3fffffffffff  0x0000000004d10000       128K         r  w       pte  valid  present        dirty  accessed
  ---[ kasan shadow mem end ]---

So, also verify KASAN readiness before allocating and poisoning
shadow mem for VMAs.

Link: https://lkml.kernel.org/r/150768c55722311699fdcf8f5379e8256749f47d.1674716617.git.christophe.leroy@csgroup.eu
Fixes: 41b7a34 ("powerpc: Book3S 64-bit outline-only KASAN support")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reported-by: Nathan Lynch <nathanl@linux.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org>	[5.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ojeda pushed a commit that referenced this pull request Apr 29, 2024
@saproj @storulf
mmc: moxart: fix handling of sgm->consumed, otherwise WARN_ON triggers
e027e72 
When e.g. 8 bytes are to be read, sgm->consumed equals 8 immediately after
sg_miter_next() call. The driver then increments it as bytes are read,
so sgm->consumed becomes 16 and this warning triggers in sg_miter_stop():
WARN_ON(miter->consumed > miter->length);

WARNING: CPU: 0 PID: 28 at lib/scatterlist.c:925 sg_miter_stop+0x2c/0x10c
CPU: 0 PID: 28 Comm: kworker/0:2 Tainted: G        W          6.9.0-rc5-dirty #249
Hardware name: Generic DT based system
Workqueue: events_freezable mmc_rescan
Call trace:.
 unwind_backtrace from show_stack+0x10/0x14
 show_stack from dump_stack_lvl+0x44/0x5c
 dump_stack_lvl from __warn+0x78/0x16c
 __warn from warn_slowpath_fmt+0xb0/0x160
 warn_slowpath_fmt from sg_miter_stop+0x2c/0x10c
 sg_miter_stop from moxart_request+0xb0/0x468
 moxart_request from mmc_start_request+0x94/0xa8
 mmc_start_request from mmc_wait_for_req+0x60/0xa8
 mmc_wait_for_req from mmc_app_send_scr+0xf8/0x150
 mmc_app_send_scr from mmc_sd_setup_card+0x1c/0x420
 mmc_sd_setup_card from mmc_sd_init_card+0x12c/0x4dc
 mmc_sd_init_card from mmc_attach_sd+0xf0/0x16c
 mmc_attach_sd from mmc_rescan+0x1e0/0x298
 mmc_rescan from process_scheduled_works+0x2e4/0x4ec
 process_scheduled_works from worker_thread+0x1ec/0x24c
 worker_thread from kthread+0xd4/0xe0
 kthread from ret_from_fork+0x14/0x38

This patch adds initial zeroing of sgm->consumed. It is then incremented
as bytes are read or written.

Signed-off-by: Sergei Antonov <saproj@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Fixes: 3ee0e7c ("mmc: moxart-mmc: Use sg_miter for PIO")
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240422153607.963672-1-saproj@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
rlmenge pushed a commit to rlmenge/linux that referenced this pull request Jul 11, 2025
@adam900710 @kdave
btrfs: handle csum tree error with rescue=ibadroots correctly
547e836 
[BUG]
There is syzbot based reproducer that can crash the kernel, with the
following call trace: (With some debug output added)

 DEBUG: rescue=ibadroots parsed
 BTRFS: device fsid 14d642db-7b15-43e4-81e6-4b8fac6a25f8 devid 1 transid 8 /dev/loop0 (7:0) scanned by repro (1010)
 BTRFS info (device loop0): first mount of filesystem 14d642db-7b15-43e4-81e6-4b8fac6a25f8
 BTRFS info (device loop0): using blake2b (blake2b-256-generic) checksum algorithm
 BTRFS info (device loop0): using free-space-tree
 BTRFS warning (device loop0): checksum verify failed on logical 5312512 mirror 1 wanted 0xb043382657aede36608fd3386d6b001692ff406164733d94e2d9a180412c6003 found 0x810ceb2bacb7f0f9eb2bf3b2b15c02af867cb35ad450898169f3b1f0bd818651 level 0
 DEBUG: read tree root path failed for tree csum, ret=-5
 BTRFS warning (device loop0): checksum verify failed on logical 5328896 mirror 1 wanted 0x51be4e8b303da58e6340226815b70e3a93592dac3f30dd510c7517454de8567a found 0x51be4e8b303da58e634022a315b70e3a93592dac3f30dd510c7517454de8567a level 0
 BTRFS warning (device loop0): checksum verify failed on logical 5292032 mirror 1 wanted 0x1924ccd683be9efc2fa98582ef58760e3848e9043db8649ee382681e220cdee4 found 0x0cb6184f6e8799d9f8cb335dccd1d1832da1071d12290dab3b85b587ecacca6e level 0
 process 'repro' launched './file2' with NULL argv: empty string added
 DEBUG: no csum root, idatacsums=0 ibadroots=134217728
 Oops: general protection fault, probably for non-canonical address 0xdffffc0000000041: 0000 [#1] SMP KASAN NOPTI
 KASAN: null-ptr-deref in range [0x0000000000000208-0x000000000000020f]
 CPU: 5 UID: 0 PID: 1010 Comm: repro Tainted: G           OE       6.15.0-custom+ Rust-for-Linux#249 PREEMPT(full)
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
 RIP: 0010:btrfs_lookup_csum+0x93/0x3d0 [btrfs]
 Call Trace:
  <TASK>
  btrfs_lookup_bio_sums+0x47a/0xdf0 [btrfs]
  btrfs_submit_bbio+0x43e/0x1a80 [btrfs]
  submit_one_bio+0xde/0x160 [btrfs]
  btrfs_readahead+0x498/0x6a0 [btrfs]
  read_pages+0x1c3/0xb20
  page_cache_ra_order+0x4b5/0xc20
  filemap_get_pages+0x2d3/0x19e0
  filemap_read+0x314/0xde0
  __kernel_read+0x35b/0x900
  bprm_execve+0x62e/0x1140
  do_execveat_common.isra.0+0x3fc/0x520
  __x64_sys_execveat+0xdc/0x130
  do_syscall_64+0x54/0x1d0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
 ---[ end trace 0000000000000000 ]---

[CAUSE]
Firstly the fs has a corrupted csum tree root, thus to mount the fs we
have to go "ro,rescue=ibadroots" mount option.

Normally with that mount option, a bad csum tree root should set
BTRFS_FS_STATE_NO_DATA_CSUMS flag, so that any future data read will
ignore csum search.

But in this particular case, we have the following call trace that
caused NULL csum root, but not setting BTRFS_FS_STATE_NO_DATA_CSUMS:

load_global_roots_objectid():

		ret = btrfs_search_slot();
		/* Succeeded */
		btrfs_item_key_to_cpu()
		found = true;
		/* We found the root item for csum tree. */
		root = read_tree_root_path();
		if (IS_ERR(root)) {
			if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
			/*
			 * Since we have rescue=ibadroots mount option,
			 * @ret is still 0.
			 */
			break;
	if (!found || ret) {
		/* @found is true, @ret is 0, error handling for csum
		 * tree is skipped.
		 */
	}

This means we completely skipped to set BTRFS_FS_STATE_NO_DATA_CSUMS if
the csum tree is corrupted, which results unexpected later csum lookup.

[FIX]
If read_tree_root_path() failed, always populate @ret to the error
number.

As at the end of the function, we need @ret to determine if we need to
do the extra error handling for csum tree.

Fixes: abed4aa ("btrfs: track the csum, extent, and free space trees in a rb tree")
Reported-by: Zhiyu Zhang <zhiyuzhang999@gmail.com>
Reported-by: Longxing Li <coregee2000@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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