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MAINTAINERS: Add myself as reviewer for module support#84

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modules-kpd-app[bot] wants to merge 2 commits intomodules-next_basefrom
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MAINTAINERS: Add myself as reviewer for module support#84
modules-kpd-app[bot] wants to merge 2 commits intomodules-next_basefrom
series/1013203=>modules-next

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Pull request for series with
subject: MAINTAINERS: Add myself as reviewer for module support
version: 1
url: https://patchwork.kernel.org/project/linux-modules/list/?series=1013203

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Upstream branch: 5eb4b9a
series: https://patchwork.kernel.org/project/linux-modules/list/?series=1013203
version: 1

@modules-kpd-app modules-kpd-app bot force-pushed the modules-next_base branch 2 times, most recently from e00514b to 0299e02 Compare October 22, 2025 10:24
Voluntering as a reviewer for Module support.

Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Acked-by: Daniel Gomez <da.gomez@samsung.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
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Upstream branch: 5eb4b9a
series: https://patchwork.kernel.org/project/linux-modules/list/?series=1013203
version: 1

@modules-kpd-app modules-kpd-app bot force-pushed the series/1013203=>modules-next branch from f7e530c to 46f9bf5 Compare October 22, 2025 10:40
dagomez137 pushed a commit that referenced this pull request Mar 9, 2026
tracing_record_cmdline() internally uses __this_cpu_read() and
__this_cpu_write() on the per-CPU variable trace_cmdline_save, and
trace_save_cmdline() explicitly asserts preemption is disabled via
lockdep_assert_preemption_disabled(). These operations are only safe
when preemption is off, as they were designed to be called from the
scheduler context (probe_wakeup_sched_switch() / probe_wakeup()).

__blk_add_trace() was calling tracing_record_cmdline(current) early in
the blk_tracer path, before ring buffer reservation, from process
context where preemption is fully enabled. This triggers the following
using blktests/blktrace/002:

blktrace/002 (blktrace ftrace corruption with sysfs trace)   [failed]
    runtime  0.367s  ...  0.437s
    something found in dmesg:
    [   81.211018] run blktests blktrace/002 at 2026-02-25 22:24:33
    [   81.239580] null_blk: disk nullb1 created
    [   81.357294] BUG: using __this_cpu_read() in preemptible [00000000] code: dd/2516
    [   81.362842] caller is tracing_record_cmdline+0x10/0x40
    [   81.362872] CPU: 16 UID: 0 PID: 2516 Comm: dd Tainted: G                 N  7.0.0-rc1lblk+ #84 PREEMPT(full)
    [   81.362877] Tainted: [N]=TEST
    [   81.362878] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
    [   81.362881] Call Trace:
    [   81.362884]  <TASK>
    [   81.362886]  dump_stack_lvl+0x8d/0xb0
    ...
    (See '/mnt/sda/blktests/results/nodev/blktrace/002.dmesg' for the entire message)

[   81.211018] run blktests blktrace/002 at 2026-02-25 22:24:33
[   81.239580] null_blk: disk nullb1 created
[   81.357294] BUG: using __this_cpu_read() in preemptible [00000000] code: dd/2516
[   81.362842] caller is tracing_record_cmdline+0x10/0x40
[   81.362872] CPU: 16 UID: 0 PID: 2516 Comm: dd Tainted: G                 N  7.0.0-rc1lblk+ #84 PREEMPT(full)
[   81.362877] Tainted: [N]=TEST
[   81.362878] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[   81.362881] Call Trace:
[   81.362884]  <TASK>
[   81.362886]  dump_stack_lvl+0x8d/0xb0
[   81.362895]  check_preemption_disabled+0xce/0xe0
[   81.362902]  tracing_record_cmdline+0x10/0x40
[   81.362923]  __blk_add_trace+0x307/0x5d0
[   81.362934]  ? lock_acquire+0xe0/0x300
[   81.362940]  ? iov_iter_extract_pages+0x101/0xa30
[   81.362959]  blk_add_trace_bio+0x106/0x1e0
[   81.362968]  submit_bio_noacct_nocheck+0x24b/0x3a0
[   81.362979]  ? lockdep_init_map_type+0x58/0x260
[   81.362988]  submit_bio_wait+0x56/0x90
[   81.363009]  __blkdev_direct_IO_simple+0x16c/0x250
[   81.363026]  ? __pfx_submit_bio_wait_endio+0x10/0x10
[   81.363038]  ? rcu_read_lock_any_held+0x73/0xa0
[   81.363051]  blkdev_read_iter+0xc1/0x140
[   81.363059]  vfs_read+0x20b/0x330
[   81.363083]  ksys_read+0x67/0xe0
[   81.363090]  do_syscall_64+0xbf/0xf00
[   81.363102]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   81.363106] RIP: 0033:0x7f281906029d
[   81.363111] Code: 31 c0 e9 c6 fe ff ff 50 48 8d 3d 66 63 0a 00 e8 59 ff 01 00 66 0f 1f 84 00 00 00 00 00 80 3d 41 33 0e 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec
[   81.363113] RSP: 002b:00007ffca127dd48 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[   81.363120] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f281906029d
[   81.363122] RDX: 0000000000001000 RSI: 0000559f8bfae000 RDI: 0000000000000000
[   81.363123] RBP: 0000000000001000 R08: 0000002863a10a81 R09: 00007f281915f000
[   81.363124] R10: 00007f2818f77b60 R11: 0000000000000246 R12: 0000559f8bfae000
[   81.363126] R13: 0000000000000000 R14: 0000000000000000 R15: 000000000000000a
[   81.363142]  </TASK>

The same BUG fires from blk_add_trace_plug(), blk_add_trace_unplug(),
and blk_add_trace_rq() paths as well.

The purpose of tracing_record_cmdline() is to cache the task->comm for
a given PID so that the trace can later resolve it. It is only
meaningful when a trace event is actually being recorded. Ring buffer
reservation via ring_buffer_lock_reserve() disables preemption, and
preemption remains disabled until the event is committed :-

__blk_add_trace()
       	__trace_buffer_lock_reserve()
       		__trace_buffer_lock_reserve()
       			ring_buffer_lock_reserve()
       				preempt_disable_notrace();  <---

With this fix blktests for blktrace pass:

  blktests (master) # ./check blktrace
  blktrace/001 (blktrace zone management command tracing)      [passed]
      runtime  3.650s  ...  3.647s
  blktrace/002 (blktrace ftrace corruption with sysfs trace)   [passed]
      runtime  0.411s  ...  0.384s

Fixes: 7ffbd48 ("tracing: Cache comms only after an event occurred")
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
dagomez137 pushed a commit that referenced this pull request Mar 16, 2026
user_scan() invokes updated sas_user_scan() for channel 0, and if
successful, iteratively scans remaining channels (1 to shost->max_channel)
via scsi_scan_host_selected() in commit 37c4e72 ("scsi: Fix
sas_user_scan() to handle wildcard and multi-channel scans"). However,
hisi_sas supports only one channel, and the current value of max_channel is
1. sas_user_scan() for channel 1 will trigger the following NULL pointer
exception:

[  441.554662] Unable to handle kernel NULL pointer dereference at virtual address 00000000000008b0
[  441.554699] Mem abort info:
[  441.554710]   ESR = 0x0000000096000004
[  441.554718]   EC = 0x25: DABT (current EL), IL = 32 bits
[  441.554723]   SET = 0, FnV = 0
[  441.554726]   EA = 0, S1PTW = 0
[  441.554730]   FSC = 0x04: level 0 translation fault
[  441.554735] Data abort info:
[  441.554737]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[  441.554742]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[  441.554747]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[  441.554752] user pgtable: 4k pages, 48-bit VAs, pgdp=00000828377a6000
[  441.554757] [00000000000008b0] pgd=0000000000000000, p4d=0000000000000000
[  441.554769] Internal error: Oops: 0000000096000004 [#1]  SMP
[  441.629589] Modules linked in: arm_spe_pmu arm_smmuv3_pmu tpm_tis_spi hisi_uncore_sllc_pmu hisi_uncore_pa_pmu hisi_uncore_l3c_pmu hisi_uncore_hha_pmu hisi_uncore_ddrc_pmu hisi_uncore_cpa_pmu hns3_pmu hisi_ptt hisi_pcie_pmu tpm_tis_core spidev spi_hisi_sfc_v3xx hisi_uncore_pmu spi_dw_mmio fuse hclge hclge_common hisi_sec2 hisi_hpre hisi_zip hisi_qm hns3 hisi_sas_v3_hw sm3_ce sbsa_gwdt hnae3 hisi_sas_main uacce hisi_dma i2c_hisi dm_mirror dm_region_hash dm_log dm_mod
[  441.670819] CPU: 46 UID: 0 PID: 6994 Comm: bash Kdump: loaded Not tainted 7.0.0-rc2+ #84 PREEMPT
[  441.691327] pstate: 81400009 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[  441.698277] pc : sas_find_dev_by_rphy+0x44/0x118
[  441.702896] lr : sas_find_dev_by_rphy+0x3c/0x118
[  441.707502] sp : ffff80009abbba40
[  441.710805] x29: ffff80009abbba40 x28: ffff082819a40008 x27: ffff082810c37c08
[  441.717930] x26: ffff082810c37c28 x25: ffff082819a40290 x24: ffff082810c37c00
[  441.725054] x23: 0000000000000000 x22: 0000000000000001 x21: ffff082819a40000
[  441.732179] x20: ffff082819a40290 x19: 0000000000000000 x18: 0000000000000020
[  441.739304] x17: 0000000000000000 x16: ffffb5dad6bda690 x15: 00000000ffffffff
[  441.746428] x14: ffff082814c3b26c x13: 00000000ffffffff x12: ffff082814c3b26a
[  441.753553] x11: 00000000000000c0 x10: 000000000000003a x9 : ffffb5dad5ea94f4
[  441.760678] x8 : 000000000000003a x7 : ffff80009abbbab0 x6 : 0000000000000030
[  441.767802] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
[  441.774926] x2 : ffff08280f35a300 x1 : ffffb5dad7127180 x0 : 0000000000000000
[  441.782053] Call trace:
[  441.784488]  sas_find_dev_by_rphy+0x44/0x118 (P)
[  441.789095]  sas_target_alloc+0x24/0xb0
[  441.792920]  scsi_alloc_target+0x290/0x330
[  441.797010]  __scsi_scan_target+0x88/0x258
[  441.801096]  scsi_scan_channel+0x74/0xb8
[  441.805008]  scsi_scan_host_selected+0x170/0x188
[  441.809615]  sas_user_scan+0xfc/0x148
[  441.813267]  store_scan+0x10c/0x180
[  441.816743]  dev_attr_store+0x20/0x40
[  441.820398]  sysfs_kf_write+0x84/0xa8
[  441.824054]  kernfs_fop_write_iter+0x130/0x1c8
[  441.828487]  vfs_write+0x2c0/0x370
[  441.831880]  ksys_write+0x74/0x118
[  441.835271]  __arm64_sys_write+0x24/0x38
[  441.839182]  invoke_syscall+0x50/0x120
[  441.842919]  el0_svc_common.constprop.0+0xc8/0xf0
[  441.847611]  do_el0_svc+0x24/0x38
[  441.850913]  el0_svc+0x38/0x158
[  441.854043]  el0t_64_sync_handler+0xa0/0xe8
[  441.858214]  el0t_64_sync+0x1ac/0x1b0
[  441.861865] Code: aa1303e0 97ff70a8 34ffff80 d10a427 (f9445a75)
[  441.867946] ---[ end trace 0000000000000000 ]---

Therefore, set max_channel to 0.

Fixes: e21fe3a ("scsi: hisi_sas: add initialisation for v3 pci-based controller")
Signed-off-by: Xingui Yang <yangxingui@huawei.com>
Signed-off-by: Yihang Li <liyihang9@huawei.com>
Link: https://patch.msgid.link/20260305064039.4096775-1-liyihang9@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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