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6.5: tcp patches #3

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6.5: tcp patches #3

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Kaz205 and others added 2 commits September 23, 2023 19:25
Adds a lot of overhead.

Signed-off-by: Kazuki Hashimoto <[email protected]>
…tency

`TCP_NODELAY` will disable Nagle's algorithm, which basically collects
small outgoing packets to send all at once.
Thus `TCP_NODELAY` will send the data whenever it is available without
waiting for any period to collect packets.

It will basically optimize network video games and applications
using chatty protocols (source: ExtraHop[1], RedHat[2])

[1]: https://www.extrahop.com/company/blog/2016/tcp-nodelay-nagle-quickack-best-practices/#:~:text=The%20TCP_NODELAY%20socket%20option%20allows,buffer%2C%20whatever%20the%20packet%20size.
[2]: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux_for_real_time/7/html/tuning_guide/tcp_nodelay_and_small_buffer_writes

Signed-off-by: Panchajanya1999 <[email protected]>
[Rasenkai: forward-port to 5.4]
Signed-off-by: Rasenkai <[email protected]>
Change-Id: I2518d04969975c69c61d5e0acab7295702190b0d
ptr1337 pushed a commit that referenced this pull request Oct 3, 2023
Hou Tao says:

====================
Fix the unmatched unit_size of bpf_mem_cache

From: Hou Tao <[email protected]>

Hi,

The patchset aims to fix the reported warning [0] when the unit_size of
bpf_mem_cache is mismatched with the object size of underly slab-cache.

Patch #1 fixes the warning by adjusting size_index according to the
value of KMALLOC_MIN_SIZE, so bpf_mem_cache with unit_size which is
smaller than KMALLOC_MIN_SIZE or is not aligned with KMALLOC_MIN_SIZE
will be redirected to bpf_mem_cache with bigger unit_size. Patch #2
doesn't do prefill for these redirected bpf_mem_cache to save memory.
Patch #3 adds further error check in bpf_mem_alloc_init() to ensure the
unit_size and object_size are always matched and to prevent potential
issues due to the mismatch.

Please see individual patches for more details. And comments are always
welcome.

[0]: https://lore.kernel.org/bpf/[email protected]
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
ptr1337 pushed a commit that referenced this pull request Oct 3, 2023
macb_set_tx_clk() is called under a spinlock but itself calls clk_set_rate()
which can sleep. This results in:

| BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
| pps pps1: new PPS source ptp1
| in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 40, name: kworker/u4:3
| preempt_count: 1, expected: 0
| RCU nest depth: 0, expected: 0
| 4 locks held by kworker/u4:3/40:
|  #0: ffff000003409148
| macb ff0c0000.ethernet: gem-ptp-timer ptp clock registered.
|  ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x14c/0x51c
|  #1: ffff8000833cbdd8 ((work_completion)(&pl->resolve)){+.+.}-{0:0}, at: process_one_work+0x14c/0x51c
|  #2: ffff000004f01578 (&pl->state_mutex){+.+.}-{4:4}, at: phylink_resolve+0x44/0x4e8
|  #3: ffff000004f06f50 (&bp->lock){....}-{3:3}, at: macb_mac_link_up+0x40/0x2ac
| irq event stamp: 113998
| hardirqs last  enabled at (113997): [<ffff800080e8503c>] _raw_spin_unlock_irq+0x30/0x64
| hardirqs last disabled at (113998): [<ffff800080e84478>] _raw_spin_lock_irqsave+0xac/0xc8
| softirqs last  enabled at (113608): [<ffff800080010630>] __do_softirq+0x430/0x4e4
| softirqs last disabled at (113597): [<ffff80008001614c>] ____do_softirq+0x10/0x1c
| CPU: 0 PID: 40 Comm: kworker/u4:3 Not tainted 6.5.0-11717-g9355ce8b2f50-dirty torvalds#368
| Hardware name: ... ZynqMP ... (DT)
| Workqueue: events_power_efficient phylink_resolve
| Call trace:
|  dump_backtrace+0x98/0xf0
|  show_stack+0x18/0x24
|  dump_stack_lvl+0x60/0xac
|  dump_stack+0x18/0x24
|  __might_resched+0x144/0x24c
|  __might_sleep+0x48/0x98
|  __mutex_lock+0x58/0x7b0
|  mutex_lock_nested+0x24/0x30
|  clk_prepare_lock+0x4c/0xa8
|  clk_set_rate+0x24/0x8c
|  macb_mac_link_up+0x25c/0x2ac
|  phylink_resolve+0x178/0x4e8
|  process_one_work+0x1ec/0x51c
|  worker_thread+0x1ec/0x3e4
|  kthread+0x120/0x124
|  ret_from_fork+0x10/0x20

The obvious fix is to move the call to macb_set_tx_clk() out of the
protected area. This seems safe as rx and tx are both disabled anyway at
this point.
It is however not entirely clear what the spinlock shall protect. It
could be the read-modify-write access to the NCFGR register, but this
is accessed in macb_set_rx_mode() and macb_set_rxcsum_feature() as well
without holding the spinlock. It could also be the register accesses
done in mog_init_rings() or macb_init_buffers(), but again these
functions are called without holding the spinlock in macb_hresp_error_task().
The locking seems fishy in this driver and it might deserve another look
before this patch is applied.

Fixes: 633e98a ("net: macb: use resolved link config in mac_link_up()")
Signed-off-by: Sascha Hauer <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
ptr1337 pushed a commit that referenced this pull request Oct 3, 2023
Fix an error detected by memory sanitizer:
```
==4033==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x55fb0fbedfc7 in read_alias_info tools/perf/util/pmu.c:457:6
    #1 0x55fb0fbea339 in check_info_data tools/perf/util/pmu.c:1434:2
    #2 0x55fb0fbea339 in perf_pmu__check_alias tools/perf/util/pmu.c:1504:9
    #3 0x55fb0fbdca85 in parse_events_add_pmu tools/perf/util/parse-events.c:1429:32
    #4 0x55fb0f965230 in parse_events_parse tools/perf/util/parse-events.y:299:6
    #5 0x55fb0fbdf6b2 in parse_events__scanner tools/perf/util/parse-events.c:1822:8
    torvalds#6 0x55fb0fbdf8c1 in __parse_events tools/perf/util/parse-events.c:2094:8
    torvalds#7 0x55fb0fa8ffa9 in parse_events tools/perf/util/parse-events.h:41:9
    torvalds#8 0x55fb0fa8ffa9 in test_event tools/perf/tests/parse-events.c:2393:8
    torvalds#9 0x55fb0fa8f458 in test__pmu_events tools/perf/tests/parse-events.c:2551:15
    torvalds#10 0x55fb0fa6d93f in run_test tools/perf/tests/builtin-test.c:242:9
    torvalds#11 0x55fb0fa6d93f in test_and_print tools/perf/tests/builtin-test.c:271:8
    torvalds#12 0x55fb0fa6d082 in __cmd_test tools/perf/tests/builtin-test.c:442:5
    torvalds#13 0x55fb0fa6d082 in cmd_test tools/perf/tests/builtin-test.c:564:9
    torvalds#14 0x55fb0f942720 in run_builtin tools/perf/perf.c:322:11
    torvalds#15 0x55fb0f942486 in handle_internal_command tools/perf/perf.c:375:8
    torvalds#16 0x55fb0f941dab in run_argv tools/perf/perf.c:419:2
    torvalds#17 0x55fb0f941dab in main tools/perf/perf.c:535:3
```

Fixes: 7b723db ("perf pmu: Be lazy about loading event info files from sysfs")
Signed-off-by: Ian Rogers <[email protected]>
Cc: James Clark <[email protected]>
Cc: Kan Liang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
ptr1337 pushed a commit that referenced this pull request Oct 3, 2023
Syzkaller reported a sleep in atomic context bug relating to the HASHCHK
handler logic:

  BUG: sleeping function called from invalid context at arch/powerpc/kernel/traps.c:1518
  in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 25040, name: syz-executor
  preempt_count: 0, expected: 0
  RCU nest depth: 0, expected: 0
  no locks held by syz-executor/25040.
  irq event stamp: 34
  hardirqs last  enabled at (33): [<c000000000048b38>] prep_irq_for_enabled_exit arch/powerpc/kernel/interrupt.c:56 [inline]
  hardirqs last  enabled at (33): [<c000000000048b38>] interrupt_exit_user_prepare_main+0x148/0x600 arch/powerpc/kernel/interrupt.c:230
  hardirqs last disabled at (34): [<c00000000003e6a4>] interrupt_enter_prepare+0x144/0x4f0 arch/powerpc/include/asm/interrupt.h:176
  softirqs last  enabled at (0): [<c000000000281954>] copy_process+0x16e4/0x4750 kernel/fork.c:2436
  softirqs last disabled at (0): [<0000000000000000>] 0x0
  CPU: 15 PID: 25040 Comm: syz-executor Not tainted 6.5.0-rc5-00001-g3ccdff6bb06d #3
  Hardware name: IBM,9105-22A POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1040.00 (NL1040_021) hv:phyp pSeries
  Call Trace:
  [c0000000a8247ce0] [c00000000032b0e4] __might_resched+0x3b4/0x400 kernel/sched/core.c:10189
  [c0000000a8247d80] [c0000000008c7dc8] __might_fault+0xa8/0x170 mm/memory.c:5853
  [c0000000a8247dc0] [c00000000004160c] do_program_check+0x32c/0xb20 arch/powerpc/kernel/traps.c:1518
  [c0000000a8247e50] [c000000000009b2c] program_check_common_virt+0x3bc/0x3c0

To determine if a trap was caused by a HASHCHK instruction, we inspect
the user instruction that triggered the trap. However this may sleep
if the page needs to be faulted in (get_user_instr() reaches
__get_user(), which calls might_fault() and triggers the bug message).

Move the HASHCHK handler logic to after we allow IRQs, which is fine
because we are only interested in HASHCHK if it's a user space trap.

Fixes: 5bcba4e ("powerpc/dexcr: Handle hashchk exception")
Signed-off-by: Benjamin Gray <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]
ptr1337 pushed a commit that referenced this pull request Oct 3, 2023
Sebastian Andrzej Siewior says:

====================
net: hsr: Properly parse HSRv1 supervisor frames.

this is a follow-up to
	https://lore.kernel.org/all/[email protected]/
replacing
	https://lore.kernel.org/all/[email protected]/

by grabing/ adding tags and reposting with a commit message plus a
missing __packed to a struct (#2) plus extending the testsuite to sover
HSRv1 which is what broke here (#3-#5).

HSRv0 is (was) not affected.
====================

Signed-off-by: David S. Miller <[email protected]>
ptr1337 pushed a commit that referenced this pull request Oct 6, 2023
[ Upstream commit c3f4309 ]

Syzkaller reported a sleep in atomic context bug relating to the HASHCHK
handler logic:

  BUG: sleeping function called from invalid context at arch/powerpc/kernel/traps.c:1518
  in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 25040, name: syz-executor
  preempt_count: 0, expected: 0
  RCU nest depth: 0, expected: 0
  no locks held by syz-executor/25040.
  irq event stamp: 34
  hardirqs last  enabled at (33): [<c000000000048b38>] prep_irq_for_enabled_exit arch/powerpc/kernel/interrupt.c:56 [inline]
  hardirqs last  enabled at (33): [<c000000000048b38>] interrupt_exit_user_prepare_main+0x148/0x600 arch/powerpc/kernel/interrupt.c:230
  hardirqs last disabled at (34): [<c00000000003e6a4>] interrupt_enter_prepare+0x144/0x4f0 arch/powerpc/include/asm/interrupt.h:176
  softirqs last  enabled at (0): [<c000000000281954>] copy_process+0x16e4/0x4750 kernel/fork.c:2436
  softirqs last disabled at (0): [<0000000000000000>] 0x0
  CPU: 15 PID: 25040 Comm: syz-executor Not tainted 6.5.0-rc5-00001-g3ccdff6bb06d #3
  Hardware name: IBM,9105-22A POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1040.00 (NL1040_021) hv:phyp pSeries
  Call Trace:
  [c0000000a8247ce0] [c00000000032b0e4] __might_resched+0x3b4/0x400 kernel/sched/core.c:10189
  [c0000000a8247d80] [c0000000008c7dc8] __might_fault+0xa8/0x170 mm/memory.c:5853
  [c0000000a8247dc0] [c00000000004160c] do_program_check+0x32c/0xb20 arch/powerpc/kernel/traps.c:1518
  [c0000000a8247e50] [c000000000009b2c] program_check_common_virt+0x3bc/0x3c0

To determine if a trap was caused by a HASHCHK instruction, we inspect
the user instruction that triggered the trap. However this may sleep
if the page needs to be faulted in (get_user_instr() reaches
__get_user(), which calls might_fault() and triggers the bug message).

Move the HASHCHK handler logic to after we allow IRQs, which is fine
because we are only interested in HASHCHK if it's a user space trap.

Fixes: 5bcba4e ("powerpc/dexcr: Handle hashchk exception")
Signed-off-by: Benjamin Gray <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Oct 9, 2023
Fix the deadlock by refactoring the MR cache cleanup flow to flush the
workqueue without holding the rb_lock.
This adds a race between cache cleanup and creation of new entries which
we solve by denied creation of new entries after cache cleanup started.

Lockdep:
WARNING: possible circular locking dependency detected
 [ 2785.326074 ] 6.2.0-rc6_for_upstream_debug_2023_01_31_14_02 #1 Not tainted
 [ 2785.339778 ] ------------------------------------------------------
 [ 2785.340848 ] devlink/53872 is trying to acquire lock:
 [ 2785.341701 ] ffff888124f8c0c8 ((work_completion)(&(&ent->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0xc8/0x900
 [ 2785.343403 ]
 [ 2785.343403 ] but task is already holding lock:
 [ 2785.344464 ] ffff88817e8f1260 (&dev->cache.rb_lock){+.+.}-{3:3}, at: mlx5_mkey_cache_cleanup+0x77/0x250 [mlx5_ib]
 [ 2785.346273 ]
 [ 2785.346273 ] which lock already depends on the new lock.
 [ 2785.346273 ]
 [ 2785.347720 ]
 [ 2785.347720 ] the existing dependency chain (in reverse order) is:
 [ 2785.349003 ]
 [ 2785.349003 ] -> #1 (&dev->cache.rb_lock){+.+.}-{3:3}:
 [ 2785.350160 ]        __mutex_lock+0x14c/0x15c0
 [ 2785.350962 ]        delayed_cache_work_func+0x2d1/0x610 [mlx5_ib]
 [ 2785.352044 ]        process_one_work+0x7c2/0x1310
 [ 2785.352879 ]        worker_thread+0x59d/0xec0
 [ 2785.353636 ]        kthread+0x28f/0x330
 [ 2785.354370 ]        ret_from_fork+0x1f/0x30
 [ 2785.355135 ]
 [ 2785.355135 ] -> #0 ((work_completion)(&(&ent->dwork)->work)){+.+.}-{0:0}:
 [ 2785.356515 ]        __lock_acquire+0x2d8a/0x5fe0
 [ 2785.357349 ]        lock_acquire+0x1c1/0x540
 [ 2785.358121 ]        __flush_work+0xe8/0x900
 [ 2785.358852 ]        __cancel_work_timer+0x2c7/0x3f0
 [ 2785.359711 ]        mlx5_mkey_cache_cleanup+0xfb/0x250 [mlx5_ib]
 [ 2785.360781 ]        mlx5_ib_stage_pre_ib_reg_umr_cleanup+0x16/0x30 [mlx5_ib]
 [ 2785.361969 ]        __mlx5_ib_remove+0x68/0x120 [mlx5_ib]
 [ 2785.362960 ]        mlx5r_remove+0x63/0x80 [mlx5_ib]
 [ 2785.363870 ]        auxiliary_bus_remove+0x52/0x70
 [ 2785.364715 ]        device_release_driver_internal+0x3c1/0x600
 [ 2785.365695 ]        bus_remove_device+0x2a5/0x560
 [ 2785.366525 ]        device_del+0x492/0xb80
 [ 2785.367276 ]        mlx5_detach_device+0x1a9/0x360 [mlx5_core]
 [ 2785.368615 ]        mlx5_unload_one_devl_locked+0x5a/0x110 [mlx5_core]
 [ 2785.369934 ]        mlx5_devlink_reload_down+0x292/0x580 [mlx5_core]
 [ 2785.371292 ]        devlink_reload+0x439/0x590
 [ 2785.372075 ]        devlink_nl_cmd_reload+0xaef/0xff0
 [ 2785.372973 ]        genl_family_rcv_msg_doit.isra.0+0x1bd/0x290
 [ 2785.374011 ]        genl_rcv_msg+0x3ca/0x6c0
 [ 2785.374798 ]        netlink_rcv_skb+0x12c/0x360
 [ 2785.375612 ]        genl_rcv+0x24/0x40
 [ 2785.376295 ]        netlink_unicast+0x438/0x710
 [ 2785.377121 ]        netlink_sendmsg+0x7a1/0xca0
 [ 2785.377926 ]        sock_sendmsg+0xc5/0x190
 [ 2785.378668 ]        __sys_sendto+0x1bc/0x290
 [ 2785.379440 ]        __x64_sys_sendto+0xdc/0x1b0
 [ 2785.380255 ]        do_syscall_64+0x3d/0x90
 [ 2785.381031 ]        entry_SYSCALL_64_after_hwframe+0x46/0xb0
 [ 2785.381967 ]
 [ 2785.381967 ] other info that might help us debug this:
 [ 2785.381967 ]
 [ 2785.383448 ]  Possible unsafe locking scenario:
 [ 2785.383448 ]
 [ 2785.384544 ]        CPU0                    CPU1
 [ 2785.385383 ]        ----                    ----
 [ 2785.386193 ]   lock(&dev->cache.rb_lock);
 [ 2785.386940 ]				lock((work_completion)(&(&ent->dwork)->work));
 [ 2785.388327 ]				lock(&dev->cache.rb_lock);
 [ 2785.389425 ]   lock((work_completion)(&(&ent->dwork)->work));
 [ 2785.390414 ]
 [ 2785.390414 ]  *** DEADLOCK ***
 [ 2785.390414 ]
 [ 2785.391579 ] 6 locks held by devlink/53872:
 [ 2785.392341 ]  #0: ffffffff84c17a50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40
 [ 2785.393630 ]  #1: ffff888142280218 (&devlink->lock_key){+.+.}-{3:3}, at: devlink_get_from_attrs_lock+0x12d/0x2d0
 [ 2785.395324 ]  #2: ffff8881422d3c38 (&dev->lock_key){+.+.}-{3:3}, at: mlx5_unload_one_devl_locked+0x4a/0x110 [mlx5_core]
 [ 2785.397322 ]  #3: ffffffffa0e59068 (mlx5_intf_mutex){+.+.}-{3:3}, at: mlx5_detach_device+0x60/0x360 [mlx5_core]
 [ 2785.399231 ]  #4: ffff88810e3cb0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x8d/0x600
 [ 2785.400864 ]  #5: ffff88817e8f1260 (&dev->cache.rb_lock){+.+.}-{3:3}, at: mlx5_mkey_cache_cleanup+0x77/0x250 [mlx5_ib]

Fixes: b958451 ("RDMA/mlx5: Change the cache structure to an RB-tree")
Signed-off-by: Shay Drory <[email protected]>
Signed-off-by: Michael Guralnik <[email protected]>
Signed-off-by: Leon Romanovsky <[email protected]>
ptr1337 pushed a commit that referenced this pull request Oct 9, 2023
The following call trace shows a deadlock issue due to recursive locking of
mutex "device_mutex". First lock acquire is in target_for_each_device() and
second in target_free_device().

 PID: 148266   TASK: ffff8be21ffb5d00  CPU: 10   COMMAND: "iscsi_ttx"
  #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f
  #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224
  #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee
  #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7
  #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3
  #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c
  torvalds#6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod]
  torvalds#7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod]
  torvalds#8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f
  torvalds#9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583
 torvalds#10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod]
 torvalds#11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc
 torvalds#12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod]
 torvalds#13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod]
 torvalds#14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod]
 torvalds#15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod]
 torvalds#16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07
 torvalds#17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod]
 torvalds#18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod]
 torvalds#19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080
 torvalds#20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364

Fixes: 36d4cb4 ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion")
Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
ptr1337 pushed a commit that referenced this pull request Oct 11, 2023
[ Upstream commit a154f5f ]

The following call trace shows a deadlock issue due to recursive locking of
mutex "device_mutex". First lock acquire is in target_for_each_device() and
second in target_free_device().

 PID: 148266   TASK: ffff8be21ffb5d00  CPU: 10   COMMAND: "iscsi_ttx"
  #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f
  #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224
  #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee
  #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7
  #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3
  #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c
  torvalds#6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod]
  torvalds#7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod]
  torvalds#8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f
  torvalds#9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583
 torvalds#10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod]
 torvalds#11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc
 torvalds#12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod]
 torvalds#13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod]
 torvalds#14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod]
 torvalds#15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod]
 torvalds#16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07
 torvalds#17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod]
 torvalds#18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod]
 torvalds#19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080
 torvalds#20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364

Fixes: 36d4cb4 ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion")
Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Oct 11, 2023
commit 374012b upstream.

Fix the deadlock by refactoring the MR cache cleanup flow to flush the
workqueue without holding the rb_lock.
This adds a race between cache cleanup and creation of new entries which
we solve by denied creation of new entries after cache cleanup started.

Lockdep:
WARNING: possible circular locking dependency detected
 [ 2785.326074 ] 6.2.0-rc6_for_upstream_debug_2023_01_31_14_02 #1 Not tainted
 [ 2785.339778 ] ------------------------------------------------------
 [ 2785.340848 ] devlink/53872 is trying to acquire lock:
 [ 2785.341701 ] ffff888124f8c0c8 ((work_completion)(&(&ent->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0xc8/0x900
 [ 2785.343403 ]
 [ 2785.343403 ] but task is already holding lock:
 [ 2785.344464 ] ffff88817e8f1260 (&dev->cache.rb_lock){+.+.}-{3:3}, at: mlx5_mkey_cache_cleanup+0x77/0x250 [mlx5_ib]
 [ 2785.346273 ]
 [ 2785.346273 ] which lock already depends on the new lock.
 [ 2785.346273 ]
 [ 2785.347720 ]
 [ 2785.347720 ] the existing dependency chain (in reverse order) is:
 [ 2785.349003 ]
 [ 2785.349003 ] -> #1 (&dev->cache.rb_lock){+.+.}-{3:3}:
 [ 2785.350160 ]        __mutex_lock+0x14c/0x15c0
 [ 2785.350962 ]        delayed_cache_work_func+0x2d1/0x610 [mlx5_ib]
 [ 2785.352044 ]        process_one_work+0x7c2/0x1310
 [ 2785.352879 ]        worker_thread+0x59d/0xec0
 [ 2785.353636 ]        kthread+0x28f/0x330
 [ 2785.354370 ]        ret_from_fork+0x1f/0x30
 [ 2785.355135 ]
 [ 2785.355135 ] -> #0 ((work_completion)(&(&ent->dwork)->work)){+.+.}-{0:0}:
 [ 2785.356515 ]        __lock_acquire+0x2d8a/0x5fe0
 [ 2785.357349 ]        lock_acquire+0x1c1/0x540
 [ 2785.358121 ]        __flush_work+0xe8/0x900
 [ 2785.358852 ]        __cancel_work_timer+0x2c7/0x3f0
 [ 2785.359711 ]        mlx5_mkey_cache_cleanup+0xfb/0x250 [mlx5_ib]
 [ 2785.360781 ]        mlx5_ib_stage_pre_ib_reg_umr_cleanup+0x16/0x30 [mlx5_ib]
 [ 2785.361969 ]        __mlx5_ib_remove+0x68/0x120 [mlx5_ib]
 [ 2785.362960 ]        mlx5r_remove+0x63/0x80 [mlx5_ib]
 [ 2785.363870 ]        auxiliary_bus_remove+0x52/0x70
 [ 2785.364715 ]        device_release_driver_internal+0x3c1/0x600
 [ 2785.365695 ]        bus_remove_device+0x2a5/0x560
 [ 2785.366525 ]        device_del+0x492/0xb80
 [ 2785.367276 ]        mlx5_detach_device+0x1a9/0x360 [mlx5_core]
 [ 2785.368615 ]        mlx5_unload_one_devl_locked+0x5a/0x110 [mlx5_core]
 [ 2785.369934 ]        mlx5_devlink_reload_down+0x292/0x580 [mlx5_core]
 [ 2785.371292 ]        devlink_reload+0x439/0x590
 [ 2785.372075 ]        devlink_nl_cmd_reload+0xaef/0xff0
 [ 2785.372973 ]        genl_family_rcv_msg_doit.isra.0+0x1bd/0x290
 [ 2785.374011 ]        genl_rcv_msg+0x3ca/0x6c0
 [ 2785.374798 ]        netlink_rcv_skb+0x12c/0x360
 [ 2785.375612 ]        genl_rcv+0x24/0x40
 [ 2785.376295 ]        netlink_unicast+0x438/0x710
 [ 2785.377121 ]        netlink_sendmsg+0x7a1/0xca0
 [ 2785.377926 ]        sock_sendmsg+0xc5/0x190
 [ 2785.378668 ]        __sys_sendto+0x1bc/0x290
 [ 2785.379440 ]        __x64_sys_sendto+0xdc/0x1b0
 [ 2785.380255 ]        do_syscall_64+0x3d/0x90
 [ 2785.381031 ]        entry_SYSCALL_64_after_hwframe+0x46/0xb0
 [ 2785.381967 ]
 [ 2785.381967 ] other info that might help us debug this:
 [ 2785.381967 ]
 [ 2785.383448 ]  Possible unsafe locking scenario:
 [ 2785.383448 ]
 [ 2785.384544 ]        CPU0                    CPU1
 [ 2785.385383 ]        ----                    ----
 [ 2785.386193 ]   lock(&dev->cache.rb_lock);
 [ 2785.386940 ]				lock((work_completion)(&(&ent->dwork)->work));
 [ 2785.388327 ]				lock(&dev->cache.rb_lock);
 [ 2785.389425 ]   lock((work_completion)(&(&ent->dwork)->work));
 [ 2785.390414 ]
 [ 2785.390414 ]  *** DEADLOCK ***
 [ 2785.390414 ]
 [ 2785.391579 ] 6 locks held by devlink/53872:
 [ 2785.392341 ]  #0: ffffffff84c17a50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40
 [ 2785.393630 ]  #1: ffff888142280218 (&devlink->lock_key){+.+.}-{3:3}, at: devlink_get_from_attrs_lock+0x12d/0x2d0
 [ 2785.395324 ]  #2: ffff8881422d3c38 (&dev->lock_key){+.+.}-{3:3}, at: mlx5_unload_one_devl_locked+0x4a/0x110 [mlx5_core]
 [ 2785.397322 ]  #3: ffffffffa0e59068 (mlx5_intf_mutex){+.+.}-{3:3}, at: mlx5_detach_device+0x60/0x360 [mlx5_core]
 [ 2785.399231 ]  #4: ffff88810e3cb0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x8d/0x600
 [ 2785.400864 ]  #5: ffff88817e8f1260 (&dev->cache.rb_lock){+.+.}-{3:3}, at: mlx5_mkey_cache_cleanup+0x77/0x250 [mlx5_ib]

Fixes: b958451 ("RDMA/mlx5: Change the cache structure to an RB-tree")
Signed-off-by: Shay Drory <[email protected]>
Signed-off-by: Michael Guralnik <[email protected]>
Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit that referenced this pull request Nov 20, 2023
[ Upstream commit a84fbf2 ]

Generating metrics llc_code_read_mpi_demand_plus_prefetch,
llc_data_read_mpi_demand_plus_prefetch,
llc_miss_local_memory_bandwidth_read,
llc_miss_local_memory_bandwidth_write,
nllc_miss_remote_memory_bandwidth_read, memory_bandwidth_read,
memory_bandwidth_write, uncore_frequency, upi_data_transmit_bw,
C2_Pkg_Residency, C3_Core_Residency, C3_Pkg_Residency,
C6_Core_Residency, C6_Pkg_Residency, C7_Core_Residency,
C7_Pkg_Residency, UNCORE_FREQ and tma_info_system_socket_clks would
trigger an address sanitizer heap-buffer-overflows on a SkylakeX.

```
==2567752==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x5020003ed098 at pc 0x5621a816654e bp 0x7fffb55d4da0 sp 0x7fffb55d4d98
READ of size 4 at 0x5020003eee78 thread T0
    #0 0x558265d6654d in aggr_cpu_id__is_empty tools/perf/util/cpumap.c:694:12
    #1 0x558265c914da in perf_stat__get_aggr tools/perf/builtin-stat.c:1490:6
    #2 0x558265c914da in perf_stat__get_global_cached tools/perf/builtin-stat.c:1530:9
    #3 0x558265e53290 in should_skip_zero_counter tools/perf/util/stat-display.c:947:31
    #4 0x558265e53290 in print_counter_aggrdata tools/perf/util/stat-display.c:985:18
    #5 0x558265e51931 in print_counter tools/perf/util/stat-display.c:1110:3
    torvalds#6 0x558265e51931 in evlist__print_counters tools/perf/util/stat-display.c:1571:5
    torvalds#7 0x558265c8ec87 in print_counters tools/perf/builtin-stat.c:981:2
    torvalds#8 0x558265c8cc71 in cmd_stat tools/perf/builtin-stat.c:2837:3
    torvalds#9 0x558265bb9bd4 in run_builtin tools/perf/perf.c:323:11
    torvalds#10 0x558265bb98eb in handle_internal_command tools/perf/perf.c:377:8
    torvalds#11 0x558265bb9389 in run_argv tools/perf/perf.c:421:2
    torvalds#12 0x558265bb9389 in main tools/perf/perf.c:537:3
```

The issue was the use of testing a cpumap with NULL rather than using
empty, as a map containing the dummy value isn't NULL and the -1
results in an empty aggr map being allocated which legitimately
overflows when any member is accessed.

Fixes: 8a96f45 ("perf stat: Avoid SEGV if core.cpus isn't set")
Signed-off-by: Ian Rogers <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Nov 20, 2023
[ Upstream commit ede72dc ]

Fuzzing found that an invalid tracepoint name would create a memory
leak with an address sanitizer build:
```
$ perf stat -e '*:o/' true
event syntax error: '*:o/'
                       \___ parser error
Run 'perf list' for a list of valid events

 Usage: perf stat [<options>] [<command>]

    -e, --event <event>   event selector. use 'perf list' to list available events

=================================================================
==59380==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 4 byte(s) in 2 object(s) allocated from:
    #0 0x7f38ac07077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439
    #1 0x55f2f41be73b in str util/parse-events.l:49
    #2 0x55f2f41d08e8 in parse_events_lex util/parse-events.l:338
    #3 0x55f2f41dc3b1 in parse_events_parse util/parse-events-bison.c:1464
    #4 0x55f2f410b8b3 in parse_events__scanner util/parse-events.c:1822
    #5 0x55f2f410d1b9 in __parse_events util/parse-events.c:2094
    torvalds#6 0x55f2f410e57f in parse_events_option util/parse-events.c:2279
    torvalds#7 0x55f2f4427b56 in get_value tools/lib/subcmd/parse-options.c:251
    torvalds#8 0x55f2f4428d98 in parse_short_opt tools/lib/subcmd/parse-options.c:351
    torvalds#9 0x55f2f4429d80 in parse_options_step tools/lib/subcmd/parse-options.c:539
    torvalds#10 0x55f2f442acb9 in parse_options_subcommand tools/lib/subcmd/parse-options.c:654
    torvalds#11 0x55f2f3ec99fc in cmd_stat tools/perf/builtin-stat.c:2501
    torvalds#12 0x55f2f4093289 in run_builtin tools/perf/perf.c:322
    torvalds#13 0x55f2f40937f5 in handle_internal_command tools/perf/perf.c:375
    torvalds#14 0x55f2f4093bbd in run_argv tools/perf/perf.c:419
    torvalds#15 0x55f2f409412b in main tools/perf/perf.c:535

SUMMARY: AddressSanitizer: 4 byte(s) leaked in 2 allocation(s).
```
Fix by adding the missing destructor.

Fixes: 865582c ("perf tools: Adds the tracepoint name parsing support")
Signed-off-by: Ian Rogers <[email protected]>
Cc: He Kuang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Nov 20, 2023
[ Upstream commit d45c4b4 ]

A thread started via eg. user_mode_thread() runs in the kernel to begin
with and then may later return to userspace. While it's running in the
kernel it has a pt_regs at the base of its kernel stack, but that
pt_regs is all zeroes.

If the thread oopses in that state, it leads to an ugly stack trace with
a big block of zero GPRs, as reported by Joel:

  Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc7-00004-gf7757129e3de-dirty #3
  Hardware name: IBM PowerNV (emulated by qemu) POWER9 0x4e1200 opal:v7.0 PowerNV
  Call Trace:
  [c0000000036afb00] [c0000000010dd058] dump_stack_lvl+0x6c/0x9c (unreliable)
  [c0000000036afb30] [c00000000013c524] panic+0x178/0x424
  [c0000000036afbd0] [c000000002005100] mount_root_generic+0x250/0x324
  [c0000000036afca0] [c0000000020057d0] prepare_namespace+0x2d4/0x344
  [c0000000036afd20] [c0000000020049c0] kernel_init_freeable+0x358/0x3ac
  [c0000000036afdf0] [c0000000000111b0] kernel_init+0x30/0x1a0
  [c0000000036afe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  NIP:  0000000000000000 LR: 0000000000000000 CTR: 0000000000000000
  REGS: c0000000036afe80 TRAP: 0000   Not tainted  (6.5.0-rc7-00004-gf7757129e3de-dirty)
  MSR:  0000000000000000 <>  CR: 00000000  XER: 00000000
  CFAR: 0000000000000000 IRQMASK: 0
  GPR00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR12: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR28: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  NIP [0000000000000000] 0x0
  LR [0000000000000000] 0x0
  --- interrupt: 0

The all-zero pt_regs looks ugly and conveys no useful information, other
than its presence. So detect that case and just show the presence of the
frame by printing the interrupt marker, eg:

  Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc3-00126-g18e9506562a0-dirty torvalds#301
  Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
  Call Trace:
  [c000000003aabb00] [c000000001143db8] dump_stack_lvl+0x6c/0x9c (unreliable)
  [c000000003aabb30] [c00000000014c624] panic+0x178/0x424
  [c000000003aabbd0] [c0000000020050fc] mount_root_generic+0x250/0x324
  [c000000003aabca0] [c0000000020057cc] prepare_namespace+0x2d4/0x344
  [c000000003aabd20] [c0000000020049bc] kernel_init_freeable+0x358/0x3ac
  [c000000003aabdf0] [c0000000000111b0] kernel_init+0x30/0x1a0
  [c000000003aabe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0

To avoid ever suppressing a valid pt_regs make sure the pt_regs has a
zero MSR and TRAP value, and is located at the very base of the stack.

Fixes: 6895dfc ("powerpc: copy_thread fill in interrupt frame marker and back chain")
Reported-by: Joel Stanley <[email protected]>
Reported-by: Nicholas Piggin <[email protected]>
Reviewed-by: Joel Stanley <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Nov 20, 2023
[ Upstream commit 34c4eff ]

KMSAN reported the following uninit-value access issue:

=====================================================
BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
 virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
 kthread+0x3cc/0x520 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was stored to memory at:
 virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
 virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415
 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
 kthread+0x3cc/0x520 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was created at:
 slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523
 kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559
 __alloc_skb+0x2fd/0x770 net/core/skbuff.c:650
 alloc_skb include/linux/skbuff.h:1286 [inline]
 virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
 virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58
 virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
 virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387
 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
 kthread+0x3cc/0x520 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
Workqueue: vsock-loopback vsock_loopback_work
=====================================================

The following simple reproducer can cause the issue described above:

int main(void)
{
  int sock;
  struct sockaddr_vm addr = {
    .svm_family = AF_VSOCK,
    .svm_cid = VMADDR_CID_ANY,
    .svm_port = 1234,
  };

  sock = socket(AF_VSOCK, SOCK_STREAM, 0);
  connect(sock, (struct sockaddr *)&addr, sizeof(addr));
  return 0;
}

This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the
`struct virtio_vsock_hdr` are not initialized when a new skb is allocated
in `virtio_transport_init_hdr()`. This patch resolves the issue by
initializing these fields during allocation.

Fixes: 71dc9ec ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Reported-and-tested-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
Signed-off-by: Shigeru Yoshida <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Nov 27, 2023
Andrii Nakryiko says:

====================
BPF control flow graph and precision backtrack fixes

A small fix to BPF verifier's CFG logic around handling and reporting ldimm64
instructions. Patch #1 was previously submitted separately ([0]), and so this
patch set supersedes that patch.

Second patch is fixing obscure corner case in mark_chain_precise() logic. See
patch for details. Patch #3 adds a dedicated test, however fragile it might.

  [0] https://patchwork.kernel.org/project/netdevbpf/patch/[email protected]/
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
ptr1337 pushed a commit that referenced this pull request Nov 27, 2023
This allows it to break the following circular locking dependency.

Aug 10 07:01:29 dg1test kernel: ======================================================
Aug 10 07:01:29 dg1test kernel: WARNING: possible circular locking dependency detected
Aug 10 07:01:29 dg1test kernel: 6.4.0-rc7+ torvalds#10 Not tainted
Aug 10 07:01:29 dg1test kernel: ------------------------------------------------------
Aug 10 07:01:29 dg1test kernel: wireplumber/2236 is trying to acquire lock:
Aug 10 07:01:29 dg1test kernel: ffff8fca5320da18 (&fctx->lock){-...}-{2:2}, at: nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:
                                but task is already holding lock:
Aug 10 07:01:29 dg1test kernel: ffff8fca41208610 (&event->list_lock#2){-...}-{2:2}, at: nvkm_event_ntfy+0x50/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:
                                which lock already depends on the new lock.
Aug 10 07:01:29 dg1test kernel:
                                the existing dependency chain (in reverse order) is:
Aug 10 07:01:29 dg1test kernel:
                                -> #3 (&event->list_lock#2){-...}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy+0x50/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        ga100_fifo_nonstall_intr+0x24/0x30 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_intr+0x12c/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __handle_irq_event_percpu+0x88/0x240
Aug 10 07:01:29 dg1test kernel:        handle_irq_event+0x38/0x80
Aug 10 07:01:29 dg1test kernel:        handle_edge_irq+0xa3/0x240
Aug 10 07:01:29 dg1test kernel:        __common_interrupt+0x72/0x160
Aug 10 07:01:29 dg1test kernel:        common_interrupt+0x60/0xe0
Aug 10 07:01:29 dg1test kernel:        asm_common_interrupt+0x26/0x40
Aug 10 07:01:29 dg1test kernel:
                                -> #2 (&device->intr.lock){-...}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nvkm_inth_allow+0x2c/0x80 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_state+0x181/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_allow+0x63/0xd0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_uevent_mthd+0x4d/0x70 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_ioctl+0x10b/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_object_mthd+0xa8/0x1f0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_event_allow+0x2a/0xa0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_fence_enable_signaling+0x78/0x80 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __dma_fence_enable_signaling+0x5e/0x100
Aug 10 07:01:29 dg1test kernel:        dma_fence_add_callback+0x4b/0xd0
Aug 10 07:01:29 dg1test kernel:        nouveau_cli_work_queue+0xae/0x110 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_gem_object_close+0x1d1/0x2a0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        drm_gem_handle_delete+0x70/0xe0 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl_kernel+0xa5/0x150 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl+0x256/0x490 [drm]
Aug 10 07:01:29 dg1test kernel:        nouveau_drm_ioctl+0x5a/0xb0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __x64_sys_ioctl+0x91/0xd0
Aug 10 07:01:29 dg1test kernel:        do_syscall_64+0x3c/0x90
Aug 10 07:01:29 dg1test kernel:        entry_SYSCALL_64_after_hwframe+0x72/0xdc
Aug 10 07:01:29 dg1test kernel:
                                -> #1 (&event->refs_lock#4){....}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_state+0x37/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_allow+0x63/0xd0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_uevent_mthd+0x4d/0x70 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_ioctl+0x10b/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_object_mthd+0xa8/0x1f0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_event_allow+0x2a/0xa0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_fence_enable_signaling+0x78/0x80 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __dma_fence_enable_signaling+0x5e/0x100
Aug 10 07:01:29 dg1test kernel:        dma_fence_add_callback+0x4b/0xd0
Aug 10 07:01:29 dg1test kernel:        nouveau_cli_work_queue+0xae/0x110 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_gem_object_close+0x1d1/0x2a0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        drm_gem_handle_delete+0x70/0xe0 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl_kernel+0xa5/0x150 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl+0x256/0x490 [drm]
Aug 10 07:01:29 dg1test kernel:        nouveau_drm_ioctl+0x5a/0xb0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __x64_sys_ioctl+0x91/0xd0
Aug 10 07:01:29 dg1test kernel:        do_syscall_64+0x3c/0x90
Aug 10 07:01:29 dg1test kernel:        entry_SYSCALL_64_after_hwframe+0x72/0xdc
Aug 10 07:01:29 dg1test kernel:
                                -> #0 (&fctx->lock){-...}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        __lock_acquire+0x14e3/0x2240
Aug 10 07:01:29 dg1test kernel:        lock_acquire+0xc8/0x2a0
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_client_event+0xf/0x20 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy+0x9b/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        ga100_fifo_nonstall_intr+0x24/0x30 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_intr+0x12c/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __handle_irq_event_percpu+0x88/0x240
Aug 10 07:01:29 dg1test kernel:        handle_irq_event+0x38/0x80
Aug 10 07:01:29 dg1test kernel:        handle_edge_irq+0xa3/0x240
Aug 10 07:01:29 dg1test kernel:        __common_interrupt+0x72/0x160
Aug 10 07:01:29 dg1test kernel:        common_interrupt+0x60/0xe0
Aug 10 07:01:29 dg1test kernel:        asm_common_interrupt+0x26/0x40
Aug 10 07:01:29 dg1test kernel:
                                other info that might help us debug this:
Aug 10 07:01:29 dg1test kernel: Chain exists of:
                                  &fctx->lock --> &device->intr.lock --> &event->list_lock#2
Aug 10 07:01:29 dg1test kernel:  Possible unsafe locking scenario:
Aug 10 07:01:29 dg1test kernel:        CPU0                    CPU1
Aug 10 07:01:29 dg1test kernel:        ----                    ----
Aug 10 07:01:29 dg1test kernel:   lock(&event->list_lock#2);
Aug 10 07:01:29 dg1test kernel:                                lock(&device->intr.lock);
Aug 10 07:01:29 dg1test kernel:                                lock(&event->list_lock#2);
Aug 10 07:01:29 dg1test kernel:   lock(&fctx->lock);
Aug 10 07:01:29 dg1test kernel:
                                 *** DEADLOCK ***
Aug 10 07:01:29 dg1test kernel: 2 locks held by wireplumber/2236:
Aug 10 07:01:29 dg1test kernel:  #0: ffff8fca53177bf8 (&device->intr.lock){-...}-{2:2}, at: nvkm_intr+0x29/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:  #1: ffff8fca41208610 (&event->list_lock#2){-...}-{2:2}, at: nvkm_event_ntfy+0x50/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:
                                stack backtrace:
Aug 10 07:01:29 dg1test kernel: CPU: 6 PID: 2236 Comm: wireplumber Not tainted 6.4.0-rc7+ torvalds#10
Aug 10 07:01:29 dg1test kernel: Hardware name: Gigabyte Technology Co., Ltd. Z390 I AORUS PRO WIFI/Z390 I AORUS PRO WIFI-CF, BIOS F8 11/05/2021
Aug 10 07:01:29 dg1test kernel: Call Trace:
Aug 10 07:01:29 dg1test kernel:  <TASK>
Aug 10 07:01:29 dg1test kernel:  dump_stack_lvl+0x5b/0x90
Aug 10 07:01:29 dg1test kernel:  check_noncircular+0xe2/0x110
Aug 10 07:01:29 dg1test kernel:  __lock_acquire+0x14e3/0x2240
Aug 10 07:01:29 dg1test kernel:  lock_acquire+0xc8/0x2a0
Aug 10 07:01:29 dg1test kernel:  ? nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:  ? lock_acquire+0xc8/0x2a0
Aug 10 07:01:29 dg1test kernel:  _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:  ? nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nvkm_client_event+0xf/0x20 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nvkm_event_ntfy+0x9b/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:  ga100_fifo_nonstall_intr+0x24/0x30 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nvkm_intr+0x12c/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:  __handle_irq_event_percpu+0x88/0x240
Aug 10 07:01:29 dg1test kernel:  handle_irq_event+0x38/0x80
Aug 10 07:01:29 dg1test kernel:  handle_edge_irq+0xa3/0x240
Aug 10 07:01:29 dg1test kernel:  __common_interrupt+0x72/0x160
Aug 10 07:01:29 dg1test kernel:  common_interrupt+0x60/0xe0
Aug 10 07:01:29 dg1test kernel:  asm_common_interrupt+0x26/0x40
Aug 10 07:01:29 dg1test kernel: RIP: 0033:0x7fb66174d700
Aug 10 07:01:29 dg1test kernel: Code: c1 e2 05 29 ca 8d 0c 10 0f be 07 84 c0 75 eb 89 c8 c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa e9 d7 0f fc ff 0f 1f 80 00 00 00 00 <f3> 0f 1e fa e9 c7 0f fc>
Aug 10 07:01:29 dg1test kernel: RSP: 002b:00007ffdd3c48438 EFLAGS: 00000206
Aug 10 07:01:29 dg1test kernel: RAX: 000055bb758763c0 RBX: 000055bb758752c0 RCX: 00000000000028b0
Aug 10 07:01:29 dg1test kernel: RDX: 000055bb758752c0 RSI: 000055bb75887490 RDI: 000055bb75862950
Aug 10 07:01:29 dg1test kernel: RBP: 00007ffdd3c48490 R08: 000055bb75873b10 R09: 0000000000000001
Aug 10 07:01:29 dg1test kernel: R10: 0000000000000004 R11: 000055bb7587f000 R12: 000055bb75887490
Aug 10 07:01:29 dg1test kernel: R13: 000055bb757f6280 R14: 000055bb758875c0 R15: 000055bb757f6280
Aug 10 07:01:29 dg1test kernel:  </TASK>

Signed-off-by: Dave Airlie <[email protected]>
Tested-by: Danilo Krummrich <[email protected]>
Reviewed-by: Danilo Krummrich <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
ptr1337 pushed a commit that referenced this pull request Nov 27, 2023
…f-times'

Eduard Zingerman says:

====================
verify callbacks as if they are called unknown number of times

This series updates verifier logic for callback functions handling.
Current master simulates callback body execution exactly once,
which leads to verifier not detecting unsafe programs like below:

    static int unsafe_on_zero_iter_cb(__u32 idx, struct num_context *ctx)
    {
        ctx->i = 0;
        return 0;
    }

    SEC("?raw_tp")
    int unsafe_on_zero_iter(void *unused)
    {
        struct num_context loop_ctx = { .i = 32 };
        __u8 choice_arr[2] = { 0, 1 };

        bpf_loop(100, unsafe_on_zero_iter_cb, &loop_ctx, 0);
        return choice_arr[loop_ctx.i];
    }

This was reported previously in [0].
The basic idea of the fix is to schedule callback entry state for
verification in env->head until some identical, previously visited
state in current DFS state traversal is found. Same logic as with open
coded iterators, and builds on top recent fixes [1] for those.

The series is structured as follows:
- patches #1,2,3 update strobemeta, xdp_synproxy selftests and
  bpf_loop_bench benchmark to allow convergence of the bpf_loop
  callback states;
- patches #4,5 just shuffle the code a bit;
- patch torvalds#6 is the main part of the series;
- patch torvalds#7 adds test cases for torvalds#6;
- patch torvalds#8 extend patch torvalds#6 with same speculative scalar widening
  logic, as used for open coded iterators;
- patch torvalds#9 adds test cases for torvalds#8;
- patch torvalds#10 extends patch torvalds#6 to track maximal number of callback
  executions specifically for bpf_loop();
- patch torvalds#11 adds test cases for torvalds#10.

Veristat results comparing this series to master+patches #1,2,3 using selftests
show the following difference:

File                       Program        States (A)  States (B)  States (DIFF)
-------------------------  -------------  ----------  ----------  -------------
bpf_loop_bench.bpf.o       benchmark               1           2  +1 (+100.00%)
pyperf600_bpf_loop.bpf.o   on_event              322         407  +85 (+26.40%)
strobemeta_bpf_loop.bpf.o  on_event              113         151  +38 (+33.63%)
xdp_synproxy_kern.bpf.o    syncookie_tc          341         291  -50 (-14.66%)
xdp_synproxy_kern.bpf.o    syncookie_xdp         344         301  -43 (-12.50%)

Veristat results comparing this series to master using Tetragon BPF
files [2] also show some differences.
States diff varies from +2% to +15% on 23 programs out of 186,
no new failures.

Changelog:
- V3 [5] -> V4, changes suggested by Andrii:
  - validate mark_chain_precision() result in patch torvalds#10;
  - renaming s/cumulative_callback_depth/callback_unroll_depth/.
- V2 [4] -> V3:
  - fixes in expected log messages for test cases:
    - callback_result_precise;
    - parent_callee_saved_reg_precise_with_callback;
    - parent_stack_slot_precise_with_callback;
  - renamings (suggested by Alexei):
    - s/callback_iter_depth/cumulative_callback_depth/
    - s/is_callback_iter_next/calls_callback/
    - s/mark_callback_iter_next/mark_calls_callback/
  - prepare_func_exit() updated to exit with -EFAULT when
    callee->in_callback_fn is true but calls_callback() is not true
    for callsite;
  - test case 'bpf_loop_iter_limit_nested' rewritten to use return
    value check instead of verifier log message checks
    (suggested by Alexei).
- V1 [3] -> V2, changes suggested by Andrii:
  - small changes for error handling code in __check_func_call();
  - callback body processing log is now matched in relevant
    verifier_subprog_precision.c tests;
  - R1 passed to bpf_loop() is now always marked as precise;
  - log level 2 message for bpf_loop() iteration termination instead of
    iteration depth messages;
  - __no_msg macro removed;
  - bpf_loop_iter_limit_nested updated to avoid using __no_msg;
  - commit message for patch #3 updated according to Alexei's request.

[0] https://lore.kernel.org/bpf/CA+vRuzPChFNXmouzGG+wsy=6eMcfr1mFG0F3g7rbg-sedGKW3w@mail.gmail.com/
[1] https://lore.kernel.org/bpf/[email protected]/
[2] [email protected]:cilium/tetragon.git
[3] https://lore.kernel.org/bpf/[email protected]/T/#t
[4] https://lore.kernel.org/bpf/[email protected]/T/#t
[5] https://lore.kernel.org/bpf/[email protected]/T/#t
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
ptr1337 pushed a commit that referenced this pull request Nov 29, 2023
commit dd976a9 upstream.

The smp_processor_id() shouldn't be called from preemptible code.
Instead use get_cpu() and put_cpu() which disables preemption in
addition to getting the processor id. Enable preemption back after
calling schedule_work() to make sure that the work gets scheduled on all
cores other than the current core. We want to avoid a scenario where
current core's stack trace is printed multiple times and one core's
stack trace isn't printed because of scheduling of current task.

This fixes the following bug:

[  119.143590] sysrq: Show backtrace of all active CPUs
[  119.143902] BUG: using smp_processor_id() in preemptible [00000000] code: bash/873
[  119.144586] caller is debug_smp_processor_id+0x20/0x30
[  119.144827] CPU: 6 PID: 873 Comm: bash Not tainted 5.10.124-dirty #3
[  119.144861] Hardware name: QEMU QEMU Virtual Machine, BIOS 2023.05-1 07/22/2023
[  119.145053] Call trace:
[  119.145093]  dump_backtrace+0x0/0x1a0
[  119.145122]  show_stack+0x18/0x70
[  119.145141]  dump_stack+0xc4/0x11c
[  119.145159]  check_preemption_disabled+0x100/0x110
[  119.145175]  debug_smp_processor_id+0x20/0x30
[  119.145195]  sysrq_handle_showallcpus+0x20/0xc0
[  119.145211]  __handle_sysrq+0x8c/0x1a0
[  119.145227]  write_sysrq_trigger+0x94/0x12c
[  119.145247]  proc_reg_write+0xa8/0xe4
[  119.145266]  vfs_write+0xec/0x280
[  119.145282]  ksys_write+0x6c/0x100
[  119.145298]  __arm64_sys_write+0x20/0x30
[  119.145315]  el0_svc_common.constprop.0+0x78/0x1e4
[  119.145332]  do_el0_svc+0x24/0x8c
[  119.145348]  el0_svc+0x10/0x20
[  119.145364]  el0_sync_handler+0x134/0x140
[  119.145381]  el0_sync+0x180/0x1c0

Cc: [email protected]
Cc: [email protected]
Fixes: 47cab6a ("debug lockups: Improve lockup detection, fix generic arch fallback")
Signed-off-by: Muhammad Usama Anjum <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit that referenced this pull request Nov 29, 2023
commit 807252f upstream.

Running smb2.rename test from Samba smbtorture suite against a kernel built
with lockdep triggers a "possible recursive locking detected" warning.

This is because mnt_want_write() is called twice with no mnt_drop_write()
in between:
  -> ksmbd_vfs_mkdir()
    -> ksmbd_vfs_kern_path_create()
       -> kern_path_create()
          -> filename_create()
            -> mnt_want_write()
       -> mnt_want_write()

Fix this by removing the mnt_want_write/mnt_drop_write calls from vfs
helpers that call kern_path_create().

Full lockdep trace below:

============================================
WARNING: possible recursive locking detected
6.6.0-rc5 torvalds#775 Not tainted
--------------------------------------------
kworker/1:1/32 is trying to acquire lock:
ffff888005ac83f8 (sb_writers#5){.+.+}-{0:0}, at: ksmbd_vfs_mkdir+0xe1/0x410

but task is already holding lock:
ffff888005ac83f8 (sb_writers#5){.+.+}-{0:0}, at: filename_create+0xb6/0x260

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

       CPU0
       ----
  lock(sb_writers#5);
  lock(sb_writers#5);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by kworker/1:1/32:
 #0: ffff8880064e4138 ((wq_completion)ksmbd-io){+.+.}-{0:0}, at: process_one_work+0x40e/0x980
 #1: ffff888005b0fdd0 ((work_completion)(&work->work)){+.+.}-{0:0}, at: process_one_work+0x40e/0x980
 #2: ffff888005ac83f8 (sb_writers#5){.+.+}-{0:0}, at: filename_create+0xb6/0x260
 #3: ffff8880057ce760 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x123/0x260

Cc: [email protected]
Fixes: 40b268d ("ksmbd: add mnt_want_write to ksmbd vfs functions")
Signed-off-by: Marios Makassikis <[email protected]>
Acked-by: Namjae Jeon <[email protected]>
Signed-off-by: Steve French <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit that referenced this pull request Nov 29, 2023
commit 5a22fbc upstream.

When LAN9303 is MDIO-connected two callchains exist into
mdio->bus->write():

1. switch ports 1&2 ("physical" PHYs):

virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})->
  lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested

2. LAN9303 virtual PHY:

virtual MDIO bus (lan9303_phy_{read|write}) ->
  lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write}

If the latter functions just take
mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP
false-positive splat. It's false-positive because the first
mdio_lock in the second callchain above belongs to virtual MDIO bus, the
second mdio_lock belongs to physical MDIO bus.

Consequent annotation in lan9303_mdio_{read|write} as nested lock
(similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus)
prevents the following splat:

WARNING: possible circular locking dependency detected
5.15.71 #1 Not tainted
------------------------------------------------------
kworker/u4:3/609 is trying to acquire lock:
ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex
but task is already holding lock:
ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&bus->mdio_lock){+.+.}-{3:3}:
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       lan9303_mdio_read
       _regmap_read
       regmap_read
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
-> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}:
       __lock_acquire
       lock_acquire.part.0
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       regmap_lock_mutex
       regmap_read
       lan9303_phy_read
       dsa_slave_phy_read
       __mdiobus_read
       mdiobus_read
       get_phy_device
       mdiobus_scan
       __mdiobus_register
       dsa_register_switch
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&bus->mdio_lock);
                               lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
                               lock(&bus->mdio_lock);
  lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
*** DEADLOCK ***
5 locks held by kworker/u4:3/609:
 #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work
 #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work
 #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach
 #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch
 #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
stack backtrace:
CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1
Workqueue: events_unbound deferred_probe_work_func
Call trace:
 dump_backtrace
 show_stack
 dump_stack_lvl
 dump_stack
 print_circular_bug
 check_noncircular
 __lock_acquire
 lock_acquire.part.0
 lock_acquire
 __mutex_lock
 mutex_lock_nested
 regmap_lock_mutex
 regmap_read
 lan9303_phy_read
 dsa_slave_phy_read
 __mdiobus_read
 mdiobus_read
 get_phy_device
 mdiobus_scan
 __mdiobus_register
 dsa_register_switch
 lan9303_probe
 lan9303_mdio_probe
...

Cc: [email protected]
Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support")
Signed-off-by: Alexander Sverdlin <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 4, 2023
When scanning namespaces, it is possible to get valid data from the first
call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second
call in nvme_update_ns_info_block().  In particular, if the NSID becomes
inactive between the two commands, a storage device may return a buffer
filled with zero as per 4.1.5.1.  In this case, we can get a kernel crash
due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will
be set to zero.

PID: 326      TASK: ffff95fec3cd8000  CPU: 29   COMMAND: "kworker/u98:10"
 #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7
 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa
 #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788
 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb
 #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce
 #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595
 torvalds#6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6
 torvalds#7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926
    [exception RIP: blk_stack_limits+434]
    RIP: ffffffff92191872  RSP: ffffad8f8702fc80  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff95efa0c91800  RCX: 0000000000000001
    RDX: 0000000000000000  RSI: 0000000000000001  RDI: 0000000000000001
    RBP: 00000000ffffffff   R8: ffff95fec7df35a8   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000001  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: ffff95fed33c09a8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 torvalds#8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core]
 torvalds#9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core]

This happened when the check for valid data was moved out of nvme_identify_ns()
into one of the callers.  Fix this by checking in both callers.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186
Fixes: 0dd6fff ("nvme: bring back auto-removal of deleted namespaces during sequential scan")
Cc: [email protected]
Signed-off-by: Ewan D. Milne <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 8, 2023
commit d8b90d6 upstream.

When scanning namespaces, it is possible to get valid data from the first
call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second
call in nvme_update_ns_info_block().  In particular, if the NSID becomes
inactive between the two commands, a storage device may return a buffer
filled with zero as per 4.1.5.1.  In this case, we can get a kernel crash
due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will
be set to zero.

PID: 326      TASK: ffff95fec3cd8000  CPU: 29   COMMAND: "kworker/u98:10"
 #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7
 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa
 #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788
 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb
 #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce
 #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595
 torvalds#6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6
 torvalds#7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926
    [exception RIP: blk_stack_limits+434]
    RIP: ffffffff92191872  RSP: ffffad8f8702fc80  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff95efa0c91800  RCX: 0000000000000001
    RDX: 0000000000000000  RSI: 0000000000000001  RDI: 0000000000000001
    RBP: 00000000ffffffff   R8: ffff95fec7df35a8   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000001  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: ffff95fed33c09a8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 torvalds#8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core]
 torvalds#9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core]

This happened when the check for valid data was moved out of nvme_identify_ns()
into one of the callers.  Fix this by checking in both callers.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186
Fixes: 0dd6fff ("nvme: bring back auto-removal of deleted namespaces during sequential scan")
Cc: [email protected]
Signed-off-by: Ewan D. Milne <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 11, 2023
When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a
cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when
removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be
dereferenced as wrong struct in irdma_free_pending_cqp_request().

  PID: 3669   TASK: ffff88aef892c000  CPU: 28  COMMAND: "kworker/28:0"
   #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34
   #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2
   #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f
   #3 [fffffe0000549eb8] do_nmi at ffffffff81079582
   #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4
      [exception RIP: native_queued_spin_lock_slowpath+1291]
      RIP: ffffffff8127e72b  RSP: ffff88aa841ef778  RFLAGS: 00000046
      RAX: 0000000000000000  RBX: ffff88b01f849700  RCX: ffffffff8127e47e
      RDX: 0000000000000000  RSI: 0000000000000004  RDI: ffffffff83857ec0
      RBP: ffff88afe3e4efc8   R8: ffffed15fc7c9dfa   R9: ffffed15fc7c9dfa
      R10: 0000000000000001  R11: ffffed15fc7c9df9  R12: 0000000000740000
      R13: ffff88b01f849708  R14: 0000000000000003  R15: ffffed1603f092e1
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
  -- <NMI exception stack> --
   #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b
   torvalds#6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4
   torvalds#7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363
   torvalds#8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma]
   torvalds#9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma]
   torvalds#10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma]
   torvalds#11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma]
   torvalds#12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb
   torvalds#13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6
   torvalds#14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278
   torvalds#15 [ffff88aa841efb88] device_del at ffffffff82179d23
   torvalds#16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice]
   torvalds#17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice]
   torvalds#18 [ffff88aa841efde8] process_one_work at ffffffff811c589a
   torvalds#19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff
   torvalds#20 [ffff88aa841eff10] kthread at ffffffff811d87a0
   torvalds#21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f

Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions")
Link: https://lore.kernel.org/r/[email protected]
Suggested-by: "Ismail, Mustafa" <[email protected]>
Signed-off-by: Shifeng Li <[email protected]>
Reviewed-by: Shiraz Saleem <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 11, 2023
When working on LED support for r8169 I got the following lockdep
warning. Easiest way to prevent this scenario seems to be to take
the RTNL lock before the trigger_data lock in set_device_name().

======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc2-next-20231124+ #2 Not tainted
------------------------------------------------------
bash/383 is trying to acquire lock:
ffff888103aa1c68 (&trigger_data->lock){+.+.}-{3:3}, at: netdev_trig_notify+0xec/0x190 [ledtrig_netdev]

but task is already holding lock:
ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (rtnl_mutex){+.+.}-{3:3}:
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       rtnl_lock+0x12/0x20
       set_device_name+0xa9/0x120 [ledtrig_netdev]
       netdev_trig_activate+0x1a1/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

-> #0 (&trigger_data->lock){+.+.}-{3:3}:
       __lock_acquire+0x1459/0x25a0
       lock_acquire+0xc8/0x2d0
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
       call_netdevice_register_net_notifiers+0x5a/0x100
       register_netdevice_notifier+0x85/0x120
       netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(rtnl_mutex);
                               lock(&trigger_data->lock);
                               lock(rtnl_mutex);
  lock(&trigger_data->lock);

 *** DEADLOCK ***

8 locks held by bash/383:
 #0: ffff888103ff33f0 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x6c/0xf0
 #1: ffff888103aa1e88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x114/0x210
 #2: ffff8881036f1890 (kn->active#82){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x11d/0x210
 #3: ffff888108e2c358 (&led_cdev->led_access){+.+.}-{3:3}, at: led_trigger_write+0x30/0x140
 #4: ffffffff8cdd9e10 (triggers_list_lock){++++}-{3:3}, at: led_trigger_write+0x75/0x140
 #5: ffff888108e2c270 (&led_cdev->trigger_lock){++++}-{3:3}, at: led_trigger_write+0xe3/0x140
 torvalds#6: ffffffff8cdde3d0 (pernet_ops_rwsem){++++}-{3:3}, at: register_netdevice_notifier+0x1c/0x120
 torvalds#7: ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

stack backtrace:
CPU: 0 PID: 383 Comm: bash Not tainted 6.7.0-rc2-next-20231124+ #2
Hardware name: Default string Default string/Default string, BIOS ADLN.M6.SODIMM.ZB.CY.015 08/08/2023
Call Trace:
 <TASK>
 dump_stack_lvl+0x5c/0xd0
 dump_stack+0x10/0x20
 print_circular_bug+0x2dd/0x410
 check_noncircular+0x131/0x150
 __lock_acquire+0x1459/0x25a0
 lock_acquire+0xc8/0x2d0
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 __mutex_lock+0x9b/0xb50
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __this_cpu_preempt_check+0x13/0x20
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __cancel_work_timer+0x11c/0x1b0
 ? __mutex_lock+0x123/0xb50
 mutex_lock_nested+0x16/0x20
 ? mutex_lock_nested+0x16/0x20
 netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 call_netdevice_register_net_notifiers+0x5a/0x100
 register_netdevice_notifier+0x85/0x120
 netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
 led_trigger_set+0x172/0x2c0
 ? preempt_count_add+0x49/0xc0
 led_trigger_write+0xf1/0x140
 sysfs_kf_bin_write+0x5d/0x80
 kernfs_fop_write_iter+0x15d/0x210
 vfs_write+0x1f0/0x510
 ksys_write+0x6c/0xf0
 __x64_sys_write+0x14/0x20
 do_syscall_64+0x3f/0xf0
 entry_SYSCALL_64_after_hwframe+0x6c/0x74
RIP: 0033:0x7f269055d034
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 35 c3 0d 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 48 89 54 24 18 48
RSP: 002b:00007ffddb7ef748 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007f269055d034
RDX: 0000000000000007 RSI: 000055bf5f4af3c0 RDI: 0000000000000001
RBP: 000055bf5f4af3c0 R08: 0000000000000073 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000007
R13: 00007f26906325c0 R14: 00007f269062ff20 R15: 0000000000000000
 </TASK>

Fixes: d5e0126 ("leds: trigger: netdev: add additional specific link speed mode")
Cc: [email protected]
Signed-off-by: Heiner Kallweit <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Acked-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 16, 2023
[ Upstream commit a2e36cd ]

This allows it to break the following circular locking dependency.

Aug 10 07:01:29 dg1test kernel: ======================================================
Aug 10 07:01:29 dg1test kernel: WARNING: possible circular locking dependency detected
Aug 10 07:01:29 dg1test kernel: 6.4.0-rc7+ torvalds#10 Not tainted
Aug 10 07:01:29 dg1test kernel: ------------------------------------------------------
Aug 10 07:01:29 dg1test kernel: wireplumber/2236 is trying to acquire lock:
Aug 10 07:01:29 dg1test kernel: ffff8fca5320da18 (&fctx->lock){-...}-{2:2}, at: nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:
                                but task is already holding lock:
Aug 10 07:01:29 dg1test kernel: ffff8fca41208610 (&event->list_lock#2){-...}-{2:2}, at: nvkm_event_ntfy+0x50/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:
                                which lock already depends on the new lock.
Aug 10 07:01:29 dg1test kernel:
                                the existing dependency chain (in reverse order) is:
Aug 10 07:01:29 dg1test kernel:
                                -> #3 (&event->list_lock#2){-...}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy+0x50/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        ga100_fifo_nonstall_intr+0x24/0x30 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_intr+0x12c/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __handle_irq_event_percpu+0x88/0x240
Aug 10 07:01:29 dg1test kernel:        handle_irq_event+0x38/0x80
Aug 10 07:01:29 dg1test kernel:        handle_edge_irq+0xa3/0x240
Aug 10 07:01:29 dg1test kernel:        __common_interrupt+0x72/0x160
Aug 10 07:01:29 dg1test kernel:        common_interrupt+0x60/0xe0
Aug 10 07:01:29 dg1test kernel:        asm_common_interrupt+0x26/0x40
Aug 10 07:01:29 dg1test kernel:
                                -> #2 (&device->intr.lock){-...}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nvkm_inth_allow+0x2c/0x80 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_state+0x181/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_allow+0x63/0xd0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_uevent_mthd+0x4d/0x70 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_ioctl+0x10b/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_object_mthd+0xa8/0x1f0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_event_allow+0x2a/0xa0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_fence_enable_signaling+0x78/0x80 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __dma_fence_enable_signaling+0x5e/0x100
Aug 10 07:01:29 dg1test kernel:        dma_fence_add_callback+0x4b/0xd0
Aug 10 07:01:29 dg1test kernel:        nouveau_cli_work_queue+0xae/0x110 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_gem_object_close+0x1d1/0x2a0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        drm_gem_handle_delete+0x70/0xe0 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl_kernel+0xa5/0x150 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl+0x256/0x490 [drm]
Aug 10 07:01:29 dg1test kernel:        nouveau_drm_ioctl+0x5a/0xb0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __x64_sys_ioctl+0x91/0xd0
Aug 10 07:01:29 dg1test kernel:        do_syscall_64+0x3c/0x90
Aug 10 07:01:29 dg1test kernel:        entry_SYSCALL_64_after_hwframe+0x72/0xdc
Aug 10 07:01:29 dg1test kernel:
                                -> #1 (&event->refs_lock#4){....}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_state+0x37/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy_allow+0x63/0xd0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_uevent_mthd+0x4d/0x70 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_ioctl+0x10b/0x250 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_object_mthd+0xa8/0x1f0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvif_event_allow+0x2a/0xa0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_fence_enable_signaling+0x78/0x80 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __dma_fence_enable_signaling+0x5e/0x100
Aug 10 07:01:29 dg1test kernel:        dma_fence_add_callback+0x4b/0xd0
Aug 10 07:01:29 dg1test kernel:        nouveau_cli_work_queue+0xae/0x110 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nouveau_gem_object_close+0x1d1/0x2a0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        drm_gem_handle_delete+0x70/0xe0 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl_kernel+0xa5/0x150 [drm]
Aug 10 07:01:29 dg1test kernel:        drm_ioctl+0x256/0x490 [drm]
Aug 10 07:01:29 dg1test kernel:        nouveau_drm_ioctl+0x5a/0xb0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __x64_sys_ioctl+0x91/0xd0
Aug 10 07:01:29 dg1test kernel:        do_syscall_64+0x3c/0x90
Aug 10 07:01:29 dg1test kernel:        entry_SYSCALL_64_after_hwframe+0x72/0xdc
Aug 10 07:01:29 dg1test kernel:
                                -> #0 (&fctx->lock){-...}-{2:2}:
Aug 10 07:01:29 dg1test kernel:        __lock_acquire+0x14e3/0x2240
Aug 10 07:01:29 dg1test kernel:        lock_acquire+0xc8/0x2a0
Aug 10 07:01:29 dg1test kernel:        _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:        nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_client_event+0xf/0x20 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_event_ntfy+0x9b/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:        ga100_fifo_nonstall_intr+0x24/0x30 [nouveau]
Aug 10 07:01:29 dg1test kernel:        nvkm_intr+0x12c/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:        __handle_irq_event_percpu+0x88/0x240
Aug 10 07:01:29 dg1test kernel:        handle_irq_event+0x38/0x80
Aug 10 07:01:29 dg1test kernel:        handle_edge_irq+0xa3/0x240
Aug 10 07:01:29 dg1test kernel:        __common_interrupt+0x72/0x160
Aug 10 07:01:29 dg1test kernel:        common_interrupt+0x60/0xe0
Aug 10 07:01:29 dg1test kernel:        asm_common_interrupt+0x26/0x40
Aug 10 07:01:29 dg1test kernel:
                                other info that might help us debug this:
Aug 10 07:01:29 dg1test kernel: Chain exists of:
                                  &fctx->lock --> &device->intr.lock --> &event->list_lock#2
Aug 10 07:01:29 dg1test kernel:  Possible unsafe locking scenario:
Aug 10 07:01:29 dg1test kernel:        CPU0                    CPU1
Aug 10 07:01:29 dg1test kernel:        ----                    ----
Aug 10 07:01:29 dg1test kernel:   lock(&event->list_lock#2);
Aug 10 07:01:29 dg1test kernel:                                lock(&device->intr.lock);
Aug 10 07:01:29 dg1test kernel:                                lock(&event->list_lock#2);
Aug 10 07:01:29 dg1test kernel:   lock(&fctx->lock);
Aug 10 07:01:29 dg1test kernel:
                                 *** DEADLOCK ***
Aug 10 07:01:29 dg1test kernel: 2 locks held by wireplumber/2236:
Aug 10 07:01:29 dg1test kernel:  #0: ffff8fca53177bf8 (&device->intr.lock){-...}-{2:2}, at: nvkm_intr+0x29/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:  #1: ffff8fca41208610 (&event->list_lock#2){-...}-{2:2}, at: nvkm_event_ntfy+0x50/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:
                                stack backtrace:
Aug 10 07:01:29 dg1test kernel: CPU: 6 PID: 2236 Comm: wireplumber Not tainted 6.4.0-rc7+ torvalds#10
Aug 10 07:01:29 dg1test kernel: Hardware name: Gigabyte Technology Co., Ltd. Z390 I AORUS PRO WIFI/Z390 I AORUS PRO WIFI-CF, BIOS F8 11/05/2021
Aug 10 07:01:29 dg1test kernel: Call Trace:
Aug 10 07:01:29 dg1test kernel:  <TASK>
Aug 10 07:01:29 dg1test kernel:  dump_stack_lvl+0x5b/0x90
Aug 10 07:01:29 dg1test kernel:  check_noncircular+0xe2/0x110
Aug 10 07:01:29 dg1test kernel:  __lock_acquire+0x14e3/0x2240
Aug 10 07:01:29 dg1test kernel:  lock_acquire+0xc8/0x2a0
Aug 10 07:01:29 dg1test kernel:  ? nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:  ? lock_acquire+0xc8/0x2a0
Aug 10 07:01:29 dg1test kernel:  _raw_spin_lock_irqsave+0x4b/0x70
Aug 10 07:01:29 dg1test kernel:  ? nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nvkm_client_event+0xf/0x20 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nvkm_event_ntfy+0x9b/0xf0 [nouveau]
Aug 10 07:01:29 dg1test kernel:  ga100_fifo_nonstall_intr+0x24/0x30 [nouveau]
Aug 10 07:01:29 dg1test kernel:  nvkm_intr+0x12c/0x240 [nouveau]
Aug 10 07:01:29 dg1test kernel:  __handle_irq_event_percpu+0x88/0x240
Aug 10 07:01:29 dg1test kernel:  handle_irq_event+0x38/0x80
Aug 10 07:01:29 dg1test kernel:  handle_edge_irq+0xa3/0x240
Aug 10 07:01:29 dg1test kernel:  __common_interrupt+0x72/0x160
Aug 10 07:01:29 dg1test kernel:  common_interrupt+0x60/0xe0
Aug 10 07:01:29 dg1test kernel:  asm_common_interrupt+0x26/0x40
Aug 10 07:01:29 dg1test kernel: RIP: 0033:0x7fb66174d700
Aug 10 07:01:29 dg1test kernel: Code: c1 e2 05 29 ca 8d 0c 10 0f be 07 84 c0 75 eb 89 c8 c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa e9 d7 0f fc ff 0f 1f 80 00 00 00 00 <f3> 0f 1e fa e9 c7 0f fc>
Aug 10 07:01:29 dg1test kernel: RSP: 002b:00007ffdd3c48438 EFLAGS: 00000206
Aug 10 07:01:29 dg1test kernel: RAX: 000055bb758763c0 RBX: 000055bb758752c0 RCX: 00000000000028b0
Aug 10 07:01:29 dg1test kernel: RDX: 000055bb758752c0 RSI: 000055bb75887490 RDI: 000055bb75862950
Aug 10 07:01:29 dg1test kernel: RBP: 00007ffdd3c48490 R08: 000055bb75873b10 R09: 0000000000000001
Aug 10 07:01:29 dg1test kernel: R10: 0000000000000004 R11: 000055bb7587f000 R12: 000055bb75887490
Aug 10 07:01:29 dg1test kernel: R13: 000055bb757f6280 R14: 000055bb758875c0 R15: 000055bb757f6280
Aug 10 07:01:29 dg1test kernel:  </TASK>

Signed-off-by: Dave Airlie <[email protected]>
Tested-by: Danilo Krummrich <[email protected]>
Reviewed-by: Danilo Krummrich <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 16, 2023
[ Upstream commit e3e82fc ]

When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a
cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when
removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be
dereferenced as wrong struct in irdma_free_pending_cqp_request().

  PID: 3669   TASK: ffff88aef892c000  CPU: 28  COMMAND: "kworker/28:0"
   #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34
   #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2
   #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f
   #3 [fffffe0000549eb8] do_nmi at ffffffff81079582
   #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4
      [exception RIP: native_queued_spin_lock_slowpath+1291]
      RIP: ffffffff8127e72b  RSP: ffff88aa841ef778  RFLAGS: 00000046
      RAX: 0000000000000000  RBX: ffff88b01f849700  RCX: ffffffff8127e47e
      RDX: 0000000000000000  RSI: 0000000000000004  RDI: ffffffff83857ec0
      RBP: ffff88afe3e4efc8   R8: ffffed15fc7c9dfa   R9: ffffed15fc7c9dfa
      R10: 0000000000000001  R11: ffffed15fc7c9df9  R12: 0000000000740000
      R13: ffff88b01f849708  R14: 0000000000000003  R15: ffffed1603f092e1
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
  -- <NMI exception stack> --
   #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b
   torvalds#6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4
   torvalds#7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363
   torvalds#8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma]
   torvalds#9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma]
   torvalds#10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma]
   torvalds#11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma]
   torvalds#12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb
   torvalds#13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6
   torvalds#14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278
   torvalds#15 [ffff88aa841efb88] device_del at ffffffff82179d23
   torvalds#16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice]
   torvalds#17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice]
   torvalds#18 [ffff88aa841efde8] process_one_work at ffffffff811c589a
   torvalds#19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff
   torvalds#20 [ffff88aa841eff10] kthread at ffffffff811d87a0
   torvalds#21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f

Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions")
Link: https://lore.kernel.org/r/[email protected]
Suggested-by: "Ismail, Mustafa" <[email protected]>
Signed-off-by: Shifeng Li <[email protected]>
Reviewed-by: Shiraz Saleem <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 16, 2023
commit fe2b122 upstream.

When working on LED support for r8169 I got the following lockdep
warning. Easiest way to prevent this scenario seems to be to take
the RTNL lock before the trigger_data lock in set_device_name().

======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc2-next-20231124+ #2 Not tainted
------------------------------------------------------
bash/383 is trying to acquire lock:
ffff888103aa1c68 (&trigger_data->lock){+.+.}-{3:3}, at: netdev_trig_notify+0xec/0x190 [ledtrig_netdev]

but task is already holding lock:
ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (rtnl_mutex){+.+.}-{3:3}:
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       rtnl_lock+0x12/0x20
       set_device_name+0xa9/0x120 [ledtrig_netdev]
       netdev_trig_activate+0x1a1/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

-> #0 (&trigger_data->lock){+.+.}-{3:3}:
       __lock_acquire+0x1459/0x25a0
       lock_acquire+0xc8/0x2d0
       __mutex_lock+0x9b/0xb50
       mutex_lock_nested+0x16/0x20
       netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
       call_netdevice_register_net_notifiers+0x5a/0x100
       register_netdevice_notifier+0x85/0x120
       netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
       led_trigger_set+0x172/0x2c0
       led_trigger_write+0xf1/0x140
       sysfs_kf_bin_write+0x5d/0x80
       kernfs_fop_write_iter+0x15d/0x210
       vfs_write+0x1f0/0x510
       ksys_write+0x6c/0xf0
       __x64_sys_write+0x14/0x20
       do_syscall_64+0x3f/0xf0
       entry_SYSCALL_64_after_hwframe+0x6c/0x74

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(rtnl_mutex);
                               lock(&trigger_data->lock);
                               lock(rtnl_mutex);
  lock(&trigger_data->lock);

 *** DEADLOCK ***

8 locks held by bash/383:
 #0: ffff888103ff33f0 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x6c/0xf0
 #1: ffff888103aa1e88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x114/0x210
 #2: ffff8881036f1890 (kn->active#82){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x11d/0x210
 #3: ffff888108e2c358 (&led_cdev->led_access){+.+.}-{3:3}, at: led_trigger_write+0x30/0x140
 #4: ffffffff8cdd9e10 (triggers_list_lock){++++}-{3:3}, at: led_trigger_write+0x75/0x140
 #5: ffff888108e2c270 (&led_cdev->trigger_lock){++++}-{3:3}, at: led_trigger_write+0xe3/0x140
 torvalds#6: ffffffff8cdde3d0 (pernet_ops_rwsem){++++}-{3:3}, at: register_netdevice_notifier+0x1c/0x120
 torvalds#7: ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20

stack backtrace:
CPU: 0 PID: 383 Comm: bash Not tainted 6.7.0-rc2-next-20231124+ #2
Hardware name: Default string Default string/Default string, BIOS ADLN.M6.SODIMM.ZB.CY.015 08/08/2023
Call Trace:
 <TASK>
 dump_stack_lvl+0x5c/0xd0
 dump_stack+0x10/0x20
 print_circular_bug+0x2dd/0x410
 check_noncircular+0x131/0x150
 __lock_acquire+0x1459/0x25a0
 lock_acquire+0xc8/0x2d0
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 __mutex_lock+0x9b/0xb50
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __this_cpu_preempt_check+0x13/0x20
 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 ? __cancel_work_timer+0x11c/0x1b0
 ? __mutex_lock+0x123/0xb50
 mutex_lock_nested+0x16/0x20
 ? mutex_lock_nested+0x16/0x20
 netdev_trig_notify+0xec/0x190 [ledtrig_netdev]
 call_netdevice_register_net_notifiers+0x5a/0x100
 register_netdevice_notifier+0x85/0x120
 netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev]
 led_trigger_set+0x172/0x2c0
 ? preempt_count_add+0x49/0xc0
 led_trigger_write+0xf1/0x140
 sysfs_kf_bin_write+0x5d/0x80
 kernfs_fop_write_iter+0x15d/0x210
 vfs_write+0x1f0/0x510
 ksys_write+0x6c/0xf0
 __x64_sys_write+0x14/0x20
 do_syscall_64+0x3f/0xf0
 entry_SYSCALL_64_after_hwframe+0x6c/0x74
RIP: 0033:0x7f269055d034
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 35 c3 0d 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 48 89 54 24 18 48
RSP: 002b:00007ffddb7ef748 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007f269055d034
RDX: 0000000000000007 RSI: 000055bf5f4af3c0 RDI: 0000000000000001
RBP: 000055bf5f4af3c0 R08: 0000000000000073 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000007
R13: 00007f26906325c0 R14: 00007f269062ff20 R15: 0000000000000000
 </TASK>

Fixes: d5e0126 ("leds: trigger: netdev: add additional specific link speed mode")
Cc: [email protected]
Signed-off-by: Heiner Kallweit <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Acked-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 5, 2024
[ Upstream commit 953e549 ]

Lockdep gives a false positive splat as it can't distinguish the lock
which is taken by different IRQ descriptors from different IRQ chips
that are organized in a way of a hierarchy:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.12.0-rc5-next-20241101-00148-g9fabf8160b53 torvalds#562 Tainted: G        W
   ------------------------------------------------------
   modprobe/141 is trying to acquire lock:
   ffff899446947868 (intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock){+.+.}-{4:4}, at: regmap_update_bits_base+0x33/0x90

   but task is already holding lock:
   ffff899446947c68 (&d->lock){+.+.}-{4:4}, at: __setup_irq+0x682/0x790

   which lock already depends on the new lock.

   -> #3 (&d->lock){+.+.}-{4:4}:
   -> #2 (&desc->request_mutex){+.+.}-{4:4}:
   -> #1 (ipclock){+.+.}-{4:4}:
   -> #0 (intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock){+.+.}-{4:4}:

   Chain exists of:
     intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock --> &desc->request_mutex --> &d->lock

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(&d->lock);
                                  lock(&desc->request_mutex);
                                  lock(&d->lock);
     lock(intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock);

    *** DEADLOCK ***

   3 locks held by modprobe/141:
    #0: ffff8994419368f8 (&dev->mutex){....}-{4:4}, at: __driver_attach+0xf6/0x250
    #1: ffff89944690b250 (&desc->request_mutex){+.+.}-{4:4}, at: __setup_irq+0x1a2/0x790
    #2: ffff899446947c68 (&d->lock){+.+.}-{4:4}, at: __setup_irq+0x682/0x790

Set a lockdep class when we map the IRQ so that it doesn't warn about
a lockdep bug that doesn't exist.

Fixes: 4af8be6 ("regmap: Convert regmap_irq to use irq_domain")
Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 5, 2024
[ Upstream commit f364cde ]

LTP reported a NULL pointer dereference as followed:

 CPU: 7 UID: 0 PID: 5995 Comm: cat Kdump: loaded Not tainted 6.12.0-rc6+ #3
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : __pi_strcmp+0x24/0x140
 lr : zcomp_available_show+0x60/0x100 [zram]
 sp : ffff800088b93b90
 x29: ffff800088b93b90 x28: 0000000000000001 x27: 0000000000400cc0
 x26: 0000000000000ffe x25: ffff80007b3e2388 x24: 0000000000000000
 x23: ffff80007b3e2390 x22: ffff0004041a9000 x21: ffff80007b3e2900
 x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000
 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
 x11: 0000000000000000 x10: ffff80007b3e2900 x9 : ffff80007b3cb280
 x8 : 0101010101010101 x7 : 0000000000000000 x6 : 0000000000000000
 x5 : 0000000000000040 x4 : 0000000000000000 x3 : 00656c722d6f7a6c
 x2 : 0000000000000000 x1 : ffff80007b3e2900 x0 : 0000000000000000
 Call trace:
  __pi_strcmp+0x24/0x140
  comp_algorithm_show+0x40/0x70 [zram]
  dev_attr_show+0x28/0x80
  sysfs_kf_seq_show+0x90/0x140
  kernfs_seq_show+0x34/0x48
  seq_read_iter+0x1d4/0x4e8
  kernfs_fop_read_iter+0x40/0x58
  new_sync_read+0x9c/0x168
  vfs_read+0x1a8/0x1f8
  ksys_read+0x74/0x108
  __arm64_sys_read+0x24/0x38
  invoke_syscall+0x50/0x120
  el0_svc_common.constprop.0+0xc8/0xf0
  do_el0_svc+0x24/0x38
  el0_svc+0x38/0x138
  el0t_64_sync_handler+0xc0/0xc8
  el0t_64_sync+0x188/0x190

The zram->comp_algs[ZRAM_PRIMARY_COMP] can be NULL in zram_add() if
comp_algorithm_set() has not been called.  User can access the zram device
by sysfs after device_add_disk(), so there is a time window to trigger the
NULL pointer dereference.  Move it ahead device_add_disk() to make sure
when user can access the zram device, it is ready.  comp_algorithm_set()
is protected by zram->init_lock in other places and no such problem.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 7ac07a2 ("zram: preparation for multi-zcomp support")
Signed-off-by: Liu Shixin <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 5, 2024
commit 0b83c86 upstream.

The function blk_revalidate_disk_zones() calls the function
disk_update_zone_resources() after freezing the device queue. In turn,
disk_update_zone_resources() calls queue_limits_start_update() which
takes a queue limits mutex lock, resulting in the ordering:
q->q_usage_counter check -> q->limits_lock. However, the usual ordering
is to always take a queue limit lock before freezing the queue to commit
the limits updates, e.g., the code pattern:

lim = queue_limits_start_update(q);
...
blk_mq_freeze_queue(q);
ret = queue_limits_commit_update(q, &lim);
blk_mq_unfreeze_queue(q);

Thus, blk_revalidate_disk_zones() introduces a potential circular
locking dependency deadlock that lockdep sometimes catches with the
splat:

[   51.934109] ======================================================
[   51.935916] WARNING: possible circular locking dependency detected
[   51.937561] 6.12.0+ #2107 Not tainted
[   51.938648] ------------------------------------------------------
[   51.940351] kworker/u16:4/157 is trying to acquire lock:
[   51.941805] ffff9fff0aa0bea8 (&q->limits_lock){+.+.}-{4:4}, at: disk_update_zone_resources+0x86/0x170
[   51.944314]
               but task is already holding lock:
[   51.945688] ffff9fff0aa0b890 (&q->q_usage_counter(queue)#3){++++}-{0:0}, at: blk_revalidate_disk_zones+0x15f/0x340
[   51.948527]
               which lock already depends on the new lock.

[   51.951296]
               the existing dependency chain (in reverse order) is:
[   51.953708]
               -> #1 (&q->q_usage_counter(queue)#3){++++}-{0:0}:
[   51.956131]        blk_queue_enter+0x1c9/0x1e0
[   51.957290]        blk_mq_alloc_request+0x187/0x2a0
[   51.958365]        scsi_execute_cmd+0x78/0x490 [scsi_mod]
[   51.959514]        read_capacity_16+0x111/0x410 [sd_mod]
[   51.960693]        sd_revalidate_disk.isra.0+0x872/0x3240 [sd_mod]
[   51.962004]        sd_probe+0x2d7/0x520 [sd_mod]
[   51.962993]        really_probe+0xd5/0x330
[   51.963898]        __driver_probe_device+0x78/0x110
[   51.964925]        driver_probe_device+0x1f/0xa0
[   51.965916]        __driver_attach_async_helper+0x60/0xe0
[   51.967017]        async_run_entry_fn+0x2e/0x140
[   51.968004]        process_one_work+0x21f/0x5a0
[   51.968987]        worker_thread+0x1dc/0x3c0
[   51.969868]        kthread+0xe0/0x110
[   51.970377]        ret_from_fork+0x31/0x50
[   51.970983]        ret_from_fork_asm+0x11/0x20
[   51.971587]
               -> #0 (&q->limits_lock){+.+.}-{4:4}:
[   51.972479]        __lock_acquire+0x1337/0x2130
[   51.973133]        lock_acquire+0xc5/0x2d0
[   51.973691]        __mutex_lock+0xda/0xcf0
[   51.974300]        disk_update_zone_resources+0x86/0x170
[   51.975032]        blk_revalidate_disk_zones+0x16c/0x340
[   51.975740]        sd_zbc_revalidate_zones+0x73/0x160 [sd_mod]
[   51.976524]        sd_revalidate_disk.isra.0+0x465/0x3240 [sd_mod]
[   51.977824]        sd_probe+0x2d7/0x520 [sd_mod]
[   51.978917]        really_probe+0xd5/0x330
[   51.979915]        __driver_probe_device+0x78/0x110
[   51.981047]        driver_probe_device+0x1f/0xa0
[   51.982143]        __driver_attach_async_helper+0x60/0xe0
[   51.983282]        async_run_entry_fn+0x2e/0x140
[   51.984319]        process_one_work+0x21f/0x5a0
[   51.985873]        worker_thread+0x1dc/0x3c0
[   51.987289]        kthread+0xe0/0x110
[   51.988546]        ret_from_fork+0x31/0x50
[   51.989926]        ret_from_fork_asm+0x11/0x20
[   51.991376]
               other info that might help us debug this:

[   51.994127]  Possible unsafe locking scenario:

[   51.995651]        CPU0                    CPU1
[   51.996694]        ----                    ----
[   51.997716]   lock(&q->q_usage_counter(queue)#3);
[   51.998817]                                lock(&q->limits_lock);
[   52.000043]                                lock(&q->q_usage_counter(queue)#3);
[   52.001638]   lock(&q->limits_lock);
[   52.002485]
                *** DEADLOCK ***

Prevent this issue by moving the calls to blk_mq_freeze_queue() and
blk_mq_unfreeze_queue() around the call to queue_limits_commit_update()
in disk_update_zone_resources(). In case of revalidation failure, the
call to disk_free_zone_resources() in blk_revalidate_disk_zones()
is still done with the queue frozen as before.

Fixes: 843283e ("block: Fake max open zones limit when there is no limit")
Cc: [email protected]
Signed-off-by: Damien Le Moal <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 9, 2024
Kernel will hang on destroy admin_q while we create ctrl failed, such
as following calltrace:

PID: 23644    TASK: ff2d52b40f439fc0  CPU: 2    COMMAND: "nvme"
 #0 [ff61d23de260fb78] __schedule at ffffffff8323bc15
 #1 [ff61d23de260fc08] schedule at ffffffff8323c014
 #2 [ff61d23de260fc28] blk_mq_freeze_queue_wait at ffffffff82a3dba1
 #3 [ff61d23de260fc78] blk_freeze_queue at ffffffff82a4113a
 #4 [ff61d23de260fc90] blk_cleanup_queue at ffffffff82a33006
 #5 [ff61d23de260fcb0] nvme_rdma_destroy_admin_queue at ffffffffc12686ce
 torvalds#6 [ff61d23de260fcc8] nvme_rdma_setup_ctrl at ffffffffc1268ced
 torvalds#7 [ff61d23de260fd28] nvme_rdma_create_ctrl at ffffffffc126919b
 torvalds#8 [ff61d23de260fd68] nvmf_dev_write at ffffffffc024f362
 torvalds#9 [ff61d23de260fe38] vfs_write at ffffffff827d5f25
    RIP: 00007fda7891d574  RSP: 00007ffe2ef06958  RFLAGS: 00000202
    RAX: ffffffffffffffda  RBX: 000055e8122a4d90  RCX: 00007fda7891d574
    RDX: 000000000000012b  RSI: 000055e8122a4d90  RDI: 0000000000000004
    RBP: 00007ffe2ef079c0   R8: 000000000000012b   R9: 000055e8122a4d90
    R10: 0000000000000000  R11: 0000000000000202  R12: 0000000000000004
    R13: 000055e8122923c0  R14: 000000000000012b  R15: 00007fda78a54500
    ORIG_RAX: 0000000000000001  CS: 0033  SS: 002b

This due to we have quiesced admi_q before cancel requests, but forgot
to unquiesce before destroy it, as a result we fail to drain the
pending requests, and hang on blk_mq_freeze_queue_wait() forever. Here
try to reuse nvme_rdma_teardown_admin_queue() to fix this issue and
simplify the code.

Fixes: 958dc1d ("nvme-rdma: add clean action for failed reconnection")
Reported-by: Yingfu.zhou <[email protected]>
Signed-off-by: Chunguang.xu <[email protected]>
Signed-off-by: Yue.zhao <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 9, 2024
Konstantin Shkolnyy says:

====================
vsock/test: fix wrong setsockopt() parameters

Parameters were created using wrong C types, which caused them to be of
wrong size on some architectures, causing problems.

The problem with SO_RCVLOWAT was found on s390 (big endian), while x86-64
didn't show it. After the fix, all tests pass on s390.
Then Stefano Garzarella pointed out that SO_VM_SOCKETS_* calls might have
a similar problem, which turned out to be true, hence, the second patch.

Changes for v8:
- Fix whitespace warnings from "checkpatch.pl --strict"
- Add maintainers to Cc:
Changes for v7:
- Rebase on top of https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git
- Add the "net" tags to the subjects
Changes for v6:
- rework the patch #3 to avoid creating a new file for new functions,
and exclude vsock_perf from calling the new functions.
- add "Reviewed-by:" to the patch #2.
Changes for v5:
- in the patch #2 replace the introduced uint64_t with unsigned long long
to match documentation
- add a patch #3 that verifies every setsockopt() call.
Changes for v4:
- add "Reviewed-by:" to the first patch, and add a second patch fixing
SO_VM_SOCKETS_* calls, which depends on the first one (hence, it's now
a patch series.)
Changes for v3:
- fix the same problem in vsock_perf and update commit message
Changes for v2:
- add "Fixes:" lines to the commit message
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 9, 2024
Hou Tao says:

====================
This patch set fixes several issues for LPM trie. These issues were
found during adding new test cases or were reported by syzbot.

The patch set is structured as follows:

Patch #1~#2 are clean-ups for lpm_trie_update_elem().
Patch #3 handles BPF_EXIST and BPF_NOEXIST correctly for LPM trie.
Patch #4 fixes the accounting of n_entries when doing in-place update.
Patch #5 fixes the exact match condition in trie_get_next_key() and it
may skip keys when the passed key is not found in the map.
Patch torvalds#6~torvalds#7 switch from kmalloc() to bpf memory allocator for LPM trie
to fix several lock order warnings reported by syzbot. It also enables
raw_spinlock_t for LPM trie again. After these changes, the LPM trie will
be closer to being usable in any context (though the reentrance check of
trie->lock is still missing, but it is on my todo list).
Patch torvalds#8: move test_lpm_map to map_tests to make it run regularly.
Patch torvalds#9: add test cases for the issues fixed by patch #3~#5.

Please see individual patches for more details. Comments are always
welcome.

Change Log:
v3:
  * patch #2: remove the unnecessary NULL-init for im_node
  * patch torvalds#6: alloc the leaf node before disabling IRQ to low
    the possibility of -ENOMEM when leaf_size is large; Free
    these nodes outside the trie lock (Suggested by Alexei)
  * collect review and ack tags (Thanks for Toke & Daniel)

v2: https://lore.kernel.org/bpf/[email protected]/
  * collect review tags (Thanks for Toke)
  * drop "Add bpf_mem_cache_is_mergeable() helper" patch
  * patch #3~#4: add fix tag
  * patch #4: rename the helper to trie_check_add_elem() and increase
    n_entries in it.
  * patch torvalds#6: use one bpf mem allocator and update commit message to
    clarify that using bpf mem allocator is more appropriate.
  * patch torvalds#7: update commit message to add the possible max running time
    for update operation.
  * patch torvalds#9: update commit message to specify the purpose of these test
    cases.

v1: https://lore.kernel.org/bpf/[email protected]/
====================

Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Alexei Starovoitov <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 14, 2024
[ Upstream commit 5858b68 ]

Kernel will hang on destroy admin_q while we create ctrl failed, such
as following calltrace:

PID: 23644    TASK: ff2d52b40f439fc0  CPU: 2    COMMAND: "nvme"
 #0 [ff61d23de260fb78] __schedule at ffffffff8323bc15
 #1 [ff61d23de260fc08] schedule at ffffffff8323c014
 #2 [ff61d23de260fc28] blk_mq_freeze_queue_wait at ffffffff82a3dba1
 #3 [ff61d23de260fc78] blk_freeze_queue at ffffffff82a4113a
 #4 [ff61d23de260fc90] blk_cleanup_queue at ffffffff82a33006
 #5 [ff61d23de260fcb0] nvme_rdma_destroy_admin_queue at ffffffffc12686ce
 torvalds#6 [ff61d23de260fcc8] nvme_rdma_setup_ctrl at ffffffffc1268ced
 torvalds#7 [ff61d23de260fd28] nvme_rdma_create_ctrl at ffffffffc126919b
 torvalds#8 [ff61d23de260fd68] nvmf_dev_write at ffffffffc024f362
 torvalds#9 [ff61d23de260fe38] vfs_write at ffffffff827d5f25
    RIP: 00007fda7891d574  RSP: 00007ffe2ef06958  RFLAGS: 00000202
    RAX: ffffffffffffffda  RBX: 000055e8122a4d90  RCX: 00007fda7891d574
    RDX: 000000000000012b  RSI: 000055e8122a4d90  RDI: 0000000000000004
    RBP: 00007ffe2ef079c0   R8: 000000000000012b   R9: 000055e8122a4d90
    R10: 0000000000000000  R11: 0000000000000202  R12: 0000000000000004
    R13: 000055e8122923c0  R14: 000000000000012b  R15: 00007fda78a54500
    ORIG_RAX: 0000000000000001  CS: 0033  SS: 002b

This due to we have quiesced admi_q before cancel requests, but forgot
to unquiesce before destroy it, as a result we fail to drain the
pending requests, and hang on blk_mq_freeze_queue_wait() forever. Here
try to reuse nvme_rdma_teardown_admin_queue() to fix this issue and
simplify the code.

Fixes: 958dc1d ("nvme-rdma: add clean action for failed reconnection")
Reported-by: Yingfu.zhou <[email protected]>
Signed-off-by: Chunguang.xu <[email protected]>
Signed-off-by: Yue.zhao <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 14, 2024
[ Upstream commit 59458fa ]

Ran Xiaokai reports that with a KCSAN-enabled PREEMPT_RT kernel, we can see
splats like:

| BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
| in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
| preempt_count: 10002, expected: 0
| RCU nest depth: 0, expected: 0
| no locks held by swapper/1/0.
| irq event stamp: 156674
| hardirqs last  enabled at (156673): [<ffffffff81130bd9>] do_idle+0x1f9/0x240
| hardirqs last disabled at (156674): [<ffffffff82254f84>] sysvec_apic_timer_interrupt+0x14/0xc0
| softirqs last  enabled at (0): [<ffffffff81099f47>] copy_process+0xfc7/0x4b60
| softirqs last disabled at (0): [<0000000000000000>] 0x0
| Preemption disabled at:
| [<ffffffff814a3e2a>] paint_ptr+0x2a/0x90
| CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.11.0+ #3
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
| Call Trace:
|  <IRQ>
|  dump_stack_lvl+0x7e/0xc0
|  dump_stack+0x1d/0x30
|  __might_resched+0x1a2/0x270
|  rt_spin_lock+0x68/0x170
|  kcsan_skip_report_debugfs+0x43/0xe0
|  print_report+0xb5/0x590
|  kcsan_report_known_origin+0x1b1/0x1d0
|  kcsan_setup_watchpoint+0x348/0x650
|  __tsan_unaligned_write1+0x16d/0x1d0
|  hrtimer_interrupt+0x3d6/0x430
|  __sysvec_apic_timer_interrupt+0xe8/0x3a0
|  sysvec_apic_timer_interrupt+0x97/0xc0
|  </IRQ>

On a detected data race, KCSAN's reporting logic checks if it should
filter the report. That list is protected by the report_filterlist_lock
*non-raw* spinlock which may sleep on RT kernels.

Since KCSAN may report data races in any context, convert it to a
raw_spinlock.

This requires being careful about when to allocate memory for the filter
list itself which can be done via KCSAN's debugfs interface. Concurrent
modification of the filter list via debugfs should be rare: the chosen
strategy is to optimistically pre-allocate memory before the critical
section and discard if unused.

Link: https://lore.kernel.org/all/[email protected]/
Reported-by: Ran Xiaokai <[email protected]>
Tested-by: Ran Xiaokai <[email protected]>
Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 14, 2024
…dfl()

[ Upstream commit f39489f ]

When getting an LLC CPU mask in the default CPU selection policy,
scx_select_cpu_dfl(), a pointer to the sched_domain is dereferenced
using rcu_read_lock() without holding rcu_read_lock(). Such an unprotected
dereference often causes the following warning and can cause an invalid
memory access in the worst case.

Therefore, protect dereference of a sched_domain pointer using a pair
of rcu_read_lock() and unlock().

[   20.996135] =============================
[   20.996345] WARNING: suspicious RCU usage
[   20.996563] 6.11.0-virtme torvalds#17 Tainted: G        W
[   20.996576] -----------------------------
[   20.996576] kernel/sched/ext.c:3323 suspicious rcu_dereference_check() usage!
[   20.996576]
[   20.996576] other info that might help us debug this:
[   20.996576]
[   20.996576]
[   20.996576] rcu_scheduler_active = 2, debug_locks = 1
[   20.996576] 4 locks held by kworker/8:1/140:
[   20.996576]  #0: ffff8b18c00dd348 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work+0x4a0/0x590
[   20.996576]  #1: ffffb3da01f67e58 ((work_completion)(&dev->power.work)){+.+.}-{0:0}, at: process_one_work+0x1ba/0x590
[   20.996576]  #2: ffffffffa316f9f0 (&rcu_state.gp_wq){..-.}-{2:2}, at: swake_up_one+0x15/0x60
[   20.996576]  #3: ffff8b1880398a60 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x59/0x7d0
[   20.996576]
[   20.996576] stack backtrace:
[   20.996576] CPU: 8 UID: 0 PID: 140 Comm: kworker/8:1 Tainted: G        W          6.11.0-virtme torvalds#17
[   20.996576] Tainted: [W]=WARN
[   20.996576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[   20.996576] Workqueue: pm pm_runtime_work
[   20.996576] Sched_ext: simple (disabling+all), task: runnable_at=-6ms
[   20.996576] Call Trace:
[   20.996576]  <IRQ>
[   20.996576]  dump_stack_lvl+0x6f/0xb0
[   20.996576]  lockdep_rcu_suspicious.cold+0x4e/0x96
[   20.996576]  scx_select_cpu_dfl+0x234/0x260
[   20.996576]  select_task_rq_scx+0xfb/0x190
[   20.996576]  select_task_rq+0x47/0x110
[   20.996576]  try_to_wake_up+0x110/0x7d0
[   20.996576]  swake_up_one+0x39/0x60
[   20.996576]  rcu_core+0xb08/0xe50
[   20.996576]  ? srso_alias_return_thunk+0x5/0xfbef5
[   20.996576]  ? mark_held_locks+0x40/0x70
[   20.996576]  handle_softirqs+0xd3/0x410
[   20.996576]  irq_exit_rcu+0x78/0xa0
[   20.996576]  sysvec_apic_timer_interrupt+0x73/0x80
[   20.996576]  </IRQ>
[   20.996576]  <TASK>
[   20.996576]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[   20.996576] RIP: 0010:_raw_spin_unlock_irqrestore+0x36/0x70
[   20.996576] Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 11 b4 36 ff 48 89 df e8 99 0d 37 ff f7 c5 00 02 00 00 75 17 9c 58 f6 c4 02 75 2b <65> ff 0d 5b 55 3c 5e 74 16 5b 5d e9 95 8e 28 00 e8 a5 ee 44 ff 9c
[   20.996576] RSP: 0018:ffffb3da01f67d20 EFLAGS: 00000246
[   20.996576] RAX: 0000000000000002 RBX: ffffffffa4640220 RCX: 0000000000000040
[   20.996576] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa1c7b27b
[   20.996576] RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
[   20.996576] R10: 0000000000000001 R11: 000000000000021c R12: 0000000000000246
[   20.996576] R13: ffff8b1881363958 R14: 0000000000000000 R15: ffff8b1881363800
[   20.996576]  ? _raw_spin_unlock_irqrestore+0x4b/0x70
[   20.996576]  serial_port_runtime_resume+0xd4/0x1a0
[   20.996576]  ? __pfx_serial_port_runtime_resume+0x10/0x10
[   20.996576]  __rpm_callback+0x44/0x170
[   20.996576]  ? __pfx_serial_port_runtime_resume+0x10/0x10
[   20.996576]  rpm_callback+0x55/0x60
[   20.996576]  ? __pfx_serial_port_runtime_resume+0x10/0x10
[   20.996576]  rpm_resume+0x582/0x7b0
[   20.996576]  pm_runtime_work+0x7c/0xb0
[   20.996576]  process_one_work+0x1fb/0x590
[   20.996576]  worker_thread+0x18e/0x350
[   20.996576]  ? __pfx_worker_thread+0x10/0x10
[   20.996576]  kthread+0xe2/0x110
[   20.996576]  ? __pfx_kthread+0x10/0x10
[   20.996576]  ret_from_fork+0x34/0x50
[   20.996576]  ? __pfx_kthread+0x10/0x10
[   20.996576]  ret_from_fork_asm+0x1a/0x30
[   20.996576]  </TASK>
[   21.056592] sched_ext: BPF scheduler "simple" disabled (unregistered from user space)

Signed-off-by: Changwoo Min <[email protected]>
Acked-by: Andrea Righi <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 16, 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
  torvalds#6  0x00000000004c0414 in run_builtin (p=0xec3068 <commands+648>, argc=5, argv=0x7fffffffde60) at perf.c:351
  torvalds#7  0x00000000004c06bb in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:404
  torvalds#8  0x00000000004c0814 in run_argv (argcp=0x7fffffffdc4c, argv=0x7fffffffdc40) at perf.c:448
  torvalds#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 <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Veronika Molnarova <[email protected]>
Acked-by: Michael Petlan <[email protected]>
Tested-by: Michael Petlan <[email protected]>
Link: https://lore.kernel.org/r/Z0XffUgNSv_9OjOi@x1
Signed-off-by: Namhyung Kim <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 16, 2024
This reworks hci_cb_list to not use mutex hci_cb_list_lock to avoid bugs
like the bellow:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5070, name: kworker/u9:2
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
4 locks held by kworker/u9:2/5070:
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
 #2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915
CPU: 0 PID: 5070 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 __might_resched+0x5d4/0x780 kernel/sched/core.c:10187
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752
 hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
 hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
 hci_event_func net/bluetooth/hci_event.c:7514 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Reported-by: [email protected]
Tested-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 16, 2024
This fixes the circular locking dependency warning below, by
releasing the socket lock before enterning iso_listen_bis, to
avoid any potential deadlock with hdev lock.

[   75.307983] ======================================================
[   75.307984] WARNING: possible circular locking dependency detected
[   75.307985] 6.12.0-rc6+ torvalds#22 Not tainted
[   75.307987] ------------------------------------------------------
[   75.307987] kworker/u81:2/2623 is trying to acquire lock:
[   75.307988] ffff8fde1769da58 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO)
               at: iso_connect_cfm+0x253/0x840 [bluetooth]
[   75.308021]
               but task is already holding lock:
[   75.308022] ffff8fdd61a10078 (&hdev->lock)
               at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]
[   75.308053]
               which lock already depends on the new lock.

[   75.308054]
               the existing dependency chain (in reverse order) is:
[   75.308055]
               -> #1 (&hdev->lock){+.+.}-{3:3}:
[   75.308057]        __mutex_lock+0xad/0xc50
[   75.308061]        mutex_lock_nested+0x1b/0x30
[   75.308063]        iso_sock_listen+0x143/0x5c0 [bluetooth]
[   75.308085]        __sys_listen_socket+0x49/0x60
[   75.308088]        __x64_sys_listen+0x4c/0x90
[   75.308090]        x64_sys_call+0x2517/0x25f0
[   75.308092]        do_syscall_64+0x87/0x150
[   75.308095]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   75.308098]
               -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
[   75.308100]        __lock_acquire+0x155e/0x25f0
[   75.308103]        lock_acquire+0xc9/0x300
[   75.308105]        lock_sock_nested+0x32/0x90
[   75.308107]        iso_connect_cfm+0x253/0x840 [bluetooth]
[   75.308128]        hci_connect_cfm+0x6c/0x190 [bluetooth]
[   75.308155]        hci_le_per_adv_report_evt+0x27b/0x2f0 [bluetooth]
[   75.308180]        hci_le_meta_evt+0xe7/0x200 [bluetooth]
[   75.308206]        hci_event_packet+0x21f/0x5c0 [bluetooth]
[   75.308230]        hci_rx_work+0x3ae/0xb10 [bluetooth]
[   75.308254]        process_one_work+0x212/0x740
[   75.308256]        worker_thread+0x1bd/0x3a0
[   75.308258]        kthread+0xe4/0x120
[   75.308259]        ret_from_fork+0x44/0x70
[   75.308261]        ret_from_fork_asm+0x1a/0x30
[   75.308263]
               other info that might help us debug this:

[   75.308264]  Possible unsafe locking scenario:

[   75.308264]        CPU0                CPU1
[   75.308265]        ----                ----
[   75.308265]   lock(&hdev->lock);
[   75.308267]                            lock(sk_lock-
                                                AF_BLUETOOTH-BTPROTO_ISO);
[   75.308268]                            lock(&hdev->lock);
[   75.308269]   lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
[   75.308270]
                *** DEADLOCK ***

[   75.308271] 4 locks held by kworker/u81:2/2623:
[   75.308272]  #0: ffff8fdd66e52148 ((wq_completion)hci0#2){+.+.}-{0:0},
                at: process_one_work+0x443/0x740
[   75.308276]  #1: ffffafb488b7fe48 ((work_completion)(&hdev->rx_work)),
                at: process_one_work+0x1ce/0x740
[   75.308280]  #2: ffff8fdd61a10078 (&hdev->lock){+.+.}-{3:3}
                at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]
[   75.308304]  #3: ffffffffb6ba4900 (rcu_read_lock){....}-{1:2},
                at: hci_connect_cfm+0x29/0x190 [bluetooth]

Fixes: 02171da ("Bluetooth: ISO: Add hcon for listening bis sk")
Signed-off-by: Iulia Tanasescu <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 16, 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 torvalds#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)torvalds#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: [email protected]
Fixes: af28141 ("block: freeze the queue in queue_attr_store")
Tested-by: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Nilay Shroff <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 19, 2024
[ Upstream commit 88a6e2f ]

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
  torvalds#6  0x00000000004c0414 in run_builtin (p=0xec3068 <commands+648>, argc=5, argv=0x7fffffffde60) at perf.c:351
  torvalds#7  0x00000000004c06bb in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:404
  torvalds#8  0x00000000004c0814 in run_argv (argcp=0x7fffffffdc4c, argv=0x7fffffffdc40) at perf.c:448
  torvalds#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 <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Veronika Molnarova <[email protected]>
Acked-by: Michael Petlan <[email protected]>
Tested-by: Michael Petlan <[email protected]>
Link: https://lore.kernel.org/r/Z0XffUgNSv_9OjOi@x1
Signed-off-by: Namhyung Kim <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 19, 2024
[ Upstream commit 168e283 ]

This fixes the circular locking dependency warning below, by
releasing the socket lock before enterning iso_listen_bis, to
avoid any potential deadlock with hdev lock.

[   75.307983] ======================================================
[   75.307984] WARNING: possible circular locking dependency detected
[   75.307985] 6.12.0-rc6+ torvalds#22 Not tainted
[   75.307987] ------------------------------------------------------
[   75.307987] kworker/u81:2/2623 is trying to acquire lock:
[   75.307988] ffff8fde1769da58 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO)
               at: iso_connect_cfm+0x253/0x840 [bluetooth]
[   75.308021]
               but task is already holding lock:
[   75.308022] ffff8fdd61a10078 (&hdev->lock)
               at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]
[   75.308053]
               which lock already depends on the new lock.

[   75.308054]
               the existing dependency chain (in reverse order) is:
[   75.308055]
               -> #1 (&hdev->lock){+.+.}-{3:3}:
[   75.308057]        __mutex_lock+0xad/0xc50
[   75.308061]        mutex_lock_nested+0x1b/0x30
[   75.308063]        iso_sock_listen+0x143/0x5c0 [bluetooth]
[   75.308085]        __sys_listen_socket+0x49/0x60
[   75.308088]        __x64_sys_listen+0x4c/0x90
[   75.308090]        x64_sys_call+0x2517/0x25f0
[   75.308092]        do_syscall_64+0x87/0x150
[   75.308095]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   75.308098]
               -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
[   75.308100]        __lock_acquire+0x155e/0x25f0
[   75.308103]        lock_acquire+0xc9/0x300
[   75.308105]        lock_sock_nested+0x32/0x90
[   75.308107]        iso_connect_cfm+0x253/0x840 [bluetooth]
[   75.308128]        hci_connect_cfm+0x6c/0x190 [bluetooth]
[   75.308155]        hci_le_per_adv_report_evt+0x27b/0x2f0 [bluetooth]
[   75.308180]        hci_le_meta_evt+0xe7/0x200 [bluetooth]
[   75.308206]        hci_event_packet+0x21f/0x5c0 [bluetooth]
[   75.308230]        hci_rx_work+0x3ae/0xb10 [bluetooth]
[   75.308254]        process_one_work+0x212/0x740
[   75.308256]        worker_thread+0x1bd/0x3a0
[   75.308258]        kthread+0xe4/0x120
[   75.308259]        ret_from_fork+0x44/0x70
[   75.308261]        ret_from_fork_asm+0x1a/0x30
[   75.308263]
               other info that might help us debug this:

[   75.308264]  Possible unsafe locking scenario:

[   75.308264]        CPU0                CPU1
[   75.308265]        ----                ----
[   75.308265]   lock(&hdev->lock);
[   75.308267]                            lock(sk_lock-
                                                AF_BLUETOOTH-BTPROTO_ISO);
[   75.308268]                            lock(&hdev->lock);
[   75.308269]   lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
[   75.308270]
                *** DEADLOCK ***

[   75.308271] 4 locks held by kworker/u81:2/2623:
[   75.308272]  #0: ffff8fdd66e52148 ((wq_completion)hci0#2){+.+.}-{0:0},
                at: process_one_work+0x443/0x740
[   75.308276]  #1: ffffafb488b7fe48 ((work_completion)(&hdev->rx_work)),
                at: process_one_work+0x1ce/0x740
[   75.308280]  #2: ffff8fdd61a10078 (&hdev->lock){+.+.}-{3:3}
                at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]
[   75.308304]  #3: ffffffffb6ba4900 (rcu_read_lock){....}-{1:2},
                at: hci_connect_cfm+0x29/0x190 [bluetooth]

Fixes: 02171da ("Bluetooth: ISO: Add hcon for listening bis sk")
Signed-off-by: Iulia Tanasescu <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Dec 19, 2024
…s_lock

[ Upstream commit be26ba9 ]

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 torvalds#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)torvalds#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: [email protected]
Fixes: af28141 ("block: freeze the queue in queue_attr_store")
Tested-by: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Nilay Shroff <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
1Naim pushed a commit that referenced this pull request Jan 6, 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 torvalds#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 torvalds#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: [email protected]
Fixes: 020b40f ("io_uring: make ctx->timeout_lock a raw spinlock")
Signed-off-by: Jens Axboe <[email protected]>
1Naim pushed a commit that referenced this pull request Jan 6, 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
 torvalds#6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 torvalds#7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 torvalds#8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 torvalds#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.

[[email protected]: coding-style cleanups]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
1Naim pushed a commit that referenced this pull request Jan 6, 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+ torvalds#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/[email protected]
Fixes: 3a6f33d ("mm/kmemleak: use %pK to display kernel pointers in backtrace")
Signed-off-by: Alessandro Carminati <[email protected]>
Acked-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Clément Léger <[email protected]>
Cc: Alessandro Carminati <[email protected]>
Cc: Eric Chanudet <[email protected]>
Cc: Gabriele Paoloni <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Weißschuh <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
ptr1337 pushed a commit that referenced this pull request Jan 9, 2025
[ Upstream commit 4d94f05 ]

This reworks hci_cb_list to not use mutex hci_cb_list_lock to avoid bugs
like the bellow:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5070, name: kworker/u9:2
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
4 locks held by kworker/u9:2/5070:
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
 #2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915
CPU: 0 PID: 5070 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 __might_resched+0x5d4/0x780 kernel/sched/core.c:10187
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752
 hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
 hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
 hci_event_func net/bluetooth/hci_event.c:7514 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Reported-by: [email protected]
Tested-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Jan 9, 2025
…nt message

commit cddc76b upstream.

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+ torvalds#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/[email protected]
Fixes: 3a6f33d ("mm/kmemleak: use %pK to display kernel pointers in backtrace")
Signed-off-by: Alessandro Carminati <[email protected]>
Acked-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Clément Léger <[email protected]>
Cc: Alessandro Carminati <[email protected]>
Cc: Eric Chanudet <[email protected]>
Cc: Gabriele Paoloni <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Weißschuh <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit that referenced this pull request Jan 9, 2025
…le_direct_reclaim()

commit 6aaced5 upstream.

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
 torvalds#6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 torvalds#7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 torvalds#8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 torvalds#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.

[[email protected]: coding-style cleanups]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit that referenced this pull request Jan 13, 2025
If GuC fails to load, the driver wedges, but in the process it tries to
do stuff that may not be initialized yet. This moves the
xe_gt_tlb_invalidation_init() to be done earlier: as its own doc says,
it's a software-only initialization and should had been named with the
_early() suffix.

Move it to be called by xe_gt_init_early(), so the locks and seqno are
initialized, avoiding a NULL ptr deref when wedging:

	xe 0000:03:00.0: [drm] *ERROR* GT0: load failed: status: Reset = 0, BootROM = 0x50, UKernel = 0x00, MIA = 0x00, Auth = 0x01
	xe 0000:03:00.0: [drm] *ERROR* GT0: firmware signature verification failed
	xe 0000:03:00.0: [drm] *ERROR* CRITICAL: Xe has declared device 0000:03:00.0 as wedged.
	...
	BUG: kernel NULL pointer dereference, address: 0000000000000000
	#PF: supervisor read access in kernel mode
	#PF: error_code(0x0000) - not-present page
	PGD 0 P4D 0
	Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
	CPU: 9 UID: 0 PID: 3908 Comm: modprobe Tainted: G     U  W          6.13.0-rc4-xe+ #3
	Tainted: [U]=USER, [W]=WARN
	Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-S ADP-S DDR5 UDIMM CRB, BIOS ADLSFWI1.R00.3275.A00.2207010640 07/01/2022
	RIP: 0010:xe_gt_tlb_invalidation_reset+0x75/0x110 [xe]

This can be easily triggered by poking the GuC binary to force a
signature failure. There will still be an extra message,

	xe 0000:03:00.0: [drm] *ERROR* GT0: GuC mmio request 0x4100: no reply 0x4100

but that's better than a NULL ptr deref.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3956
Fixes: c9474b7 ("drm/xe: Wedge the entire device")
Reviewed-by: Matthew Brost <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Lucas De Marchi <[email protected]>
(cherry picked from commit 5001ef3)
Signed-off-by: Thomas Hellström <[email protected]>
ptr1337 pushed a commit that referenced this pull request Jan 13, 2025
We found a timeout problem with the pldm command on our system.  The
reason is that the MCTP-I3C driver has a race condition when receiving
multiple-packet messages in multi-thread, resulting in a wrong packet
order problem.

We identified this problem by adding a debug message to the
mctp_i3c_read function.

According to the MCTP spec, a multiple-packet message must be composed
in sequence, and if there is a wrong sequence, the whole message will be
discarded and wait for the next SOM.
For example, SOM → Pkt Seq #2 → Pkt Seq #1 → Pkt Seq #3 → EOM.

Therefore, we try to solve this problem by adding a mutex to the
mctp_i3c_read function.  Before the modification, when a command
requesting a multiple-packet message response is sent consecutively, an
error usually occurs within 100 loops.  After the mutex, it can go
through 40000 loops without any error, and it seems to run well.

Fixes: c8755b2 ("mctp i3c: MCTP I3C driver")
Signed-off-by: Leo Yang <[email protected]>
Link: https://patch.msgid.link/[email protected]
[[email protected]: dropped already answered question from changelog]
Signed-off-by: Paolo Abeni <[email protected]>
ptr1337 pushed a commit that referenced this pull request Jan 13, 2025
…ux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 6.13, part #3

 - Always check page state in hyp_ack_unshare()

 - Align set_id_regs selftest with the fact that ASIDBITS field is RO

 - Various vPMU fixes for bugs that only affect nested virt
ptr1337 pushed a commit that referenced this pull request Jan 17, 2025
[ Upstream commit 2d2d4f6 ]

We found a timeout problem with the pldm command on our system.  The
reason is that the MCTP-I3C driver has a race condition when receiving
multiple-packet messages in multi-thread, resulting in a wrong packet
order problem.

We identified this problem by adding a debug message to the
mctp_i3c_read function.

According to the MCTP spec, a multiple-packet message must be composed
in sequence, and if there is a wrong sequence, the whole message will be
discarded and wait for the next SOM.
For example, SOM → Pkt Seq #2 → Pkt Seq #1 → Pkt Seq #3 → EOM.

Therefore, we try to solve this problem by adding a mutex to the
mctp_i3c_read function.  Before the modification, when a command
requesting a multiple-packet message response is sent consecutively, an
error usually occurs within 100 loops.  After the mutex, it can go
through 40000 loops without any error, and it seems to run well.

Fixes: c8755b2 ("mctp i3c: MCTP I3C driver")
Signed-off-by: Leo Yang <[email protected]>
Link: https://patch.msgid.link/[email protected]
[[email protected]: dropped already answered question from changelog]
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ptr1337 pushed a commit that referenced this pull request Jan 17, 2025
[ Upstream commit 9ab4981 ]

If GuC fails to load, the driver wedges, but in the process it tries to
do stuff that may not be initialized yet. This moves the
xe_gt_tlb_invalidation_init() to be done earlier: as its own doc says,
it's a software-only initialization and should had been named with the
_early() suffix.

Move it to be called by xe_gt_init_early(), so the locks and seqno are
initialized, avoiding a NULL ptr deref when wedging:

	xe 0000:03:00.0: [drm] *ERROR* GT0: load failed: status: Reset = 0, BootROM = 0x50, UKernel = 0x00, MIA = 0x00, Auth = 0x01
	xe 0000:03:00.0: [drm] *ERROR* GT0: firmware signature verification failed
	xe 0000:03:00.0: [drm] *ERROR* CRITICAL: Xe has declared device 0000:03:00.0 as wedged.
	...
	BUG: kernel NULL pointer dereference, address: 0000000000000000
	#PF: supervisor read access in kernel mode
	#PF: error_code(0x0000) - not-present page
	PGD 0 P4D 0
	Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
	CPU: 9 UID: 0 PID: 3908 Comm: modprobe Tainted: G     U  W          6.13.0-rc4-xe+ #3
	Tainted: [U]=USER, [W]=WARN
	Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-S ADP-S DDR5 UDIMM CRB, BIOS ADLSFWI1.R00.3275.A00.2207010640 07/01/2022
	RIP: 0010:xe_gt_tlb_invalidation_reset+0x75/0x110 [xe]

This can be easily triggered by poking the GuC binary to force a
signature failure. There will still be an extra message,

	xe 0000:03:00.0: [drm] *ERROR* GT0: GuC mmio request 0x4100: no reply 0x4100

but that's better than a NULL ptr deref.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3956
Fixes: c9474b7 ("drm/xe: Wedge the entire device")
Reviewed-by: Matthew Brost <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Lucas De Marchi <[email protected]>
(cherry picked from commit 5001ef3)
Signed-off-by: Thomas Hellström <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
1Naim pushed a commit that referenced this pull request Jan 20, 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+ torvalds#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+ torvalds#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 <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>
1Naim pushed a commit that referenced this pull request Jan 20, 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 torvalds#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 torvalds#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 <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Suggested-by: Alex Deucher <[email protected]>
Reviewed-by: Alex Deucher <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
(cherry picked from commit 0b6b2dd)
Cc: [email protected]
1Naim pushed a commit that referenced this pull request Jan 20, 2025
Fix a lockdep warning [1] observed during the write combining test.

The warning indicates a potential nested lock scenario that could lead
to a deadlock.

However, this is a false positive alarm because the SF lock and its
parent lock are distinct ones.

The lockdep confusion arises because the locks belong to the same object
class (i.e., struct mlx5_core_dev).

To resolve this, the code has been refactored to avoid taking both
locks. Instead, only the parent lock is acquired.

[1]
raw_ethernet_bw/2118 is trying to acquire lock:
[  213.619032] ffff88811dd75e08 (&dev->wc_state_lock){+.+.}-{3:3}, at:
               mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.620270]
[  213.620270] but task is already holding lock:
[  213.620943] ffff88810b585e08 (&dev->wc_state_lock){+.+.}-{3:3}, at:
               mlx5_wc_support_get+0x10c/0x210 [mlx5_core]
[  213.622045]
[  213.622045] other info that might help us debug this:
[  213.622778]  Possible unsafe locking scenario:
[  213.622778]
[  213.623465]        CPU0
[  213.623815]        ----
[  213.624148]   lock(&dev->wc_state_lock);
[  213.624615]   lock(&dev->wc_state_lock);
[  213.625071]
[  213.625071]  *** DEADLOCK ***
[  213.625071]
[  213.625805]  May be due to missing lock nesting notation
[  213.625805]
[  213.626522] 4 locks held by raw_ethernet_bw/2118:
[  213.627019]  #0: ffff88813f80d578 (&uverbs_dev->disassociate_srcu){.+.+}-{0:0},
                at: ib_uverbs_ioctl+0xc4/0x170 [ib_uverbs]
[  213.628088]  #1: ffff88810fb23930 (&file->hw_destroy_rwsem){.+.+}-{3:3},
                at: ib_init_ucontext+0x2d/0xf0 [ib_uverbs]
[  213.629094]  #2: ffff88810fb23878 (&file->ucontext_lock){+.+.}-{3:3},
                at: ib_init_ucontext+0x49/0xf0 [ib_uverbs]
[  213.630106]  #3: ffff88810b585e08 (&dev->wc_state_lock){+.+.}-{3:3},
                at: mlx5_wc_support_get+0x10c/0x210 [mlx5_core]
[  213.631185]
[  213.631185] stack backtrace:
[  213.631718] CPU: 1 UID: 0 PID: 2118 Comm: raw_ethernet_bw Not tainted
               6.12.0-rc7_internal_net_next_mlx5_89a0ad0 #1
[  213.632722] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
               rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[  213.633785] Call Trace:
[  213.634099]
[  213.634393]  dump_stack_lvl+0x7e/0xc0
[  213.634806]  print_deadlock_bug+0x278/0x3c0
[  213.635265]  __lock_acquire+0x15f4/0x2c40
[  213.635712]  lock_acquire+0xcd/0x2d0
[  213.636120]  ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.636722]  ? mlx5_ib_enable_lb+0x24/0xa0 [mlx5_ib]
[  213.637277]  __mutex_lock+0x81/0xda0
[  213.637697]  ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.638305]  ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.638902]  ? rcu_read_lock_sched_held+0x3f/0x70
[  213.639400]  ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.640016]  mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.640615]  set_ucontext_resp+0x68/0x2b0 [mlx5_ib]
[  213.641144]  ? debug_mutex_init+0x33/0x40
[  213.641586]  mlx5_ib_alloc_ucontext+0x18e/0x7b0 [mlx5_ib]
[  213.642145]  ib_init_ucontext+0xa0/0xf0 [ib_uverbs]
[  213.642679]  ib_uverbs_handler_UVERBS_METHOD_GET_CONTEXT+0x95/0xc0
                [ib_uverbs]
[  213.643426]  ? _copy_from_user+0x46/0x80
[  213.643878]  ib_uverbs_cmd_verbs+0xa6b/0xc80 [ib_uverbs]
[  213.644426]  ? ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x130/0x130
               [ib_uverbs]
[  213.645213]  ? __lock_acquire+0xa99/0x2c40
[  213.645675]  ? lock_acquire+0xcd/0x2d0
[  213.646101]  ? ib_uverbs_ioctl+0xc4/0x170 [ib_uverbs]
[  213.646625]  ? reacquire_held_locks+0xcf/0x1f0
[  213.647102]  ? do_user_addr_fault+0x45d/0x770
[  213.647586]  ib_uverbs_ioctl+0xe0/0x170 [ib_uverbs]
[  213.648102]  ? ib_uverbs_ioctl+0xc4/0x170 [ib_uverbs]
[  213.648632]  __x64_sys_ioctl+0x4d3/0xaa0
[  213.649060]  ? do_user_addr_fault+0x4a8/0x770
[  213.649528]  do_syscall_64+0x6d/0x140
[  213.649947]  entry_SYSCALL_64_after_hwframe+0x4b/0x53
[  213.650478] RIP: 0033:0x7fa179b0737b
[  213.650893] Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c
               89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8
               10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d
               7d 2a 0f 00 f7 d8 64 89 01 48
[  213.652619] RSP: 002b:00007ffd2e6d46e8 EFLAGS: 00000246 ORIG_RAX:
               0000000000000010
[  213.653390] RAX: ffffffffffffffda RBX: 00007ffd2e6d47f8 RCX:
               00007fa179b0737b
[  213.654084] RDX: 00007ffd2e6d47e0 RSI: 00000000c0181b01 RDI:
               0000000000000003
[  213.654767] RBP: 00007ffd2e6d47c0 R08: 00007fa1799be010 R09:
               0000000000000002
[  213.655453] R10: 00007ffd2e6d4960 R11: 0000000000000246 R12:
               00007ffd2e6d487c
[  213.656170] R13: 0000000000000027 R14: 0000000000000001 R15:
               00007ffd2e6d4f70

Fixes: d98995b ("net/mlx5: Reimplement write combining test")
Signed-off-by: Yishai Hadas <[email protected]>
Reviewed-by: Michael Guralnik <[email protected]>
Reviewed-by: Larysa Zaremba <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
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4 participants