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2021-03-04tracing: Skip selftests if tracing is disabledSteven Rostedt (VMware)
If tracing is disabled for some reason (traceoff_on_warning, command line, etc), the ftrace selftests are guaranteed to fail, as their results are defined by trace data in the ring buffers. If the ring buffers are turned off, the tests will fail, due to lack of data. Because tracing being disabled is for a specific reason (warning, user decided to, etc), it does not make sense to enable tracing to run the self tests, as the test output may corrupt the reason for the tracing to be disabled. Instead, simply skip the self tests and report that they are being skipped due to tracing being disabled. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-03-04tracing: Fix memory leak in __create_synth_event()Vamshi K Sthambamkadi
kmemleak report: unreferenced object 0xc5a6f708 (size 8): comm "ftracetest", pid 1209, jiffies 4294911500 (age 6.816s) hex dump (first 8 bytes): 00 c1 3d 60 14 83 1f 8a ..=`.... backtrace: [<f0aa4ac4>] __kmalloc_track_caller+0x2a6/0x460 [<7d3d60a6>] kstrndup+0x37/0x70 [<45a0e739>] argv_split+0x1c/0x120 [<c17982f8>] __create_synth_event+0x192/0xb00 [<0708b8a3>] create_synth_event+0xbb/0x150 [<3d1941e1>] create_dyn_event+0x5c/0xb0 [<5cf8b9e3>] trace_parse_run_command+0xa7/0x140 [<04deb2ef>] dyn_event_write+0x10/0x20 [<8779ac95>] vfs_write+0xa9/0x3c0 [<ed93722a>] ksys_write+0x89/0xc0 [<b9ca0507>] __ia32_sys_write+0x15/0x20 [<7ce02d85>] __do_fast_syscall_32+0x45/0x80 [<cb0ecb35>] do_fast_syscall_32+0x29/0x60 [<2467454a>] do_SYSENTER_32+0x15/0x20 [<9beaa61d>] entry_SYSENTER_32+0xa9/0xfc unreferenced object 0xc5a6f078 (size 8): comm "ftracetest", pid 1209, jiffies 4294911500 (age 6.816s) hex dump (first 8 bytes): 08 f7 a6 c5 00 00 00 00 ........ backtrace: [<bbac096a>] __kmalloc+0x2b6/0x470 [<aa2624b4>] argv_split+0x82/0x120 [<c17982f8>] __create_synth_event+0x192/0xb00 [<0708b8a3>] create_synth_event+0xbb/0x150 [<3d1941e1>] create_dyn_event+0x5c/0xb0 [<5cf8b9e3>] trace_parse_run_command+0xa7/0x140 [<04deb2ef>] dyn_event_write+0x10/0x20 [<8779ac95>] vfs_write+0xa9/0x3c0 [<ed93722a>] ksys_write+0x89/0xc0 [<b9ca0507>] __ia32_sys_write+0x15/0x20 [<7ce02d85>] __do_fast_syscall_32+0x45/0x80 [<cb0ecb35>] do_fast_syscall_32+0x29/0x60 [<2467454a>] do_SYSENTER_32+0x15/0x20 [<9beaa61d>] entry_SYSENTER_32+0xa9/0xfc In __create_synth_event(), while iterating field/type arguments, the argv_split() will return array of atleast 2 elements even when zero arguments(argc=0) are passed. for e.g. when there is double delimiter or string ends with delimiter To fix call argv_free() even when argc=0. Link: https://lkml.kernel.org/r/20210304094521.GA1826@cosmos Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-03-04ring-buffer: Add a little more information and a WARN when time stamp going ↵Steven Rostedt (VMware)
backwards is detected When the CONFIG_RING_BUFFER_VALIDATE_TIME_DELTAS is enabled, and the time stamps are detected as not being valid, it reports information about the write stamp, but does not show the before_stamp which is still useful information. Also, it should give a warning once, such that tests detect this happening. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-03-04ring-buffer: Force before_stamp and write_stamp to be different on discardSteven Rostedt (VMware)
Part of the logic of the new time stamp code depends on the before_stamp and the write_stamp to be different if the write_stamp does not match the last event on the buffer, as it will be used to calculate the delta of the next event written on the buffer. The discard logic depends on this, as the next event to come in needs to inject a full timestamp as it can not rely on the last event timestamp in the buffer because it is unknown due to events after it being discarded. But by changing the write_stamp back to the time before it, it forces the next event to use a full time stamp, instead of relying on it. The issue came when a full time stamp was used for the event, and rb_time_delta() returns zero in that case. The update to the write_stamp (which subtracts delta) made it not change. Then when the event is removed from the buffer, because the before_stamp and write_stamp still match, the next event written would calculate its delta from the write_stamp, but that would be wrong as the write_stamp is of the time of the event that was discarded. In the case that the delta change being made to write_stamp is zero, set the before_stamp to zero as well, and this will force the next event to inject a full timestamp and not use the current write_stamp. Cc: stable@vger.kernel.org Fixes: a389d86f7fd09 ("ring-buffer: Have nested events still record running time stamp") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-03-04tracing: Fix help text of TRACEPOINT_BENCHMARK in KconfigRolf Eike Beer
It's "cond_resched()" not "cond_sched()". Link: https://lkml.kernel.org/r/1863065.aFVDpXsuPd@devpool47 Signed-off-by: Rolf Eike Beer <eb@emlix.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-03-04tracing: Remove duplicate declaration from trace.hYordan Karadzhov (VMware)
A declaration of function "int trace_empty(struct trace_iterator *iter)" shows up twice in the header file kernel/trace/trace.h Link: https://lkml.kernel.org/r/20210304092348.208033-1-y.karadz@gmail.com Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-03-04io-wq: ensure all pending work is canceled on exitJens Axboe
If we race on shutting down the io-wq, then we should ensure that any work that was queued after workers shutdown is canceled. Harden the add work check a bit too, checking for IO_WQ_BIT_EXIT and cancel if it's set. Add a WARN_ON() for having any work before we kill the io-wq context. Reported-by: syzbot+91b4b56ead187d35c9d3@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: ensure that threads freeze on suspendJens Axboe
Alex reports that his system fails to suspend using 5.12-rc1, with the following dump: [ 240.650300] PM: suspend entry (deep) [ 240.650748] Filesystems sync: 0.000 seconds [ 240.725605] Freezing user space processes ... [ 260.739483] Freezing of tasks failed after 20.013 seconds (3 tasks refusing to freeze, wq_busy=0): [ 260.739497] task:iou-mgr-446 state:S stack: 0 pid: 516 ppid: 439 flags:0x00004224 [ 260.739504] Call Trace: [ 260.739507] ? sysvec_apic_timer_interrupt+0xb/0x81 [ 260.739515] ? pick_next_task_fair+0x197/0x1cde [ 260.739519] ? sysvec_reschedule_ipi+0x2f/0x6a [ 260.739522] ? asm_sysvec_reschedule_ipi+0x12/0x20 [ 260.739525] ? __schedule+0x57/0x6d6 [ 260.739529] ? del_timer_sync+0xb9/0x115 [ 260.739533] ? schedule+0x63/0xd5 [ 260.739536] ? schedule_timeout+0x219/0x356 [ 260.739540] ? __next_timer_interrupt+0xf1/0xf1 [ 260.739544] ? io_wq_manager+0x73/0xb1 [ 260.739549] ? io_wq_create+0x262/0x262 [ 260.739553] ? ret_from_fork+0x22/0x30 [ 260.739557] task:iou-mgr-517 state:S stack: 0 pid: 522 ppid: 439 flags:0x00004224 [ 260.739561] Call Trace: [ 260.739563] ? sysvec_apic_timer_interrupt+0xb/0x81 [ 260.739566] ? pick_next_task_fair+0x16f/0x1cde [ 260.739569] ? sysvec_apic_timer_interrupt+0xb/0x81 [ 260.739571] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 260.739574] ? __schedule+0x5b7/0x6d6 [ 260.739578] ? del_timer_sync+0x70/0x115 [ 260.739581] ? schedule_timeout+0x211/0x356 [ 260.739585] ? __next_timer_interrupt+0xf1/0xf1 [ 260.739588] ? io_wq_check_workers+0x15/0x11f [ 260.739592] ? io_wq_manager+0x69/0xb1 [ 260.739596] ? io_wq_create+0x262/0x262 [ 260.739600] ? ret_from_fork+0x22/0x30 [ 260.739603] task:iou-wrk-517 state:S stack: 0 pid: 523 ppid: 439 flags:0x00004224 [ 260.739607] Call Trace: [ 260.739609] ? __schedule+0x5b7/0x6d6 [ 260.739614] ? schedule+0x63/0xd5 [ 260.739617] ? schedule_timeout+0x219/0x356 [ 260.739621] ? __next_timer_interrupt+0xf1/0xf1 [ 260.739624] ? task_thread.isra.0+0x148/0x3af [ 260.739628] ? task_thread_unbound+0xa/0xa [ 260.739632] ? task_thread_bound+0x7/0x7 [ 260.739636] ? ret_from_fork+0x22/0x30 [ 260.739647] OOM killer enabled. [ 260.739648] Restarting tasks ... done. [ 260.740077] PM: suspend exit Play nice and ensure that any thread we create will call try_to_freeze() at an opportune time so that memory suspend can proceed. For the io-wq worker threads, mark them as PF_NOFREEZE. They could potentially be blocked for a long time. Reported-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca> Tested-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: remove extra in_idle wake upPavel Begunkov
io_dismantle_req() is always followed by io_put_task(), which already do proper in_idle wake ups, so we can skip waking the owner task in io_dismantle_req(). The rules are simpler now, do io_put_task() shortly after ending a request, and it will be fine. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: inline __io_queue_async_work()Pavel Begunkov
__io_queue_async_work() is only called from io_queue_async_work(), inline it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: inline io_req_clean_work()Pavel Begunkov
Inline io_req_clean_work(), less code and easier to analyse tctx dependencies and refs usage. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: choose right tctx->io_wq for try cancelPavel Begunkov
When we cancel SQPOLL, @task in io_uring_try_cancel_requests() will differ from current. Use the right tctx from passed in @task, and don't forget that it can be NULL when the io_uring ctx exits. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: fix -EAGAIN retry with IOPOLLJens Axboe
We no longer revert the iovec on -EIOCBQUEUED, see commit ab2125df921d, and this started causing issues for IOPOLL on devies that run out of request slots. Turns out what outside of needing a revert for those, we also had a bug where we didn't properly setup retry inside the submission path. That could cause re-import of the iovec, if any, and that could lead to spurious results if the application had those allocated on the stack. Catch -EAGAIN retry and make the iovec stable for IOPOLL, just like we do for !IOPOLL retries. Cc: <stable@vger.kernel.org> # 5.9+ Reported-by: Abaci Robot <abaci@linux.alibaba.com> Reported-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io-wq: fix error path leak of buffered write hash mapJens Axboe
The 'err' path should include the hash put, we already grabbed a reference once we get that far. Fixes: e941894eae31 ("io-wq: make buffered file write hashed work map per-ctx") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: remove sqo_taskPavel Begunkov
Now, sqo_task is used only for a warning that is not interesting anymore since sqo_dead is gone, remove all of that including ctx->sqo_task. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: kill sqo_dead and sqo submission haltingPavel Begunkov
As SQPOLL task doesn't poke into ->sqo_task anymore, there is no need to kill the sqo when the master task exits. Before it was necessary to avoid races accessing sqo_task->files with removing them. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> [axboe: don't forget to enable SQPOLL before exit, if started disabled] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: ignore double poll add on the same waitqueue headJens Axboe
syzbot reports a deadlock, attempting to lock the same spinlock twice: ============================================ WARNING: possible recursive locking detected 5.11.0-syzkaller #0 Not tainted -------------------------------------------- swapper/1/0 is trying to acquire lock: ffff88801b2b1130 (&runtime->sleep){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline] ffff88801b2b1130 (&runtime->sleep){..-.}-{2:2}, at: io_poll_double_wake+0x25f/0x6a0 fs/io_uring.c:4960 but task is already holding lock: ffff88801b2b3130 (&runtime->sleep){..-.}-{2:2}, at: __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&runtime->sleep); lock(&runtime->sleep); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by swapper/1/0: #0: ffff888147474908 (&group->lock){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x9f/0xd0 sound/core/pcm_native.c:170 #1: ffff88801b2b3130 (&runtime->sleep){..-.}-{2:2}, at: __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 stack backtrace: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.11.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0xfa/0x151 lib/dump_stack.c:120 print_deadlock_bug kernel/locking/lockdep.c:2829 [inline] check_deadlock kernel/locking/lockdep.c:2872 [inline] validate_chain kernel/locking/lockdep.c:3661 [inline] __lock_acquire.cold+0x14c/0x3b4 kernel/locking/lockdep.c:4900 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] io_poll_double_wake+0x25f/0x6a0 fs/io_uring.c:4960 __wake_up_common+0x147/0x650 kernel/sched/wait.c:108 __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:138 snd_pcm_update_state+0x46a/0x540 sound/core/pcm_lib.c:203 snd_pcm_update_hw_ptr0+0xa75/0x1a50 sound/core/pcm_lib.c:464 snd_pcm_period_elapsed+0x160/0x250 sound/core/pcm_lib.c:1805 dummy_hrtimer_callback+0x94/0x1b0 sound/drivers/dummy.c:378 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1583 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1600 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 invoke_softirq kernel/softirq.c:221 [inline] __irq_exit_rcu kernel/softirq.c:422 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:434 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 </IRQ> asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:137 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] RIP: 0010:acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:516 Code: dd 38 6e f8 84 db 75 ac e8 54 32 6e f8 e8 0f 1c 74 f8 e9 0c 00 00 00 e8 45 32 6e f8 0f 00 2d 4e 4a c5 00 e8 39 32 6e f8 fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 14 3a 6e f8 48 85 db RSP: 0018:ffffc90000d47d18 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8880115c3780 RSI: ffffffff89052537 RDI: 0000000000000000 RBP: ffff888141127064 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff81794168 R11: 0000000000000000 R12: 0000000000000001 R13: ffff888141127000 R14: ffff888141127064 R15: ffff888143331804 acpi_idle_enter+0x361/0x500 drivers/acpi/processor_idle.c:647 cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3e1/0x590 kernel/sched/idle.c:300 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:397 start_secondary+0x274/0x350 arch/x86/kernel/smpboot.c:272 secondary_startup_64_no_verify+0xb0/0xbb which is due to the driver doing poll_wait() twice on the same wait_queue_head. That is perfectly valid, but from checking the rest of the kernel tree, it's the only driver that does this. We can handle this just fine, we just need to ignore the second addition as we'll get woken just fine on the first one. Cc: stable@vger.kernel.org # 5.8+ Fixes: 18bceab101ad ("io_uring: allow POLL_ADD with double poll_wait() users") Reported-by: syzbot+28abd693db9e92c160d8@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: ensure that SQPOLL thread is started for exitJens Axboe
If we create it in a disabled state because IORING_SETUP_R_DISABLED is set on ring creation, we need to ensure that we've kicked the thread if we're exiting before it's been explicitly disabled. Otherwise we can run into a deadlock where exit is waiting go park the SQPOLL thread, but the SQPOLL thread itself is waiting to get a signal to start. That results in the below trace of both tasks hung, waiting on each other: INFO: task syz-executor458:8401 blocked for more than 143 seconds. Not tainted 5.11.0-next-20210226-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor458 state:D stack:27536 pid: 8401 ppid: 8400 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5075 schedule+0xcf/0x270 kernel/sched/core.c:5154 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 io_sq_thread_park fs/io_uring.c:7115 [inline] io_sq_thread_park+0xd5/0x130 fs/io_uring.c:7103 io_uring_cancel_task_requests+0x24c/0xd90 fs/io_uring.c:8745 __io_uring_files_cancel+0x110/0x230 fs/io_uring.c:8840 io_uring_files_cancel include/linux/io_uring.h:47 [inline] do_exit+0x299/0x2a60 kernel/exit.c:780 do_group_exit+0x125/0x310 kernel/exit.c:922 __do_sys_exit_group kernel/exit.c:933 [inline] __se_sys_exit_group kernel/exit.c:931 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x43e899 RSP: 002b:00007ffe89376d48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00000000004af2f0 RCX: 000000000043e899 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000010000000 R10: 0000000000008011 R11: 0000000000000246 R12: 00000000004af2f0 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 INFO: task iou-sqp-8401:8402 can't die for more than 143 seconds. task:iou-sqp-8401 state:D stack:30272 pid: 8402 ppid: 8400 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5075 schedule+0xcf/0x270 kernel/sched/core.c:5154 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 io_sq_thread+0x27d/0x1ae0 fs/io_uring.c:6717 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INFO: task iou-sqp-8401:8402 blocked for more than 143 seconds. Reported-by: syzbot+fb5458330b4442f2090d@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: replace cmpxchg in fallback with xchgPavel Begunkov
io_run_ctx_fallback() can use xchg() instead of cmpxchg(). It's simpler and faster. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: fix __tctx_task_work() ctx racePavel Begunkov
There is an unlikely but possible race using a freed context. That's because req->task_work.func() can free a request, but we won't necessarily find a completion in submit_state.comp and so all ctx refs may be put by the time we do mutex_lock(&ctx->uring_ctx); There are several reasons why it can miss going through submit_state.comp: 1) req->task_work.func() didn't complete it itself, but punted to iowq (e.g. reissue) and it got freed later, or a similar situation with it overflowing and getting flushed by someone else, or being submitted to IRQ completion, 2) As we don't hold the uring_lock, someone else can do io_submit_flush_completions() and put our ref. 3) Bugs and code obscurities, e.g. failing to propagate issue_flags properly. One example is as follows CPU1 | CPU2 ======================================================================= @req->task_work.func() | -> @req overflwed, | so submit_state.comp,nr==0 | | flush overflows, and free @req | ctx refs == 0, free it ctx is dead, but we do | lock + flush + unlock | So take a ctx reference for each new ctx we see in __tctx_task_work(), and do release it until we do all our flushing. Fixes: 65453d1efbd2 ("io_uring: enable req cache for task_work items") Reported-by: syzbot+a157ac7c03a56397f553@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> [axboe: fold in my one-liner and fix ref mismatch] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: kill io_uring_flush()Jens Axboe
This was always a weird work-around or file referencing, and we don't need it anymore. Get rid of it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: kill unnecessary io_run_ctx_fallback() in io_ring_exit_work()Jens Axboe
We already run the fallback task_work in io_uring_try_cancel_requests(), no need to duplicate at ring exit explicitly. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: move cred assignment into io_issue_sqe()Jens Axboe
If we move it in there, then we no longer have to care about it in io-wq. This means we can drop the cred handling in io-wq, and we can drop the REQ_F_WORK_INITIALIZED flag and async init functions as that was the last user of it since we moved to the new workers. Then we can also drop io_wq_work->creds, and just hold the personality u16 in there instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: kill unnecessary REQ_F_WORK_INITIALIZED checksJens Axboe
We're no longer checking anything that requires the work item to be initialized, as we're not carrying any file related state there. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: remove unused argument 'tsk' from io_req_caches_free()Jens Axboe
We prune the full cache regardless, get rid of the dead argument. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: destroy io-wq on execPavel Begunkov
Destroy current's io-wq backend and tctx on __io_uring_task_cancel(), aka exec(). Looks it's not strictly necessary, because it will be done at some point when the task dies and changes of creds/files/etc. are handled, but better to do that earlier to free io-wq and not potentially lock previous mm and other resources for the time being. It's safe to do because we wait for all requests of the current task to complete, so no request will use tctx afterwards. Note, that io_uring_files_cancel() may leave some requests for later reaping, so it leaves tctx intact, that's ok as the task is dying anyway. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: warn on not destroyed io-wqPavel Begunkov
Make sure that we killed an io-wq by the time a task is dead. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: fix race condition in task_work add and clearJens Axboe
We clear the bit marking the ctx task_work as active after having run the queued work, but we really should be clearing it before. Otherwise we can hit a tiny race ala: CPU0 CPU1 io_task_work_add() tctx_task_work() run_work add_to_list test_and_set_bit clear_bit already set and CPU0 will return thinking the task_work is queued, while in reality it's already being run. If we hit the condition after __tctx_task_work() found no more work, but before we've cleared the bit, then we'll end up thinking it's queued and will be run. In reality it is queued, but we didn't queue the ctx task_work to ensure that it gets run. Fixes: 7cbf1722d5fc ("io_uring: provide FIFO ordering for task_work") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io-wq: provide an io_wq_put_and_exit() helperJens Axboe
If we put the io-wq from io_uring, we really want it to exit. Provide a helper that does that for us. Couple that with not having the manager hold a reference to the 'wq' and the normal SQPOLL exit will tear down the io-wq context appropriate. On the io-wq side, our wq context is per task, so only the task itself is manipulating ->manager and hence it's safe to check and clear without any extra locking. We just need to ensure that the manager task stays around, in case it exits. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: don't use complete_all() on SQPOLL thread exitJens Axboe
We want to reuse this completion, and a single complete should do just fine. Ensure that we park ourselves first if requested, as that is what lead to the initial deadlock in this area. If we've got someone attempting to park us, then we can't proceed without having them finish first. Fixes: 37d1e2e3642e ("io_uring: move SQPOLL thread io-wq forked worker") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: run fallback on cancellationPavel Begunkov
io_uring_try_cancel_requests() matches not only current's requests, but also of other exiting tasks, so we need to actively cancel them and not just wait, especially since the function can be called on flush during do_exit() -> exit_files(). Even if it's not a problem for now, it's much nicer to know that the function tries to cancel everything it can. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: SQPOLL stop error handling fixesJens Axboe
If we fail to fork an SQPOLL worker, we can hit cancel, and hence attempted thread stop, with the thread already being stopped. Ensure we check for that. Also guard thread stop fully by the sqd mutex, just like we do for park. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io-wq: fix double put of 'wq' in error pathJens Axboe
We are already freeing the wq struct in both spots, so don't put it and get it freed twice. Reported-by: syzbot+7bf785eedca35ca05501@syzkaller.appspotmail.com Fixes: 4fb6ac326204 ("io-wq: improve manager/worker handling over exec") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io-wq: wait for manager exit on wq destroyJens Axboe
The manager waits for the workers, hence the manager is always valid if workers are running. Now also have wq destroy wait for the manager on exit, so we now everything is gone. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io-wq: rename wq->done completion to wq->startedJens Axboe
This is a leftover from a different use cases, it's used to wait for the manager to startup. Rename it as such. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io-wq: don't ask for a new worker if we're exitingJens Axboe
If we're in the process of shutting down the async context, then don't create new workers if we already have at least the fixed one. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io-wq: have manager wait for all workers to exitJens Axboe
Instead of having to wait separately on workers and manager, just have the manager wait on the workers. We use an atomic_t for the reference here, as we need to start at 0 and allow increment from that. Since the number of workers is naturally capped by the allowed nr of processes, and that uses an int, there is no risk of overflow. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04iommu/vt-d: Fix status code for Allocate/Free PASID commandZenghui Yu
As per Intel vt-d spec, Rev 3.0 (section 10.4.45 "Virtual Command Response Register"), the status code of "No PASID available" error in response to the Allocate PASID command is 2, not 1. The same for "Invalid PASID" error in response to the Free PASID command. We will otherwise see confusing kernel log under the command failure from guest side. Fix it. Fixes: 24f27d32ab6b ("iommu/vt-d: Enlightened PASID allocation") Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20210227073909.432-1-yuzenghui@huawei.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-03-04iommu: Don't use lazy flush for untrusted deviceLu Baolu
The lazy IOTLB flushing setup leaves a time window, in which the device can still access some system memory, which has already been unmapped by the device driver. It's not suitable for untrusted devices. A malicious device might use this to attack the system by obtaining data that it shouldn't obtain. Fixes: c588072bba6b5 ("iommu/vt-d: Convert intel iommu driver to the iommu ops") Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20210225061454.2864009-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-03-04iommu/tegra-smmu: Fix mc errors on tegra124-nyanNicolin Chen
Commit 25938c73cd79 ("iommu/tegra-smmu: Rework tegra_smmu_probe_device()") removed certain hack in the tegra_smmu_probe() by relying on IOMMU core to of_xlate SMMU's SID per device, so as to get rid of tegra_smmu_find() and tegra_smmu_configure() that are typically done in the IOMMU core also. This approach works for both existing devices that have DT nodes and other devices (like PCI device) that don't exist in DT, on Tegra210 and Tegra3 upon testing. However, Page Fault errors are reported on tegra124-Nyan: tegra-mc 70019000.memory-controller: display0a: read @0xfe056b40: EMEM address decode error (SMMU translation error [--S]) tegra-mc 70019000.memory-controller: display0a: read @0xfe056b40: Page fault (SMMU translation error [--S]) After debugging, I found that the mentioned commit changed some function callback sequence of tegra-smmu's, resulting in enabling SMMU for display client before display driver gets initialized. I couldn't reproduce exact same issue on Tegra210 as Tegra124 (arm-32) differs at arch-level code. Actually this Page Fault is a known issue, as on most of Tegra platforms, display gets enabled by the bootloader for the splash screen feature, so it keeps filling the framebuffer memory. A proper fix to this issue is to 1:1 linear map the framebuffer memory to IOVA space so the SMMU will have the same address as the physical address in its page table. Yet, Thierry has been working on the solution above for a year, and it hasn't merged. Therefore, let's partially revert the mentioned commit to fix the errors. The reason why we do a partial revert here is that we can still set priv in ->of_xlate() callback for PCI devices. Meanwhile, devices existing in DT, like display, will go through tegra_smmu_configure() at the stage of bus_set_iommu() when SMMU gets probed(), as what it did before we merged the mentioned commit. Once we have the linear map solution for framebuffer memory, this change can be cleaned away. [Big thank to Guillaume who reported and helped debugging/verification] Fixes: 25938c73cd79 ("iommu/tegra-smmu: Rework tegra_smmu_probe_device()") Reported-by: Guillaume Tucker <guillaume.tucker@collabora.com> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Tested-by: Guillaume Tucker <guillaume.tucker@collabora.com> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20210218220702.1962-1-nicoleotsuka@gmail.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-03-04iommu/amd: Fix sleeping in atomic in increase_address_space()Andrey Ryabinin
increase_address_space() calls get_zeroed_page(gfp) under spin_lock with disabled interrupts. gfp flags passed to increase_address_space() may allow sleeping, so it comes to this: BUG: sleeping function called from invalid context at mm/page_alloc.c:4342 in_atomic(): 1, irqs_disabled(): 1, pid: 21555, name: epdcbbf1qnhbsd8 Call Trace: dump_stack+0x66/0x8b ___might_sleep+0xec/0x110 __alloc_pages_nodemask+0x104/0x300 get_zeroed_page+0x15/0x40 iommu_map_page+0xdd/0x3e0 amd_iommu_map+0x50/0x70 iommu_map+0x106/0x220 vfio_iommu_type1_ioctl+0x76e/0x950 [vfio_iommu_type1] do_vfs_ioctl+0xa3/0x6f0 ksys_ioctl+0x66/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x4e/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix this by moving get_zeroed_page() out of spin_lock/unlock section. Fixes: 754265bcab ("iommu/amd: Fix race in increase_address_space()") Signed-off-by: Andrey Ryabinin <arbn@yandex-team.com> Acked-by: Will Deacon <will@kernel.org> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210217143004.19165-1-arbn@yandex-team.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-03-03drm/amdgpu: fix parameter error of RREG32_PCIE() in amdgpu_regs_pcieKevin Wang
the register offset isn't needed division by 4 to pass RREG32_PCIE() Signed-off-by: Kevin Wang <kevin1.wang@amd.com> Reviewed-by: Lijo Lazar <lijo.lazar@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2021-03-03drm/amd/display: fix the return of the uninitialized value in retColin Ian King
Currently if stream->signal is neither SIGNAL_TYPE_DISPLAY_PORT_MST or SIGNAL_TYPE_DISPLAY_PORT then variable ret is uninitialized and this is checked for > 0 at the end of the function. Ret should be initialized, I believe setting it to zero is a correct default. Addresses-Coverity: ("Uninitialized scalar variable") Fixes: bd0c064c161c ("drm/amd/display: Add return code instead of boolean for future use") Reviewed-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2021-03-03drm/amdgpu: enable BACO runpm by default on sienna cichlid and navy flounderAlex Deucher
It works fine and was only disabled because primary GPUs don't enter runpm if there is a console bound to the fbdev due to the kmap. This will at least allow runpm on secondary cards. Reviewed-by: Evan Quan <evan.quan@amd.com> Reviewed-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2021-03-03drm/amd/pm: correct Arcturus mmTHM_BACO_CNTL register addressEvan Quan
Arcturus has a different register address from other SMU V11 ASICs. Signed-off-by: Evan Quan <evan.quan@amd.com> Acked-by: Guchun Chen <guchun.chen@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2021-03-03drm/amdgpu/swsmu/vangogh: Only use RLCPowerNotify msg for disableAlex Deucher
Per discussions with PMFW team, the driver only needs to notify the PMFW when the RLC is disabled. The RLC FW will notify the PMFW directly when it's enabled. Acked-by: Evan Quan <evan.quan@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2021-03-03drm/amdgpu/pm: make unsupported power profile messages debugAlex Deucher
Making them an error confuses users and the errors are harmless as not all asics support all profiles. Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1488 Acked-by: Nirmoy Das <nirmoy.das@amd.com> Reviewed-by: Evan Quan <evan.quan@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2021-03-03drm/amdgpu:disable VCN for Navi12 SKUAsher.Song
Navi12 0x7360/C7 SKU has no video support, so remove it. Reviewed-by: Guchun Chen <guchun.chen@amd.com> Signed-off-by: Asher.Song <Asher.Song@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2021-03-03drm/amdgpu: Only check for S0ix if AMD_PMC is configuredAlex Deucher
The S0ix check only makes sense if the AMD PMC driver is present. We need to use the legacy S3 pathes when the PMC driver is not present. Reviewed-by: Prike Liang <Prike.Liang@amd.com> Reviewed-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2021-03-03ACPI: bus: Constify is_acpi_node() and friends (part 2)Andy Shevchenko
Commit 8b9d6802583a ("ACPI: Constify acpi_bus helper functions, switch to macros") only changed functions for CONFIG_ACPI=y case. This part adjusts the rest. Fixes: 8b9d6802583a ("ACPI: Constify acpi_bus helper functions, switch to macros") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>