kernel/fs/io_uring.c, branch linux-5.1.y

signal: remove the wrong signal_pending() check in restore_user_sigmask()

2019-07-10T07:52:20Z

commit 97abc889ee296faf95ca0e978340fb7b942a3e32 upstream. This is the minimal fix for stable, I'll send cleanups later. Commit 854a6ed56839 ("signal: Add restore_user_sigmask()") introduced the visible change which breaks user-space: a signal temporary unblocked by set_user_sigmask() can be delivered even if the caller returns success or timeout. Change restore_user_sigmask() to accept the additional "interrupted" argument which should be used instead of signal_pending() check, and update the callers. Eric said: : For clarity. I don't think this is required by posix, or fundamentally to : remove the races in select. It is what linux has always done and we have : applications who care so I agree this fix is needed. : : Further in any case where the semantic change that this patch rolls back : (aka where allowing a signal to be delivered and the select like call to : complete) would be advantage we can do as well if not better by using : signalfd. : : Michael is there any chance we can get this guarantee of the linux : implementation of pselect and friends clearly documented. The guarantee : that if the system call completes successfully we are guaranteed that no : signal that is unblocked by using sigmask will be delivered? Link: http://lkml.kernel.org/r/20190604134117.GA29963@redhat.com Fixes: 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add restore_user_sigmask()") Signed-off-by: Oleg Nesterov Reported-by: Eric Wong Tested-by: Eric Wong Acked-by: "Eric W. Biederman" Acked-by: Arnd Bergmann Acked-by: Deepa Dinamani Cc: Michael Kerrisk Cc: Jens Axboe Cc: Davidlohr Bueso Cc: Jason Baron Cc: Thomas Gleixner Cc: Al Viro Cc: David Laight Cc: [5.0+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

io_uring: ensure req->file is cleared on allocation

2019-07-03T11:13:38Z

commit 60c112b0ada09826cc4ae6a4e55df677f76f1313 upstream. Stephen reports: I hit the following General Protection Fault when testing io_uring via the io_uring engine in fio. This was on a VM running 5.2-rc5 and the latest version of fio. The issue occurs for both null_blk and fake NVMe drives. I have not tested bare metal or real NVMe SSDs. The fio script used is given below. [io_uring] time_based=1 runtime=60 filename=/dev/nvme2n1 (note /dev/nullb0 also fails) ioengine=io_uring bs=4k rw=readwrite direct=1 fixedbufs=1 sqthread_poll=1 sqthread_poll_cpu=0 general protection fault: 0000 [#1] SMP PTI CPU: 0 PID: 872 Comm: io_uring-sq Not tainted 5.2.0-rc5-cpacket-io-uring #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 RIP: 0010:fput_many+0x7/0x90 Code: 01 48 85 ff 74 17 55 48 89 e5 53 48 8b 1f e8 a0 f9 ff ff 48 85 db 48 89 df 75 f0 5b 5d f3 c3 0f 1f 40 00 0f 1f 44 00 00 89 f6 48 29 77 38 74 01 c3 55 48 89 e5 53 48 89 fb 65 48 \ RSP: 0018:ffffadeb817ebc50 EFLAGS: 00010246 RAX: 0000000000000004 RBX: ffff8f46ad477480 RCX: 0000000000001805 RDX: 0000000000000000 RSI: 0000000000000001 RDI: f18b51b9a39552b5 RBP: ffffadeb817ebc58 R08: ffff8f46b7a318c0 R09: 000000000000015d R10: ffffadeb817ebce8 R11: 0000000000000020 R12: ffff8f46ad4cd000 R13: 00000000fffffff7 R14: ffffadeb817ebe30 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff8f46b7a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055828f0bbbf0 CR3: 0000000232176004 CR4: 00000000003606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? fput+0x13/0x20 io_free_req+0x20/0x40 io_put_req+0x1b/0x20 io_submit_sqe+0x40a/0x680 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 io_submit_sqes+0xb9/0x160 ? io_submit_sqes+0xb9/0x160 ? __switch_to_asm+0x40/0x70 ? __switch_to_asm+0x34/0x70 ? __schedule+0x3f2/0x6a0 ? __switch_to_asm+0x34/0x70 io_sq_thread+0x1af/0x470 ? __switch_to_asm+0x34/0x70 ? wait_woken+0x80/0x80 ? __switch_to+0x85/0x410 ? __switch_to_asm+0x40/0x70 ? __switch_to_asm+0x34/0x70 ? __schedule+0x3f2/0x6a0 kthread+0x105/0x140 ? io_submit_sqes+0x160/0x160 ? kthread+0x105/0x140 ? io_submit_sqes+0x160/0x160 ? kthread_destroy_worker+0x50/0x50 ret_from_fork+0x35/0x40 which occurs because using a kernel side submission thread isn't valid without using fixed files (registered through io_uring_register()). This causes io_uring to put the request after logging an error, but before the file field is set in the request. If it happens to be non-zero, we attempt to fput() garbage. Fix this by ensuring that req->file is initialized when the request is allocated. Cc: stable@vger.kernel.org # 5.1+ Reported-by: Stephen Bates Tested-by: Stephen Bates Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: Fix __io_uring_register() false success

2019-06-22T06:09:10Z

[ Upstream commit a278682dad37fd2f8d2f30d8e84e376a856ab472 ] If io_copy_iov() fails, it will break the loop and report success, albeit partially completed operation. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

io_uring: fix memory leak of UNIX domain socket inode

2019-06-19T06:00:02Z

commit 355e8d26f719c207aa2e00e6f3cfab3acf21769b upstream. Opening and closing an io_uring instance leaks a UNIX domain socket inode. This is because the ->file of the io_uring instance's internal UNIX domain socket is set to point to the io_uring file, but then sock_release() sees the non-NULL ->file and assumes the inode reference is held by the file so doesn't call iput(). That's not the case here, since the reference is still meant to be held by the socket; the actual inode of the io_uring file is different. Fix this leak by NULL-ing out ->file before releasing the socket. Reported-by: syzbot+111cb28d9f583693aefa@syzkaller.appspotmail.com Fixes: 2b188cc1bb85 ("Add io_uring IO interface") Cc: # v5.1+ Signed-off-by: Eric Biggers Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: fix failure to verify SQ_AFF cpu

2019-06-15T09:53:06Z

commit 44a9bd18a0f06bba19d155aeaa11e2edce898293 upstream. The test case we have is rightfully failing with the current kernel: io_uring_setup(1, 0x7ffe2cafebe0), flags: IORING_SETUP_SQPOLL|IORING_SETUP_SQ_AFF, resv: 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000, sq_thread_cpu: 4 expected -1, got 3 This is in a vm, and CPU3 is the last valid one, hence asking for 4 should fail the setup with -EINVAL, not succeed. The problem is that we're using array_index_nospec() with nr_cpu_ids as the index, hence we wrap and end up using CPU0 instead of CPU4. This makes the setup succeed where it should be failing. We don't need to use array_index_nospec() as we're not indexing any array with this. Instead just compare with nr_cpu_ids directly. This is fine as we're checking with cpu_online() afterwards. Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: use cpu_online() to check p->sq_thread_cpu instead of cpu_possible()

2019-05-31T13:43:14Z

[ Upstream commit 7889f44dd9cee15aff1c3f7daf81ca4dfed48fc7 ] This issue is found by running liburing/test/io_uring_setup test. When test run, the testcase "attempt to bind to invalid cpu" would not pass with messages like: io_uring_setup(1, 0xbfc2f7c8), \ flags: IORING_SETUP_SQPOLL|IORING_SETUP_SQ_AFF, \ resv: 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000, \ sq_thread_cpu: 2 expected -1, got 3 FAIL On my system, there is: CPU(s) possible : 0-3 CPU(s) online : 0-1 CPU(s) offline : 2-3 CPU(s) present : 0-1 The sq_thread_cpu 2 is offline on my system, so the bind should fail. But cpu_possible() will pass the check. We shouldn't be able to bind to an offline cpu. Use cpu_online() to do the check. After the change, the testcase run as expected: EINVAL will be returned for cpu offlined. Reviewed-by: Jeff Moyer Signed-off-by: Shenghui Wang Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

io_uring: avoid page allocation warnings

2019-05-01T16:00:25Z

In io_sqe_buffer_register() we allocate a number of arrays based on the iov_len from the user-provided iov. While we limit iov_len to SZ_1G, we can still attempt to allocate arrays exceeding MAX_ORDER. On a 64-bit system with 4KiB pages, for an iov where iov_base = 0x10 and iov_len = SZ_1G, we'll calculate that nr_pages = 262145. When we try to allocate a corresponding array of (16-byte) bio_vecs, requiring 4194320 bytes, which is greater than 4MiB. This results in SLUB warning that we're trying to allocate greater than MAX_ORDER, and failing the allocation. Avoid this by using kvmalloc() for allocations dependent on the user-provided iov_len. At the same time, fix a leak of imu->bvec when registration fails. Full splat from before this patch: WARNING: CPU: 1 PID: 2314 at mm/page_alloc.c:4595 __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2314 Comm: syz-executor326 Not tainted 5.1.0-rc7-dirty #4 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x2f0 include/linux/compiler.h:193 show_stack+0x20/0x30 arch/arm64/kernel/traps.c:158 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x110/0x190 lib/dump_stack.c:113 panic+0x384/0x68c kernel/panic.c:214 __warn+0x2bc/0x2c0 kernel/panic.c:571 report_bug+0x228/0x2d8 lib/bug.c:186 bug_handler+0xa0/0x1a0 arch/arm64/kernel/traps.c:956 call_break_hook arch/arm64/kernel/debug-monitors.c:301 [inline] brk_handler+0x1d4/0x388 arch/arm64/kernel/debug-monitors.c:316 do_debug_exception+0x1a0/0x468 arch/arm64/mm/fault.c:831 el1_dbg+0x18/0x8c __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 alloc_pages_current+0x164/0x278 mm/mempolicy.c:2132 alloc_pages include/linux/gfp.h:509 [inline] kmalloc_order+0x20/0x50 mm/slab_common.c:1231 kmalloc_order_trace+0x30/0x2b0 mm/slab_common.c:1243 kmalloc_large include/linux/slab.h:480 [inline] __kmalloc+0x3dc/0x4f0 mm/slub.c:3791 kmalloc_array include/linux/slab.h:670 [inline] io_sqe_buffer_register fs/io_uring.c:2472 [inline] __io_uring_register fs/io_uring.c:2962 [inline] __do_sys_io_uring_register fs/io_uring.c:3008 [inline] __se_sys_io_uring_register fs/io_uring.c:2990 [inline] __arm64_sys_io_uring_register+0x9e0/0x1bc8 fs/io_uring.c:2990 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall arch/arm64/kernel/syscall.c:47 [inline] el0_svc_common.constprop.0+0x148/0x2e0 arch/arm64/kernel/syscall.c:83 el0_svc_handler+0xdc/0x100 arch/arm64/kernel/syscall.c:129 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:948 SMP: stopping secondary CPUs Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled CPU features: 0x002,23000438 Memory Limit: none Rebooting in 1 seconds.. Fixes: edafccee56ff3167 ("io_uring: add support for pre-mapped user IO buffers") Signed-off-by: Mark Rutland Cc: Alexander Viro Cc: Jens Axboe Cc: linux-fsdevel@vger.kernel.org Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Jens Axboe

io_uring: drop req submit reference always in async punt

2019-05-01T14:38:47Z

If we don't end up actually calling submit in io_sq_wq_submit_work(), we still need to drop the submit reference to the request. If we don't, then we can leak the request. This can happen if we race with ring shutdown while flushing the workqueue for requests that require use of the mm_struct. Fixes: e65ef56db494 ("io_uring: use regular request ref counts") Signed-off-by: Jens Axboe

io_uring: free allocated io_memory once

2019-05-01T14:38:47Z

If io_allocate_scq_urings() fails to allocate an sq_* region, it will call io_mem_free() for any previously allocated regions, but leave dangling pointers to these regions in the ctx. Any regions which have not yet been allocated are left NULL. Note that when returning -EOVERFLOW, the previously allocated sq_ring is not freed, which appears to be an unintentional leak. When io_allocate_scq_urings() fails, io_uring_create() will call io_ring_ctx_wait_and_kill(), which calls io_mem_free() on all the sq_* regions, assuming the pointers are valid and not NULL. This can result in pages being freed multiple times, which has been observed to corrupt the page state, leading to subsequent fun. This can also result in virt_to_page() on NULL, resulting in the use of bogus page addresses, and yet more subsequent fun. The latter can be detected with CONFIG_DEBUG_VIRTUAL on arm64. Adding a cleanup path to io_allocate_scq_urings() complicates the logic, so let's leave it to io_ring_ctx_free() to consistently free these pointers, and simplify the io_allocate_scq_urings() error paths. Full splats from before this patch below. Note that the pointer logged by the DEBUG_VIRTUAL "non-linear address" warning has been hashed, and is actually NULL. [ 26.098129] page:ffff80000e949a00 count:0 mapcount:-128 mapping:0000000000000000 index:0x0 [ 26.102976] flags: 0x63fffc000000() [ 26.104373] raw: 000063fffc000000 ffff80000e86c188 ffff80000ea3df08 0000000000000000 [ 26.108917] raw: 0000000000000000 0000000000000001 00000000ffffff7f 0000000000000000 [ 26.137235] page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0) [ 26.143960] ------------[ cut here ]------------ [ 26.146020] kernel BUG at include/linux/mm.h:547! [ 26.147586] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 26.149163] Modules linked in: [ 26.150287] Process syz-executor.21 (pid: 20204, stack limit = 0x000000000e9cefeb) [ 26.153307] CPU: 2 PID: 20204 Comm: syz-executor.21 Not tainted 5.1.0-rc7-00004-g7d30b2ea43d6 #18 [ 26.156566] Hardware name: linux,dummy-virt (DT) [ 26.158089] pstate: 40400005 (nZcv daif +PAN -UAO) [ 26.159869] pc : io_mem_free+0x9c/0xa8 [ 26.161436] lr : io_mem_free+0x9c/0xa8 [ 26.162720] sp : ffff000013003d60 [ 26.164048] x29: ffff000013003d60 x28: ffff800025048040 [ 26.165804] x27: 0000000000000000 x26: ffff800025048040 [ 26.167352] x25: 00000000000000c0 x24: ffff0000112c2820 [ 26.169682] x23: 0000000000000000 x22: 0000000020000080 [ 26.171899] x21: ffff80002143b418 x20: ffff80002143b400 [ 26.174236] x19: ffff80002143b280 x18: 0000000000000000 [ 26.176607] x17: 0000000000000000 x16: 0000000000000000 [ 26.178997] x15: 0000000000000000 x14: 0000000000000000 [ 26.181508] x13: 00009178a5e077b2 x12: 0000000000000001 [ 26.183863] x11: 0000000000000000 x10: 0000000000000980 [ 26.186437] x9 : ffff000013003a80 x8 : ffff800025048a20 [ 26.189006] x7 : ffff8000250481c0 x6 : ffff80002ffe9118 [ 26.191359] x5 : ffff80002ffe9118 x4 : 0000000000000000 [ 26.193863] x3 : ffff80002ffefe98 x2 : 44c06ddd107d1f00 [ 26.196642] x1 : 0000000000000000 x0 : 000000000000003e [ 26.198892] Call trace: [ 26.199893] io_mem_free+0x9c/0xa8 [ 26.201155] io_ring_ctx_wait_and_kill+0xec/0x180 [ 26.202688] io_uring_setup+0x6c4/0x6f0 [ 26.204091] __arm64_sys_io_uring_setup+0x18/0x20 [ 26.205576] el0_svc_common.constprop.0+0x7c/0xe8 [ 26.207186] el0_svc_handler+0x28/0x78 [ 26.208389] el0_svc+0x8/0xc [ 26.209408] Code: aa0203e0 d0006861 9133a021 97fcdc3c (d4210000) [ 26.211995] ---[ end trace bdb81cd43a21e50d ]--- [ 81.770626] ------------[ cut here ]------------ [ 81.825015] virt_to_phys used for non-linear address: 000000000d42f2c7 ( (null)) [ 81.827860] WARNING: CPU: 1 PID: 30171 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x48/0x68 [ 81.831202] Modules linked in: [ 81.832212] CPU: 1 PID: 30171 Comm: syz-executor.20 Not tainted 5.1.0-rc7-00004-g7d30b2ea43d6 #19 [ 81.835616] Hardware name: linux,dummy-virt (DT) [ 81.836863] pstate: 60400005 (nZCv daif +PAN -UAO) [ 81.838727] pc : __virt_to_phys+0x48/0x68 [ 81.840572] lr : __virt_to_phys+0x48/0x68 [ 81.842264] sp : ffff80002cf67c70 [ 81.843858] x29: ffff80002cf67c70 x28: ffff800014358e18 [ 81.846463] x27: 0000000000000000 x26: 0000000020000080 [ 81.849148] x25: 0000000000000000 x24: ffff80001bb01f40 [ 81.851986] x23: ffff200011db06c8 x22: ffff2000127e3c60 [ 81.854351] x21: ffff800014358cc0 x20: ffff800014358d98 [ 81.856711] x19: 0000000000000000 x18: 0000000000000000 [ 81.859132] x17: 0000000000000000 x16: 0000000000000000 [ 81.861586] x15: 0000000000000000 x14: 0000000000000000 [ 81.863905] x13: 0000000000000000 x12: ffff1000037603e9 [ 81.866226] x11: 1ffff000037603e8 x10: 0000000000000980 [ 81.868776] x9 : ffff80002cf67840 x8 : ffff80001bb02920 [ 81.873272] x7 : ffff1000037603e9 x6 : ffff80001bb01f47 [ 81.875266] x5 : ffff1000037603e9 x4 : dfff200000000000 [ 81.876875] x3 : ffff200010087528 x2 : ffff1000059ecf58 [ 81.878751] x1 : 44c06ddd107d1f00 x0 : 0000000000000000 [ 81.880453] Call trace: [ 81.881164] __virt_to_phys+0x48/0x68 [ 81.882919] io_mem_free+0x18/0x110 [ 81.886585] io_ring_ctx_wait_and_kill+0x13c/0x1f0 [ 81.891212] io_uring_setup+0xa60/0xad0 [ 81.892881] __arm64_sys_io_uring_setup+0x2c/0x38 [ 81.894398] el0_svc_common.constprop.0+0xac/0x150 [ 81.896306] el0_svc_handler+0x34/0x88 [ 81.897744] el0_svc+0x8/0xc [ 81.898715] ---[ end trace b4a703802243cbba ]--- Fixes: 2b188cc1bb857a9d ("Add io_uring IO interface") Signed-off-by: Mark Rutland Cc: Jens Axboe Cc: Alexander Viro Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Jens Axboe

io_uring: fix SQPOLL cpu validation

2019-05-01T14:38:37Z

In io_sq_offload_start(), we call cpu_possible() on an unbounded cpu value from userspace. On v5.1-rc7 on arm64 with CONFIG_DEBUG_PER_CPU_MAPS, this results in a splat: WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpu_max_bits_warn include/linux/cpumask.h:121 [inline] There was an attempt to fix this in commit: 917257daa0fea7a0 ("io_uring: only test SQPOLL cpu after we've verified it") ... by adding a check after the cpu value had been limited to NR_CPU_IDS using array_index_nospec(). However, this left an unbound check at the start of the function, for which the warning still fires. Let's fix this correctly by checking that the cpu value is bound by nr_cpu_ids before passing it to cpu_possible(). Note that only nr_cpu_ids of a cpumask are guaranteed to exist at runtime, and nr_cpu_ids can be significantly smaller than NR_CPUs. For example, an arm64 defconfig has NR_CPUS=256, while my test VM has 4 vCPUs. Following the intent from the commit message for 917257daa0fea7a0, the check is moved under the SQ_AFF branch, which is the only branch where the cpu values is consumed. The check is performed before bounding the value with array_index_nospec() so that we don't silently accept bogus cpu values from userspace, where array_index_nospec() would force these values to 0. I suspect we can remove the array_index_nospec() call entirely, but I've conservatively left that in place, updated to use nr_cpu_ids to match the prior check. Tested on arm64 with the Syzkaller reproducer: https://syzkaller.appspot.com/bug?extid=cd714a07c6de2bc34293 https://syzkaller.appspot.com/x/repro.syz?x=15d8b397200000 Full splat from before this patch: WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpu_max_bits_warn include/linux/cpumask.h:121 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpumask_check include/linux/cpumask.h:128 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpumask_test_cpu include/linux/cpumask.h:344 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 io_sq_offload_start fs/io_uring.c:2244 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 io_uring_create fs/io_uring.c:2864 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 io_uring_setup+0x1108/0x15a0 fs/io_uring.c:2916 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 27601 Comm: syz-executor.0 Not tainted 5.1.0-rc7 #3 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x2f0 include/linux/compiler.h:193 show_stack+0x20/0x30 arch/arm64/kernel/traps.c:158 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x110/0x190 lib/dump_stack.c:113 panic+0x384/0x68c kernel/panic.c:214 __warn+0x2bc/0x2c0 kernel/panic.c:571 report_bug+0x228/0x2d8 lib/bug.c:186 bug_handler+0xa0/0x1a0 arch/arm64/kernel/traps.c:956 call_break_hook arch/arm64/kernel/debug-monitors.c:301 [inline] brk_handler+0x1d4/0x388 arch/arm64/kernel/debug-monitors.c:316 do_debug_exception+0x1a0/0x468 arch/arm64/mm/fault.c:831 el1_dbg+0x18/0x8c cpu_max_bits_warn include/linux/cpumask.h:121 [inline] cpumask_check include/linux/cpumask.h:128 [inline] cpumask_test_cpu include/linux/cpumask.h:344 [inline] io_sq_offload_start fs/io_uring.c:2244 [inline] io_uring_create fs/io_uring.c:2864 [inline] io_uring_setup+0x1108/0x15a0 fs/io_uring.c:2916 __do_sys_io_uring_setup fs/io_uring.c:2929 [inline] __se_sys_io_uring_setup fs/io_uring.c:2926 [inline] __arm64_sys_io_uring_setup+0x50/0x70 fs/io_uring.c:2926 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall arch/arm64/kernel/syscall.c:47 [inline] el0_svc_common.constprop.0+0x148/0x2e0 arch/arm64/kernel/syscall.c:83 el0_svc_handler+0xdc/0x100 arch/arm64/kernel/syscall.c:129 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:948 SMP: stopping secondary CPUs Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled CPU features: 0x002,23000438 Memory Limit: none Rebooting in 1 seconds.. Fixes: 917257daa0fea7a0 ("io_uring: only test SQPOLL cpu after we've verified it") Signed-off-by: Mark Rutland Cc: Jens Axboe Cc: Alexander Viro Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Simplied the logic Signed-off-by: Jens Axboe