- 01 Oct, 2020 15 commits
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Jens Axboe authored
We're not handling signals by default in kernel threads, and we never use TWA_SIGNAL for the SQPOLL thread internally. Hence we can never have a signal pending, and we don't need to check for it (nor flush it). Signed-off-by:Jens Axboe <axboe@kernel.dk>
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Sebastian Andrzej Siewior authored
During a context switch the scheduler invokes wq_worker_sleeping() with disabled preemption. Disabling preemption is needed because it protects access to `worker->sleeping'. As an optimisation it avoids invoking schedule() within the schedule path as part of possible wake up (thus preempt_enable_no_resched() afterwards). The io-wq has been added to the mix in the same section with disabled preemption. This breaks on PREEMPT_RT because io_wq_worker_sleeping() acquires a spinlock_t. Also within the schedule() the spinlock_t must be acquired after tsk_is_pi_blocked() otherwise it will block on the sleeping lock again while scheduling out. While playing with `io_uring-bench' I didn't notice a significant latency spike after converting io_wqe::lock to a raw_spinlock_t. The latency was more or less the same. In order to keep the spinlock_t it would have to be moved after the tsk_is_pi_blocked() check which would introduce a branch instruction into the hot path. The lock is used to maintain the `work_list' and wakes one task up at most. Should io_wqe_cancel_pending_work() cause latency spikes, while searching for a specific item, then it would need to drop the lock during iterations. revert_creds() is also invoked under the lock. According to debug cred::non_rcu is 0. Otherwise it should be moved outside of the locked section because put_cred_rcu()->free_uid() acquires a sleeping lock. Convert io_wqe::lock to a raw_spinlock_t.c Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
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Stefano Garzarella authored
This patch adds a new IORING_SETUP_R_DISABLED flag to start the rings disabled, allowing the user to register restrictions, buffers, files, before to start processing SQEs. When IORING_SETUP_R_DISABLED is set, SQE are not processed and SQPOLL kthread is not started. The restrictions registration are allowed only when the rings are disable to prevent concurrency issue while processing SQEs. The rings can be enabled using IORING_REGISTER_ENABLE_RINGS opcode with io_uring_register(2). Suggested-by:
Stefano Garzarella <sgarzare@redhat.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
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Stefano Garzarella authored
The new io_uring_register(2) IOURING_REGISTER_RESTRICTIONS opcode permanently installs a feature allowlist on an io_ring_ctx. The io_ring_ctx can then be passed to untrusted code with the knowledge that only operations present in the allowlist can be executed. The allowlist approach ensures that new features added to io_uring do not accidentally become available when an existing application is launched on a newer kernel version. Currently is it possible to restrict sqe opcodes, sqe flags, and register opcodes. IOURING_REGISTER_RESTRICTIONS can only be made once. Afterwards it is not possible to change restrictions anymore. This prevents untrusted code from removing restrictions. Suggested-by:
Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by:
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Stefano Garzarella authored
The enumeration allows us to keep track of the last io_uring_register(2) opcode available. Behaviour and opcodes names don't change. Signed-off-by:
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Jens Axboe authored
Now we have a io_uring kernel header, move this definition out of fs.h and into io_uring.h where it belongs. Signed-off-by: -
Jens Axboe authored
If we don't get and assign the namespace for the async work, then certain paths just don't work properly (like /dev/stdin, /proc/mounts, etc). Anything that references the current namespace of the given task should be assigned for async work on behalf of that task. Cc: stable@vger.kernel.org # v5.5+ Reported-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Jens Axboe authored
Grab actual references to the files_struct. To avoid circular references issues due to this, we add a per-task note that keeps track of what io_uring contexts a task has used. When the tasks execs or exits its assigned files, we cancel requests based on this tracking. With that, we can grab proper references to the files table, and no longer need to rely on stashing away ring_fd and ring_file to check if the ring_fd may have been closed. Cc: stable@vger.kernel.org # v5.5+ Reviewed-by:
Pavel Begunkov <asml.silence@gmail.com> Signed-off-by:
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Jens Axboe authored
This allows us to selectively flush out pending overflows, depending on the task and/or files_struct being passed in. No intended functional changes in this patch. Reviewed-by:
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Jens Axboe authored
Return whether we found and canceled requests or not. This is in preparation for using this information, no functional changes in this patch. Reviewed-by:
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Jens Axboe authored
Sometimes we assign a weak reference to it, sometimes we grab a reference to it. Clean this up and make it unconditional, and drop the flag related to tracking this state. Reviewed-by:
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Jens Axboe authored
We can grab a reference to the task instead of stashing away the task files_struct. This is doable without creating a circular reference between the ring fd and the task itself. Reviewed-by:
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Jens Axboe authored
No functional changes in this patch, prep patch for grabbing references to the files_struct. Reviewed-by:
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Jens Axboe authored
We currently cancel these when the ring exits, and we cancel all of them. This is in preparation for killing only the ones associated with a given task. Reviewed-by:
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Jens Axboe authored
* io_uring-5.9: io_uring: fix async buffered reads when readahead is disabled io_uring: fix potential ABBA deadlock in ->show_fdinfo() io_uring: always delete double poll wait entry on match
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- 29 Sep, 2020 1 commit
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Hao Xu authored
The async buffered reads feature is not working when readahead is turned off. There are two things to concern: - when doing retry in io_read, not only the IOCB_WAITQ flag but also the IOCB_NOWAIT flag is still set, which makes it goes to would_block phase in generic_file_buffered_read() and then return -EAGAIN. After that, the io-wq thread work is queued, and later doing the async reads in the old way. - even if we remove IOCB_NOWAIT when doing retry, the feature is still not running properly, since in generic_file_buffered_read() it goes to lock_page_killable() after calling mapping->a_ops->readpage() to do IO, and thus causing process to sleep. Fixes: 1a0a7853 ("mm: support async buffered reads in generic_file_buffered_read()") Fixes: 3b2a4439 ("io_uring: get rid of kiocb_wait_page_queue_init()") Signed-off-by:
Hao Xu <haoxu@linux.alibaba.com> Signed-off-by:
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- 28 Sep, 2020 4 commits
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git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds authored
Pull NFS client bugfixes from Trond Myklebust: "Highlights include: - NFSv4.2: copy_file_range needs to invalidate caches on success - NFSv4.2: Fix security label length not being reset - pNFS/flexfiles: Ensure we initialise the mirror bsizes correctly on read - pNFS/flexfiles: Fix signed/unsigned type issues with mirror indices" * tag 'nfs-for-5.9-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: pNFS/flexfiles: Be consistent about mirror index types pNFS/flexfiles: Ensure we initialise the mirror bsizes correctly on read NFSv4.2: fix client's attribute cache management for copy_file_range nfs: Fix security label length not being reset -
Jason A. Donenfeld authored
It seems likely this block was pasted from internal_get_user_pages_fast, which is not passed an mm struct and therefore uses current's. But __get_user_pages_locked is passed an explicit mm, and current->mm is not always valid. This was hit when being called from i915, which uses: pin_user_pages_remote-> __get_user_pages_remote-> __gup_longterm_locked-> __get_user_pages_locked Before, this would lead to an OOPS: BUG: kernel NULL pointer dereference, address: 0000000000000064 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page CPU: 10 PID: 1431 Comm: kworker/u33:1 Tainted: P S U O 5.9.0-rc7+ #140 Hardware name: LENOVO 20QTCTO1WW/20QTCTO1WW, BIOS N2OET47W (1.34 ) 08/06/2020 Workqueue: i915-userptr-acquire __i915_gem_userptr_get_pages_worker [i915] RIP: 0010:__get_user_pages_remote+0xd7/0x310 Call Trace: __i915_gem_userptr_get_pages_worker+0xc8/0x260 [i915] process_one_work+0x1ca/0x390 worker_thread+0x48/0x3c0 kthread+0x114/0x130 ret_from_fork+0x1f/0x30 CR2: 0000000000000064 This commit fixes the problem by using the mm pointer passed to the function rather than the bogus one in current. Fixes: 008cfe44 ("mm: Introduce mm_struct.has_pinned") Tested-by:Chris Wilson <chris@chris-wilson.co.uk> Reported-by:
Harald Arnesen <harald@skogtun.org> Reviewed-by:
Jason Gunthorpe <jgg@nvidia.com> Reviewed-by:
Peter Xu <peterx@redhat.com> Signed-off-by:
Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Jens Axboe authored
syzbot reports a potential lock deadlock between the normal IO path and ->show_fdinfo(): ====================================================== WARNING: possible circular locking dependency detected 5.9.0-rc6-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/19710 is trying to acquire lock: ffff888098ddc450 (sb_writers#4){.+.+}-{0:0}, at: io_write+0x6b5/0xb30 fs/io_uring.c:3296 but task is already holding lock: ffff8880a11b8428 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0xe9a/0x1bd0 fs/io_uring.c:8348 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ctx->uring_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x10e0 kernel/locking/mutex.c:1103 __io_uring_show_fdinfo fs/io_uring.c:8417 [inline] io_uring_show_fdinfo+0x194/0xc70 fs/io_uring.c:8460 seq_show+0x4a8/0x700 fs/proc/fd.c:65 seq_read+0x432/0x1070 fs/seq_file.c:208 do_loop_readv_writev fs/read_write.c:734 [inline] do_loop_readv_writev fs/read_write.c:721 [inline] do_iter_read+0x48e/0x6e0 fs/read_write.c:955 vfs_readv+0xe5/0x150 fs/read_write.c:1073 kernel_readv fs/splice.c:355 [inline] default_file_splice_read.constprop.0+0x4e6/0x9e0 fs/splice.c:412 do_splice_to+0x137/0x170 fs/splice.c:871 splice_direct_to_actor+0x307/0x980 fs/splice.c:950 do_splice_direct+0x1b3/0x280 fs/splice.c:1059 do_sendfile+0x55f/0xd40 fs/read_write.c:1540 __do_sys_sendfile64 fs/read_write.c:1601 [inline] __se_sys_sendfile64 fs/read_write.c:1587 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1587 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #1 (&p->lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x10e0 kernel/locking/mutex.c:1103 seq_read+0x61/0x1070 fs/seq_file.c:155 pde_read fs/proc/inode.c:306 [inline] proc_reg_read+0x221/0x300 fs/proc/inode.c:318 do_loop_readv_writev fs/read_write.c:734 [inline] do_loop_readv_writev fs/read_write.c:721 [inline] do_iter_read+0x48e/0x6e0 fs/read_write.c:955 vfs_readv+0xe5/0x150 fs/read_write.c:1073 kernel_readv fs/splice.c:355 [inline] default_file_splice_read.constprop.0+0x4e6/0x9e0 fs/splice.c:412 do_splice_to+0x137/0x170 fs/splice.c:871 splice_direct_to_actor+0x307/0x980 fs/splice.c:950 do_splice_direct+0x1b3/0x280 fs/splice.c:1059 do_sendfile+0x55f/0xd40 fs/read_write.c:1540 __do_sys_sendfile64 fs/read_write.c:1601 [inline] __se_sys_sendfile64 fs/read_write.c:1587 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1587 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (sb_writers#4){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:2496 [inline] check_prevs_add kernel/locking/lockdep.c:2601 [inline] validate_chain kernel/locking/lockdep.c:3218 [inline] __lock_acquire+0x2a96/0x5780 kernel/locking/lockdep.c:4441 lock_acquire+0x1f3/0xaf0 kernel/locking/lockdep.c:5029 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write+0x228/0x450 fs/super.c:1672 io_write+0x6b5/0xb30 fs/io_uring.c:3296 io_issue_sqe+0x18f/0x5c50 fs/io_uring.c:5719 __io_queue_sqe+0x280/0x1160 fs/io_uring.c:6175 io_queue_sqe+0x692/0xfa0 fs/io_uring.c:6254 io_submit_sqe fs/io_uring.c:6324 [inline] io_submit_sqes+0x1761/0x2400 fs/io_uring.c:6521 __do_sys_io_uring_enter+0xeac/0x1bd0 fs/io_uring.c:8349 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Chain exists of: sb_writers#4 --> &p->lock --> &ctx->uring_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ctx->uring_lock); lock(&p->lock); lock(&ctx->uring_lock); lock(sb_writers#4); *** DEADLOCK *** 1 lock held by syz-executor.2/19710: #0: ffff8880a11b8428 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0xe9a/0x1bd0 fs/io_uring.c:8348 stack backtrace: CPU: 0 PID: 19710 Comm: syz-executor.2 Not tainted 5.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 check_noncircular+0x324/0x3e0 kernel/locking/lockdep.c:1827 check_prev_add kernel/locking/lockdep.c:2496 [inline] check_prevs_add kernel/locking/lockdep.c:2601 [inline] validate_chain kernel/locking/lockdep.c:3218 [inline] __lock_acquire+0x2a96/0x5780 kernel/locking/lockdep.c:4441 lock_acquire+0x1f3/0xaf0 kernel/locking/lockdep.c:5029 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write+0x228/0x450 fs/super.c:1672 io_write+0x6b5/0xb30 fs/io_uring.c:3296 io_issue_sqe+0x18f/0x5c50 fs/io_uring.c:5719 __io_queue_sqe+0x280/0x1160 fs/io_uring.c:6175 io_queue_sqe+0x692/0xfa0 fs/io_uring.c:6254 io_submit_sqe fs/io_uring.c:6324 [inline] io_submit_sqes+0x1761/0x2400 fs/io_uring.c:6521 __do_sys_io_uring_enter+0xeac/0x1bd0 fs/io_uring.c:8349 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e179 Code: 3d b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1194e74c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00000000000082c0 RCX: 000000000045e179 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000004 RBP: 000000000118cf98 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffd1aa5756f R14: 00007f1194e759c0 R15: 000000000118cf4c Fix this by just not diving into details if we fail to trylock the io_uring mutex. We know the ctx isn't going away during this operation, but we cannot safely iterate buffers/files/personalities if we don't hold the io_uring mutex. Reported-by: syzbot+2f8fa4e860edc3066aba@syzkaller.appspotmail.com Signed-off-by: -
Jens Axboe authored
syzbot reports a crash with tty polling, which is using the double poll handling: general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f] CPU: 0 PID: 6874 Comm: syz-executor749 Not tainted 5.9.0-rc6-next-20200924-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:io_poll_get_single fs/io_uring.c:4778 [inline] RIP: 0010:io_poll_double_wake+0x51/0x510 fs/io_uring.c:4845 Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 9e 03 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 5d 08 48 8d 7b 48 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 63 03 00 00 0f b6 6b 48 bf 06 00 00 RSP: 0018:ffffc90001c1fb70 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000004 RDX: 0000000000000009 RSI: ffffffff81d9b3ad RDI: 0000000000000048 RBP: dffffc0000000000 R08: ffff8880a3cac798 R09: ffffc90001c1fc60 R10: fffff52000383f73 R11: 0000000000000000 R12: 0000000000000004 R13: ffff8880a3cac798 R14: ffff8880a3cac7a0 R15: 0000000000000004 FS: 0000000001f98880(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f18886916c0 CR3: 0000000094c5a000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __wake_up_common+0x147/0x650 kernel/sched/wait.c:93 __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:123 tty_ldisc_hangup+0x1cf/0x680 drivers/tty/tty_ldisc.c:735 __tty_hangup.part.0+0x403/0x870 drivers/tty/tty_io.c:625 __tty_hangup drivers/tty/tty_io.c:575 [inline] tty_vhangup+0x1d/0x30 drivers/tty/tty_io.c:698 pty_close+0x3f5/0x550 drivers/tty/pty.c:79 tty_release+0x455/0xf60 drivers/tty/tty_io.c:1679 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:141 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:165 [inline] exit_to_user_mode_prepare+0x1e2/0x1f0 kernel/entry/common.c:192 syscall_exit_to_user_mode+0x7a/0x2c0 kernel/entry/common.c:267 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x401210 which is due to a failure in removing the double poll wait entry if we hit a wakeup match. This can cause multiple invocations of the wakeup, which isn't safe. Cc: stable@vger.kernel.org # v5.8 Reported-by: syzbot+81b3883093f772addf6d@syzkaller.appspotmail.com Signed-off-by:
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- 27 Sep, 2020 9 commits
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Linus Torvalds authored
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Linus Torvalds authored
Merge tag 'kbuild-fixes-v5.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - ignore compiler stubs for PPC to fix builds - fix the usage of --target mentioned in the LLVM document * tag 'kbuild-fixes-v5.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: Documentation/llvm: Fix clang target examples scripts/kallsyms: skip ppc compiler stub *.long_branch.* / *.plt_branch.*
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Thomas Gleixner: "Two fixes for the x86 interrupt code: - Unbreak the magic 'search the timer interrupt' logic in IO/APIC code which got wreckaged when the core interrupt code made the state tracking logic stricter. That caused the interrupt line to stay masked after switching from IO/APIC to PIC delivery mode, which obviously prevents interrupts from being delivered. - Make run_on_irqstack_code() typesafe. The function argument is a void pointer which is then cast to 'void (*fun)(void *). This breaks Control Flow Integrity checking in clang. Use proper helper functions for the three variants reuqired" * tag 'x86-urgent-2020-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/ioapic: Unbreak check_timer() x86/irq: Make run_on_irqstack_cond() typesafe -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer updates from Thomas Gleixner: "A set of clocksource/clockevents updates: - Reset the TI/DM timer before enabling it instead of doing it the other way round. - Initialize the reload value for the GX6605s timer correctly so the hardware counter starts at 0 again after overrun. - Make error return value negative in the h8300 timer init function" * tag 'timers-urgent-2020-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/timer-gx6605s: Fixup counter reload clocksource/drivers/timer-ti-dm: Do reset before enable clocksource/drivers/h8300_timer8: Fix wrong return value in h8300_8timer_init() -
Peter Xu authored
Pinned pages shouldn't be write-protected when fork() happens, because follow up copy-on-write on these pages could cause the pinned pages to be replaced by random newly allocated pages. For huge PMDs, we split the huge pmd if pinning is detected. So that future handling will be done by the PTE level (with our latest changes, each of the small pages will be copied). We can achieve this by let copy_huge_pmd() return -EAGAIN for pinned pages, so that we'll fallthrough in copy_pmd_range() and finally land the next copy_pte_range() call. Huge PUDs will be even more special - so far it does not support anonymous pages. But it can actually be done the same as the huge PMDs even if the split huge PUDs means to erase the PUD entries. It'll guarantee the follow up fault ins will remap the same pages in either parent/child later. This might not be the most efficient way, but it should be easy and clean enough. It should be fine, since we're tackling with a very rare case just to make sure userspaces that pinned some thps will still work even without MADV_DONTFORK and after they fork()ed. Signed-off-by:
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Peter Xu authored
This allows copy_pte_range() to do early cow if the pages were pinned on the source mm. Currently we don't have an accurate way to know whether a page is pinned or not. The only thing we have is page_maybe_dma_pinned(). However that's good enough for now. Especially, with the newly added mm->has_pinned flag to make sure we won't affect processes that never pinned any pages. It would be easier if we can do GFP_KERNEL allocation within copy_one_pte(). Unluckily, we can't because we're with the page table locks held for both the parent and child processes. So the page allocation needs to be done outside copy_one_pte(). Some trick is there in copy_present_pte(), majorly the wrprotect trick to block concurrent fast-gup. Comments in the function should explain better in place. Oleg Nesterov reported a (probably harmless) bug during review that we didn't reset entry.val properly in copy_pte_range() so that potentially there's chance to call add_swap_count_continuation() multiple times on the same swp entry. However that should be harmless since even if it happens, the same function (add_swap_count_continuation()) will return directly noticing that there're enough space for the swp counter. So instead of a standalone stable patch, it is touched up in this patch directly. Link: https://lore.kernel.org/lkml/20200914143829.GA1424636@nvidia.com/Suggested-by:
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Peter Xu authored
This prepares for the future work to trigger early cow on pinned pages during fork(). No functional change intended. Signed-off-by:
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Peter Xu authored
(Commit message majorly collected from Jason Gunthorpe) Reduce the chance of false positive from page_maybe_dma_pinned() by keeping track if the mm_struct has ever been used with pin_user_pages(). This allows cases that might drive up the page ref_count to avoid any penalty from handling dma_pinned pages. Future work is planned, to provide a more sophisticated solution, likely to turn it into a real counter. For now, make it atomic_t but use it as a boolean for simplicity. Suggested-by:
Jason Gunthorpe <jgg@ziepe.ca> Signed-off-by:
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Thomas Gleixner authored
Merge tag 'timers-v5.9-rc4' of https://git.linaro.org/people/daniel.lezcano/linux into timers/urgent Pull clocksource/clockevent fixes from Daniel Lezcano: - Fix wrong signed return value when checking of_iomap in the probe function for the h8300 timer (Tianjia Zhang) - Fix reset sequence when setting up the timer on the dm_timer (Tony Lindgren) - Fix counter reload when the interrupt fires on gx6605s (Guo Ren)
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- 26 Sep, 2020 11 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Three fixes: one in drivers (lpfc) and two for zoned block devices. The latter also impinges on the block layer but only to introduce a new block API for setting the zone model rather than fiddling with the queue directly in the zoned block driver" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: sd: sd_zbc: Fix ZBC disk initialization scsi: sd: sd_zbc: Fix handling of host-aware ZBC disks scsi: lpfc: Fix initial FLOGI failure due to BBSCN not supported
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git://git.kernel.dk/linux-blockLinus Torvalds authored
Pull io_uring fixes from Jens Axboe: "Two fixes for regressions in this cycle, and one that goes to 5.8 stable: - fix leak of getname() retrieved filename - remove plug->nowait assignment, fixing a regression with btrfs - fix for async buffered retry" * tag 'io_uring-5.9-2020-09-25' of git://git.kernel.dk/linux-block: io_uring: ensure async buffered read-retry is setup properly io_uring: don't unconditionally set plug->nowait = true io_uring: ensure open/openat2 name is cleaned on cancelation
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git://git.kernel.dk/linux-blockLinus Torvalds authored
Pull block fixes from Jens Axboe: "NVMe pull request from Christoph, and removal of a dead define. - fix error during controller probe that cause double free irqs (Keith Busch) - FC connection establishment fix (James Smart) - properly handle completions for invalid tags (Xianting Tian) - pass the correct nsid to the command effects and supported log (Chaitanya Kulkarni)" * tag 'block-5.9-2020-09-25' of git://git.kernel.dk/linux-block: block: remove unused BLK_QC_T_EAGAIN flag nvme-core: don't use NVME_NSID_ALL for command effects and supported log nvme-fc: fail new connections to a deleted host or remote port nvme-pci: fix NULL req in completion handler nvme: return errors for hwmon init -
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linuxLinus Torvalds authored
Pull s390 fix from Vasily Gorbik: "Fix truncated ZCRYPT_PERDEV_REQCNT ioctl result. Copy entire reqcnt list" * tag 's390-5.9-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/zcrypt: Fix ZCRYPT_PERDEV_REQCNT ioctl
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Linus Torvalds authored
Merge misc fixes from Andrew Morton: "9 patches. Subsystems affected by this patch series: mm (thp, memcg, gup, migration, memory-hotplug), lib, and x86" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm: don't rely on system state to detect hot-plug operations mm: replace memmap_context by meminit_context arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback lib/memregion.c: include memregion.h lib/string.c: implement stpcpy mm/migrate: correct thp migration stats mm/gup: fix gup_fast with dynamic page table folding mm: memcontrol: fix missing suffix of workingset_restore mm, THP, swap: fix allocating cluster for swapfile by mistake
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Minchan Kim authored
syzbot reported the following KASAN splat: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 1 PID: 6826 Comm: syz-executor142 Not tainted 5.9.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x84/0x2ae0 kernel/locking/lockdep.c:4296 Code: ff df 8a 04 30 84 c0 0f 85 e3 16 00 00 83 3d 56 58 35 08 00 0f 84 0e 17 00 00 83 3d 25 c7 f5 07 00 74 2c 4c 89 e8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ef e8 3e d1 5a 00 48 be 00 00 00 00 00 fc RSP: 0018:ffffc90004b9f850 EFLAGS: 00010006 Call Trace: lock_acquire+0x140/0x6f0 kernel/locking/lockdep.c:5006 __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] madvise_cold_or_pageout_pte_range+0x52f/0x25c0 mm/madvise.c:389 walk_pmd_range mm/pagewalk.c:89 [inline] walk_pud_range mm/pagewalk.c:160 [inline] walk_p4d_range mm/pagewalk.c:193 [inline] walk_pgd_range mm/pagewalk.c:229 [inline] __walk_page_range+0xe7b/0x1da0 mm/pagewalk.c:331 walk_page_range+0x2c3/0x5c0 mm/pagewalk.c:427 madvise_pageout_page_range mm/madvise.c:521 [inline] madvise_pageout mm/madvise.c:557 [inline] madvise_vma mm/madvise.c:946 [inline] do_madvise+0x12d0/0x2090 mm/madvise.c:1145 __do_sys_madvise mm/madvise.c:1171 [inline] __se_sys_madvise mm/madvise.c:1169 [inline] __x64_sys_madvise+0x76/0x80 mm/madvise.c:1169 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The backing vma was shmem. In case of split page of file-backed THP, madvise zaps the pmd instead of remapping of sub-pages. So we need to check pmd validity after split. Reported-by: syzbot+ecf80462cb7d5d552bc7@syzkaller.appspotmail.com Fixes: 1a4e58cc ("mm: introduce MADV_PAGEOUT") Signed-off-by:Minchan Kim <minchan@kernel.org> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by:
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Laurent Dufour authored
In register_mem_sect_under_node() the system_state's value is checked to detect whether the call is made during boot time or during an hot-plug operation. Unfortunately, that check against SYSTEM_BOOTING is wrong because regular memory is registered at SYSTEM_SCHEDULING state. In addition, memory hot-plug operation can be triggered at this system state by the ACPI [1]. So checking against the system state is not enough. The consequence is that on system with interleaved node's ranges like this: Early memory node ranges node 1: [mem 0x0000000000000000-0x000000011fffffff] node 2: [mem 0x0000000120000000-0x000000014fffffff] node 1: [mem 0x0000000150000000-0x00000001ffffffff] node 0: [mem 0x0000000200000000-0x000000048fffffff] node 2: [mem 0x0000000490000000-0x00000007ffffffff] This can be seen on PowerPC LPAR after multiple memory hot-plug and hot-unplug operations are done. At the next reboot the node's memory ranges can be interleaved and since the call to link_mem_sections() is made in topology_init() while the system is in the SYSTEM_SCHEDULING state, the node's id is not checked, and the sections registered to multiple nodes: $ ls -l /sys/devices/system/memory/memory21/node* total 0 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node1 -> ../../node/node1 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node2 -> ../../node/node2 In that case, the system is able to boot but if later one of theses memory blocks is hot-unplugged and then hot-plugged, the sysfs inconsistency is detected and this is triggering a BUG_ON(): kernel BUG at /Users/laurent/src/linux-ppc/mm/memory_hotplug.c:1084! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp pseries_rng rng_core vmx_crypto gf128mul binfmt_misc ip_tables x_tables xfs libcrc32c crc32c_vpmsum autofs4 CPU: 8 PID: 10256 Comm: drmgr Not tainted 5.9.0-rc1+ #25 Call Trace: add_memory_resource+0x23c/0x340 (unreliable) __add_memory+0x5c/0xf0 dlpar_add_lmb+0x1b4/0x500 dlpar_memory+0x1f8/0xb80 handle_dlpar_errorlog+0xc0/0x190 dlpar_store+0x198/0x4a0 kobj_attr_store+0x30/0x50 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1b0/0x290 vfs_write+0xe8/0x290 ksys_write+0xdc/0x130 system_call_exception+0x160/0x270 system_call_common+0xf0/0x27c This patch addresses the root cause by not relying on the system_state value to detect whether the call is due to a hot-plug operation. An extra parameter is added to link_mem_sections() detailing whether the operation is due to a hot-plug operation. [1] According to Oscar Salvador, using this qemu command line, ACPI memory hotplug operations are raised at SYSTEM_SCHEDULING state: $QEMU -enable-kvm -machine pc -smp 4,sockets=4,cores=1,threads=1 -cpu host -monitor pty \ -m size=$MEM,slots=255,maxmem=4294967296k \ -numa node,nodeid=0,cpus=0-3,mem=512 -numa node,nodeid=1,mem=512 \ -object memory-backend-ram,id=memdimm0,size=134217728 -device pc-dimm,node=0,memdev=memdimm0,id=dimm0,slot=0 \ -object memory-backend-ram,id=memdimm1,size=134217728 -device pc-dimm,node=0,memdev=memdimm1,id=dimm1,slot=1 \ -object memory-backend-ram,id=memdimm2,size=134217728 -device pc-dimm,node=0,memdev=memdimm2,id=dimm2,slot=2 \ -object memory-backend-ram,id=memdimm3,size=134217728 -device pc-dimm,node=0,memdev=memdimm3,id=dimm3,slot=3 \ -object memory-backend-ram,id=memdimm4,size=134217728 -device pc-dimm,node=1,memdev=memdimm4,id=dimm4,slot=4 \ -object memory-backend-ram,id=memdimm5,size=134217728 -device pc-dimm,node=1,memdev=memdimm5,id=dimm5,slot=5 \ -object memory-backend-ram,id=memdimm6,size=134217728 -device pc-dimm,node=1,memdev=memdimm6,id=dimm6,slot=6 \ Fixes: 4fbce633 ("mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()") Signed-off-by:Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Reviewed-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
Oscar Salvador <osalvador@suse.de> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200915094143.79181-3-ldufour@linux.ibm.comSigned-off-by:
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Laurent Dufour authored
Patch series "mm: fix memory to node bad links in sysfs", v3. Sometimes, firmware may expose interleaved memory layout like this: Early memory node ranges node 1: [mem 0x0000000000000000-0x000000011fffffff] node 2: [mem 0x0000000120000000-0x000000014fffffff] node 1: [mem 0x0000000150000000-0x00000001ffffffff] node 0: [mem 0x0000000200000000-0x000000048fffffff] node 2: [mem 0x0000000490000000-0x00000007ffffffff] In that case, we can see memory blocks assigned to multiple nodes in sysfs: $ ls -l /sys/devices/system/memory/memory21 total 0 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node1 -> ../../node/node1 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node2 -> ../../node/node2 -rw-r--r-- 1 root root 65536 Aug 24 05:27 online -r--r--r-- 1 root root 65536 Aug 24 05:27 phys_device -r--r--r-- 1 root root 65536 Aug 24 05:27 phys_index drwxr-xr-x 2 root root 0 Aug 24 05:27 power -r--r--r-- 1 root root 65536 Aug 24 05:27 removable -rw-r--r-- 1 root root 65536 Aug 24 05:27 state lrwxrwxrwx 1 root root 0 Aug 24 05:25 subsystem -> ../../../../bus/memory -rw-r--r-- 1 root root 65536 Aug 24 05:25 uevent -r--r--r-- 1 root root 65536 Aug 24 05:27 valid_zones The same applies in the node's directory with a memory21 link in both the node1 and node2's directory. This is wrong but doesn't prevent the system to run. However when later, one of these memory blocks is hot-unplugged and then hot-plugged, the system is detecting an inconsistency in the sysfs layout and a BUG_ON() is raised: kernel BUG at /Users/laurent/src/linux-ppc/mm/memory_hotplug.c:1084! LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp pseries_rng rng_core vmx_crypto gf128mul binfmt_misc ip_tables x_tables xfs libcrc32c crc32c_vpmsum autofs4 CPU: 8 PID: 10256 Comm: drmgr Not tainted 5.9.0-rc1+ #25 Call Trace: add_memory_resource+0x23c/0x340 (unreliable) __add_memory+0x5c/0xf0 dlpar_add_lmb+0x1b4/0x500 dlpar_memory+0x1f8/0xb80 handle_dlpar_errorlog+0xc0/0x190 dlpar_store+0x198/0x4a0 kobj_attr_store+0x30/0x50 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1b0/0x290 vfs_write+0xe8/0x290 ksys_write+0xdc/0x130 system_call_exception+0x160/0x270 system_call_common+0xf0/0x27c This has been seen on PowerPC LPAR. The root cause of this issue is that when node's memory is registered, the range used can overlap another node's range, thus the memory block is registered to multiple nodes in sysfs. There are two issues here: (a) The sysfs memory and node's layouts are broken due to these multiple links (b) The link errors in link_mem_sections() should not lead to a system panic. To address (a) register_mem_sect_under_node should not rely on the system state to detect whether the link operation is triggered by a hot plug operation or not. This is addressed by the patches 1 and 2 of this series. Issue (b) will be addressed separately. This patch (of 2): The memmap_context enum is used to detect whether a memory operation is due to a hot-add operation or happening at boot time. Make it general to the hotplug operation and rename it as meminit_context. There is no functional change introduced by this patch Suggested-by: -
Mikulas Patocka authored
If we copy less than 8 bytes and if the destination crosses a cache line, __copy_user_flushcache would invalidate only the first cache line. This patch makes it invalidate the second cache line as well. Fixes: 0aed55af ("x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations") Signed-off-by:
Mikulas Patocka <mpatocka@redhat.com> Signed-off-by:
Dan Williams <dan.j.wiilliams@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/alpine.LRH.2.02.2009161451140.21915@file01.intranet.prod.int.rdu2.redhat.comSigned-off-by:
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Jason Yan authored
This addresses the following sparse warning: lib/memregion.c:8:5: warning: symbol 'memregion_alloc' was not declared. Should it be static? lib/memregion.c:14:6: warning: symbol 'memregion_free' was not declared. Should it be static? Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
Jason Yan <yanaijie@huawei.com> Signed-off-by:
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Nick Desaulniers authored
LLVM implemented a recent "libcall optimization" that lowers calls to `sprintf(dest, "%s", str)` where the return value is used to `stpcpy(dest, str) - dest`. This generally avoids the machinery involved in parsing format strings. `stpcpy` is just like `strcpy` except it returns the pointer to the new tail of `dest`. This optimization was introduced into clang-12. Implement this so that we don't observe linkage failures due to missing symbol definitions for `stpcpy`. Similar to last year's fire drill with: commit 5f074f3e ("lib/string.c: implement a basic bcmp") The kernel is somewhere between a "freestanding" environment (no full libc) and "hosted" environment (many symbols from libc exist with the same type, function signature, and semantics). As Peter Anvin notes, there's not really a great way to inform the compiler that you're targeting a freestanding environment but would like to opt-in to some libcall optimizations (see pr/47280 below), rather than opt-out. Arvind notes, -fno-builtin-* behaves slightly differently between GCC and Clang, and Clang is missing many __builtin_* definitions, which I consider a bug in Clang and am working on fixing. Masahiro summarizes the subtle distinction between compilers justly: To prevent transformation from foo() into bar(), there are two ways in Clang to do that; -fno-builtin-foo, and -fno-builtin-bar. There is only one in GCC; -fno-buitin-foo. (Any difference in that behavior in Clang is likely a bug from a missing __builtin_* definition.) Masahiro also notes: We want to disable optimization from foo() to bar(), but we may still benefit from the optimization from foo() into something else. If GCC implements the same transform, we would run into a problem because it is not -fno-builtin-bar, but -fno-builtin-foo that disables that optimization. In this regard, -fno-builtin-foo would be more future-proof than -fno-built-bar, but -fno-builtin-foo is still potentially overkill. We may want to prevent calls from foo() being optimized into calls to bar(), but we still may want other optimization on calls to foo(). It seems that compilers today don't quite provide the fine grain control over which libcall optimizations pseudo-freestanding environments would prefer. Finally, Kees notes that this interface is unsafe, so we should not encourage its use. As such, I've removed the declaration from any header, but it still needs to be exported to avoid linkage errors in modules. Reported-by:
Sami Tolvanen <samitolvanen@google.com> Suggested-by:
Andy Lavr <andy.lavr@gmail.com> Suggested-by:
Arvind Sankar <nivedita@alum.mit.edu> Suggested-by:
Joe Perches <joe@perches.com> Suggested-by:
Masahiro Yamada <masahiroy@kernel.org> Suggested-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by:
Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
Nathan Chancellor <natechancellor@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200914161643.938408-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=47162 Link: https://bugs.llvm.org/show_bug.cgi?id=47280 Link: https://github.com/ClangBuiltLinux/linux/issues/1126 Link: https://man7.org/linux/man-pages/man3/stpcpy.3.html Link: https://pubs.opengroup.org/onlinepubs/9699919799/functions/stpcpy.html Link: https://reviews.llvm.org/D85963Signed-off-by:
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