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2020-08-03Merge tag 'for-5.9/io_uring-20200802' of git://git.kernel.dk/linux-blockLinus Torvalds1-1096/+1449
Pull io_uring updates from Jens Axboe: "Lots of cleanups in here, hardening the code and/or making it easier to read and fixing bugs, but a core feature/change too adding support for real async buffered reads. With the latter in place, we just need buffered write async support and we're done relying on kthreads for the fast path. In detail: - Cleanup how memory accounting is done on ring setup/free (Bijan) - sq array offset calculation fixup (Dmitry) - Consistently handle blocking off O_DIRECT submission path (me) - Support proper async buffered reads, instead of relying on kthread offload for that. This uses the page waitqueue to drive retries from task_work, like we handle poll based retry. (me) - IO completion optimizations (me) - Fix race with accounting and ring fd install (me) - Support EPOLLEXCLUSIVE (Jiufei) - Get rid of the io_kiocb unionizing, made possible by shrinking other bits (Pavel) - Completion side cleanups (Pavel) - Cleanup REQ_F_ flags handling, and kill off many of them (Pavel) - Request environment grabbing cleanups (Pavel) - File and socket read/write cleanups (Pavel) - Improve kiocb_set_rw_flags() (Pavel) - Tons of fixes and cleanups (Pavel) - IORING_SQ_NEED_WAKEUP clear fix (Xiaoguang)" * tag 'for-5.9/io_uring-20200802' of git://git.kernel.dk/linux-block: (127 commits) io_uring: flip if handling after io_setup_async_rw fs: optimise kiocb_set_rw_flags() io_uring: don't touch 'ctx' after installing file descriptor io_uring: get rid of atomic FAA for cq_timeouts io_uring: consolidate *_check_overflow accounting io_uring: fix stalled deferred requests io_uring: fix racy overflow count reporting io_uring: deduplicate __io_complete_rw() io_uring: de-unionise io_kiocb io-wq: update hash bits io_uring: fix missing io_queue_linked_timeout() io_uring: mark ->work uninitialised after cleanup io_uring: deduplicate io_grab_files() calls io_uring: don't do opcode prep twice io_uring: clear IORING_SQ_NEED_WAKEUP after executing task works io_uring: batch put_task_struct() tasks: add put_task_struct_many() io_uring: return locked and pinned page accounting io_uring: don't miscount pinned memory io_uring: don't open-code recv kbuf managment ...
2020-08-01io_uring: flip if handling after io_setup_async_rwPavel Begunkov1-74/+72
As recently done with with send/recv, flip the if after rw_verify_aread() in io_{read,write}() and tabulise left bits left. This removes mispredicted by a compiler jump on the success/fast path. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-31io_uring: don't touch 'ctx' after installing file descriptorJens Axboe1-3/+9
As soon as we install the file descriptor, we have to assume that it can get arbitrarily closed. We currently account memory (and note that we did) after installing the ring fd, which means that it could be a potential use-after-free condition if the fd is closed right after being installed, but before we fiddle with the ctx. In fact, syzbot reported this exact scenario: BUG: KASAN: use-after-free in io_account_mem fs/io_uring.c:7397 [inline] BUG: KASAN: use-after-free in io_uring_create fs/io_uring.c:8369 [inline] BUG: KASAN: use-after-free in io_uring_setup+0x2797/0x2910 fs/io_uring.c:8400 Read of size 1 at addr ffff888087a41044 by task syz-executor.5/18145 CPU: 0 PID: 18145 Comm: syz-executor.5 Not tainted 5.8.0-rc7-next-20200729-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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 io_account_mem fs/io_uring.c:7397 [inline] io_uring_create fs/io_uring.c:8369 [inline] io_uring_setup+0x2797/0x2910 fs/io_uring.c:8400 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c429 Code: 8d b6 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 5b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f8f121d0c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000000008540 RCX: 000000000045c429 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000196 RBP: 000000000078bf38 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007fff86698cff R14: 00007f8f121d19c0 R15: 000000000078bf0c Move the accounting of the ring used locked memory before we get and install the ring file descriptor. Cc: stable@vger.kernel.org Reported-by: syzbot+9d46305e76057f30c74e@syzkaller.appspotmail.com Fixes: 309758254ea6 ("io_uring: report pinned memory usage") Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-30io_uring: get rid of atomic FAA for cq_timeoutsPavel Begunkov1-3/+5
If ->cq_timeouts modifications are done under ->completion_lock, we don't really nee any fetch-and-add and other complex atomics. Replace it with non-atomic FAA, that saves an implicit full memory barrier. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-30io_uring: consolidate *_check_overflow accountingPavel Begunkov1-10/+13
Add a helper to mark ctx->{cq,sq}_check_overflow to get rid of duplicates, and it's clearer to check cq_overflow_list directly anyway. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-30io_uring: fix stalled deferred requestsPavel Begunkov1-0/+1
Always do io_commit_cqring() after completing a request, even if it was accounted as overflowed on the CQ side. Failing to do that may lead to not to pushing deferred requests when needed, and so stalling the whole ring. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-30io_uring: fix racy overflow count reportingPavel Begunkov1-2/+1
All ->cq_overflow modifications should be under completion_lock, otherwise it can report a wrong number to the userspace. Fix it in io_uring_cancel_files(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-30io_uring: deduplicate __io_complete_rw()Pavel Begunkov1-5/+3
Call __io_complete_rw() in io_iopoll_queue() instead of hand coding it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-30io_uring: de-unionise io_kiocbPavel Begunkov1-45/+14
As io_kiocb have enough space, move ->work out of a union. It's safer this way and removes ->work memcpy bouncing. By the way make tabulation in struct io_kiocb consistent. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-25io_uring: fix missing io_queue_linked_timeout()Pavel Begunkov1-13/+13
Whoever called io_prep_linked_timeout() should also do io_queue_linked_timeout(). __io_queue_sqe() doesn't follow that for the punting path leaving linked timeouts prepared but never queued. Fixes: 6df1db6b54243 ("io_uring: fix mis-refcounting linked timeouts") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-25io_uring: mark ->work uninitialised after cleanupPavel Begunkov1-1/+2
Remove REQ_F_WORK_INITIALIZED after io_req_clean_work(). That's a cold path but is safer for those using io_req_clean_work() out of *dismantle_req()/*io_free(). And for the same reason zero work.fs Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: deduplicate io_grab_files() callsPavel Begunkov1-16/+16
Move io_req_init_async() into io_grab_files(), it's safer this way. Note that io_queue_async_work() does *init_async(), so it's valid to move out of __io_queue_sqe() punt path. Also, add a helper around io_grab_files(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: don't do opcode prep twicePavel Begunkov1-1/+2
Calling into opcode prep handlers may be dangerous, as they re-read SQE but might not re-initialise requests completely. If io_req_defer() passed fast checks and is done with preparations, punt it async. As all other cases are covered with nulling @sqe, this guarantees that io_[opcode]_prep() are visited only once per request. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: clear IORING_SQ_NEED_WAKEUP after executing task worksXiaoguang Wang1-10/+19
In io_sq_thread(), if there are task works to handle, current codes will skip schedule() and go on polling sq again, but forget to clear IORING_SQ_NEED_WAKEUP flag, fix this issue. Also add two helpers to set and clear IORING_SQ_NEED_WAKEUP flag, Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: batch put_task_struct()Pavel Begunkov1-2/+27
As every iopoll request have a task ref, it becomes expensive to put them one by one, instead we can put several at once integrating that into io_req_free_batch(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: return locked and pinned page accountingPavel Begunkov1-4/+5
Locked and pinned memory accounting in io_{,un}account_mem() depends on having ->sqo_mm, which is NULL after a recent change for non SQPOLL'ed io_ring. That disables the accounting. Return ->sqo_mm initialisation back, and do __io_sq_thread_acquire_mm() based on IORING_SETUP_SQPOLL flag. Fixes: 8eb06d7e8dd85 ("io_uring: fix missing ->mm on exit") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: don't miscount pinned memoryPavel Begunkov1-1/+1
io_sqe_buffer_unregister() uses cxt->sqo_mm for memory accounting, but io_ring_ctx_free() drops ->sqo_mm before leaving pinned_vm over-accounted. Postpone mm cleanup for when it's not needed anymore. Fixes: 309758254ea62 ("io_uring: report pinned memory usage") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: don't open-code recv kbuf managmentPavel Begunkov1-14/+14
Don't implement fast path of kbuf freeing and management inlined into io_recv{,msg}(), that's error prone and duplicates handling. Replace it with a helper io_put_recv_kbuf(), which mimics io_put_rw_kbuf() in the io_read/write(). This also keeps cflags calculation in one place, removing duplication between rw and recv/send. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: extract io_put_kbuf() helperPavel Begunkov1-7/+12
Extract a common helper for cleaning up a selected buffer, this will be used shortly. By the way, correct cflags types to unsigned and, as kbufs are anyway tracked by a flag, remove useless zeroing req->rw.addr. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: move BUFFER_SELECT check into *recv[msg]Pavel Begunkov1-12/+10
Move REQ_F_BUFFER_SELECT flag check out of io_recv_buffer_select(), and do that in its call sites That saves us from double error checking and possibly an extra function call. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: free selected-bufs if error'edPavel Begunkov1-41/+44
io_clean_op() may be skipped even if there is a selected io_buffer, that's because *select_buffer() funcions never set REQ_F_NEED_CLEANUP. Trigger io_clean_op() when REQ_F_BUFFER_SELECTED is set as well, and and clear the flag if was freed out of it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: don't forget cflags in io_recv()Pavel Begunkov1-6/+4
Instead of returning error from io_recv(), go through generic cleanup path, because it'll retain cflags for userspace. Do the same for io_send() for consistency. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: remove extra checks in send/recvPavel Begunkov1-5/+5
With the return on a bad socket, kmsg is always non-null by the end of the function, prune left extra checks and initialisations. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: indent left {send,recv}[msg]()Pavel Begunkov1-134/+131
Flip over "if (sock)" condition with return on error, the upper layer will take care. That change will be handy later, but already removes an extra jump from hot path. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: simplify file ref tracking in submission statePavel Begunkov1-8/+4
Currently, file refs in struct io_submit_state are tracked with 2 vars: @has_refs -- how many refs were initially taken @used_refs -- number of refs used Replace it with a single variable counting how many refs left at the current moment. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring/io-wq: move RLIMIT_FSIZE to io-wqPavel Begunkov1-13/+9
RLIMIT_SIZE in needed only for execution from an io-wq context, hence move all preparations from hot path to io-wq work setup. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: alloc ->io in io_req_defer_prep()Pavel Begunkov1-15/+7
Every call to io_req_defer_prep() is prepended with allocating ->io, just do that in the function. And while we're at it, mark error paths with unlikey and replace "if (ret < 0)" with "if (ret)". There is only one change in the observable behaviour, that's instead of killing the head request right away on error, it postpones it until the link is assembled, that looks more preferable. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: remove empty cleanup of OP_OPEN* reqsPavel Begunkov1-3/+0
A switch in __io_clean_op() doesn't have default, it's pointless to list opcodes that doesn't do any cleanup. Remove IORING_OP_OPEN* from there. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: inline io_req_work_grab_env()Pavel Begunkov1-30/+20
The only caller of io_req_work_grab_env() is io_prep_async_work(), and they are both initialising req->work. Inline grab_env(), it's easier to keep this way, moreover there already were bugs with misplacing io_req_init_async(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: place cflags into completion dataPavel Begunkov1-5/+5
req->cflags is used only for defer-completion path, just use completion data to store it. With the 4 bytes from the ->sequence patch and compacting io_kiocb, this frees 8 bytes. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: remove sequence from io_kiocbPavel Begunkov1-14/+30
req->sequence is used only for deferred (i.e. DRAIN) requests, but initialised for every request. Remove req->sequence from io_kiocb together with its initialisation in io_init_req(). Replace it with a new field in struct io_defer_entry, that will be calculated only when needed in io_req_defer(), which is a slow path. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: use non-intrusive list for deferPavel Begunkov1-7/+18
The only left user of req->list is DRAIN, hence instead of keeping a separate per request list for it, do that with old fashion non-intrusive lists allocated on demand. That's a really slow path, so that's OK. This removes req->list and so sheds 16 bytes from io_kiocb. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: remove init for unused listPavel Begunkov1-1/+0
poll*() doesn't use req->list, don't init it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: add req->timeout.listPavel Begunkov1-10/+12
Instead of using shared req->list, hang timeouts up on their own list entry. struct io_timeout have enough extra space for it, but if that will be a problem ->inflight_entry can reused for that. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: use completion list for CQ overflowPavel Begunkov1-7/+8
As with the completion path, also use compl.list for overflowed requests. If cleaned up properly, nobody needs per-op data there anymore. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: use inflight_entry list for iopoll'ingPavel Begunkov1-11/+15
req->inflight_entry is used to track requests that grabbed files_struct. Let's share it with iopoll list, because the only iopoll'ed ops are reads and writes, which don't need a file table. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: rename ctx->poll into ctx->iopollPavel Begunkov1-18/+18
It supports both polling and I/O polling. Rename ctx->poll to clearly show that it's only in I/O poll case. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: share completion list w/ per-op spacePavel Begunkov1-7/+20
Calling io_req_complete(req) means that the request is done, and there is nothing left but to clean it up. That also means that per-op data after that should not be used, so we're free to reuse it in completion path, e.g. to store overflow_list as done in this patch. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: follow **iovec idiom in io_import_iovecPavel Begunkov1-6/+8
As for import_iovec(), return !=NULL iovec from io_import_iovec() only when it should be freed. That includes returning NULL when iovec is already in req->io, because it should be deallocated by other means, e.g. inside op handler. After io_setup_async_rw() local iovec to ->io, just mark it NULL, to follow the idea in io_{read,write} as well. That's easier to follow, and especially useful if we want to reuse per-op space for completion data. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> [axboe: only call kfree() on non-NULL pointer] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: add a helper for async rw iovec prepPavel Begunkov1-26/+20
Preparing reads/writes for async is a bit tricky. Extract a helper to not repeat it twice. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: simplify io_req_map_rw()Pavel Begunkov1-7/+9
Don't deref req->io->rw every time, but put it in a local variable. This looks prettier, generates less instructions, and doesn't break alias analysis. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: replace rw->task_work with rq->task_workPavel Begunkov1-27/+4
io_kiocb::task_work was de-unionised, and is not planned to be shared back, because it's too useful and commonly used. Hence, instead of keeping a separate task_work in struct io_async_rw just reuse req->task_work. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: extract io_sendmsg_copy_hdr()Pavel Begunkov1-10/+11
Don't repeat send msg initialisation code, it's error prone. Extract and use a helper function. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: use more specific type in rcv/snd msg cpPavel Begunkov1-32/+31
send/recv msghdr initialisation works with struct io_async_msghdr, but pulls the whole struct io_async_ctx for no reason. That complicates it with composite accessing, e.g. io->msg. Use and pass the most specific type, which is struct io_async_msghdr. It is the larget field in union io_async_ctx and doesn't save stack space, but looks clearer. The most of the changes are replacing "io->msg." with "iomsg->" Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: rename sr->msg into umsgPavel Begunkov1-9/+9
Every second field in send/recv is called msg, make it a bit more understandable by renaming ->msg, which is a user provided ptr, to ->umsg. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: fix sq array offset calculationDmitry Vyukov1-3/+3
rings_size() sets sq_offset to the total size of the rings (the returned value which is used for memory allocation). This is wrong: sq array should be located within the rings, not after them. Set sq_offset to where it should be. Fixes: 75b28affdd6a ("io_uring: allocate the two rings together") Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Hristo Venev <hristo@venev.name> Cc: io-uring@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24Merge branch 'io_uring-5.8' into for-5.9/io_uringJens Axboe1-32/+74
Merge in io_uring-5.8 fixes, as changes/cleanups to how we do locked mem accounting require a fixup, and only one of the spots are noticed by git as the other merges cleanly. The flags fix from io_uring-5.8 also causes a merge conflict, the leak fix for recvmsg, the double poll fix, and the link failure locking fix. * io_uring-5.8: io_uring: fix lockup in io_fail_links() io_uring: fix ->work corruption with poll_add io_uring: missed req_init_async() for IOSQE_ASYNC io_uring: always allow drain/link/hardlink/async sqe flags io_uring: ensure double poll additions work with both request types io_uring: fix recvmsg memory leak with buffer selection io_uring: fix not initialised work->flags io_uring: fix missing msg_name assignment io_uring: account user memory freed when exit has been queued io_uring: fix memleak in io_sqe_files_register() io_uring: fix memleak in __io_sqe_files_update() io_uring: export cq overflow status to userspace Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: fix lockup in io_fail_links()Pavel Begunkov1-2/+1
io_fail_links() doesn't consider REQ_F_COMP_LOCKED leading to nested spin_lock(completion_lock) and lockup. [ 197.680409] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 6-... } 18239 jiffies s: 1421 root: 0x40/. [ 197.680411] rcu: blocking rcu_node structures: [ 197.680412] Task dump for CPU 6: [ 197.680413] link-timeout R running task 0 1669 1 0x8000008a [ 197.680414] Call Trace: [ 197.680420] ? io_req_find_next+0xa0/0x200 [ 197.680422] ? io_put_req_find_next+0x2a/0x50 [ 197.680423] ? io_poll_task_func+0xcf/0x140 [ 197.680425] ? task_work_run+0x67/0xa0 [ 197.680426] ? do_exit+0x35d/0xb70 [ 197.680429] ? syscall_trace_enter+0x187/0x2c0 [ 197.680430] ? do_group_exit+0x43/0xa0 [ 197.680448] ? __x64_sys_exit_group+0x18/0x20 [ 197.680450] ? do_syscall_64+0x52/0xa0 [ 197.680452] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: fix ->work corruption with poll_addPavel Begunkov1-0/+4
req->work might be already initialised by the time it gets into __io_arm_poll_handler(), which will corrupt it by using fields that are in an union with req->work. Luckily, the only side effect is missing put_creds(). Clean req->work before going there. Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-23io_uring: missed req_init_async() for IOSQE_ASYNCPavel Begunkov1-0/+1
IOSQE_ASYNC branch of io_queue_sqe() is another place where an unitialised req->work can be accessed (i.e. prior io_req_init_async()). Nothing really bad though, it just looses IO_WQ_WORK_CONCURRENT flag. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>