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2024-08-14io_uring/net: don't pick multiple buffers for non-bundle sendJens Axboe1-2/+3
commit 8fe8ac24adcd76b12edbfdefa078567bfff117d4 upstream. If a send is issued marked with IOSQE_BUFFER_SELECT for selecting a buffer, unless it's a bundle, it should not select multiple buffers. Cc: stable@vger.kernel.org Fixes: a05d1f625c7a ("io_uring/net: support bundles for send") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-14io_uring/net: ensure expanded bundle send gets marked for cleanupJens Axboe1-0/+1
commit 70ed519ed59da3a92c3acedeb84a30e5a66051ce upstream. If the iovec inside the kmsg isn't already allocated AND one gets expanded beyond the fixed size, then the request may not already have been marked for cleanup. Ensure that it is. Cc: stable@vger.kernel.org Fixes: a05d1f625c7a ("io_uring/net: support bundles for send") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-14io_uring/net: ensure expanded bundle recv gets marked for cleanupJens Axboe1-0/+1
commit 11893e144ed75be55d99349760513ca104781fc0 upstream. If the iovec inside the kmsg isn't already allocated AND one gets expanded beyond the fixed size, then the request may not already have been marked for cleanup. Ensure that it is. Cc: stable@vger.kernel.org Fixes: 2f9c9515bdfd ("io_uring/net: support bundles for recv") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-11io_uring: keep multishot request NAPI timeout currentOlivier Langlois1-0/+1
commit 2c762be5b798c443612c1bb9b011de4fdaebd1c5 upstream. This refresh statement was originally present in the original patch: https://lore.kernel.org/netdev/20221121191437.996297-2-shr@devkernel.io/ It has been removed with no explanation in v6: https://lore.kernel.org/netdev/20230201222254.744422-2-shr@devkernel.io/ It is important to make the refresh for multishot requests, because if no new requests using the same NAPI device are added to the ring, the entry will become stale and be removed silently. The unsuspecting user will not know that their ring had busy polling for only 60 seconds before being pruned. Signed-off-by: Olivier Langlois <olivier@trillion01.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Fixes: 8d0c12a80cdeb ("io-uring: add napi busy poll support") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/0fe61a019ec61e5708cd117cb42ed0dab95e1617.1722294646.git.olivier@trillion01.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03io_uring: fix io_match_task must_holdPavel Begunkov1-1/+1
[ Upstream commit e142e9cd8891b0c6f277ac2c2c254199a6aa56e3 ] The __must_hold annotation in io_match_task() uses a non existing parameter "req", fix it. Fixes: 6af3f48bf6156 ("io_uring: fix link traversal locking") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3e65ee7709e96507cef3d93291746f2c489f2307.1721819383.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03io_uring: don't allow netpolling with SETUP_IOPOLLPavel Begunkov1-0/+2
commit bd44d7e902c2b34c217d3b48874b079760ca7b6e upstream. IORING_SETUP_IOPOLL rings don't have any netpoll handling, let's fail attempts to register netpolling in this case, there might be people who will mix up IOPOLL and netpoll. Cc: stable@vger.kernel.org Fixes: ef1186c1a875b ("io_uring: add register/unregister napi function") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1e7553aee0a8ae4edec6742cd6dd0c1e6914fba8.1721819383.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03io_uring: tighten task exit cancellationsPavel Begunkov1-1/+4
commit f8b632e89a101dae349a7b212c1771d7925f441b upstream. io_uring_cancel_generic() should retry if any state changes like a request is completed, however in case of a task exit it only goes for another loop and avoids schedule() if any tracked (i.e. REQ_F_INFLIGHT) request got completed. Let's assume we have a non-tracked request executing in iowq and a tracked request linked to it. Let's also assume io_uring_cancel_generic() fails to find and cancel the request, i.e. via io_run_local_work(), which may happen as io-wq has gaps. Next, the request logically completes, io-wq still hold a ref but queues it for completion via tw, which happens in io_uring_try_cancel_requests(). After, right before prepare_to_wait() io-wq puts the request, grabs the linked one and tries executes it, e.g. arms polling. Finally the cancellation loop calls prepare_to_wait(), there are no tw to run, no tracked request was completed, so the tctx_inflight() check passes and the task is put to indefinite sleep. Cc: stable@vger.kernel.org Fixes: 3f48cf18f886c ("io_uring: unify files and task cancel") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/acac7311f4e02ce3c43293f8f1fda9c705d158f1.1721819383.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03io_uring: fix lost getsockopt completionsPavel Begunkov1-1/+1
commit 24dce1c538a7ceac43f2f97aae8dfd4bb93ea9b9 upstream. There is a report that iowq executed getsockopt never completes. The reason being that io_uring_cmd_sock() can return a positive result, and io_uring_cmd() propagates it back to core io_uring, instead of IOU_OK. In case of io_wq_submit_work(), the request will be dropped without completing it. The offending code was introduced by a hack in a9c3eda7eada9 ("io_uring: fix submission-failure handling for uring-cmd"), however it was fine until getsockopt was introduced and started returning positive results. The right solution is to always return IOU_OK, since e0b23d9953b0c ("io_uring: optimise ltimeout for inline execution"), we should be able to do it without problems, however for the sake of backporting and minimising side effects, let's keep returning negative return codes and otherwise do IOU_OK. Link: https://github.com/axboe/liburing/issues/1181 Cc: stable@vger.kernel.org Fixes: 8e9fad0e70b7b ("io_uring: Add io_uring command support for sockets") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/ff349cf0654018189b6077e85feed935f0f8839e.1721149870.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03io_uring/io-wq: limit retrying worker initialisationPavel Begunkov1-3/+7
commit 0453aad676ff99787124b9b3af4a5f59fbe808e2 upstream. If io-wq worker creation fails, we retry it by queueing up a task_work. tasK_work is needed because it should be done from the user process context. The problem is that retries are not limited, and if queueing a task_work is the reason for the failure, we might get into an infinite loop. It doesn't seem to happen now but it would with the following patch executing task_work in the freezer's loop. For now, arbitrarily limit the number of attempts to create a worker. Cc: stable@vger.kernel.org Fixes: 3146cba99aa28 ("io-wq: make worker creation resilient against signals") Reported-by: Julian Orth <ju.orth@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/8280436925db88448c7c85c6656edee1a43029ea.1720634146.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03io_uring: Fix probe of disabled operationsGabriel Krisman Bertazi3-3/+11
[ Upstream commit 3e05b222382ec67dce7358d50b6006e91d028d8b ] io_probe checks io_issue_def->not_supported, but we never really set that field, as we mark non-supported functions through a specific ->prep handler. This means we end up returning IO_URING_OP_SUPPORTED, even for disabled operations. Fix it by just checking the prep handler itself. Fixes: 66f4af93da57 ("io_uring: add support for probing opcodes") Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20240619020620.5301-2-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-24io_uring: fix error pbuf checkingPavel Begunkov1-1/+3
commit bcc87d978b834c298bbdd9c52454c5d0a946e97e upstream. Syz reports a problem, which boils down to NULL vs IS_ERR inconsistent error handling in io_alloc_pbuf_ring(). KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:__io_remove_buffers+0xac/0x700 io_uring/kbuf.c:341 Call Trace: <TASK> io_put_bl io_uring/kbuf.c:378 [inline] io_destroy_buffers+0x14e/0x490 io_uring/kbuf.c:392 io_ring_ctx_free+0xa00/0x1070 io_uring/io_uring.c:2613 io_ring_exit_work+0x80f/0x8a0 io_uring/io_uring.c:2844 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Cc: stable@vger.kernel.org Reported-by: syzbot+2074b1a3d447915c6f1c@syzkaller.appspotmail.com Fixes: 87585b05757dc ("io_uring/kbuf: use vm_insert_pages() for mmap'ed pbuf ring") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/c5f9df20560bd9830401e8e48abc029e7cfd9f5e.1721329239.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-02io_uring/net: don't clear msg_inq before io_recv_buf_select() needs itJens Axboe1-4/+6
For bundle receives to function properly, the previous iteration msg_inq value is needed to make a judgement call on how much data there is to receive. A previous fix ended up clearing it earlier as an error case would potentially errantly set IORING_CQE_F_SOCK_NONEMPTY if the request got failed. Move the assignment to post assigning buffers for the receive, but ensure that it's cleared for the buffer selection error case. With that, buffer selection has the right msg_inq value and can correctly bundle receives as designed. Noticed while testing where it was apparent than more than 1 buffer was never received. After fix was in place, multiple buffers are correctly picked for receive. This provides a 10x speedup for the test case, as the buffer size used was 64b. Fixes: 18414a4a2eab ("io_uring/net: assign kmsg inq/flags before buffer selection") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-25io_uring: signal SQPOLL task_work with TWA_SIGNAL_NO_IPIJens Axboe1-2/+2
Before SQPOLL was transitioned to managing its own task_work, the core used TWA_SIGNAL_NO_IPI to ensure that task_work was processed. If not, we can't be sure that all task_work is processed at SQPOLL thread exit time. Fixes: af5d68f8892f ("io_uring/sqpoll: manage task_work privately") Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-20io_uring/rsrc: fix incorrect assignment of iter->nr_segs in io_import_fixedChenliang Li1-1/+0
In io_import_fixed when advancing the iter within the first bvec, the iter->nr_segs is set to bvec->bv_len. nr_segs should be the number of bvecs, plus we don't need to adjust it here, so just remove it. Fixes: b000ae0ec2d7 ("io_uring/rsrc: optimise single entry advance") Signed-off-by: Chenliang Li <cliang01.li@samsung.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/20240619063819.2445-1-cliang01.li@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-14io_uring: fix cancellation overwriting req->flagsPavel Begunkov2-2/+3
Only the current owner of a request is allowed to write into req->flags. Hence, the cancellation path should never touch it. Add a new field instead of the flag, move it into the 3rd cache line because it should always be initialised. poll_refs can move further as polling is an involved process anyway. It's a minimal patch, in the future we can and should find a better place for it and remove now unused REQ_F_CANCEL_SEQ. Fixes: 521223d7c229f ("io_uring/cancel: don't default to setting req->work.cancel_seq") Cc: stable@vger.kernel.org Reported-by: Li Shi <sl1589472800@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/6827b129f8f0ad76fa9d1f0a773de938b240ffab.1718323430.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-12io_uring/rsrc: don't lock while !TASK_RUNNINGPavel Begunkov1-0/+1
There is a report of io_rsrc_ref_quiesce() locking a mutex while not TASK_RUNNING, which is due to forgetting restoring the state back after io_run_task_work_sig() and attempts to break out of the waiting loop. do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff815d2494>] prepare_to_wait+0xa4/0x380 kernel/sched/wait.c:237 WARNING: CPU: 2 PID: 397056 at kernel/sched/core.c:10099 __might_sleep+0x114/0x160 kernel/sched/core.c:10099 RIP: 0010:__might_sleep+0x114/0x160 kernel/sched/core.c:10099 Call Trace: <TASK> __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0xb4/0x940 kernel/locking/mutex.c:752 io_rsrc_ref_quiesce+0x590/0x940 io_uring/rsrc.c:253 io_sqe_buffers_unregister+0xa2/0x340 io_uring/rsrc.c:799 __io_uring_register io_uring/register.c:424 [inline] __do_sys_io_uring_register+0x5b9/0x2400 io_uring/register.c:613 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd8/0x270 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 Reported-by: Li Shi <sl1589472800@gmail.com> Fixes: 4ea15b56f0810 ("io_uring/rsrc: use wq for quiescing") Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/77966bc104e25b0534995d5dbb152332bc8f31c0.1718196953.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-04io_uring: fix possible deadlock in io_register_iowq_max_workers()Hagar Hemdan1-0/+4
The io_register_iowq_max_workers() function calls io_put_sq_data(), which acquires the sqd->lock without releasing the uring_lock. Similar to the commit 009ad9f0c6ee ("io_uring: drop ctx->uring_lock before acquiring sqd->lock"), this can lead to a potential deadlock situation. To resolve this issue, the uring_lock is released before calling io_put_sq_data(), and then it is re-acquired after the function call. This change ensures that the locks are acquired in the correct order, preventing the possibility of a deadlock. Suggested-by: Maximilian Heyne <mheyne@amazon.de> Signed-off-by: Hagar Hemdan <hagarhem@amazon.com> Link: https://lore.kernel.org/r/20240604130527.3597-1-hagarhem@amazon.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-04io_uring/io-wq: avoid garbage value of 'match' in io_wq_enqueue()Su Hui1-5/+5
Clang static checker (scan-build) warning: o_uring/io-wq.c:line 1051, column 3 The expression is an uninitialized value. The computed value will also be garbage. 'match.nr_pending' is used in io_acct_cancel_pending_work(), but it is not fully initialized. Change the order of assignment for 'match' to fix this problem. Fixes: 42abc95f05bf ("io-wq: decouple work_list protection from the big wqe->lock") Signed-off-by: Su Hui <suhui@nfschina.com> Link: https://lore.kernel.org/r/20240604121242.2661244-1-suhui@nfschina.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-04io_uring/napi: fix timeout calculationJens Axboe1-11/+13
Not quite sure what __io_napi_adjust_timeout() was attemping to do, it's adjusting both the NAPI timeout and the general overall timeout, and calculating a value that is never used. The overall timeout is a super set of the NAPI timeout, and doesn't need adjusting. The only thing we really need to care about is that the NAPI timeout doesn't exceed the overall timeout. If a user asked for a timeout of eg 5 usec and NAPI timeout is 10 usec, then we should not spin for 10 usec. While in there, sanitize the time checking a bit. If we have a negative value in the passed in timeout, discard it. Round up the value as well, so we don't end up with a NAPI timeout for the majority of the wait, with only a tiny sleep value at the end. Hence the only case we need to care about is if the NAPI timeout is larger than the overall timeout. If it is, cap the NAPI timeout at what the overall timeout is. Cc: stable@vger.kernel.org Fixes: 8d0c12a80cde ("io-uring: add napi busy poll support") Reported-by: Lewis Baker <lewissbaker@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-01io_uring: check for non-NULL file pointer in io_file_can_poll()Jens Axboe1-1/+1
In earlier kernels, it was possible to trigger a NULL pointer dereference off the forced async preparation path, if no file had been assigned. The trace leading to that looks as follows: BUG: kernel NULL pointer dereference, address: 00000000000000b0 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 67 PID: 1633 Comm: buf-ring-invali Not tainted 6.8.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 2/2/2022 RIP: 0010:io_buffer_select+0xc3/0x210 Code: 00 00 48 39 d1 0f 82 ae 00 00 00 48 81 4b 48 00 00 01 00 48 89 73 70 0f b7 50 0c 66 89 53 42 85 ed 0f 85 d2 00 00 00 48 8b 13 <48> 8b 92 b0 00 00 00 48 83 7a 40 00 0f 84 21 01 00 00 4c 8b 20 5b RSP: 0018:ffffb7bec38c7d88 EFLAGS: 00010246 RAX: ffff97af2be61000 RBX: ffff97af234f1700 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffff97aecfb04820 RDI: ffff97af234f1700 RBP: 0000000000000000 R08: 0000000000200030 R09: 0000000000000020 R10: ffffb7bec38c7dc8 R11: 000000000000c000 R12: ffffb7bec38c7db8 R13: ffff97aecfb05800 R14: ffff97aecfb05800 R15: ffff97af2be5e000 FS: 00007f852f74b740(0000) GS:ffff97b1eeec0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000b0 CR3: 000000016deab005 CR4: 0000000000370ef0 Call Trace: <TASK> ? __die+0x1f/0x60 ? page_fault_oops+0x14d/0x420 ? do_user_addr_fault+0x61/0x6a0 ? exc_page_fault+0x6c/0x150 ? asm_exc_page_fault+0x22/0x30 ? io_buffer_select+0xc3/0x210 __io_import_iovec+0xb5/0x120 io_readv_prep_async+0x36/0x70 io_queue_sqe_fallback+0x20/0x260 io_submit_sqes+0x314/0x630 __do_sys_io_uring_enter+0x339/0xbc0 ? __do_sys_io_uring_register+0x11b/0xc50 ? vm_mmap_pgoff+0xce/0x160 do_syscall_64+0x5f/0x180 entry_SYSCALL_64_after_hwframe+0x46/0x4e RIP: 0033:0x55e0a110a67e Code: ba cc 00 00 00 45 31 c0 44 0f b6 92 d0 00 00 00 31 d2 41 b9 08 00 00 00 41 83 e2 01 41 c1 e2 04 41 09 c2 b8 aa 01 00 00 0f 05 <c3> 90 89 30 eb a9 0f 1f 40 00 48 8b 42 20 8b 00 a8 06 75 af 85 f6 because the request is marked forced ASYNC and has a bad file fd, and hence takes the forced async prep path. Current kernels with the request async prep cleaned up can no longer hit this issue, but for ease of backporting, let's add this safety check in here too as it really doesn't hurt. For both cases, this will inevitably end with a CQE posted with -EBADF. Cc: stable@vger.kernel.org Fixes: a76c0b31eef5 ("io_uring: commit non-pollable provided mapped buffers upfront") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-30io_uring/net: assign kmsg inq/flags before buffer selectionJens Axboe1-3/+3
syzbot reports that recv is using an uninitialized value: ===================================================== BUG: KMSAN: uninit-value in io_req_cqe_overflow io_uring/io_uring.c:810 [inline] BUG: KMSAN: uninit-value in io_req_complete_post io_uring/io_uring.c:937 [inline] BUG: KMSAN: uninit-value in io_issue_sqe+0x1f1b/0x22c0 io_uring/io_uring.c:1763 io_req_cqe_overflow io_uring/io_uring.c:810 [inline] io_req_complete_post io_uring/io_uring.c:937 [inline] io_issue_sqe+0x1f1b/0x22c0 io_uring/io_uring.c:1763 io_wq_submit_work+0xa17/0xeb0 io_uring/io_uring.c:1860 io_worker_handle_work+0xc04/0x2000 io_uring/io-wq.c:597 io_wq_worker+0x447/0x1410 io_uring/io-wq.c:651 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was stored to memory at: io_req_set_res io_uring/io_uring.h:215 [inline] io_recv_finish+0xf10/0x1560 io_uring/net.c:861 io_recv+0x12ec/0x1ea0 io_uring/net.c:1175 io_issue_sqe+0x429/0x22c0 io_uring/io_uring.c:1751 io_wq_submit_work+0xa17/0xeb0 io_uring/io_uring.c:1860 io_worker_handle_work+0xc04/0x2000 io_uring/io-wq.c:597 io_wq_worker+0x447/0x1410 io_uring/io-wq.c:651 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was created at: slab_post_alloc_hook mm/slub.c:3877 [inline] slab_alloc_node mm/slub.c:3918 [inline] __do_kmalloc_node mm/slub.c:4038 [inline] __kmalloc+0x6e4/0x1060 mm/slub.c:4052 kmalloc include/linux/slab.h:632 [inline] io_alloc_async_data+0xc0/0x220 io_uring/io_uring.c:1662 io_msg_alloc_async io_uring/net.c:166 [inline] io_recvmsg_prep_setup io_uring/net.c:725 [inline] io_recvmsg_prep+0xbe8/0x1a20 io_uring/net.c:806 io_init_req io_uring/io_uring.c:2135 [inline] io_submit_sqe io_uring/io_uring.c:2182 [inline] io_submit_sqes+0x1135/0x2f10 io_uring/io_uring.c:2335 __do_sys_io_uring_enter io_uring/io_uring.c:3246 [inline] __se_sys_io_uring_enter+0x40f/0x3c80 io_uring/io_uring.c:3183 __x64_sys_io_uring_enter+0x11f/0x1a0 io_uring/io_uring.c:3183 x64_sys_call+0x2c0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:427 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f which appears to be io_recv_finish() reading kmsg->msg.msg_inq to decide if it needs to set IORING_CQE_F_SOCK_NONEMPTY or not. If the recv is entered with buffer selection, but no buffer is available, then we jump error path which calls io_recv_finish() without having assigned kmsg->msg_inq. This might cause an errant setting of the NONEMPTY flag for a request get gets errored with -ENOBUFS. Reported-by: syzbot+b1647099e82b3b349fbf@syzkaller.appspotmail.com Fixes: 4a3223f7bfda ("io_uring/net: switch io_recv() to using io_async_msghdr") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-30io_uring/rw: Free iovec before cleaning async dataBreno Leitao1-0/+5
kmemleak shows that there is a memory leak in io_uring read operation, where a buffer is allocated at iovec import, but never de-allocated. The memory is allocated at io_async_rw->free_iovec, but, then io_async_rw is kfreed, taking the allocated memory with it. I saw this happening when the read operation fails with -11 (EAGAIN). This is the kmemleak splat. unreferenced object 0xffff8881da591c00 (size 256): ... backtrace (crc 7a15bdee): [<00000000256f2de4>] __kmalloc+0x2d6/0x410 [<000000007a9f5fc7>] iovec_from_user.part.0+0xc6/0x160 [<00000000cecdf83a>] __import_iovec+0x50/0x220 [<00000000d1d586a2>] __io_import_iovec+0x13d/0x220 [<0000000054ee9bd2>] io_prep_rw+0x186/0x340 [<00000000a9c0372d>] io_prep_rwv+0x31/0x120 [<000000001d1170b9>] io_prep_readv+0xe/0x30 [<0000000070b8eb67>] io_submit_sqes+0x1bd/0x780 [<00000000812496d4>] __do_sys_io_uring_enter+0x3ed/0x5b0 [<0000000081499602>] do_syscall_64+0x5d/0x170 [<00000000de1c5a4d>] entry_SYSCALL_64_after_hwframe+0x76/0x7e This occurs because the async data cleanup functions are not set for read/write operations. As a result, the potentially allocated iovec in the rw async data is not freed before the async data is released, leading to a memory leak. With this following patch, kmemleak does not show the leaked memory anymore, and all liburing tests pass. Fixes: a9165b83c193 ("io_uring/rw: always setup io_async_rw for read/write requests") Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240530142340.1248216-1-leitao@debian.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-29io_uring: don't attempt to mmap larger than what the user asks forJens Axboe1-2/+3
If IORING_FEAT_SINGLE_MMAP is ignored, as can happen if an application uses an ancient liburing or does setup manually, then 3 mmap's are required to map the ring into userspace. The kernel will still have collapsed the mappings, however userspace may ask for mapping them individually. If so, then we should not use the full number of ring pages, as it may exceed the partial mapping. Doing so will yield an -EFAULT from vm_insert_pages(), as we pass in more pages than what the application asked for. Cap the number of pages to match what the application asked for, for the particular mapping operation. Reported-by: Lucas Mülling <lmulling@proton.me> Link: https://github.com/axboe/liburing/issues/1157 Fixes: 3ab1db3c6039 ("io_uring: get rid of remap_pfn_range() for mapping rings/sqes") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-23Merge tag 'io_uring-6.10-20240523' of git://git.kernel.dk/linuxLinus Torvalds2-6/+6
Pull io_uring fixes from Jens Axboe: "Single fix here for a regression in 6.9, and then a simple cleanup removing some dead code" * tag 'io_uring-6.10-20240523' of git://git.kernel.dk/linux: io_uring: remove checks for NULL 'sq_offset' io_uring/sqpoll: ensure that normal task_work is also run timely
2024-05-22io_uring: remove checks for NULL 'sq_offset'Jens Axboe1-4/+2
Since the 5.12 kernel release, nobody has been passing NULL as the sq_offset pointer. Remove the checks for it being NULL or not, it will always be valid. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-21Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-2/+2
Pull misc vfs updates from Al Viro: "Assorted commits that had missed the last merge window..." * tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: remove call_{read,write}_iter() functions do_dentry_open(): kill inode argument kernel_file_open(): get rid of inode argument get_file_rcu(): no need to check for NULL separately fd_is_open(): move to fs/file.c close_on_exec(): pass files_struct instead of fdtable
2024-05-21io_uring/sqpoll: ensure that normal task_work is also run timelyJens Axboe1-2/+4
With the move to private task_work, SQPOLL neglected to also run the normal task_work, if any is pending. This will eventually get run, but we should run it with the private task_work to ensure that things like a final fput() is processed in a timely fashion. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/313824bc-799d-414f-96b7-e6de57c7e21d@gmail.com/ Reported-by: Andrew Udvare <audvare@gmail.com> Fixes: af5d68f8892f ("io_uring/sqpoll: manage task_work privately") Tested-by: Christian Heusel <christian@heusel.eu> Tested-by: Andrew Udvare <audvare@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-19Merge tag 'mm-stable-2024-05-17-19-19' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
2024-05-18Merge tag 'net-accept-more-20240515' of git://git.kernel.dk/linuxLinus Torvalds1-6/+20
Pull more io_uring updates from Jens Axboe: "This adds support for IORING_CQE_F_SOCK_NONEMPTY for io_uring accept requests. This is very similar to previous work that enabled the same hint for doing receives on sockets. By far the majority of the work here is refactoring to enable the networking side to pass back whether or not the socket had more pending requests after accepting the current one, the last patch just wires it up for io_uring. Not only does this enable applications to know whether there are more connections to accept right now, it also enables smarter logic for io_uring multishot accept on whether to retry immediately or wait for a poll trigger" * tag 'net-accept-more-20240515' of git://git.kernel.dk/linux: io_uring/net: wire up IORING_CQE_F_SOCK_NONEMPTY for accept net: pass back whether socket was empty post accept net: have do_accept() take a struct proto_accept_arg argument net: change proto and proto_ops accept type
2024-05-14io_uring/net: wire up IORING_CQE_F_SOCK_NONEMPTY for acceptJens Axboe1-4/+16
If the given protocol supports passing back whether or not we had more pending accept post this one, pass back this information to userspace. This is done by setting IORING_CQE_F_SOCK_NONEMPTY in the CQE flags, just like we do for recv/recvmsg if there's more data available post a receive operation. We can also use this information to be smarter about multishot retry, as we don't need to do a pointless retry if we know for a fact that there aren't any more connections to accept. Suggested-by: Norman Maurer <norman_maurer@apple.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-14net: have do_accept() take a struct proto_accept_arg argumentJens Axboe1-2/+4
In preparation for passing in more information via this API, change do_accept() to take a proto_accept_arg struct pointer rather than just the file flags separately. No functional changes in this patch. Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-13Merge tag 'for-6.10/io_uring-20240511' of git://git.kernel.dk/linuxLinus Torvalds35-1698/+1898
Pull io_uring updates from Jens Axboe: - Greatly improve send zerocopy performance, by enabling coalescing of sent buffers. MSG_ZEROCOPY already does this with send(2) and sendmsg(2), but the io_uring side did not. In local testing, the crossover point for send zerocopy being faster is now around 3000 byte packets, and it performs better than the sync syscall variants as well. This feature relies on a shared branch with net-next, which was pulled into both branches. - Unification of how async preparation is done across opcodes. Previously, opcodes that required extra memory for async retry would allocate that as needed, using on-stack state until that was the case. If async retry was needed, the on-stack state was adjusted appropriately for a retry and then copied to the allocated memory. This led to some fragile and ugly code, particularly for read/write handling, and made storage retries more difficult than they needed to be. Allocate the memory upfront, as it's cheap from our pools, and use that state consistently both initially and also from the retry side. - Move away from using remap_pfn_range() for mapping the rings. This is really not the right interface to use and can cause lifetime issues or leaks. Additionally, it means the ring sq/cq arrays need to be physically contigious, which can cause problems in production with larger rings when services are restarted, as memory can be very fragmented at that point. Move to using vm_insert_page(s) for the ring sq/cq arrays, and apply the same treatment to mapped ring provided buffers. This also helps unify the code we have dealing with allocating and mapping memory. Hard to see in the diffstat as we're adding a few features as well, but this kills about ~400 lines of code from the codebase as well. - Add support for bundles for send/recv. When used with provided buffers, bundles support sending or receiving more than one buffer at the time, improving the efficiency by only needing to call into the networking stack once for multiple sends or receives. - Tweaks for our accept operations, supporting both a DONTWAIT flag for skipping poll arm and retry if we can, and a POLLFIRST flag that the application can use to skip the initial accept attempt and rely purely on poll for triggering the operation. Both of these have identical flags on the receive side already. - Make the task_work ctx locking unconditional. We had various code paths here that would do a mix of lock/trylock and set the task_work state to whether or not it was locked. All of that goes away, we lock it unconditionally and get rid of the state flag indicating whether it's locked or not. The state struct still exists as an empty type, can go away in the future. - Add support for specifying NOP completion values, allowing it to be used for error handling testing. - Use set/test bit for io-wq worker flags. Not strictly needed, but also doesn't hurt and helps silence a KCSAN warning. - Cleanups for io-wq locking and work assignments, closing a tiny race where cancelations would not be able to find the work item reliably. - Misc fixes, cleanups, and improvements * tag 'for-6.10/io_uring-20240511' of git://git.kernel.dk/linux: (97 commits) io_uring: support to inject result for NOP io_uring: fail NOP if non-zero op flags is passed in io_uring/net: add IORING_ACCEPT_POLL_FIRST flag io_uring/net: add IORING_ACCEPT_DONTWAIT flag io_uring/filetable: don't unnecessarily clear/reset bitmap io_uring/io-wq: Use set_bit() and test_bit() at worker->flags io_uring/msg_ring: cleanup posting to IOPOLL vs !IOPOLL ring io_uring: Require zeroed sqe->len on provided-buffers send io_uring/notif: disable LAZY_WAKE for linked notifs io_uring/net: fix sendzc lazy wake polling io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it io_uring/rw: reinstate thread check for retries io_uring/notif: implement notification stacking io_uring/notif: simplify io_notif_flush() net: add callback for setting a ubuf_info to skb net: extend ubuf_info callback to ops structure io_uring/net: support bundles for recv io_uring/net: support bundles for send io_uring/kbuf: add helpers for getting/peeking multiple buffers io_uring/net: add provided buffer support for IORING_OP_SEND ...
2024-05-13Merge tag 'vfs-6.10.misc' of ↵Linus Torvalds2-5/+6
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "This contains the usual miscellaneous features, cleanups, and fixes for vfs and individual fses. Features: - Free up FMODE_* bits. I've freed up bits 6, 7, 8, and 24. That means we now have six free FMODE_* bits in total (but bit #6 already got used for FMODE_WRITE_RESTRICTED) - Add FOP_HUGE_PAGES flag (follow-up to FMODE_* cleanup) - Add fd_raw cleanup class so we can make use of automatic cleanup provided by CLASS(fd_raw, f)(fd) for O_PATH fds as well - Optimize seq_puts() - Simplify __seq_puts() - Add new anon_inode_getfile_fmode() api to allow specifying f_mode instead of open-coding it in multiple places - Annotate struct file_handle with __counted_by() and use struct_size() - Warn in get_file() whether f_count resurrection from zero is attempted (epoll/drm discussion) - Folio-sophize aio - Export the subvolume id in statx() for both btrfs and bcachefs - Relax linkat(AT_EMPTY_PATH) requirements - Add F_DUPFD_QUERY fcntl() allowing to compare two file descriptors for dup*() equality replacing kcmp() Cleanups: - Compile out swapfile inode checks when swap isn't enabled - Use (1 << n) notation for FMODE_* bitshifts for clarity - Remove redundant variable assignment in fs/direct-io - Cleanup uses of strncpy in orangefs - Speed up and cleanup writeback - Move fsparam_string_empty() helper into header since it's currently open-coded in multiple places - Add kernel-doc comments to proc_create_net_data_write() - Don't needlessly read dentry->d_flags twice Fixes: - Fix out-of-range warning in nilfs2 - Fix ecryptfs overflow due to wrong encryption packet size calculation - Fix overly long line in xfs file_operations (follow-up to FMODE_* cleanup) - Don't raise FOP_BUFFER_{R,W}ASYNC for directories in xfs (follow-up to FMODE_* cleanup) - Don't call xfs_file_open from xfs_dir_open (follow-up to FMODE_* cleanup) - Fix stable offset api to prevent endless loops - Fix afs file server rotations - Prevent xattr node from overflowing the eraseblock in jffs2 - Move fdinfo PTRACE_MODE_READ procfs check into the .permission() operation instead of .open() operation since this caused userspace regressions" * tag 'vfs-6.10.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits) afs: Fix fileserver rotation getting stuck selftests: add F_DUPDFD_QUERY selftests fcntl: add F_DUPFD_QUERY fcntl() file: add fd_raw cleanup class fs: WARN when f_count resurrection is attempted seq_file: Simplify __seq_puts() seq_file: Optimize seq_puts() proc: Move fdinfo PTRACE_MODE_READ check into the inode .permission operation fs: Create anon_inode_getfile_fmode() xfs: don't call xfs_file_open from xfs_dir_open xfs: drop fop_flags for directories xfs: fix overly long line in the file_operations shmem: Fix shmem_rename2() libfs: Add simple_offset_rename() API libfs: Fix simple_offset_rename_exchange() jffs2: prevent xattr node from overflowing the eraseblock vfs, swap: compile out IS_SWAPFILE() on swapless configs vfs: relax linkat() AT_EMPTY_PATH - aka flink() - requirements fs/direct-io: remove redundant assignment to variable retval fs/dcache: Re-use value stored to dentry->d_flags instead of re-reading ...
2024-05-10io_uring: support to inject result for NOPMing Lei1-5/+21
Support to inject result for NOP so that we can inject failure from userspace. It is very helpful for covering failure handling code in io_uring core change. With nop flags, it becomes possible to add more test features on NOP in future. Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20240510035031.78874-3-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-10io_uring: fail NOP if non-zero op flags is passed inMing Lei1-0/+2
The NOP op flags should have been checked from beginning like any other opcode, otherwise NOP may not be extended with the op flags. Given both liburing and Rust io-uring crate always zeros SQE op flags, just ignore users which play raw NOP uring interface without zeroing SQE, because NOP is just for test purpose. Then we can save one NOP2 opcode. Suggested-by: Jens Axboe <axboe@kernel.dk> Fixes: 2b188cc1bb85 ("Add io_uring IO interface") Cc: stable@vger.kernel.org Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20240510035031.78874-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-09io_uring/net: add IORING_ACCEPT_POLL_FIRST flagJens Axboe1-1/+8
Similarly to how polling first is supported for receive, it makes sense to provide the same for accept. An accept operation does a lot of expensive setup, like allocating an fd, a socket/inode, etc. If no connection request is already pending, this is wasted and will just be cleaned up and freed, only to retry via the usual poll trigger. Add IORING_ACCEPT_POLL_FIRST, which tells accept to only initiate the accept request if poll says we have something to accept. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-09io_uring/net: add IORING_ACCEPT_DONTWAIT flagJens Axboe1-6/+9
This allows the caller to perform a non-blocking attempt, similarly to how recvmsg has MSG_DONTWAIT. If set, and we get -EAGAIN on a connection attempt, propagate the result to userspace rather than arm poll and wait for a retry. Suggested-by: Norman Maurer <norman_maurer@apple.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-08io_uring/filetable: don't unnecessarily clear/reset bitmapJens Axboe1-2/+2
If we're updating an existing slot, we clear the slot bitmap only to set it again right after. Just leave the bit set rather than toggle it off and on, and move the unused slot setting into the branch of not already having a file occupy this slot. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-07io_uring/io-wq: Use set_bit() and test_bit() at worker->flagsBreno Leitao1-23/+24
Utilize set_bit() and test_bit() on worker->flags within io_uring/io-wq to address potential data races. The structure io_worker->flags may be accessed through various data paths, leading to concurrency issues. When KCSAN is enabled, it reveals data races occurring in io_worker_handle_work and io_wq_activate_free_worker functions. BUG: KCSAN: data-race in io_worker_handle_work / io_wq_activate_free_worker write to 0xffff8885c4246404 of 4 bytes by task 49071 on cpu 28: io_worker_handle_work (io_uring/io-wq.c:434 io_uring/io-wq.c:569) io_wq_worker (io_uring/io-wq.c:?) <snip> read to 0xffff8885c4246404 of 4 bytes by task 49024 on cpu 5: io_wq_activate_free_worker (io_uring/io-wq.c:? io_uring/io-wq.c:285) io_wq_enqueue (io_uring/io-wq.c:947) io_queue_iowq (io_uring/io_uring.c:524) io_req_task_submit (io_uring/io_uring.c:1511) io_handle_tw_list (io_uring/io_uring.c:1198) <snip> Line numbers against commit 18daea77cca6 ("Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm"). These races involve writes and reads to the same memory location by different tasks running on different CPUs. To mitigate this, refactor the code to use atomic operations such as set_bit(), test_bit(), and clear_bit() instead of basic "and" and "or" operations. This ensures thread-safe manipulation of worker flags. Also, move `create_index` to avoid holes in the structure. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240507170002.2269003-1-leitao@debian.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-02io_uring/msg_ring: cleanup posting to IOPOLL vs !IOPOLL ringJens Axboe1-6/+4
Move the posting outside the checking and locking, it's cleaner that way. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01io_uring: Require zeroed sqe->len on provided-buffers sendGabriel Krisman Bertazi1-1/+3
When sending from a provided buffer, we set sr->len to be the smallest between the actual buffer size and sqe->len. But, now that we disconnect the buffer from the submission request, we can get in a situation where the buffers and requests mismatch, and only part of a buffer gets sent. Assume: * buf[1]->len = 128; buf[2]->len = 256 * sqe[1]->len = 128; sqe[2]->len = 256 If sqe1 runs first, it picks buff[1] and it's all good. But, if sqe[2] runs first, sqe[1] picks buff[2], and the last half of buff[2] is never sent. While arguably the use-case of different-length sends is questionable, it has already raised confusion with potential users of this feature. Let's make the interface less tricky by forcing the length to only come from the buffer ring entry itself. Fixes: ac5f71a3d9d7 ("io_uring/net: add provided buffer support for IORING_OP_SEND") Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-30io_uring/notif: disable LAZY_WAKE for linked notifsPavel Begunkov1-1/+4
Notifications may now be linked and thus a single tw can post multiple CQEs, it's not safe to use LAZY_WAKE with them. Disable LAZY_WAKE for now, if that'd prove to be a problem we can count them and pass the expected number of CQEs into __io_req_task_work_add(). Fixes: 6fe4220912d19 ("io_uring/notif: implement notification stacking") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0a5accdb7d2d0d27ebec14f8106e14e0192fae17.1714488419.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-30io_uring/net: fix sendzc lazy wake pollingPavel Begunkov1-0/+1
SEND[MSG]_ZC produces multiple CQEs via notifications, LAZY_WAKE doesn't handle it and so disable LAZY_WAKE for sendzc polling. It should be fine, sends are not likely to be polled in the first place. Fixes: 6ce4a93dbb5b ("io_uring/poll: use IOU_F_TWQ_LAZY_WAKE for wakeups") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/5b360fb352d91e3aec751d75c87dfb4753a084ee.1714488419.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-26io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of ↵linke li1-1/+1
re-reading it In io_msg_exec_remote(), ctx->submitter_task is read using READ_ONCE at the beginning of the function, checked, and then re-read from ctx->submitter_task, voiding all guarantees of the checks. Reuse the value that was read by READ_ONCE to ensure the consistency of the task struct throughout the function. Signed-off-by: linke li <lilinke99@qq.com> Link: https://lore.kernel.org/r/tencent_F9B2296C93928D6F68FF0C95C33475C68209@qq.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-26mm: switch mm->get_unmapped_area() to a flagRick Edgecombe1-1/+1
The mm_struct contains a function pointer *get_unmapped_area(), which is set to either arch_get_unmapped_area() or arch_get_unmapped_area_topdown() during the initialization of the mm. Since the function pointer only ever points to two functions that are named the same across all arch's, a function pointer is not really required. In addition future changes will want to add versions of the functions that take additional arguments. So to save a pointers worth of bytes in mm_struct, and prevent adding additional function pointers to mm_struct in future changes, remove it and keep the information about which get_unmapped_area() to use in a flag. Add the new flag to MMF_INIT_MASK so it doesn't get clobbered on fork by mmf_init_flags(). Most MM flags get clobbered on fork. In the pre-existing behavior mm->get_unmapped_area() would get copied to the new mm in dup_mm(), so not clobbering the flag preserves the existing behavior around inheriting the topdown-ness. Introduce a helper, mm_get_unmapped_area(), to easily convert code that refers to the old function pointer to instead select and call either arch_get_unmapped_area() or arch_get_unmapped_area_topdown() based on the flag. Then drop the mm->get_unmapped_area() function pointer. Leave the get_unmapped_area() pointer in struct file_operations alone. The main purpose of this change is to reorganize in preparation for future changes, but it also converts the calls of mm->get_unmapped_area() from indirect branches into a direct ones. The stress-ng bigheap benchmark calls realloc a lot, which calls through get_unmapped_area() in the kernel. On x86, the change yielded a ~1% improvement there on a retpoline config. In testing a few x86 configs, removing the pointer unfortunately didn't result in any actual size reductions in the compiled layout of mm_struct. But depending on compiler or arch alignment requirements, the change could shrink the size of mm_struct. Link: https://lkml.kernel.org/r/20240326021656.202649-3-rick.p.edgecombe@intel.com Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Deepak Gupta <debug@rivosinc.com> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: H. Peter Anvin (Intel) <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Brown <broonie@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25io_uring/rw: reinstate thread check for retriesJens Axboe3-25/+29
Allowing retries for everything is arguably the right thing to do, now that every command type is async read from the start. But it's exposed a few issues around missing check for a retry (which cca6571381a0 exposed), and the fixup commit for that isn't necessarily 100% sound in terms of iov_iter state. For now, just revert these two commits. This unfortunately then re-opens the fact that -EAGAIN can get bubbled to userspace for some cases where the kernel very well could just sanely retry them. But until we have all the conditions covered around that, we cannot safely enable that. This reverts commit df604d2ad480fcf7b39767280c9093e13b1de952. This reverts commit cca6571381a0bdc88021a1f7a4c2349df21279f7. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-23io_uring/notif: implement notification stackingPavel Begunkov2-7/+67
The network stack allows only one ubuf_info per skb, and unlike MSG_ZEROCOPY, each io_uring zerocopy send will carry a separate ubuf_info. That means that send requests can't reuse a previosly allocated skb and need to get one more or more of new ones. That's fine for large sends, but otherwise it would spam the stack with lots of skbs carrying just a little data each. To help with that implement linking notification (i.e. an io_uring wrapper around ubuf_info) into a list. Each is refcounted by skbs and the stack as usual. additionally all non head entries keep a reference to the head, which they put down when their refcount hits 0. When the head have no more users, it'll efficiently put all notifications in a batch. As mentioned previously about ->io_link_skb, the callback implementation always allows to bind to an skb without a ubuf_info. Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/bf1e7f9b72f9ecc99999fdc0d2cded5eea87fd0b.1713369317.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-23io_uring/notif: simplify io_notif_flush()Pavel Begunkov2-9/+6
io_notif_flush() is partially duplicating io_tx_ubuf_complete(), so instead of duplicating it, make the flush call io_tx_ubuf_complete. Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/19e41652c16718b946a5c80d2ad409df7682e47e.1713369317.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-23Merge branch 'for-uring-ubufops' of ↵Jens Axboe1-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux into for-6.10/io_uring Merge net changes required for the upcoming send zerocopy improvements. * 'for-uring-ubufops' of git://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux: net: add callback for setting a ubuf_info to skb net: extend ubuf_info callback to ops structure Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-23net: extend ubuf_info callback to ops structurePavel Begunkov1-5/+13
We'll need to associate additional callbacks with ubuf_info, introduce a structure holding ubuf_info callbacks. Apart from a more smarter io_uring notification management introduced in next patches, it can be used to generalise msg_zerocopy_put_abort() and also store ->sg_from_iter, which is currently passed in struct msghdr. Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/all/a62015541de49c0e2a8a0377a1d5d0a5aeb07016.1713369317.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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