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2022-12-14io_uring: move to separate directoryJens Axboe
[ Upstream commit ed29b0b4fd835b058ddd151c49d021e28d631ee6 ] In preparation for splitting io_uring up a bit, move it into its own top level directory. It didn't really belong in fs/ anyway, as it's not a file system only API. This adds io_uring/ and moves the core files in there, and updates the MAINTAINERS file for the new location. Signed-off-by: Jens Axboe <axboe@kernel.dk> Stable-dep-of: 998b30c3948e ("io_uring: Fix a null-ptr-deref in io_tctx_exit_cb()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08io_uring/poll: fix poll_refs race with cancelationLin Ma
[ upstream commit 12ad3d2d6c5b0131a6052de91360849e3e154846 ] There is an interesting race condition of poll_refs which could result in a NULL pointer dereference. The crash trace is like: KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 30781 Comm: syz-executor.2 Not tainted 6.0.0-g493ffd6605b2 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:io_poll_remove_entry io_uring/poll.c:154 [inline] RIP: 0010:io_poll_remove_entries+0x171/0x5b4 io_uring/poll.c:190 Code: ... RSP: 0018:ffff88810dfefba0 EFLAGS: 00010202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000040000 RDX: ffffc900030c4000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 0000000000000008 R08: ffffffff9764d3dd R09: fffffbfff3836781 R10: fffffbfff3836781 R11: 0000000000000000 R12: 1ffff11003422d60 R13: ffff88801a116b04 R14: ffff88801a116ac0 R15: dffffc0000000000 FS: 00007f9c07497700(0000) GS:ffff88811a600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffb5c00ea98 CR3: 0000000105680005 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> io_apoll_task_func+0x3f/0xa0 io_uring/poll.c:299 handle_tw_list io_uring/io_uring.c:1037 [inline] tctx_task_work+0x37e/0x4f0 io_uring/io_uring.c:1090 task_work_run+0x13a/0x1b0 kernel/task_work.c:177 get_signal+0x2402/0x25a0 kernel/signal.c:2635 arch_do_signal_or_restart+0x3b/0x660 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0xc2/0x160 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x58/0x160 kernel/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x63/0xcd The root cause for this is a tiny overlooking in io_poll_check_events() when cocurrently run with poll cancel routine io_poll_cancel_req(). The interleaving to trigger use-after-free: CPU0 | CPU1 | io_apoll_task_func() | io_poll_cancel_req() io_poll_check_events() | // do while first loop | v = atomic_read(...) | // v = poll_refs = 1 | ... | io_poll_mark_cancelled() | atomic_or() | // poll_refs = IO_POLL_CANCEL_FLAG | 1 | atomic_sub_return(...) | // poll_refs = IO_POLL_CANCEL_FLAG | // loop continue | | | io_poll_execute() | io_poll_get_ownership() | // poll_refs = IO_POLL_CANCEL_FLAG | 1 | // gets the ownership v = atomic_read(...) | // poll_refs not change | | if (v & IO_POLL_CANCEL_FLAG) | return -ECANCELED; | // io_poll_check_events return | // will go into | // io_req_complete_failed() free req | | | io_apoll_task_func() | // also go into io_req_complete_failed() And the interleaving to trigger the kernel WARNING: CPU0 | CPU1 | io_apoll_task_func() | io_poll_cancel_req() io_poll_check_events() | // do while first loop | v = atomic_read(...) | // v = poll_refs = 1 | ... | io_poll_mark_cancelled() | atomic_or() | // poll_refs = IO_POLL_CANCEL_FLAG | 1 | atomic_sub_return(...) | // poll_refs = IO_POLL_CANCEL_FLAG | // loop continue | | v = atomic_read(...) | // v = IO_POLL_CANCEL_FLAG | | io_poll_execute() | io_poll_get_ownership() | // poll_refs = IO_POLL_CANCEL_FLAG | 1 | // gets the ownership | WARN_ON_ONCE(!(v & IO_POLL_REF_MASK))) | // v & IO_POLL_REF_MASK = 0 WARN | | | io_apoll_task_func() | // also go into io_req_complete_failed() By looking up the source code and communicating with Pavel, the implementation of this atomic poll refs should continue the loop of io_poll_check_events() just to avoid somewhere else to grab the ownership. Therefore, this patch simply adds another AND operation to make sure the loop will stop if it finds the poll_refs is exactly equal to IO_POLL_CANCEL_FLAG. Since io_poll_cancel_req() grabs ownership and will finally make its way to io_req_complete_failed(), the req will be reclaimed as expected. Fixes: aa43477b0402 ("io_uring: poll rework") Signed-off-by: Lin Ma <linma@zju.edu.cn> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> [axboe: tweak description and code style] Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08io_uring: make poll refs more robustPavel Begunkov
[ upstream commit a26a35e9019fd70bf3cf647dcfdae87abc7bacea ] poll_refs carry two functions, the first is ownership over the request. The second is notifying the io_poll_check_events() that there was an event but wake up couldn't grab the ownership, so io_poll_check_events() should retry. We want to make poll_refs more robust against overflows. Instead of always incrementing it, which covers two purposes with one atomic, check if poll_refs is elevated enough and if so set a retry flag without attempts to grab ownership. The gap between the bias check and following atomics may seem racy, but we don't need it to be strict. Moreover there might only be maximum 4 parallel updates: by the first and the second poll entries, __io_arm_poll_handler() and cancellation. From those four, only poll wake ups may be executed multiple times, but they're protected by a spin. Cc: stable@vger.kernel.org Reported-by: Lin Ma <linma@zju.edu.cn> Fixes: aa43477b04025 ("io_uring: poll rework") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/c762bc31f8683b3270f3587691348a7119ef9c9d.1668963050.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08io_uring: cmpxchg for poll arm refs releasePavel Begunkov
[ upstream commit 2f3893437a4ebf2e892ca172e9e122841319d675 ] Replace atomically substracting the ownership reference at the end of arming a poll with a cmpxchg. We try to release ownership by setting 0 assuming that poll_refs didn't change while we were arming. If it did change, we keep the ownership and use it to queue a tw, which is fully capable to process all events and (even tolerates spurious wake ups). It's a bit more elegant as we reduce races b/w setting the cancellation flag and getting refs with this release, and with that we don't have to worry about any kinds of underflows. It's not the fastest path for polling. The performance difference b/w cmpxchg and atomic dec is usually negligible and it's not the fastest path. Cc: stable@vger.kernel.org Fixes: aa43477b04025 ("io_uring: poll rework") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0c95251624397ea6def568ff040cad2d7926fd51.1668963050.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08io_uring: fix tw losing poll eventsPavel Begunkov
[ upstream commit 539bcb57da2f58886d7d5c17134236b0ec9cd15d ] We may never try to process a poll wake and its mask if there was multiple wake ups racing for queueing up a tw. Force io_poll_check_events() to update the mask by vfs_poll(). Cc: stable@vger.kernel.org Fixes: aa43477b04025 ("io_uring: poll rework") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/00344d60f8b18907171178d7cf598de71d127b0b.1668710222.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08io_uring: update res mask in io_poll_check_eventsPavel Begunkov
[ upstream commit b98186aee22fa593bc8c6b2c5d839c2ee518bc8c ] When io_poll_check_events() collides with someone attempting to queue a task work, it'll spin for one more time. However, it'll continue to use the mask from the first iteration instead of updating it. For example, if the first wake up was a EPOLLIN and the second EPOLLOUT, the userspace will not get EPOLLOUT in time. Clear the mask for all subsequent iterations to force vfs_poll(). Cc: stable@vger.kernel.org Fixes: aa43477b04025 ("io_uring: poll rework") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/2dac97e8f691231049cb259c4ae57e79e40b537c.1668710222.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26io_uring/rw: fix unexpected link breakagePavel Begunkov
[ upstream commit bf68b5b34311ee57ed40749a1257a30b46127556 ] req->cqe.res is set in io_read() to the amount of bytes left to be done, which is used to figure out whether to fail a read or not. However, io_read() may do another without returning, and we stash the previous value into ->bytes_done but forget to update cqe.res. Then we ask a read to do strictly less than cqe.res but expect the return to be exactly cqe.res. Fix the bug by updating cqe.res for retries. Cc: stable@vger.kernel.org Reported-and-Tested-by: Beld Zhang <beldzhang@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3a1088440c7be98e5800267af922a67da0ef9f13.1664235732.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26io_uring/rw: fix error'ed retry return valuesPavel Begunkov
[ upstream commit 62bb0647b14646fa6c9aa25ecdf67ad18f13523c ] Kernel test robot reports that we test negativity of an unsigned in io_fixup_rw_res() after a recent change, which masks error codes and messes up the return value in case I/O is re-retried and failed with an error. Fixes: 4d9cb92ca41dd ("io_uring/rw: fix short rw error handling") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9754a0970af1861e7865f9014f735c70dc60bf79.1663071587.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26io_uring/rw: fix short rw error handlingPavel Begunkov
[ upstream commit 89473c1a9205760c4fa6d158058da7b594a815f0 ] We have a couple of problems, first reports of unexpected link breakage for reads when cqe->res indicates that the IO was done in full. The reason here is partial IO with retries. TL;DR; we compare the result in __io_complete_rw_common() against req->cqe.res, but req->cqe.res doesn't store the full length but rather the length left to be done. So, when we pass the full corrected result via kiocb_done() -> __io_complete_rw_common(), it fails. The second problem is that we don't try to correct res in io_complete_rw(), which, for instance, might be a problem for O_DIRECT but when a prefix of data was cached in the page cache. We also definitely don't want to pass a corrected result into io_rw_done(). The fix here is to leave __io_complete_rw_common() alone, always pass not corrected result into it and fix it up as the last step just before actually finishing the I/O. Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26io_uring: correct pinned_vm accountingPavel Begunkov
[ upstream commit 42b6419d0aba47c5d8644cdc0b68502254671de5 ] ->mm_account should be released only after we free all registered buffers, otherwise __io_sqe_buffers_unregister() will see a NULL ->mm_account and skip locked_vm accounting. Cc: <Stable@vger.kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/6d798f65ed4ab8db3664c4d3397d4af16ca98846.1664849932.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26io_uring/af_unix: defer registered files gc to io_uring releasePavel Begunkov
[ upstream commit 0091bfc81741b8d3aeb3b7ab8636f911b2de6e80 ] Instead of putting io_uring's registered files in unix_gc() we want it to be done by io_uring itself. The trick here is to consider io_uring registered files for cycle detection but not actually putting them down. Because io_uring can't register other ring instances, this will remove all refs to the ring file triggering the ->release path and clean up with io_ring_ctx_free(). Cc: stable@vger.kernel.org Fixes: 6b06314c47e1 ("io_uring: add file set registration") Reported-and-tested-by: David Bouman <dbouman03@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> [axboe: add kerneldoc comment to skb, fold in skb leak fix] Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26io_uring/net: don't update msg_name if not providedPavel Begunkov
commit 6f10ae8a155446248055c7ddd480ef40139af788 upstream. io_sendmsg_copy_hdr() may clear msg->msg_name if the userspace didn't provide it, we should retain NULL in this case. Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/97d49f61b5ec76d0900df658cfde3aa59ff22121.1664486545.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: fix UAF due to missing POLLFREE handlingPavel Begunkov
[ upstream commmit 791f3465c4afde02d7f16cf7424ca87070b69396 ] Fixes a problem described in 50252e4b5e989 ("aio: fix use-after-free due to missing POLLFREE handling") and copies the approach used there. In short, we have to forcibly eject a poll entry when we meet POLLFREE. We can't rely on io_poll_get_ownership() as can't wait for potentially running tw handlers, so we use the fact that wqs are RCU freed. See Eric's patch and comments for more details. Reported-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20211209010455.42744-6-ebiggers@kernel.org Reported-and-tested-by: syzbot+5426c7ed6868c705ca14@syzkaller.appspotmail.com Fixes: 221c5eb233823 ("io_uring: add support for IORING_OP_POLL") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/4ed56b6f548f7ea337603a82315750449412748a.1642161259.git.asml.silence@gmail.com [axboe: drop non-functional change from patch] Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: fix wrong arm_poll error handlingPavel Begunkov
[ upstream commmit 9d2ad2947a53abf5e5e6527a9eeed50a3a4cbc72 ] Leaving ip.error set when a request was punted to task_work execution is problematic, don't forget to clear it. Fixes: aa43477b04025 ("io_uring: poll rework") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/a6c84ef4182c6962380aebe11b35bdcb25b0ccfb.1655852245.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: fail links when poll failsPavel Begunkov
[ upstream commmit c487a5ad48831afa6784b368ec40d0ee50f2fe1b ] Don't forget to cancel all linked requests of poll request when __io_arm_poll_handler() failed. Fixes: aa43477b04025 ("io_uring: poll rework") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/a78aad962460f9fdfe4aa4c0b62425c88f9415bc.1655852245.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: bump poll refs to full 31-bitsJens Axboe
[ upstream commmit e2c0cb7c0cc72939b61a7efee376206725796625 ] The previous commit: 1bc84c40088 ("io_uring: remove poll entry from list when canceling all") removed a potential overflow condition for the poll references. They are currently limited to 20-bits, even if we have 31-bits available. The upper bit is used to mark for cancelation. Bump the poll ref space to 31-bits, making that kind of situation much harder to trigger in general. We'll separately add overflow checking and handling. Fixes: aa43477b0402 ("io_uring: poll rework") Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: remove poll entry from list when canceling allJens Axboe
[ upstream commmit 61bc84c4008812d784c398cfb54118c1ba396dfc ] When the ring is exiting, as part of the shutdown, poll requests are removed. But io_poll_remove_all() does not remove entries when finding them, and since completions are done out-of-band, we can find and remove the same entry multiple times. We do guard the poll execution by poll ownership, but that does not exclude us from reissuing a new one once the previous removal ownership goes away. This can race with poll execution as well, where we then end up seeing req->apoll be NULL because a previous task_work requeue finished the request. Remove the poll entry when we find it and get ownership of it. This prevents multiple invocations from finding it. Fixes: aa43477b0402 ("io_uring: poll rework") Reported-by: Dylan Yudaken <dylany@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: Remove unused function req_ref_putJiapeng Chong
[ upstream commmit c84b8a3fef663933007e885535591b9d30bdc860 ] Fix the following clang warnings: fs/io_uring.c:1195:20: warning: unused function 'req_ref_put' [-Wunused-function]. Fixes: aa43477b0402 ("io_uring: poll rework") Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Link: https://lore.kernel.org/r/20220113162005.3011-1-jiapeng.chong@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: poll reworkPavel Begunkov
[ upstream commmit aa43477b040251f451db0d844073ac00a8ab66ee ] It's not possible to go forward with the current state of io_uring polling, we need a more straightforward and easier synchronisation. There are a lot of problems with how it is at the moment, including missing events on rewait. The main idea here is to introduce a notion of request ownership while polling, no one but the owner can modify any part but ->poll_refs of struct io_kiocb, that grants us protection against all sorts of races. Main users of such exclusivity are poll task_work handler, so before queueing a tw one should have/acquire ownership, which will be handed off to the tw handler. The other user is __io_arm_poll_handler() do initial poll arming. It starts taking the ownership, so tw handlers won't be run until it's released later in the function after vfs_poll. note: also prevents races in __io_queue_proc(). Poll wake/etc. may not be able to get ownership, then they need to increase the poll refcount and the task_work should notice it and retry if necessary, see io_poll_check_events(). There is also IO_POLL_CANCEL_FLAG flag to notify that we want to kill request. It makes cancellations more reliable, enables double multishot polling, fixes double poll rewait, fixes missing poll events and fixes another bunch of races. Even though it adds some overhead for new refcounting, and there are a couple of nice performance wins: - no req->refs refcounting for poll requests anymore - if the data is already there (once measured for some test to be 1-2% of all apoll requests), it removes it doesn't add atomics and removes spin_lock/unlock pair. - works well with multishots, we don't do remove from queue / add to queue for each new poll event. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/6b652927c77ed9580ea4330ac5612f0e0848c946.1639605189.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: inline io_poll_completePavel Begunkov
[ upstream commmit eb6e6f0690c846f7de46181bab3954c12c96e11e ] Inline io_poll_complete(), it's simple and doesn't have any particular purpose. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/933d7ee3e4450749a2d892235462c8f18d030293.1633373302.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: kill poll linking optimisationPavel Begunkov
[ upstream commmit ab1dab960b8352cee082db0f8a54dc92a948bfd7 ] With IORING_FEAT_FAST_POLL in place, io_put_req_find_next() for poll requests doesn't make much sense, and in any case re-adding it shouldn't be a problem considering batching in tctx_task_work(). We can remove it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/15699682bf81610ec901d4e79d6da64baa9f70be.1639605189.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: move common poll bitsPavel Begunkov
[ upstream commmit 5641897a5e8fb8abeb07e89c71a788d3db3ec75e ] Move some poll helpers/etc up, we'll need them there shortly Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/6c5c3dba24c86aad5cd389a54a8c7412e6a0621d.1639605189.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: refactor poll updatePavel Begunkov
[ upstream commmit 2bbb146d96f4b45e17d6aeede300796bc1a96d68 ] Clean up io_poll_update() and unify cancellation paths for remove and update. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/5937138b6265a1285220e2fab1b28132c1d73ce3.1639605189.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: clean cqe filling functionsPavel Begunkov
[ upstream commmit 913a571affedd17239c4d4ea90c8874b32fc2191 ] Split io_cqring_fill_event() into a couple of more targeted functions. The first on is io_fill_cqe_aux() for completions that are not associated with request completions and doing the ->cq_extra accounting. Examples are additional CQEs from multishot poll and rsrc notifications. The second is io_fill_cqe_req(), should be called when it's a normal request completion. Nothing more to it at the moment, will be used in later patches. The last one is inlined __io_fill_cqe() for a finer grained control, should be used with caution and in hottest places. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/59a9117a4a44fc9efcf04b3afa51e0d080f5943c.1636559119.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05io_uring: correct fill events helpers typesPavel Begunkov
[ upstream commit 54daa9b2d80ab35824464b35a99f716e1cdf2ccb ] CQE result is a 32-bit integer, so the functions generating CQEs are better to accept not long but ints. Convert io_cqring_fill_event() and other helpers. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/7ca6f15255e9117eae28adcac272744cae29b113.1633373302.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31io_uring: fix issue with io_write() not always undoing sb_start_write()Jens Axboe
commit e053aaf4da56cbf0afb33a0fda4a62188e2c0637 upstream. This is actually an older issue, but we never used to hit the -EAGAIN path before having done sb_start_write(). Make sure that we always call kiocb_end_write() if we need to retry the write, so that we keep the calls to sb_start_write() etc balanced. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21io_uring: use original request task for inflight trackingJens Axboe
commit 386e4fb6962b9f248a80f8870aea0870ca603e89 upstream. In prior kernels, we did file assignment always at prep time. This meant that req->task == current. But after deferring that assignment and then pushing the inflight tracking back in, we've got the inflight tracking using current when it should in fact now be using req->task. Fixup that error introduced by adding the inflight tracking back after file assignments got modifed. Fixes: 9cae36a094e7 ("io_uring: reinstate the inflight tracking") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-17io_uring: mem-account pbuf bucketsPavel Begunkov
commit cc18cc5e82033d406f54144ad6f8092206004684 upstream. Potentially, someone may create as many pbuf bucket as there are indexes in an xarray without any other restrictions bounding our memory usage, put memory needed for the buckets under memory accounting. Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/d34c452e45793e978d26e2606211ec9070d329ea.1659622312.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-12io_uring: avoid io-wq -EAGAIN looping for !IOPOLLPavel Begunkov
[ Upstream commit e0deb6a025ae8c850dc8685be39fb27b06c88736 ] If an opcode handler semi-reliably returns -EAGAIN, io_wq_submit_work() might continue busily hammer the same handler over and over again, which is not ideal. The -EAGAIN handling in question was put there only for IOPOLL, so restrict it to IOPOLL mode only where there is no other recourse than to retry as we cannot wait. Fixes: def596e9557c9 ("io_uring: support for IO polling") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/f168b4f24181942f3614dd8ff648221736f572e6.1652433740.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-12io_uring: ensure that fsnotify is always calledJens Axboe
[ Upstream commit f63cf5192fe3418ad5ae1a4412eba5694b145f79 ] Ensure that we call fsnotify_modify() if we write a file, and that we do fsnotify_access() if we read it. This enables anyone using inotify on the file to get notified. Ditto for fallocate, ensure that fsnotify_modify() is called. Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-07io_uring: ensure that send/sendmsg and recv/recvmsg check sqe->ioprioJens Axboe
commit 73911426aaaadbae54fa72359b33a7b6a56947db upstream. All other opcodes correctly check if this is set and -EINVAL if it is and they don't support that field, for some reason the these were forgotten. This was unified a bit differently in the upstream tree, but had the same effect as making sure we error on this field. Rather than have a painful backport of the upstream commit, just fixup the mentioned opcodes. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-02io_uring: fix not locked access to fixed buf tablePavel Begunkov
commit 05b538c1765f8d14a71ccf5f85258dcbeaf189f7 upstream. We can look inside the fixed buffer table only while holding ->uring_lock, however in some cases we don't do the right async prep for IORING_OP_{WRITE,READ}_FIXED ending up with NULL req->imu forcing making an io-wq worker to try to resolve the fixed buffer without proper locking. Move req->imu setup into early req init paths, i.e. io_prep_rw(), which is called unconditionally for rw requests and under uring_lock. Fixes: 634d00df5e1cf ("io_uring: add full-fledged dynamic buffers support") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-22io_uring: fix races with buffer table unregisterPavel Begunkov
[ Upstream commit d11d31fc5d8a96f707facee0babdcffaafa38de2 ] Fixed buffer table quiesce might unlock ->uring_lock, potentially letting new requests to be submitted, don't allow those requests to use the table as they will race with unregistration. Reported-and-tested-by: van fantasy <g1042620637@gmail.com> Fixes: bd54b6fe3316ec ("io_uring: implement fixed buffers registration similar to fixed files") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-22io_uring: fix races with file table unregisterPavel Begunkov
[ Upstream commit b0380bf6dad4601d92025841e2b7a135d566c6e3 ] Fixed file table quiesce might unlock ->uring_lock, potentially letting new requests to be submitted, don't allow those requests to use the table as they will race with unregistration. Reported-and-tested-by: van fantasy <g1042620637@gmail.com> Fixes: 05f3fb3c53975 ("io_uring: avoid ring quiesce for fixed file set unregister and update") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25io_uring: arm poll for non-nowait filesPavel Begunkov
commit e74ead135bc4459f7d40b1f8edab1333a28b54e8 upstream. Don't check if we can do nowait before arming apoll, there are several reasons for that. First, we don't care much about files that don't support nowait. Second, it may be useful -- we don't want to be taking away extra workers from io-wq when it can go in some async. Even if it will go through io-wq eventually, it make difference in the numbers of workers actually used. And the last one, it's needed to clean nowait in future commits. [kernel test robot: fix unused-var] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9d06f3cb2c8b686d970269a87986f154edb83043.1634425438.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-09io_uring: check reserved fields for recv/recvmsgJens Axboe
[ Upstream commit 5a1e99b61b0c81388cde0c808b3e4173907df19f ] We should check unused fields for non-zero and -EINVAL if they are set, making it consistent with other opcodes. Fixes: aa1fa28fc73e ("io_uring: add support for recvmsg()") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-09io_uring: check reserved fields for send/sendmsgJens Axboe
[ Upstream commit 588faa1ea5eecb351100ee5d187b9be99210f70d ] We should check unused fields for non-zero and -EINVAL if they are set, making it consistent with other opcodes. Fixes: 0fa03c624d8f ("io_uring: add support for sendmsg()") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20io_uring: use nospec annotation for more indexesPavel Begunkov
[ Upstream commit 4cdd158be9d09223737df83136a1fb65269d809a ] There are still several places that using pre array_index_nospec() indexes, fix them up. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/b01ef5ee83f72ed35ad525912370b729f5d145f4.1649336342.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20io_uring: zero tag on rsrc removalPavel Begunkov
[ Upstream commit 8f0a24801bb44aa58496945aabb904c729176772 ] Automatically default rsrc tag in io_queue_rsrc_removal(), it's safer than leaving it there and relying on the rest of the code to behave and not use it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1cf262a50df17478ea25b22494dcc19f3a80301f.1649336342.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20io_uring: verify pad field is 0 in io_get_ext_argDylan Yudaken
[ Upstream commit d2347b9695dafe5c388a5f9aeb70e27a7a4d29cf ] Ensure that only 0 is passed for pad here. Fixes: c73ebb685fb6 ("io_uring: add timeout support for io_uring_enter()") Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220412163042.2788062-5-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20io_uring: verify that resv2 is 0 in io_uring_rsrc_update2Dylan Yudaken
[ Upstream commit d8a3ba9c143bf89c032deced8a686ffa53b46098 ] Verify that the user does not pass in anything but 0 for this field. Fixes: 992da01aa932 ("io_uring: change registration/upd/rsrc tagging ABI") Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220412163042.2788062-3-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20io_uring: move io_uring_rsrc_update2 validationDylan Yudaken
[ Upstream commit 565c5e616e8061b40a2e1d786c418a7ac3503a8d ] Move validation to be more consistently straight after copy_from_user. This is already done in io_register_rsrc_update and so this removes that redundant check. Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220412163042.2788062-2-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-13io_uring: fix race between timeout flush and removalJens Axboe
commit e677edbcabee849bfdd43f1602bccbecf736a646 upstream. io_flush_timeouts() assumes the timeout isn't in progress of triggering or being removed/canceled, so it unconditionally removes it from the timeout list and attempts to cancel it. Leave it on the list and let the normal timeout cancelation take care of it. Cc: stable@vger.kernel.org # 5.5+ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-13io_uring: implement compat handling for IORING_REGISTER_IOWQ_AFFEugene Syromiatnikov
commit 0f5e4b83b37a96e3643951588ed7176b9b187c0a upstream. Similarly to the way it is done im mbind syscall. Cc: stable@vger.kernel.org # 5.14 Fixes: fe76421d1da1dcdb ("io_uring: allow user configurable IO thread CPU affinity") Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-13io_uring: defer splice/tee file validity check until command issueJens Axboe
commit a3e4bc23d5470b2beb7cc42a86b6a3e75b704c15 upstream. In preparation for not using the file at prep time, defer checking if this file refers to a valid io_uring instance until issue time. This also means we can get rid of the cleanup flag for splice and tee. Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-13io_uring: don't check req->file in io_fsync_prep()Jens Axboe
commit ec858afda857e361182ceafc3d2ba2b164b8e889 upstream. This is a leftover from the really old days where we weren't able to track and error early if we need a file and it wasn't assigned. Kill the check. Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-13io_uring: don't touch scm_fp_list after queueing skbPavel Begunkov
[ Upstream commit a07211e3001435fe8591b992464cd8d5e3c98c5a ] It's safer to not touch scm_fp_list after we queued an skb to which it was assigned, there might be races lurking if we screw subtle sync guarantees on the io_uring side. Fixes: 6b06314c47e14 ("io_uring: add file set registration") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-13io_uring: nospec index for tags on files updatePavel Begunkov
[ Upstream commit 34bb77184123ae401100a4d156584f12fa630e5c ] Don't forget to array_index_nospec() for indexes before updating rsrc tags in __io_sqe_files_update(), just use already safe and precalculated index @i. Fixes: c3bdad0271834 ("io_uring: add generic rsrc update with tags") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08io_uring: fix memory leak of uid in files registrationPavel Begunkov
commit c86d18f4aa93e0e66cda0e55827cd03eea6bc5f8 upstream. When there are no files for __io_sqe_files_scm() to process in the range, it'll free everything and return. However, it forgets to put uid. Fixes: 08a451739a9b5 ("io_uring: allow sparse fixed file sets") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/accee442376f33ce8aaebb099d04967533efde92.1648226048.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08io_uring: terminate manual loop iterator loop correctly for non-vecsJens Axboe
[ Upstream commit 5e929367468c8f97cd1ffb0417316cecfebef94b ] The fix for not advancing the iterator if we're using fixed buffers is broken in that it can hit a condition where we don't terminate the loop. This results in io-wq looping forever, asking to read (or write) 0 bytes for every subsequent loop. Reported-by: Joel Jaeschke <joel.jaeschke@gmail.com> Link: https://github.com/axboe/liburing/issues/549 Fixes: 16c8d2df7ec0 ("io_uring: ensure symmetry in handling iter types in loop_rw_iter()") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
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