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linux/io_uring/wait.c

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io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring/wait: honour caller's time namespace for IORING_ENTER_ABS_TIMER io_uring_enter() with IORING_ENTER_ABS_TIMER takes an absolute timespec from the caller via ext_arg->ts. It arms an ABS mode hrtimer in __io_cqring_wait_schedule(). The conversion path in io_uring/wait.c parses ext_arg->ts inline rather than going through io_parse_user_time(). It therefore does not pick up the time namespace conversion added by the previous patch. Apply timens_ktime_to_host() to the parsed time on the IORING_ENTER_ABS_TIMER branch. This mirrors the IORING_TIMEOUT_ABS fix in io_parse_user_time(). Use ctx->clockid as the clock id. ctx->clockid is set either at ring creation or via IORING_REGISTER_CLOCK. timens_ktime_to_host() is a no-op for clocks not affected by time namespaces. It is also a no-op for callers in the initial time namespace. The fast path is unchanged. Reproducer: in unshare --user --time, with a -10s monotonic offset, call io_uring_enter with min_complete=1, IORING_ENTER_ABS_TIMER, and ts = now + 1s. The call returns -ETIME after <1ms instead of after the expected ~1s. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Maoyi Xie <maoyi.xie@ntu.edu.sg> Link: https://patch.msgid.link/20260504153755.1293932-3-maoyi.xie@ntu.edu.sg Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-04 23:37:55 +08:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring: protect remaining lockless ctx->rings accesses with RCU Commit 96189080265e addressed one case of ctx->rings being potentially accessed while a resize is happening on the ring, but there are still a few others that need handling. Add a helper for retrieving the rings associated with an io_uring context, and add some sanity checking to that to catch bad uses. ->rings_rcu is always valid, as long as it's used within RCU read lock. Any use of ->rings_rcu or ->rings inside either ->uring_lock or ->completion_lock is sane as well. Do the minimum fix for the current kernel, but set it up such that this basic infra can be extended for later kernels to make this harder to mess up in the future. Thanks to Junxi Qian for finding and debugging this issue. Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reviewed-by: Junxi Qian <qjx1298677004@gmail.com> Tested-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-31 07:07:47 -06:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring: protect remaining lockless ctx->rings accesses with RCU Commit 96189080265e addressed one case of ctx->rings being potentially accessed while a resize is happening on the ring, but there are still a few others that need handling. Add a helper for retrieving the rings associated with an io_uring context, and add some sanity checking to that to catch bad uses. ->rings_rcu is always valid, as long as it's used within RCU read lock. Any use of ->rings_rcu or ->rings inside either ->uring_lock or ->completion_lock is sane as well. Do the minimum fix for the current kernel, but set it up such that this basic infra can be extended for later kernels to make this harder to mess up in the future. Thanks to Junxi Qian for finding and debugging this issue. Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reviewed-by: Junxi Qian <qjx1298677004@gmail.com> Tested-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-31 07:07:47 -06:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring: protect remaining lockless ctx->rings accesses with RCU Commit 96189080265e addressed one case of ctx->rings being potentially accessed while a resize is happening on the ring, but there are still a few others that need handling. Add a helper for retrieving the rings associated with an io_uring context, and add some sanity checking to that to catch bad uses. ->rings_rcu is always valid, as long as it's used within RCU read lock. Any use of ->rings_rcu or ->rings inside either ->uring_lock or ->completion_lock is sane as well. Do the minimum fix for the current kernel, but set it up such that this basic infra can be extended for later kernels to make this harder to mess up in the future. Thanks to Junxi Qian for finding and debugging this issue. Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reviewed-by: Junxi Qian <qjx1298677004@gmail.com> Tested-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-31 07:07:47 -06:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring: protect remaining lockless ctx->rings accesses with RCU Commit 96189080265e addressed one case of ctx->rings being potentially accessed while a resize is happening on the ring, but there are still a few others that need handling. Add a helper for retrieving the rings associated with an io_uring context, and add some sanity checking to that to catch bad uses. ->rings_rcu is always valid, as long as it's used within RCU read lock. Any use of ->rings_rcu or ->rings inside either ->uring_lock or ->completion_lock is sane as well. Do the minimum fix for the current kernel, but set it up such that this basic infra can be extended for later kernels to make this harder to mess up in the future. Thanks to Junxi Qian for finding and debugging this issue. Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reviewed-by: Junxi Qian <qjx1298677004@gmail.com> Tested-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-31 07:07:47 -06:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring: protect remaining lockless ctx->rings accesses with RCU Commit 96189080265e addressed one case of ctx->rings being potentially accessed while a resize is happening on the ring, but there are still a few others that need handling. Add a helper for retrieving the rings associated with an io_uring context, and add some sanity checking to that to catch bad uses. ->rings_rcu is always valid, as long as it's used within RCU read lock. Any use of ->rings_rcu or ->rings inside either ->uring_lock or ->completion_lock is sane as well. Do the minimum fix for the current kernel, but set it up such that this basic infra can be extended for later kernels to make this harder to mess up in the future. Thanks to Junxi Qian for finding and debugging this issue. Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reviewed-by: Junxi Qian <qjx1298677004@gmail.com> Tested-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-31 07:07:47 -06:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring: protect remaining lockless ctx->rings accesses with RCU Commit 96189080265e addressed one case of ctx->rings being potentially accessed while a resize is happening on the ring, but there are still a few others that need handling. Add a helper for retrieving the rings associated with an io_uring context, and add some sanity checking to that to catch bad uses. ->rings_rcu is always valid, as long as it's used within RCU read lock. Any use of ->rings_rcu or ->rings inside either ->uring_lock or ->completion_lock is sane as well. Do the minimum fix for the current kernel, but set it up such that this basic infra can be extended for later kernels to make this harder to mess up in the future. Thanks to Junxi Qian for finding and debugging this issue. Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reviewed-by: Junxi Qian <qjx1298677004@gmail.com> Tested-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-31 07:07:47 -06:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring: protect remaining lockless ctx->rings accesses with RCU Commit 96189080265e addressed one case of ctx->rings being potentially accessed while a resize is happening on the ring, but there are still a few others that need handling. Add a helper for retrieving the rings associated with an io_uring context, and add some sanity checking to that to catch bad uses. ->rings_rcu is always valid, as long as it's used within RCU read lock. Any use of ->rings_rcu or ->rings inside either ->uring_lock or ->completion_lock is sane as well. Do the minimum fix for the current kernel, but set it up such that this basic infra can be extended for later kernels to make this harder to mess up in the future. Thanks to Junxi Qian for finding and debugging this issue. Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reviewed-by: Junxi Qian <qjx1298677004@gmail.com> Tested-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-31 07:07:47 -06:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring/wait: honour caller's time namespace for IORING_ENTER_ABS_TIMER io_uring_enter() with IORING_ENTER_ABS_TIMER takes an absolute timespec from the caller via ext_arg->ts. It arms an ABS mode hrtimer in __io_cqring_wait_schedule(). The conversion path in io_uring/wait.c parses ext_arg->ts inline rather than going through io_parse_user_time(). It therefore does not pick up the time namespace conversion added by the previous patch. Apply timens_ktime_to_host() to the parsed time on the IORING_ENTER_ABS_TIMER branch. This mirrors the IORING_TIMEOUT_ABS fix in io_parse_user_time(). Use ctx->clockid as the clock id. ctx->clockid is set either at ring creation or via IORING_REGISTER_CLOCK. timens_ktime_to_host() is a no-op for clocks not affected by time namespaces. It is also a no-op for callers in the initial time namespace. The fast path is unchanged. Reproducer: in unshare --user --time, with a -10s monotonic offset, call io_uring_enter with min_complete=1, IORING_ENTER_ABS_TIMER, and ts = now + 1s. The call returns -ETIME after <1ms instead of after the expected ~1s. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Maoyi Xie <maoyi.xie@ntu.edu.sg> Link: https://patch.msgid.link/20260504153755.1293932-3-maoyi.xie@ntu.edu.sg Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-04 23:37:55 +08:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring: protect remaining lockless ctx->rings accesses with RCU Commit 96189080265e addressed one case of ctx->rings being potentially accessed while a resize is happening on the ring, but there are still a few others that need handling. Add a helper for retrieving the rings associated with an io_uring context, and add some sanity checking to that to catch bad uses. ->rings_rcu is always valid, as long as it's used within RCU read lock. Any use of ->rings_rcu or ->rings inside either ->uring_lock or ->completion_lock is sane as well. Do the minimum fix for the current kernel, but set it up such that this basic infra can be extended for later kernels to make this harder to mess up in the future. Thanks to Junxi Qian for finding and debugging this issue. Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reviewed-by: Junxi Qian <qjx1298677004@gmail.com> Tested-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-31 07:07:47 -06:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00
io_uring: protect remaining lockless ctx->rings accesses with RCU Commit 96189080265e addressed one case of ctx->rings being potentially accessed while a resize is happening on the ring, but there are still a few others that need handling. Add a helper for retrieving the rings associated with an io_uring context, and add some sanity checking to that to catch bad uses. ->rings_rcu is always valid, as long as it's used within RCU read lock. Any use of ->rings_rcu or ->rings inside either ->uring_lock or ->completion_lock is sane as well. Do the minimum fix for the current kernel, but set it up such that this basic infra can be extended for later kernels to make this harder to mess up in the future. Thanks to Junxi Qian for finding and debugging this issue. Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reviewed-by: Junxi Qian <qjx1298677004@gmail.com> Tested-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-31 07:07:47 -06:00
io_uring: split out CQ waiting code into wait.c Move the completion queue waiting and scheduling code out of io_uring.c into a dedicated wait.c file. This further removes code out of the main io_uring C and header file, and into a topical new file. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-22 08:40:19 -07:00