linux/include
Jens Axboe cd305ee363 io_uring: defer eventfd signaling when queued from a wakeup handler
io_req_local_work_add() signals the CQ ring eventfd inline when it is the
one to push the first entry onto ->work_list. For DEFER_TASKRUN rings that
add is frequently done from a waitqueue wakeup handler, where an
arbitrary waitqueue lock is held.

eventfd_signal_mask() only refuses to recurse when current->in_eventfd
is set, but that bit is set by eventfd_signal_mask() itself. If the wake
chain starts somewhere else, signal goes out inline and can feed back
into epoll.

Add IOU_F_TWQ_IN_WAKE, set it on the task_work add done from the three
waitqueue callbacks, and use it to force io_eventfd_signal() down the
existing call_rcu_hurry() deferral instead of signaling inline.

Fixes: 21a091b970 ("io_uring: signal registered eventfd to process deferred task work")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20260813133843.2933127-1-4ncienth@gmail.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-08-15 16:56:49 -06:00
..
acpi Driver core changes for 7.2-rc1 2026-06-15 12:41:17 +05:30
asm-generic mm.git review status for mm-hotfixes-stable..mm-nonmm-stable 2026-06-21 13:20:19 -07:00
clocksource
crypto Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
cxl cxl/region: Introduce devm_cxl_probe_mem() 2026-06-12 13:47:30 -07:00
drm drm fixes for 7.2-rc1 2026-06-26 17:03:48 -07:00
dt-bindings This is all clk driver updates. Mostly new SoC support for 2026-06-25 12:48:57 -07:00
hyperv
keys keys: Pin request_key_auth payload in instantiate paths 2026-06-15 15:19:13 +03:00
kunit linux_kselftest-kunit-7.2-rc1 2026-06-16 16:33:57 +05:30
kvm Merge branch kvm-arm64/vgic-v5-PPI-fixes into kvmarm-master/next 2026-06-12 09:08:31 +01:00
linux io_uring: defer eventfd signaling when queued from a wakeup handler 2026-08-15 16:56:49 -06:00
math-emu
media media: v4l2-fwnode: Fix subdev owner overwritten in v4l2_async_register_subdev_sensor() 2026-06-05 10:28:03 +03:00
memory
misc
net Including fixes from netfilter and IPsec. 2026-06-25 12:25:36 -07:00
pcmcia
ras
rdma RDMA v7.2 merge window 2026-06-18 08:16:21 -07:00
rv rv: Prevent task migration while handling per-CPU events 2026-06-03 12:33:25 +02:00
scsi
soc This is all clk driver updates. Mostly new SoC support for 2026-06-25 12:48:57 -07:00
sound ASoC: Fixes for v7.2 2026-06-26 07:33:15 +02:00
target
trace This adds support for manual client session reset in CephFS, allowing 2026-06-26 16:15:53 -07:00
uapi Including fixes from netfilter and IPsec. 2026-06-25 12:25:36 -07:00
ufs Merge branch 7.1/scsi-fixes into 7.2/scsi-staging 2026-06-15 21:01:30 -04:00
vdso futex: Provide infrastructure to plug the non contended robust futex unlock race 2026-06-03 11:38:52 +02:00
video
xen xen: constify xsd_errors array 2026-06-08 09:00:06 +02:00
Kbuild