Stefan Hajnoczi 248aa3deb6 aio-posix: fix race between epoll upgrade and aio_set_fd_handler() ... If another thread calls aio_set_fd_handler() while the IOThread event loop is upgrading from ppoll(2) to epoll(7) then we might miss new AioHandlers. The epollfd will not monitor the new AioHandler's fd, resulting in hangs. Take the AioHandler list lock while upgrading to epoll. This prevents AioHandlers from changing while epoll is being set up. If we cannot lock because we're in a nested event loop, then don't upgrade to epoll (it will happen next time we're not in a nested call). The downside to taking the lock is that the aio_set_fd_handler() thread has to wait until the epoll upgrade is finished, which involves many epoll_ctl(2) system calls. However, this scenario is rare and I couldn't think of another solution that is still simple. Reported-by: Qing Wang <qinwang@redhat.com> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2090998 Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Fam Zheng <fam@euphon.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230323144859.1338495-1-stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> (cherry picked from commit e62da98527) Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>		2023-04-10 11:16:14 +03:00
..
aio-posix.c	util/event-loop-base: Introduce options to set the thread pool size	2022-05-09 10:43:23 +01:00
aio-posix.h	aio-posix: fix spurious ->poll_ready() callbacks in main loop	2022-03-17 11:23:18 +00:00
aio-wait.c	aio_wait_kick: add missing memory barrier	2022-06-24 17:07:06 +02:00
aio-win32.c	util/aio-win32: Correct the event array size in aio_poll()	2022-11-06 09:48:26 +01:00
aiocb.c
async-teardown.c	os-posix: asynchronous teardown for shutdown on Linux	2022-10-31 09:46:34 +01:00
async.c	replay: notify vCPU when BH is scheduled	2022-06-06 09:26:53 +02:00
atomic64.c	osdep: Move memalign-related functions to their own header	2022-03-07 13:16:49 +00:00
base64.c
bitmap.c	migration: Use non-atomic ops for clear log bitmap	2022-11-21 11:58:10 +01:00
bitops.c
block-helpers.c
block-helpers.h
buffer.c
bufferiszero.c
cacheflush.c	util/cacheflush: Optimize flushing when ppc host has coherent icache	2022-06-21 09:28:41 -07:00
compatfd.c	util: replace pipe()+cloexec with g_unix_open_pipe()	2022-05-03 15:18:14 +04:00
coroutine-sigaltstack.c	Remove qemu-common.h include from most units	2022-04-06 14:31:55 +02:00
coroutine-ucontext.c	coroutine-ucontext: use QEMU_DEFINE_STATIC_CO_TLS()	2022-05-04 15:55:23 +02:00
coroutine-win32.c	coroutine-win32: use QEMU_DEFINE_STATIC_CO_TLS()	2022-05-04 15:55:23 +02:00
crc32c.c
crc-ccitt.c
cutils.c	cutils: Add missing dyld(3) include on macOS	2022-08-12 11:33:52 +01:00
dbus.c
drm.c
envlist.c	Use g_new() & friends where that makes obvious sense	2022-03-21 15:44:44 +01:00
error-report.c	error-report: fix g_date_time_format assertion	2022-04-28 08:51:56 +02:00
error.c
event_notifier-posix.c	Replace qemu_pipe() with g_unix_open_pipe()	2022-05-03 15:17:56 +04:00
event_notifier-win32.c	Remove qemu-common.h include from most units	2022-04-06 14:31:55 +02:00
fdmon-epoll.c	aio-posix: fix race between epoll upgrade and aio_set_fd_handler()	2023-04-10 11:16:14 +03:00
fdmon-io_uring.c	aio-posix: fix build failure io_uring 2.2	2022-03-17 11:23:18 +00:00
fdmon-poll.c
fifo8.c
filemonitor-inotify.c
filemonitor-stub.c
getauxval.c
guest-random.c
hbitmap.c	block: simplify handling of try to merge different sized bitmaps	2022-06-24 17:07:06 +02:00
hexdump.c	include: move C/util-related declarations to cutils.h	2022-04-06 14:31:43 +02:00
host-utils.c	host-utils: Implemented signed 256-by-128 division	2022-06-20 08:38:58 -03:00
id.c
int128.c
iov.c	util: make do_send_recv work with partial send/recv	2022-10-12 19:22:01 +04:00
iova-tree.c	util: accept iova_tree_remove_parameter by value	2022-09-02 10:22:39 +08:00
keyval.c	include: add qemu/keyval.h	2022-04-21 17:03:51 +04:00
lockcnt.c
log.c	util/log: Ignore per-thread flag if global file already there	2022-11-07 16:00:02 -05:00
main-loop.c	util/main-loop: Avoid adding the same HANDLE twice	2022-11-06 09:48:26 +01:00
memalign.c	osdep: Move memalign-related functions to their own header	2022-03-07 13:16:49 +00:00
memfd.c
meson.build	qga: Allow building of the guest agent without system emulators or tools	2022-11-11 09:17:45 +01:00
mmap-alloc.c	util/mmap-alloc: Remove qemu_mempath_getpagesize()	2022-08-26 13:34:21 +02:00
module.c	module: add Error arguments to module_load and module_load_qom	2022-11-06 09:48:50 +01:00
notify.c
nvdimm-utils.c
osdep.c	tests/qtest: Use send/recv for socket communication	2022-10-28 11:17:12 +02:00
oslib-posix.c	util: Make qemu_prealloc_mem() optionally consume a ThreadContext	2022-10-27 11:00:56 +02:00
oslib-win32.c	util: Make qemu_prealloc_mem() optionally consume a ThreadContext	2022-10-27 11:00:56 +02:00
path.c
qdist.c
qemu-co-shared-resource.c
qemu-co-timeout.c	util: add qemu-co-timeout	2022-06-29 10:56:12 +03:00
qemu-config.c	Revert "s390x/s390-virtio-ccw: add zpcii-disable machine property"	2022-11-08 10:10:57 +01:00
qemu-coroutine-io.c	Remove qemu-common.h include from most units	2022-04-06 14:31:55 +02:00
qemu-coroutine-lock.c	coroutine: add flag to re-queue at front of CoQueue	2022-10-26 14:56:42 -04:00
qemu-coroutine-sleep.c
qemu-coroutine.c	coroutine: remove incorrect coroutine_fn annotations	2022-10-07 12:11:40 +02:00
qemu-option.c
qemu-print.c
qemu-progress.c	include: move progress API to qemu-progress.h	2022-04-06 14:31:43 +02:00
qemu-sockets.c	-----BEGIN PGP SIGNATURE-----	2022-10-30 18:30:01 -04:00
qemu-thread-common.h
qemu-thread-posix.c	util: Introduce qemu_thread_set_affinity() and qemu_thread_get_affinity()	2022-10-27 11:00:36 +02:00
qemu-thread-win32.c	util: Introduce qemu_thread_set_affinity() and qemu_thread_get_affinity()	2022-10-27 11:00:36 +02:00
qemu-timer-common.c
qemu-timer.c	qemu-timer: Skip empty timer lists before locking in qemu_clock_deadline_ns_all	2022-06-21 09:24:34 -07:00
qht.c	osdep: Move memalign-related functions to their own header	2022-03-07 13:16:49 +00:00
qsp.c
range.c
rcu.c	rcu: use coroutine TLS macros	2022-03-04 18:14:40 +01:00
readline.c
selfmap.c
stats64.c
sys_membarrier.c
systemd.c
thread-context.c	util: Add write-only "node-affinity" property for ThreadContext	2022-10-27 11:00:50 +02:00
thread-pool.c	thread-pool: remove stopping variable	2022-05-25 21:26:26 +02:00
throttle.c
timed-average.c
trace-events
trace.h
transactions.c
unicode.c
uri.c
userfaultfd.c
uuid.c
vfio-helpers.c	numa: call ->ram_block_removed() in ram_block_notifer_remove()	2022-10-26 14:56:42 -04:00
vhost-user-server.c	util: rename qemu_*block() socket functions	2022-05-03 15:53:20 +04:00
yank.c