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 e62da98527fa35fe5f532cded01a33edf9fbe7b2) 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	nomaintainer: Fix Lesser GPL version number	2020-11-15 17:04:40 +01:00
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: move logical block size check function to a common utility function	2020-10-23 13:42:16 +01:00
block-helpers.h	block: move logical block size check function to a common utility function	2020-10-23 13:42:16 +01:00
buffer.c	nomaintainer: Fix Lesser GPL version number	2020-11-15 17:04:40 +01:00
bufferiszero.c	cpuid: use unsigned for max cpuid	2022-02-04 09:07:43 -05:00
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
crc-ccitt.c	util: Add CRC16 (CCITT) calculation routines	2021-01-24 20:10:54 +01:00
crc32c.c
cutils.c	cutils: Add missing dyld(3) include on macOS	2022-08-12 11:33:52 +01:00
dbus.c	util: add dbus helper unit	2020-01-06 18:41:32 +04:00
drm.c	util/drm: make portable by avoiding struct dirent d_type	2020-07-13 14:36:10 +01:00
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	error: make Error **errp const where it is appropriate	2019-12-18 08:36:16 +01:00
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	fdmon-poll: reset npfd when upgrading to fdmon-epoll	2020-09-23 13:45:52 +01:00
fifo8.c	utils/fifo8: change fatal errors from abort() to assert()	2021-02-07 20:38:20 +00:00
filemonitor-inotify.c	nomaintainer: Fix Lesser GPL version number	2020-11-15 17:04:40 +01:00
filemonitor-stub.c	nomaintainer: Fix Lesser GPL version number	2020-11-15 17:04:40 +01:00
getauxval.c	util/getauxval: Porting to FreeBSD getauxval feature	2020-06-26 06:45:29 -04:00
guest-random.c	util/guest-random: Fix size arg to tail memcpy	2021-07-09 18:42:46 +02:00
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	net: Use id_generate() in the network subsystem, too	2021-03-09 21:47:45 +01:00
int128.c	qemu/int128: addition of div/rem 128-bit operations	2022-01-08 15:46:10 +10:00
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	qemu/atomic.h: rename atomic_ to qatomic_	2020-09-23 16:07:44 +01:00
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	Clean up includes	2020-12-10 17:16:44 +01:00
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	co-shared-resource: protect with a mutex	2021-06-25 14:24:24 +03:00
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	coroutine-sleep: introduce qemu_co_sleep	2021-05-21 18:22:33 +01:00
qemu-coroutine.c	coroutine: remove incorrect coroutine_fn annotations	2022-10-07 12:11:40 +02:00
qemu-option.c	qemu-option: Allow deleting opts during qemu_opts_foreach()	2021-10-15 16:11:22 +02:00
qemu-print.c	monitor: Use getter/setter functions for cur_mon	2020-10-09 07:08:19 +02:00
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	semihosting: Implement SYS_ELAPSED and SYS_TICKFREQ	2021-01-18 10:05:06 +00:00
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	qemu/atomic: Add aligned_{int64,uint64}_t types	2021-07-21 07:45:38 -10:00
range.c
rcu.c	rcu: use coroutine TLS macros	2022-03-04 18:14:40 +01:00
readline.c	readline: Fix possible array index out of bounds in readline_hist_add()	2021-01-04 11:13:39 +00:00
selfmap.c	util/selfmap: Discard mapping on error	2021-07-26 07:06:49 -10:00
stats64.c	qemu/atomic.h: rename atomic_ to qatomic_	2020-09-23 16:07:44 +01:00
sys_membarrier.c
systemd.c	tools: Fix use of fcntl(F_SETFD) during socket activation	2020-05-04 14:54:35 -05:00
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	Remove superfluous timer_del() calls	2021-01-08 15:13:38 +00:00
timed-average.c
trace-events	modules: add tracepoints	2021-07-09 18:20:27 +02:00
trace.h	trace: switch position of headers to what Meson requires	2020-08-21 06:18:24 -04:00
transactions.c	transactions: Invoke clean() after everything else	2021-11-16 09:43:44 +01:00
unicode.c
uri.c	util/uri: do not check argument of uri_free()	2021-07-09 12:26:05 +02:00
userfaultfd.c	migration: introduce UFFD-WP low-level interface helpers	2021-02-08 11:19:51 +00:00
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	yank: Remove dependency on qiochannel	2021-04-01 15:27:44 +04:00