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| author | Phil Dennis-Jordan <phil@philjordan.eu> | 2025-01-12 22:26:09 +0100 |
|---|---|---|
| committer | David Woodhouse <dwmw@amazon.co.uk> | 2025-01-15 18:05:19 +0000 |
| commit | e7bc0204e57836b3df611b73d2decc56ed698c4a (patch) | |
| tree | 334ef0f4a873e07c4220eb495944f58341c40a78 | |
| parent | 8b44a3e39f36540818d99ef8cf79e64bba1ed9c3 (diff) | |
| download | qemu-e7bc0204e57836b3df611b73d2decc56ed698c4a.zip qemu-e7bc0204e57836b3df611b73d2decc56ed698c4a.tar.gz qemu-e7bc0204e57836b3df611b73d2decc56ed698c4a.tar.bz2 | |
system/runstate: Fix regression, clarify BQL status of exit notifiers
By changing the way the main QEMU event loop is invoked, I inadvertently
changed the BQL status of exit notifiers: some of them implicitly
assumed they would be called with the BQL held; the BQL is however
not held during the exit(status) call in qemu_default_main().
Instead of attempting to ensuring we always call exit() from the BQL -
including any transitive calls - this change adds a BQL lock guard to
qemu_run_exit_notifiers, ensuring the BQL will always be held in the
exit notifiers.
Additionally, the BQL promise is now documented at the
qemu_{add,remove}_exit_notifier() declarations.
Fixes: f5ab12caba4f ("ui & main loop: Redesign of system-specific main
thread event handling")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2771
Reported-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Tested-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
| -rw-r--r-- | include/system/system.h | 1 | ||||
| -rw-r--r-- | system/runstate.c | 1 |
2 files changed, 2 insertions, 0 deletions
diff --git a/include/system/system.h b/include/system/system.h index 5364ad4..0cbb43e 100644 --- a/include/system/system.h +++ b/include/system/system.h @@ -15,6 +15,7 @@ extern bool qemu_uuid_set; const char *qemu_get_vm_name(void); +/* Exit notifiers will run with BQL held. */ void qemu_add_exit_notifier(Notifier *notify); void qemu_remove_exit_notifier(Notifier *notify); diff --git a/system/runstate.c b/system/runstate.c index 3a8fe86..272801d 100644 --- a/system/runstate.c +++ b/system/runstate.c @@ -850,6 +850,7 @@ void qemu_remove_exit_notifier(Notifier *notify) static void qemu_run_exit_notifiers(void) { + BQL_LOCK_GUARD(); notifier_list_notify(&exit_notifiers, NULL); } |