RIOT-OS/RIOT
RIOT-OS/RIOT
1
0
Fork 0
mirror of https://github.com/RIOT-OS/RIOT.git synced 2024-12-29 04:50:03 +01:00
Code Releases Activity

core/mutex: use thread_yield_higher() in mutex_unlock()

Browse Source 
Using `sched_switch()` in `mutex_unlock()` can result in crashes when
`mutex_unlock()` is called from IRQ context. This however is a common
pattern in RIOT to wake up a thread from IRQ. The reason for the crash
is that `sched_switch()` assumes `thread_get_active()` to always return
a non-`NULL` value. But when thread-less idle is used, no thread may be
active after the last runnable thread exited. Using
`thread_yield_higher()` instead solves the issue, as
`thread_yield_higher()` is safe to call from IRQ context without an
active thread.

This fixes https://github.com/RIOT-OS/RIOT/issues/20812
This commit is contained in:
Marian Buschsieweke 2024-10-05 21:58:26 +02:00
parent 13188e13f2
commit 1d99f4f758
No known key found for this signature in database
GPG Key ID: 77AA882EC78084E6
1 changed files with 1 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
core/mutex.c
View File

@ -216,8 +216,6 @@ void mutex_unlock(mutex_t *mutex)
mutex->queue.next = MUTEX_LOCKED; mutex->queue.next = MUTEX_LOCKED;
} }
uint16_t process_priority = process->priority;
#if IS_USED(MODULE_CORE_MUTEX_PRIORITY_INHERITANCE) #if IS_USED(MODULE_CORE_MUTEX_PRIORITY_INHERITANCE)
thread_t *owner = thread_get(mutex->owner); thread_t *owner = thread_get(mutex->owner);
if ((owner) && (owner->priority != mutex->owner_original_priority)) { if ((owner) && (owner->priority != mutex->owner_original_priority)) {
@ -232,7 +230,7 @@ void mutex_unlock(mutex_t *mutex)
#endif #endif
irq_restore(irqstate); irq_restore(irqstate);
sched_switch(process_priority); thread_yield_higher();
} }
void mutex_unlock_and_sleep(mutex_t *mutex) void mutex_unlock_and_sleep(mutex_t *mutex)