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kernel/thread_abort: Remove needless locking

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The two APIs protected by this lock are themselves internally
synchronized.  Replace the irq_lock with a spinlock anyway, because
what I think it's doing is trying to prevent a race where something
else like an ISR or something it wakes up mucks with the thread before
this completes.  Seems fragile on SMP as it stands, but this preserves
behavior on uniprocessor architectures.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This commit is contained in:
Andy Ross 2018-07-25 11:28:43 -07:00 • committed by Anas Nashif
commit f6521a360d
1 changed files with 10 additions and 4 deletions
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14
kernel/thread_abort.c
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@ -27,9 +27,15 @@ extern void _k_thread_single_abort(struct k_thread *thread);
#if !defined(CONFIG_ARCH_HAS_THREAD_ABORT)
void _impl_k_thread_abort(k_tid_t thread)
{
unsigned int key;
key = irq_lock();
/* We aren't trying to synchronize data access here (these
* APIs are internally synchronized). The original lock seems
* to have been in place to prevent the thread from waking up
* due to a delivered interrupt. Leave a dummy spinlock in
* place to do that. This API should be revisted though, it
* doesn't look SMP-safe as it stands.
*/
struct k_spinlock lock = {};
k_spinlock_key_t key = k_spin_lock(&lock);
__ASSERT((thread->base.user_options & K_ESSENTIAL) == 0,
"essential thread aborted");
@ -37,7 +43,7 @@ void _impl_k_thread_abort(k_tid_t thread)
_k_thread_single_abort(thread);
_thread_monitor_exit(thread);
_reschedule_irqlock(key);
_reschedule(&lock, key);
}
#endif