a1eb8cb5da
unlocking an unlocked mutex is not UB for robust or error-checking mutexes, so we must avoid calling __pthread_self (which might crash due to lack of thread-register initialization) until after checking that the mutex is locked.
30 lines
710 B
C
30 lines
710 B
C
#include "pthread_impl.h"
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int pthread_mutex_unlock(pthread_mutex_t *m)
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{
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pthread_t self;
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if (m->_m_type != PTHREAD_MUTEX_NORMAL) {
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if (!m->_m_lock)
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return EPERM;
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self = __pthread_self();
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if ((m->_m_lock&0x1fffffff) != self->tid)
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return EPERM;
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if ((m->_m_type&3) == PTHREAD_MUTEX_RECURSIVE && --m->_m_count)
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return 0;
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if (m->_m_type >= 4) {
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self->robust_list.pending = &m->_m_next;
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*(void **)m->_m_prev = m->_m_next;
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if (m->_m_next) ((void **)m->_m_next)[-1] = m->_m_prev;
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a_store(&m->_m_lock, 0);
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self->robust_list.pending = 0;
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} else {
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a_store(&m->_m_lock, 0);
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}
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} else {
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a_store(&m->_m_lock, 0);
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}
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if (m->_m_waiters) __wake(&m->_m_lock, 1, 0);
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return 0;
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}
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