getopt: fix null pointer arithmetic ub

[musl] / src / thread / pthread_mutex_consistent.c

#include "pthread_impl.h"
#include "atomic.h"

int pthread_mutex_consistent(pthread_mutex_t *m)
{
        int old = m->_m_lock;
        int own = old & 0x3fffffff;
        if (!(m->_m_type & 4) || !own || !(old & 0x40000000))
                return EINVAL;
        if (own != __pthread_self()->tid)
                return EPERM;
        a_and(&m->_m_lock, ~0x40000000);
        return 0;
}