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23 October 2021, 00:29:24 UTC
Revision 48887e63d6e057543067327da6b091297f7fe645 authored by Al Viro on 06 December 2008, 06:05:50 UTC, committed by Al Viro on 09 December 2008, 07:27:41 UTC 
[PATCH] fix broken timestamps in AVC generated by kernel threads
 
Timestamp in audit_context is valid only if ->in_syscall is set.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1 parent 7f0ed77
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Tip revision: 48887e63d6e057543067327da6b091297f7fe645 authored by Al Viro on 06 December 2008, 06:05:50 UTC
[PATCH] fix broken timestamps in AVC generated by kernel threads
Tip revision: 48887e6
dec_and_lock.c 
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>

/*
 * This is an implementation of the notion of "decrement a
 * reference count, and return locked if it decremented to zero".
 *
 * NOTE NOTE NOTE! This is _not_ equivalent to
 *
 *	if (atomic_dec_and_test(&atomic)) {
 *		spin_lock(&lock);
 *		return 1;
 *	}
 *	return 0;
 *
 * because the spin-lock and the decrement must be
 * "atomic".
 */
int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
{
#ifdef CONFIG_SMP
	/* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
	if (atomic_add_unless(atomic, -1, 1))
		return 0;
#endif
	/* Otherwise do it the slow way */
	spin_lock(lock);
	if (atomic_dec_and_test(atomic))
		return 1;
	spin_unlock(lock);
	return 0;
}

EXPORT_SYMBOL(_atomic_dec_and_lock);
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