signal: fix __send_signal() false positive kmemcheck warning (7a0aeb14) · Commits · 戴 / test

This false positive is due to field padding in struct sigqueue. When this dynamically allocated structure is copied to the stack (in arch- specific delivery code), kmemcheck sees a read from the padding, which is, naturally, uninitialized. Hide the false positive using the __GFP_NOTRACK_FALSE_POSITIVE flag. Also made the rlimit override code a bit clearer by introducing a new variable. Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by:

Vegard Nossum <vegard.nossum@gmail.com>

kernel/signal.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -832,6 +832,7 @@ static int __send_signal(int sig, struct siginfo info, struct task_struct t,
		{
		struct sigpending *pending;
		struct sigqueue *q;
		int override_rlimit;

		trace_sched_signal_send(sig, t);

		@@ -863,9 +864,13 @@ static int __send_signal(int sig, struct siginfo info, struct task_struct t,
		make sure at least one signal gets delivered and don't
		pass on the info struct. */

		q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN &&
		(is_si_special(info) \|\|
		info->si_code >= 0)));
		if (sig < SIGRTMIN)
		override_rlimit = (is_si_special(info) \|\| info->si_code >= 0);
		else
		override_rlimit = 0;

		q = __sigqueue_alloc(t, GFP_ATOMIC \| __GFP_NOTRACK_FALSE_POSITIVE,
		override_rlimit);
		if (q) {
		list_add_tail(&q->list, &pending->list);
		switch ((unsigned long) info) {

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