signal: fix __send_signal() false positive kmemcheck warning

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>
This commit is contained in:
Vegard Nossum 2009-05-16 11:28:33 +02:00
parent 3b5c760efc
commit 7a0aeb14e1
1 changed files with 8 additions and 3 deletions

View File

@ -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) {