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authorLinus Torvalds <torvalds@linux-foundation.org>2013-03-08 14:42:16 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-03-08 14:42:16 -0800
commitc77f8bf918e66711938a25b19b188b24971a7d30 (patch)
tree859badcf79e0e1873108a24930618b69c12835fa
parent7b54c165a0c012edbaeaa73c5c87cb73721eb580 (diff)
parentb980955236922ae6106774511c5c05003d3ad225 (diff)
downloadlinaro-lsk-c77f8bf918e66711938a25b19b188b24971a7d30.tar.gz
Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull random fixes from Ted Ts'o: "Fix a circular locking dependency in random's collection of cputime used by a thread when it exits." * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: random: fix locking dependency with the tasklist_lock
-rw-r--r--drivers/char/random.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 594bda9dcfc..32a6c576495 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -852,6 +852,7 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
int reserved)
{
unsigned long flags;
+ int wakeup_write = 0;
/* Hold lock while accounting */
spin_lock_irqsave(&r->lock, flags);
@@ -873,10 +874,8 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
else
r->entropy_count = reserved;
- if (r->entropy_count < random_write_wakeup_thresh) {
- wake_up_interruptible(&random_write_wait);
- kill_fasync(&fasync, SIGIO, POLL_OUT);
- }
+ if (r->entropy_count < random_write_wakeup_thresh)
+ wakeup_write = 1;
}
DEBUG_ENT("debiting %zu entropy credits from %s%s\n",
@@ -884,6 +883,11 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
spin_unlock_irqrestore(&r->lock, flags);
+ if (wakeup_write) {
+ wake_up_interruptible(&random_write_wait);
+ kill_fasync(&fasync, SIGIO, POLL_OUT);
+ }
+
return nbytes;
}