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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-08 14:42:16 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-08 14:42:16 -0800 |
| commit | c77f8bf918e66711938a25b19b188b24971a7d30 (patch) | |
| tree | 859badcf79e0e1873108a24930618b69c12835fa | |
| parent | 7b54c165a0c012edbaeaa73c5c87cb73721eb580 (diff) | |
| parent | b980955236922ae6106774511c5c05003d3ad225 (diff) | |
| download | linux-c77f8bf918e66711938a25b19b188b24971a7d30.tar.bz2 | |
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.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 594bda9dcfc8..32a6c5764950 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; } |