Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c77f8bf9 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents 7b54c165 b9809552

drivers/char/random.c

+8 −4
Original line number Diff line number Diff line
@@ -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;

}