From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 8 Mar 2013 22:42:16 +0000 (-0800)
Subject: Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso... 
X-Git-Url: https://git.openfabrics.org/?p=~shefty%2Frdma-dev.git;a=commitdiff_plain;h=c77f8bf918e66711938a25b19b188b24971a7d30;hp=-c

Merge tag 'random_for_linus' of git://git./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
---

c77f8bf918e66711938a25b19b188b24971a7d30
diff --combined drivers/char/random.c
index 594bda9dcfc,57d4b152267..32a6c576495
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@@ -445,7 -445,7 +445,7 @@@ static struct entropy_store input_pool 
  	.poolinfo = &poolinfo_table[0],
  	.name = "input",
  	.limit = 1,
 -	.lock = __SPIN_LOCK_UNLOCKED(&input_pool.lock),
 +	.lock = __SPIN_LOCK_UNLOCKED(input_pool.lock),
  	.pool = input_pool_data
  };
  
@@@ -454,7 -454,7 +454,7 @@@ static struct entropy_store blocking_po
  	.name = "blocking",
  	.limit = 1,
  	.pull = &input_pool,
 -	.lock = __SPIN_LOCK_UNLOCKED(&blocking_pool.lock),
 +	.lock = __SPIN_LOCK_UNLOCKED(blocking_pool.lock),
  	.pool = blocking_pool_data
  };
  
@@@ -462,7 -462,7 +462,7 @@@ static struct entropy_store nonblocking
  	.poolinfo = &poolinfo_table[1],
  	.name = "nonblocking",
  	.pull = &input_pool,
 -	.lock = __SPIN_LOCK_UNLOCKED(&nonblocking_pool.lock),
 +	.lock = __SPIN_LOCK_UNLOCKED(nonblocking_pool.lock),
  	.pool = nonblocking_pool_data
  };
  
@@@ -852,6 -852,7 +852,7 @@@ static size_t account(struct entropy_st
  		      int reserved)
  {
  	unsigned long flags;
+ 	int wakeup_write = 0;
  
  	/* Hold lock while accounting */
  	spin_lock_irqsave(&r->lock, flags);
@@@ -873,10 -874,8 +874,8 @@@
  		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 +883,11 @@@
  
  	spin_unlock_irqrestore(&r->lock, flags);
  
+ 	if (wakeup_write) {
+ 		wake_up_interruptible(&random_write_wait);
+ 		kill_fasync(&fasync, SIGIO, POLL_OUT);
+ 	}
+ 
  	return nbytes;
  }