lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[PATCH] lockdep: allow read_lock() recursion of same class

Browse Source 
From: Ingo Molnar <mingo@elte.hu>

lockdep so far only allowed read-recursion for the same lock instance.
This is enough in the overwhelming majority of cases, but a hostap case
triggered and reported by Miles Lane relies on same-class
different-instance recursion.  So we relax the restriction on read-lock
recursion.

(This change does not allow rwsem read-recursion, which is still
forbidden.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ingo Molnar
2006-07-03 00:24:51 -07:00
committed by Linus Torvalds
parent fbb9ce9530
commit 6c9076ec9c
2 changed files with 6 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
kernel/lockdep.c
View File

@@ -843,10 +843,9 @@ check_deadlock(struct task_struct *curr, struct held_lock *next,
continue;
/*
* Allow read-after-read recursion of the same
* lock instance (i.e. read_lock(lock)+read_lock(lock)):
* lock class (i.e. read_lock(lock)+read_lock(lock)):
*/
if ((read == 2) && prev->read &&
(prev->instance == next_instance))
if ((read == 2) && prev->read)
return 2;
return print_deadlock_bug(curr, prev, next);
}