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authorPeter Zijlstra <peterz@infradead.org>2016-03-30 12:36:59 +0300
committerIngo Molnar <mingo@kernel.org>2016-04-23 14:53:03 +0300
commit75dd602a5198a6e5f75534db52b6e6fbaabb33d1 (patch)
treec7ea5657c955e30f93c11127f954343519161252 /include/linux/lockdep.h
parentc24697566298df04cac9913e0601501b5ee2b3f5 (diff)
downloadlinux-75dd602a5198a6e5f75534db52b6e6fbaabb33d1.tar.xz
lockdep: Fix lock_chain::base size
lock_chain::base is used to store an index into the chain_hlocks[] array, however that array contains more elements than can be indexed using the u16. Change the lock_chain structure to use a bitfield to encode the data it needs and add BUILD_BUG_ON() assertions to check the fields are wide enough. Also, for DEBUG_LOCKDEP, assert that we don't run out of elements of that array; as that would wreck the collision detectoring. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160330093659.GS3408@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/lockdep.h')
-rw-r--r--include/linux/lockdep.h8
1 files changed, 5 insertions, 3 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index d026b190c530..d10ef06971b5 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -196,9 +196,11 @@ struct lock_list {
* We record lock dependency chains, so that we can cache them:
*/
struct lock_chain {
- u8 irq_context;
- u8 depth;
- u16 base;
+ /* see BUILD_BUG_ON()s in lookup_chain_cache() */
+ unsigned int irq_context : 2,
+ depth : 6,
+ base : 24;
+ /* 4 byte hole */
struct hlist_node entry;
u64 chain_key;
};