From 75dd602a5198a6e5f75534db52b6e6fbaabb33d1 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 30 Mar 2016 11:36:59 +0200 Subject: 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) Cc: Alfredo Alvarez Fernandez Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Sedat Dilek Cc: Theodore Ts'o Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20160330093659.GS3408@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- include/linux/lockdep.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'include/linux/lockdep.h') 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; }; -- cgit v1.2.3-55-g7522