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authorPeter Zijlstra <peterz@infradead.org>2016-03-30 11:36:59 +0200
committerIngo Molnar <mingo@kernel.org>2016-04-23 13:53:03 +0200
commit75dd602a5198a6e5f75534db52b6e6fbaabb33d1 (patch)
treec7ea5657c955e30f93c11127f954343519161252 /kernel/locking/lockdep_proc.c
parentc24697566298df04cac9913e0601501b5ee2b3f5 (diff)
downloadlinux-75dd602a5198a6e5f75534db52b6e6fbaabb33d1.tar.gz
linux-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 'kernel/locking/lockdep_proc.c')
-rw-r--r--kernel/locking/lockdep_proc.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index dbb61a302548..a0f61effad25 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -141,6 +141,8 @@ static int lc_show(struct seq_file *m, void *v)
int i;
if (v == SEQ_START_TOKEN) {
+ if (nr_chain_hlocks > MAX_LOCKDEP_CHAIN_HLOCKS)
+ seq_printf(m, "(buggered) ");
seq_printf(m, "all lock chains:\n");
return 0;
}