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| author | Ben Hutchings <ben@decadent.org.uk> | 2017-05-25 12:58:33 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-06-05 09:28:03 +0200 |
| commit | 98dcea0cfd04e083ac74137ceb9a632604740e2d (patch) | |
| tree | c93a0600dc43a829c1c3152b15942bccd5adbb5a | |
| parent | 3752466b6bf04868296ac6bc27ea1765008636d8 (diff) | |
| download | linux-98dcea0cfd04e083ac74137ceb9a632604740e2d.tar.bz2 | |
tools/lib/lockdep: Reduce MAX_LOCK_DEPTH to avoid overflowing lock_chain/: Depth
liblockdep has been broken since commit 75dd602a5198 ("lockdep: Fix
lock_chain::base size"), as that adds a check that MAX_LOCK_DEPTH is
within the range of lock_chain::depth and in liblockdep it is much
too large.
That should have resulted in a compiler error, but didn't because:
- the check uses ARRAY_SIZE(), which isn't yet defined in liblockdep
so is assumed to be an (undeclared) function
- putting a function call inside a BUILD_BUG_ON() expression quietly
turns it into some nonsense involving a variable-length array
It did produce a compiler warning, but I didn't notice because
liblockdep already produces too many warnings if -Wall is enabled
(which I'll fix shortly).
Even before that commit, which reduced lock_chain::depth from 8 bits
to 6, MAX_LOCK_DEPTH was too large.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: <stable@vger.kernel.org> # for versions before 4.6, use a value of 255
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: a.p.zijlstra@chello.nl
Link: http://lkml.kernel.org/r/20170525130005.5947-3-alexander.levin@verizon.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | tools/lib/lockdep/uinclude/linux/lockdep.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/lib/lockdep/uinclude/linux/lockdep.h b/tools/lib/lockdep/uinclude/linux/lockdep.h index c808c7d02d21..d30214221920 100644 --- a/tools/lib/lockdep/uinclude/linux/lockdep.h +++ b/tools/lib/lockdep/uinclude/linux/lockdep.h @@ -8,7 +8,7 @@ #include <linux/utsname.h> #include <linux/compiler.h> -#define MAX_LOCK_DEPTH 2000UL +#define MAX_LOCK_DEPTH 63UL #define asmlinkage #define __visible |