Messages in this thread Patch in this message | | | From | "Levin, Alexander" <> | Date | Fri, 29 Jul 2016 23:02:13 -0400 | Subject | [PATCH 2/8] liblockdep: Reduce MAX_LOCK_DEPTH to avoid overflowing lock_chain::depth |
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From: Ben Hutchings <ben@decadent.org.uk>
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.
Cc: <stable@vger.kernel.org> # for versions before 4.6, use a value of 255 Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> --- tools/lib/lockdep/uinclude/linux/lockdep.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/lockdep/uinclude/linux/lockdep.h b/tools/lib/lockdep/uinclude/linux/lockdep.h index c808c7d..d302142 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 -- 2.7.4
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