Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1643701

[PATCH 02/15] liblockdep: Reduce MAX_LOCK_DEPTH to avoid overflowing lock_chain::depth

Show all headers | View raw

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 <sasha.levin@oracle.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 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
-- 
2.11.0

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 01/15] liblockdep: Fix undefined symbol prandom_u32 alexander.levin@verizon.com - 2017-05-18 02:10 +0200
  [PATCH 02/15] liblockdep: Reduce MAX_LOCK_DEPTH to avoid overflowing  lock_chain::depth alexander.levin@verizon.com - 2017-05-18 02:10 +0200
  [PATCH 10/15] tools: add install make target for liblockdep alexander.levin@verizon.com - 2017-05-18 02:10 +0200
  [PATCH 12/15] tools: liblockdep: fix compilation for 4.11 alexander.levin@verizon.com - 2017-05-18 02:10 +0200
  [PATCH 15/15] tools: liblockdep: Use LDFLAGS alexander.levin@verizon.com - 2017-05-18 02:10 +0200
  [PATCH 08/15] liblockdep: Remove -lpthread compiler option alexander.levin@verizon.com - 2017-05-18 02:10 +0200
  [PATCH 09/15] MAINTAINERS: update email for Sasha Levin alexander.levin@verizon.com - 2017-05-18 02:10 +0200
  [PATCH 03/15] liblockdep: Define the ARRAY_SIZE() macro alexander.levin@verizon.com - 2017-05-18 02:10 +0200
  [PATCH 14/15] tools: liblockdep: Remove double-quotes from soname alexander.levin@verizon.com - 2017-05-18 02:10 +0200
  [PATCH 04/15] liblockdep: Enable -Wall by default alexander.levin@verizon.com - 2017-05-18 02:20 +0200
  [PATCH 07/15] liblockdep: Fix 'defined but not used' warning for  init_utsname() alexander.levin@verizon.com - 2017-05-18 02:20 +0200
  [PATCH 13/15] tools: liblockdep: Fix object file paths used in an  out-of-tree build alexander.levin@verizon.com - 2017-05-18 02:20 +0200
  [PATCH 11/15] tools: liblockdep: Don't mix fd-based and stream IO alexander.levin@verizon.com - 2017-05-18 02:20 +0200
  [PATCH 06/15] liblockdep: Fix 'set but not used' warnings alexander.levin@verizon.com - 2017-05-18 02:20 +0200
  Re: [PATCH 01/15] liblockdep: Fix undefined symbol prandom_u32 Ingo Molnar <mingo@kernel.org> - 2017-05-24 10:00 +0200

csiph-web