From eabe8c241a9ecbc15a9d51e0bfc3dde1c27d8a65 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 20 Apr 2010 10:33:50 -0400 Subject: [PATCH] lockdep: fix incorrect percpu usage The mainline kernel as of 2.6.34-rc5 is not affected by this problem because commit 10fad5e46f6c7bdfb01b1a012380a38e3c6ab346 fixed it by refactoring. lockdep fix incorrect percpu usage Should use per_cpu_ptr() to obfuscate the per cpu pointers (RELOC_HIDE is needed for per cpu pointers). git blame points to commit: lockdep.c: commit 8e18257d29238311e82085152741f0c3aa18b74d But it's really just moving the code around. But it's enough to say that the problems appeared before Jul 19 01:48:54 2007, which brings us back to 2.6.23. It should be applied to stable 2.6.23.x to 2.6.33.x (or whichever of these stable branches are still maintained). (tested on 2.6.33.1 x86_64) Signed-off-by: Mathieu Desnoyers CC: Randy Dunlap CC: Eric Dumazet CC: Rusty Russell CC: Peter Zijlstra CC: Tejun Heo CC: Ingo Molnar CC: Andrew Morton CC: Linus Torvalds CC: Greg Kroah-Hartman CC: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- kernel/lockdep.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/lockdep.c b/kernel/lockdep.c index c62ec14609b..493a0efbb86 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -600,9 +600,9 @@ static int static_obj(void *obj) * percpu var? */ for_each_possible_cpu(i) { - start = (unsigned long) &__per_cpu_start + per_cpu_offset(i); - end = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM - + per_cpu_offset(i); + start = (unsigned long) per_cpu_ptr(&__per_cpu_start, i); + end = (unsigned long) per_cpu_ptr(&__per_cpu_start, i) + + PERCPU_ENOUGH_ROOM; if ((addr >= start) && (addr < end)) return 1; -- 2.11.4.GIT