| Date | Wed, 28 Apr 2010 13:46:54 -0400 | From | Mathieu Desnoyers <> | Subject | Re: [170/197] lockdep: fix incorrect percpu usage |
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* Greg KH (gregkh@suse.de) wrote: > 2.6.32-stable review patch. If anyone has any objections, please let us know. > > ------------------ > > From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > > 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).
Tejun, (same as module.c patch) should this patch be applied to 2.6.32.x, or will it cause problems on ia64 ?
Thanks,
Mathieu
> > (tested on 2.6.33.1 x86_64) > > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > CC: Randy Dunlap <randy.dunlap@oracle.com> > CC: Eric Dumazet <dada1@cosmosbay.com> > CC: Rusty Russell <rusty@rustcorp.com.au> > CC: Peter Zijlstra <a.p.zijlstra@chello.nl> > CC: Tejun Heo <tj@kernel.org> > CC: Ingo Molnar <mingo@elte.hu> > CC: Andrew Morton <akpm@linux-foundation.org> > CC: Linus Torvalds <torvalds@linux-foundation.org> > CC: Greg Kroah-Hartman <gregkh@suse.de> > CC: Steven Rostedt <rostedt@goodmis.org> > Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> > > --- > kernel/lockdep.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > --- a/kernel/lockdep.c > +++ b/kernel/lockdep.c > @@ -591,9 +591,9 @@ 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 > + + PERCPU_ENOUGH_ROOM, i); > > if ((addr >= start) && (addr < end)) > return 1; > >
-- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com
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