Messages in this thread Patch in this message | | | Date | Fri, 1 Jun 2007 13:54:22 -0700 | From | Paul Jackson <> | Subject | Re: [RFC] [PATCH] cpuset operations causes Badness at mm/slab.c:777 warning |
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Christoph wrote: > Then you are deferencing an element in the pidarray that you did not > allocate! This is a bug in cpuset code.
Absolutely - as I described in more detail in a reply Jeremy a few minutes ago. Thanks for smoking it out.
If, as I suggested in my previous message to which you are responding:
> Perhaps if you moved the "if (unlikely(n == npids))" test before the > "pidarray[n++] = p->pid" assignment, it would be safe.
then it looks safe to me, without having to add the bogus "+1" to the allocated size. That is, I suspect the following patch fixes this long standing cpuset bug (warning - white space mangled):
--- kernel/cpuset.c 2006-12-10 12:27:37.000000000 -0800 +++ kernel/cpuset.c.new 2007-06-01 13:53:00.271010074 -0700 @@ -1661,9 +1661,9 @@ static int pid_array_load(pid_t *pidarra
do_each_thread(g, p) { if (p->cpuset == cs) { - pidarray[n++] = p->pid; if (unlikely(n == npids)) goto array_full; + pidarray[n++] = p->pid; } } while_each_thread(g, p);
-- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson <pj@sgi.com> 1.925.600.0401 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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