Messages in this thread | | | Date | Fri, 06 Jun 2008 06:33:49 -0700 | From | Mike Travis <> | Subject | Re: linux-next: Tree for June 5 |
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Vegard Nossum wrote: > On Fri, Jun 6, 2008 at 1:57 PM, Ingo Molnar <mingo@elte.hu> wrote: >> * Andrew Morton <akpm@linux-foundation.org> wrote: >> >>> Good >>> >>> a9ad585c8a18f7ba754b85f5786976609b9d7d29 >>> Author: Mike Travis <travis@sgi.com> 2008-05-12 12:21:12 >>> Committer: Thomas Gleixner <tglx@linutronix.de> 2008-05-23 09:07:47 >>> Parent: 543e21916497be5a4005fd5820264ce1de9bd56d (x86: restore pda nodenumber field) >>> Child: 78d49c6d890aee9cf8aea371011c9d7b0121b822 (x86: remove static boot_cpu_pda array v2) >>> Branch: >>> Follows: v2.6.26-rc2 >>> Precedes: next-20080526 >>> >>> x86: remove the static 256k node_to_cpumask_map >>> >>> crash, as described earlier. >> thanks for tracking it down! This was the origin of the commit: >> >> # tip/x86/numa: a9ad585: x86: remove the static 256k node_to_cpumask_map >> >> which has been in -tip since May 12 and in linux-next for two weeks >> AFAICS, which is beyond the point of being something freshly wrong. >> >> So i suspect something more subtle here. What compiler version are you >> using? This crash is not something that has been found in testing before >> - i use rather new compilers, gcc 4.2.2 most of the time. Previous >> compilers miscompile the kernel seriously so it's not usable for our >> regression testing grid. >> > > Hi, > > I reproced it with gc 4.1.2. I think the error is somewhere in kernel/sched.c. > > static int __build_sched_domains(const cpumask_t *cpu_map, > struct sched_domain_attr *attr) > { > ... > for (i = 0; i < MAX_NUMNODES; i++) { > ... > sg = kmalloc_node(sizeof(struct sched_group), GFP_KERNEL, i); > ... > > This code is calling into the allocator with a spurious value of i, > which causes SLAB to use an index (of 4 in my case) that is out of > bounds for its nodelist array (at least it hasn't been initialized). > > This bit of code (a bit further down, inside the same loop) is also dubious: > > sg = kmalloc_node(sizeof(struct sched_group), > GFP_KERNEL, i); > if (!sg) { > printk(KERN_WARNING > "Can not alloc domain group for node %d\n", j); > goto error; > } > > Where it passes i to kmalloc_node() but reports an allocation for node > j. Which one is correct? > > Hope this helps, will send an update if I find out more. > > > Vegard >
Thanks Vegard for tracking this down. My thoughts were along the same wavelength... ;-)
Mike
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