Re: [PATCH v2] [BUGFIX] drivers/base: fix show_mem_removable to handle missing sections

[Russ Anderson <rja@sgi.com>]

On Mon, Aug 26, 2013 at 02:49:59PM -0700, Andrew Morton wrote:
> On Fri, 23 Aug 2013 11:23:17 -0500 Russ Anderson <rja@sgi.com> wrote:
> 
> > "cat /sys/devices/system/memory/memory*/removable" crashed the system.
> > 
> > The problem is that show_mem_removable() is passing a
> > bad pfn to is_mem_section_removable(), which causes
> > if (!node_online(page_to_nid(page))) to blow up.
> > Why is it passing in a bad pfn?
> > 
> > show_mem_removable() will loop sections_per_block times.
> > sections_per_block is 16, but mem->section_count is 8,
> > indicating holes in this memory block.  Checking that
> > the memory section is present before checking to see
> > if the memory section is removable fixes the problem.
> 
> The patch textually applies to 3.10, 3.9 and perhaps earlier.  Should
> it be applied to earlier kernels?

I believe so, since this does not appear to be a recent
regression, but have not verified the problem/fix in
earlier kernels.

Thanks,
-- 
Russ Anderson, OS RAS/Partitioning Project Lead  
SGI - Silicon Graphics Inc          rja@sgi.com

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>