Commit 9fd3f88c authored Oct 01, 2008 by Nathan Fontenot Committed by Benjamin Herrenschmidt Oct 10, 2008

powerpc: Oops in pseries_lmb_remove()



Testing hotplug memory remove has revealed that we can oops in
pseries_lmb_remove().  The incorrect shift causes a NULL pointer
dereference in the page_zone() inline routine.

I have only been able to reproduce the oops on kernels with large pages
enabled.

Tested on Power5 and Power6 with and without large pages enabled.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

parent 7c12d906

arch/powerpc/platforms/pseries/hotplug-memory.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -21,7 +21,7 @@ static int pseries_remove_lmb(unsigned long base, unsigned int lmb_size)
	struct zone *zone;		struct zone *zone;
	int ret;		int ret;

	start_pfn = base >> PFN_SECTION_SHIFT;		start_pfn = base >> PAGE_SHIFT;
	zone = page_zone(pfn_to_page(start_pfn));		zone = page_zone(pfn_to_page(start_pfn));

	/*		/*