Subject: + arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map.patch added to -mm tree To: ptesarik@xxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Mon, 03 Feb 2014 14:47:39 -0800 The patch titled Subject: arch/x86/mm/numa_32.c: fix the initialization of physnode_map has been added to the -mm tree. Its filename is arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Petr Tesarik <ptesarik@xxxxxxx> Subject: arch/x86/mm/numa_32.c: fix the initialization of physnode_map With DISCONTIGMEM, the mapping between a pfn and its owning node is initialized using data provided by the BIOS. However, the initialization may fail if the extents are not aligned to section boundary (64M). The symptom of this bug is an early boot failure in pfn_to_page(), as it tries to access NODE_DATA(__nid) using index from an unitialized element of the physnode_map[] array. While the bug is always present, it is more likely to be hit in kdump kernels on large machines, because: 1. The memory map for a kdump kernel is specified as exactmap, and exactmap is more likely to be unaligned. 2. Large reservations are more likely to span across a 64M boundary. Signed-off-by: Petr Tesarik <ptesarik@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/mm/numa_32.c | 2 ++ 1 file changed, 2 insertions(+) diff -puN arch/x86/mm/numa_32.c~arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map arch/x86/mm/numa_32.c --- a/arch/x86/mm/numa_32.c~arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map +++ a/arch/x86/mm/numa_32.c @@ -52,6 +52,8 @@ void memory_present(int nid, unsigned lo nid, start, end); printk(KERN_DEBUG " Setting physnode_map array to node %d for pfns:\n", nid); printk(KERN_DEBUG " "); + pfn = round_down(pfn, PAGES_PER_SECTION); + end = round_up(end, PAGES_PER_SECTION); for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) { physnode_map[pfn / PAGES_PER_SECTION] = nid; printk(KERN_CONT "%lx ", pfn); _ Patches currently in -mm which might be from ptesarik@xxxxxxx are arch-x86-mm-numa_32c-fix-the-initialization-of-physnode_map.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html