3.19-stable review patch. If anyone has any objections, please let me know.
------------------ From: Laura Abbott <lau...@codeaurora.org> commit cfa869438282be84ad4110bba5027ef1fbbe71e4 upstream. Commit 3c605096d315 ("mm/page_alloc: restrict max order of merging on isolated pageblock") changed the logic of unset_migratetype_isolate to check the buddy allocator and explicitly call __free_pages to merge. The page that is being freed in this path never had prep_new_page called so set_page_refcounted is called explicitly but there is no call to kernel_map_pages. With the default kernel_map_pages this is mostly harmless but if kernel_map_pages does any manipulation of the page tables (unmapping or setting pages to read only) this may trigger a fault: alloc_contig_range test_pages_isolated(ceb00, ced00) failed Unable to handle kernel paging request at virtual address ffffffc0cec00000 pgd = ffffffc045fc4000 [ffffffc0cec00000] *pgd=0000000000000000 Internal error: Oops: 9600004f [#1] PREEMPT SMP Modules linked in: exfatfs CPU: 1 PID: 23237 Comm: TimedEventQueue Not tainted 3.10.49-gc72ad36-dirty #1 task: ffffffc03de52100 ti: ffffffc015388000 task.ti: ffffffc015388000 PC is at memset+0xc8/0x1c0 LR is at kernel_map_pages+0x1ec/0x244 Fix this by calling kernel_map_pages to ensure the page is set in the page table properly Fixes: 3c605096d315 ("mm/page_alloc: restrict max order of merging on isolated pageblock") Signed-off-by: Laura Abbott <lau...@codeaurora.org> Cc: Naoya Horiguchi <n-horigu...@ah.jp.nec.com> Cc: Mel Gorman <mgor...@suse.de> Acked-by: Rik van Riel <r...@redhat.com> Cc: Yasuaki Ishimatsu <isimatu.yasu...@jp.fujitsu.com> Cc: Zhang Yanfei <zhangyan...@cn.fujitsu.com> Cc: Xishi Qiu <qiuxi...@huawei.com> Cc: Vladimir Davydov <vdavy...@parallels.com> Acked-by: Joonsoo Kim <iamjoonsoo....@lge.com> Cc: Gioh Kim <gioh....@lge.com> Cc: Michal Nazarewicz <min...@mina86.com> Cc: Marek Szyprowski <m.szyprow...@samsung.com> Cc: Vlastimil Babka <vba...@suse.cz> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- mm/page_isolation.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -103,6 +103,7 @@ void unset_migratetype_isolate(struct pa if (!is_migrate_isolate_page(buddy)) { __isolate_free_page(page, order); + kernel_map_pages(page, (1 << order), 1); set_page_refcounted(page); isolated_page = page; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/