The patch titled Add VM_BUG_ON in case someone uses page_mapping on a slab page has been added to the -mm tree. Its filename is add-vm_bug_on-in-case-someone-uses-page_mapping-on-a-slab-page.patch *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: Add VM_BUG_ON in case someone uses page_mapping on a slab page From: Christoph Lameter <clameter@xxxxxxx> Detect slab objects being passed to the page oriented functions of the VM. It is not sufficient to simply return NULL because the functions calling page_mapping may depend on other items of the page_struct also to be setup properly. Moreover slab object may not be properly aligned. The page oriented functions of the VM expect to operate on page aligned, page sized objects. Operations on object straddling page boundaries may only affect the objects partially which may lead to surprising results. It is better to detect eventually remaining uses and eliminate them. Signed-off-by: Christoph Lameter <clameter@xxxxxxx> Acked-by: Hugh Dickins <hugh@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mm.h | 1 + 1 file changed, 1 insertion(+) diff -puN include/linux/mm.h~add-vm_bug_on-in-case-someone-uses-page_mapping-on-a-slab-page include/linux/mm.h --- a/include/linux/mm.h~add-vm_bug_on-in-case-someone-uses-page_mapping-on-a-slab-page +++ a/include/linux/mm.h @@ -629,6 +629,7 @@ static inline struct address_space *page { struct address_space *mapping = page->mapping; + VM_BUG_ON(PageSlab(page)); if (unlikely(PageSwapCache(page))) mapping = &swapper_space; else if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON)) _ Patches currently in -mm which might be from clameter@xxxxxxx are slub-fix-behavior-if-the-text-output-of-list_locations-overflows-page_size.patch sched-fix-next_interval-determination-in-idle_balance.patch slab-allocators-max_order-one-off-fix.patch git-ubi.patch pa-risc-use-page-allocator-instead-of-slab-allocator.patch quicklist-support-for-x86_64.patch change-zonelist-order-zonelist-order-selection-logic.patch change-zonelist-order-zonelist-order-selection-logic-add-check_highest_zone-to-build_zonelists_in_zone_order.patch change-zonelist-order-v6-zonelist-fix.patch change-zonelist-order-auto-configuration.patch change-zonelist-order-documentaion.patch make-proc-slabinfo-use-seq_list_xxx-helpers.patch make-proc-slabinfo-use-seq_list_xxx-helpers-fix.patch remove-the-deprecated-kmem_cache_t-typedef-from-slabh.patch slub-support-slub_debug-on-by-default.patch slub-support-slub_debug-on-by-default-tidy.patch numa-mempolicy-dynamic-interleave-map-for-system-init.patch numa-mempolicy-trivial-debug-fixes.patch add-__gfp_movable-for-callers-to-flag-allocations-from-high-memory-that-may-be-migrated.patch group-short-lived-and-reclaimable-kernel-allocations.patch fix-calculation-in-move_freepages_block-for-counting-pages.patch breakout-page_order-to-internalh-to-avoid-special-knowledge-of-the-buddy-allocator.patch do-not-depend-on-max_order-when-grouping-pages-by-mobility.patch print-out-statistics-in-relation-to-fragmentation-avoidance-to-proc-pagetypeinfo.patch have-kswapd-keep-a-minimum-order-free-other-than-order-0.patch have-kswapd-keep-a-minimum-order-free-other-than-order-0-fix.patch only-check-absolute-watermarks-for-alloc_high-and-alloc_harder-allocations.patch slub-mm-only-make-slub-the-default-slab-allocator.patch slub-exploit-page-mobility-to-increase-allocation-order.patch slub-reduce-antifrag-max-order.patch slub-reduce-antifrag-max-order-use-antifrag-constant-instead-of-hardcoding-page-order.patch slub-change-error-reporting-format-to-follow-lockdep-loosely.patch slub-change-error-reporting-format-to-follow-lockdep-loosely-fix.patch slub-remove-useless-export_symbol.patch slub-use-list_for_each_entry-for-loops-over-all-slabs.patch slub-slab-validation-move-tracking-information-alloc-outside-of.patch slub-ensure-that-the-object-per-slabs-stays-low-for-high-orders.patch slub-debug-fix-initial-object-debug-state-of-numa-bootstrap-objects.patch slab-allocators-consolidate-code-for-krealloc-in-mm-utilc.patch slab-allocators-consistent-zero_size_ptr-support-and-null-result-semantics.patch slab-allocators-support-__gfp_zero-in-all-allocators.patch slab-allocators-cleanup-zeroing-allocations.patch slab-allocators-replace-explicit-zeroing-with-__gfp_zero.patch slub-add-some-more-inlines-and-ifdef-config_slub_debug.patch slub-extract-dma_kmalloc_cache-from-get_cache.patch slub-do-proper-locking-during-dma-slab-creation.patch slub-faster-more-efficient-slab-determination-for-__kmalloc.patch slub-faster-more-efficient-slab-determination-for-__kmalloc-fix.patch add-vm_bug_on-in-case-someone-uses-page_mapping-on-a-slab-page.patch define-config_bounce-to-avoid-useless-inclusion-of-bounce-buffer.patch revoke-core-code.patch mm-implement-swap-prefetching.patch rename-gfp_high_movable-to-gfp_highuser_movable-prefetch.patch cpuset-zero-malloc-revert-the-old-cpuset-fix.patch containersv10-share-css_group-arrays-between-tasks-with-same-container-memberships-cpuset-zero-malloc-fix-for-new-containers.patch print-out-page_owner-statistics-in-relation-to-fragmentation-avoidance.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