The patch titled
Subject: mm, mempool: poison elements backed by page allocator
has been added to the -mm tree. Its filename is
mm-mempool-poison-elements-backed-by-page-allocator.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-mempool-poison-elements-backed-by-page-allocator.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-mempool-poison-elements-backed-by-page-allocator.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: David Rientjes <rientjes@xxxxxxxxxx>
Subject: mm, mempool: poison elements backed by page allocator
Elements backed by the slab allocator are poisoned when added to a
mempool's reserved pool.
It is also possible to poison elements backed by the page allocator
because the mempool layer knows the allocation order.
This patch extends mempool element poisoning to include memory backed by
the page allocator.
This is only effective for configs with CONFIG_DEBUG_SLAB or
CONFIG_SLUB_DEBUG_ON.
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Dave Kleikamp <shaggy@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
Cc: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mempool.c | 74 ++++++++++++++++++++++++++++++++-----------------
1 file changed, 49 insertions(+), 25 deletions(-)
diff -puN mm/mempool.c~mm-mempool-poison-elements-backed-by-page-allocator mm/mempool.c
--- a/mm/mempool.c~mm-mempool-poison-elements-backed-by-page-allocator
+++ a/mm/mempool.c
@@ -6,6 +6,7 @@
* extreme VM load.
*
* started by Ingo Molnar, Copyright (C) 2001
+ * debugging by David Rientjes, Copyright (C) 2015
*/
#include <linux/mm.h>
@@ -35,41 +36,64 @@ static void poison_error(mempool_t *pool
dump_stack();
}
-static void check_slab_element(mempool_t *pool, void *element)
+static void __check_element(mempool_t *pool, void *element, size_t size)
{
- if (pool->free == mempool_free_slab || pool->free == mempool_kfree) {
- size_t size = ksize(element);
- u8 *obj = element;
- size_t i;
-
- for (i = 0; i < size; i++) {
- u8 exp = (i < size - 1) ? POISON_FREE : POISON_END;
-
- if (obj[i] != exp) {
- poison_error(pool, element, size, i);
- return;
- }
+ u8 *obj = element;
+ size_t i;
+
+ for (i = 0; i < size; i++) {
+ u8 exp = (i < size - 1) ? POISON_FREE : POISON_END;
+
+ if (obj[i] != exp) {
+ poison_error(pool, element, size, i);
+ return;
}
- memset(obj, POISON_INUSE, size);
}
+ memset(obj, POISON_INUSE, size);
}
-static void poison_slab_element(mempool_t *pool, void *element)
+static void check_element(mempool_t *pool, void *element)
{
- if (pool->alloc == mempool_alloc_slab ||
- pool->alloc == mempool_kmalloc) {
- size_t size = ksize(element);
- u8 *obj = element;
+ /* Mempools backed by slab allocator */
+ if (pool->free == mempool_free_slab || pool->free == mempool_kfree)
+ __check_element(pool, element, ksize(element));
+
+ /* Mempools backed by page allocator */
+ if (pool->free == mempool_free_pages) {
+ int order = (int)(long)pool->pool_data;
+ void *addr = page_address(element);
+
+ __check_element(pool, addr, 1UL << (PAGE_SHIFT + order));
+ }
+}
+
+static void __poison_element(void *element, size_t size)
+{
+ u8 *obj = element;
+
+ memset(obj, POISON_FREE, size - 1);
+ obj[size - 1] = POISON_END;
+}
+
+static void poison_element(mempool_t *pool, void *element)
+{
+ /* Mempools backed by slab allocator */
+ if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)
+ __poison_element(element, ksize(element));
+
+ /* Mempools backed by page allocator */
+ if (pool->alloc == mempool_alloc_pages) {
+ int order = (int)(long)pool->pool_data;
+ void *addr = page_address(element);
- memset(obj, POISON_FREE, size - 1);
- obj[size - 1] = POISON_END;
+ __poison_element(addr, 1UL << (PAGE_SHIFT + order));
}
}
#else /* CONFIG_DEBUG_SLAB || CONFIG_SLUB_DEBUG_ON */
-static inline void check_slab_element(mempool_t *pool, void *element)
+static inline void check_element(mempool_t *pool, void *element)
{
}
-static inline void poison_slab_element(mempool_t *pool, void *element)
+static inline void poison_element(mempool_t *pool, void *element)
{
}
#endif /* CONFIG_DEBUG_SLAB || CONFIG_SLUB_DEBUG_ON */
@@ -77,7 +101,7 @@ static inline void poison_slab_element(m
static void add_element(mempool_t *pool, void *element)
{
BUG_ON(pool->curr_nr >= pool->min_nr);
- poison_slab_element(pool, element);
+ poison_element(pool, element);
pool->elements[pool->curr_nr++] = element;
}
@@ -86,7 +110,7 @@ static void *remove_element(mempool_t *p
void *element = pool->elements[--pool->curr_nr];
BUG_ON(pool->curr_nr < 0);
- check_slab_element(pool, element);
+ check_element(pool, element);
return element;
}
_
Patches currently in -mm which might be from rientjes@xxxxxxxxxx are
mm-fix-anon_vma-degree-underflow-in-anon_vma-endless-growing-prevention.patch
mm-fix-anon_vma-degree-underflow-in-anon_vma-endless-growing-prevention-v2.patch
mm-pagewalk-prevent-positive-return-value-of-walk_page_test-from-being-passed-to-callers.patch
mm-memory-hotplog-postpone-the-reset-of-obsolete-pgdat.patch
mm-slub-fix-lockups-on-preempt-smp-kernels.patch
cxgb4-drop-__gfp_nofail-allocation.patch
sh-dwarf-destroy-mempools-on-cleanup.patch
sh-dwarf-use-mempool_create_slab_pool.patch
jbd2-revert-must-not-fail-allocation-loops-back-to-gfp_nofail.patch
mm-slub-parse-slub_debug-o-option-in-switch-statement.patch
mm-slab-correct-config-option-in-comment.patch
mm-rename-foll_mlock-to-foll_populate.patch
mm-rename-__mlock_vma_pages_range-to-populate_vma_page_range.patch
mm-move-gup-posix-mlock-error-conversion-out-of-__mm_populate.patch
mm-move-mm_populate-related-code-to-mm-gupc.patch
mm-hotplug-fix-concurrent-memory-hot-add-deadlock.patch
mm-cma-change-fallback-behaviour-for-cma-freepage.patch
mm-page_alloc-factor-out-fallback-freepage-checking.patch
mm-compaction-enhance-compaction-finish-condition.patch
mm-compaction-enhance-compaction-finish-condition-fix.patch
mm-incorporate-zero-pages-into-transparent-huge-pages.patch
mm-incorporate-zero-pages-into-transparent-huge-pages-fix.patch
mm-completely-remove-dumping-per-cpu-lists-from-show_mem.patch
mm-mempolicy-migrate_to_node-should-only-migrate-to-node.patch
mm-remove-gfp_thisnode.patch
mm-thp-really-limit-transparent-hugepage-allocation-to-local-node.patch
kernel-cpuset-remove-exception-for-__gfp_thisnode.patch
mm-clarify-__gfp_nofail-deprecation-status.patch
mm-clarify-__gfp_nofail-deprecation-status-checkpatch-fixes.patch
sparc-clarify-__gfp_nofail-allocation.patch
mm-mempool-do-not-allow-atomic-resizing.patch
mm-mempool-do-not-allow-atomic-resizing-checkpatch-fixes.patch
mm-hugetlb-abort-__get_user_pages-if-current-has-been-oom-killed.patch
mm-refactor-zone_movable_is_highmem.patch
mm-memory-failurec-define-page-types-for-action_result-in-one-place.patch
mm-memory-failurec-define-page-types-for-action_result-in-one-place-fix-2.patch
page-flags-define-behavior-slb-related-flags-on-compound-pages.patch
allow-compaction-of-unevictable-pages.patch
mm-compaction-reset-compaction-scanner-positions.patch
hugetlbfs-add-minimum-size-tracking-fields-to-subpool-structure.patch
hugetlbfs-add-minimum-size-accounting-to-subpools.patch
hugetlbfs-accept-subpool-min_size-mount-option-and-setup-accordingly.patch
hugetlbfs-document-min_size-mount-option-and-cleanup.patch
mm-vmalloc-fix-possible-exhaustion-of-vmalloc-space-caused-by-vm_map_ram-allocator.patch
mm-vmalloc-occupy-newly-allocated-vmap-block-just-after-allocation.patch
mm-vmalloc-get-rid-of-dirty-bitmap-inside-vmap_block-structure.patch
mremap-should-return-enomem-when-__vm_enough_memory-fail.patch
clean-up-goto-just-return-err_ptr.patch
fs-jfs-remove-slab-object-constructor.patch
mm-mempool-disallow-mempools-based-on-slab-caches-with-constructors.patch
mm-mempool-poison-elements-backed-by-slab-allocator.patch
mm-mempool-poison-elements-backed-by-page-allocator.patch
hung_task-change-hung_taskc-to-use-for_each_process_thread.patch
mm-utilc-add-kstrimdup.patch
linux-next.patch
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