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Subject[PATCH v2 2/4] mm: clean up validate_slab()
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The function doesn't need to return any value, and the check can be
done in one pass.

There is a behavior change: before the patch, we stop at the first
invalid free object; after the patch, we stop at the first invalid
object, free or in use. This shouldn't matter because the original
behavior isn't intended anyway.

Signed-off-by: Yu Zhao <yuzhao@google.com>
---
mm/slub.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 62053ceb4464..7b7e1ee264ef 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4386,31 +4386,26 @@ static int count_total(struct page *page)
#endif

#ifdef CONFIG_SLUB_DEBUG
-static int validate_slab(struct kmem_cache *s, struct page *page,
+static void validate_slab(struct kmem_cache *s, struct page *page,
unsigned long *map)
{
void *p;
void *addr = page_address(page);

- if (!check_slab(s, page) ||
- !on_freelist(s, page, NULL))
- return 0;
+ if (!check_slab(s, page) || !on_freelist(s, page, NULL))
+ return;

/* Now we know that a valid freelist exists */
bitmap_zero(map, page->objects);

get_map(s, page, map);
for_each_object(p, s, addr, page->objects) {
- if (test_bit(slab_index(p, s, addr), map))
- if (!check_object(s, page, p, SLUB_RED_INACTIVE))
- return 0;
- }
+ u8 val = test_bit(slab_index(p, s, addr), map) ?
+ SLUB_RED_INACTIVE : SLUB_RED_ACTIVE;

- for_each_object(p, s, addr, page->objects)
- if (!test_bit(slab_index(p, s, addr), map))
- if (!check_object(s, page, p, SLUB_RED_ACTIVE))
- return 0;
- return 1;
+ if (!check_object(s, page, p, val))
+ break;
+ }
}

static void validate_slab_slab(struct kmem_cache *s, struct page *page,
--
2.23.0.162.g0b9fbb3734-goog
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