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| author | Qian Cai <cai@lca.pw> | 2020-05-27 22:20:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-05-28 11:35:40 -0700 |
| commit | af4798a5bba60af881626780cbc6457cb162bfd1 (patch) | |
| tree | 058e5a720d0ad94920f9281bd26b88a207526f70 | |
| parent | 444fc5cde64330661bf59944c43844e7d4c2ccd8 (diff) | |
| download | linux-stable-af4798a5bba60af881626780cbc6457cb162bfd1.tar.gz linux-stable-af4798a5bba60af881626780cbc6457cb162bfd1.tar.bz2 linux-stable-af4798a5bba60af881626780cbc6457cb162bfd1.zip | |
mm/z3fold: silence kmemleak false positives of slots
Kmemleak reported many leaks while under memory pressue in,
slots = alloc_slots(pool, gfp);
which is referenced by "zhdr" in init_z3fold_page(),
zhdr->slots = slots;
However, "zhdr" could be gone without freeing slots as the later will be
freed separately when the last "handle" off of "handles" array is freed.
It will be within "slots" which is always aligned.
unreferenced object 0xc000000fdadc1040 (size 104):
comm "oom04", pid 140476, jiffies 4295359280 (age 3454.970s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
z3fold_zpool_malloc+0x7b0/0xe10
alloc_slots at mm/z3fold.c:214
(inlined by) init_z3fold_page at mm/z3fold.c:412
(inlined by) z3fold_alloc at mm/z3fold.c:1161
(inlined by) z3fold_zpool_malloc at mm/z3fold.c:1735
zpool_malloc+0x34/0x50
zswap_frontswap_store+0x60c/0xda0
zswap_frontswap_store at mm/zswap.c:1093
__frontswap_store+0x128/0x330
swap_writepage+0x58/0x110
pageout+0x16c/0xa40
shrink_page_list+0x1ac8/0x25c0
shrink_inactive_list+0x270/0x730
shrink_lruvec+0x444/0xf30
shrink_node+0x2a4/0x9c0
do_try_to_free_pages+0x158/0x640
try_to_free_pages+0x1bc/0x5f0
__alloc_pages_slowpath.constprop.60+0x4dc/0x15a0
__alloc_pages_nodemask+0x520/0x650
alloc_pages_vma+0xc0/0x420
handle_mm_fault+0x1174/0x1bf0
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vitaly Wool <vitaly.wool@konsulko.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: http://lkml.kernel.org/r/20200522220052.2225-1-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/z3fold.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/z3fold.c b/mm/z3fold.c index 8c3bb5e508b8..460b0feced26 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -43,6 +43,7 @@ #include <linux/spinlock.h> #include <linux/zpool.h> #include <linux/magic.h> +#include <linux/kmemleak.h> /* * NCHUNKS_ORDER determines the internal allocation granularity, effectively @@ -215,6 +216,8 @@ static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool, (gfp & ~(__GFP_HIGHMEM | __GFP_MOVABLE))); if (slots) { + /* It will be freed separately in free_handle(). */ + kmemleak_not_leak(slots); memset(slots->slot, 0, sizeof(slots->slot)); slots->pool = (unsigned long)pool; rwlock_init(&slots->lock); |