path: root/mm
diff options
authorWang Nan <>2014-10-29 21:50:18 (GMT)
committerGreg Kroah-Hartman <>2014-11-14 16:47:59 (GMT)
commit6c8ad60fef55353a5add4d9e5aabecc1d01968c3 (patch)
tree953475039ea4649eac3704a1eec5c4739dbbec44 /mm
parente0daafbbf3cb9ea341f72e5e26f1a8fcea977c0e (diff)
cgroup/kmemleak: add kmemleak_free() for cgroup deallocations.
commit 401507d67d5c2854f5a88b3f93f64fc6f267bca5 upstream. Commit ff7ee93f4715 ("cgroup/kmemleak: Annotate alloc_page() for cgroup allocations") introduces kmemleak_alloc() for alloc_page_cgroup(), but corresponding kmemleak_free() is missing, which makes kmemleak be wrongly disabled after memory offlining. Log is pasted at the end of this commit message. This patch add kmemleak_free() into free_page_cgroup(). During page offlining, this patch removes corresponding entries in kmemleak rbtree. After that, the freed memory can be allocated again by other subsystems without killing kmemleak. bash # for x in 1 2 3 4; do echo offline > /sys/devices/system/memory/memory$x/state ; sleep 1; done ; dmesg | grep leak Offlined Pages 32768 kmemleak: Cannot insert 0xffff880016969000 into the object search tree (overlaps existing) CPU: 0 PID: 412 Comm: sleep Not tainted 3.17.0-rc5+ #86 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x46/0x58 create_object+0x266/0x2c0 kmemleak_alloc+0x26/0x50 kmem_cache_alloc+0xd3/0x160 __sigqueue_alloc+0x49/0xd0 __send_signal+0xcb/0x410 send_signal+0x45/0x90 __group_send_sig_info+0x13/0x20 do_notify_parent+0x1bb/0x260 do_exit+0x767/0xa40 do_group_exit+0x44/0xa0 SyS_exit_group+0x17/0x20 system_call_fastpath+0x16/0x1b kmemleak: Kernel memory leak detector disabled kmemleak: Object 0xffff880016900000 (size 524288): kmemleak: comm "swapper/0", pid 0, jiffies 4294667296 kmemleak: min_count = 0 kmemleak: count = 0 kmemleak: flags = 0x1 kmemleak: checksum = 0 kmemleak: backtrace: log_early+0x63/0x77 kmemleak_alloc+0x4b/0x50 init_section_page_cgroup+0x7f/0xf5 page_cgroup_init+0xc5/0xd0 start_kernel+0x333/0x408 x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0xf5/0xfc Fixes: ff7ee93f4715 (cgroup/kmemleak: Annotate alloc_page() for cgroup allocations) Signed-off-by: Wang Nan <> Acked-by: Johannes Weiner <> Acked-by: Michal Hocko <> Cc: Steven Rostedt <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <> Signed-off-by: Greg Kroah-Hartman <>
Diffstat (limited to 'mm')
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 6d757e3..e007236 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -170,6 +170,7 @@ static void free_page_cgroup(void *addr)
sizeof(struct page_cgroup) * PAGES_PER_SECTION;
+ kmemleak_free(addr);
free_pages_exact(addr, table_size);