Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753162AbaKKLLh (ORCPT ); Tue, 11 Nov 2014 06:11:37 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:57874 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752993AbaKKLL2 (ORCPT ); Tue, 11 Nov 2014 06:11:28 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Wang Nan , Steven Rostedt , Andrew Morton , Linus Torvalds , Luis Henriques Subject: [PATCH 3.16.y-ckt 151/170] cgroup/kmemleak: add kmemleak_free() for cgroup deallocations. Date: Tue, 11 Nov 2014 11:08:30 +0000 Message-Id: <1415704129-12709-152-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1415704129-12709-1-git-send-email-luis.henriques@canonical.com> References: <1415704129-12709-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Wang Nan 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: Luis Henriques --- mm/page_cgroup.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c index 3708264d2833..5331c2bd85a2 100644 --- a/mm/page_cgroup.c +++ b/mm/page_cgroup.c @@ -171,6 +171,7 @@ static void free_page_cgroup(void *addr) sizeof(struct page_cgroup) * PAGES_PER_SECTION; BUG_ON(PageReserved(page)); + kmemleak_free(addr); free_pages_exact(addr, table_size); } } -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/