From patchwork Fri Jun 24 04:23:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Lutomirski X-Patchwork-Id: 9196541 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A9EE06075F for ; Fri, 24 Jun 2016 04:24:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9F01128482 for ; Fri, 24 Jun 2016 04:24:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 939CD28488; Fri, 24 Jun 2016 04:24:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id BBA9B28482 for ; Fri, 24 Jun 2016 04:24:23 +0000 (UTC) Received: (qmail 9610 invoked by uid 550); 24 Jun 2016 04:23:42 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: kernel-hardening@lists.openwall.com Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 9424 invoked from network); 24 Jun 2016 04:23:40 -0000 From: Andy Lutomirski To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, Borislav Petkov , Nadav Amit , Kees Cook , Brian Gerst , "kernel-hardening@lists.openwall.com" , Linus Torvalds , Josh Poimboeuf , Jann Horn , Heiko Carstens , Andy Lutomirski , Vladimir Davydov , Johannes Weiner , Michal Hocko , linux-mm@kvack.org Date: Thu, 23 Jun 2016 21:23:02 -0700 Message-Id: X-Mailer: git-send-email 2.5.5 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP Subject: [kernel-hardening] [PATCH v4 07/16] mm: Fix memcg stack accounting for sub-page stacks X-Virus-Scanned: ClamAV using ClamSMTP We should account for stacks regardless of stack size, and we need to account in sub-page units if THREAD_SIZE < PAGE_SIZE. Change the units to kilobytes and Move it into account_kernel_stack(). Fixes: 12580e4b54ba8 ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat") Cc: Vladimir Davydov Cc: Johannes Weiner Cc: Michal Hocko Cc: linux-mm@kvack.org Reviewed-by: Vladimir Davydov Acked-by: Michal Hocko Signed-off-by: Andy Lutomirski Reviewed-by: Josh Poimboeuf --- include/linux/memcontrol.h | 2 +- kernel/fork.c | 15 ++++++--------- mm/memcontrol.c | 2 +- 3 files changed, 8 insertions(+), 11 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index a805474df4ab..3b653b86bb8f 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -52,7 +52,7 @@ enum mem_cgroup_stat_index { MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ MEM_CGROUP_STAT_NSTATS, /* default hierarchy stats */ - MEMCG_KERNEL_STACK = MEM_CGROUP_STAT_NSTATS, + MEMCG_KERNEL_STACK_KB = MEM_CGROUP_STAT_NSTATS, MEMCG_SLAB_RECLAIMABLE, MEMCG_SLAB_UNRECLAIMABLE, MEMCG_SOCK, diff --git a/kernel/fork.c b/kernel/fork.c index be7f006af727..ff3c41c2ba96 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -165,20 +165,12 @@ static struct thread_info *alloc_thread_info_node(struct task_struct *tsk, struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP, THREAD_SIZE_ORDER); - if (page) - memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK, - 1 << THREAD_SIZE_ORDER); - return page ? page_address(page) : NULL; } static inline void free_thread_info(struct thread_info *ti) { - struct page *page = virt_to_page(ti); - - memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK, - -(1 << THREAD_SIZE_ORDER)); - __free_kmem_pages(page, THREAD_SIZE_ORDER); + free_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER); } # else static struct kmem_cache *thread_info_cache; @@ -227,6 +219,11 @@ static void account_kernel_stack(struct thread_info *ti, int account) mod_zone_page_state(zone, NR_KERNEL_STACK_KB, THREAD_SIZE / 1024 * account); + + /* All stack pages belong to the same memcg. */ + memcg_kmem_update_page_stat( + virt_to_page(ti), MEMCG_KERNEL_STACK_KB, + account * (THREAD_SIZE / 1024)); } void free_task(struct task_struct *tsk) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 75e74408cc8f..8e13a2419dad 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5133,7 +5133,7 @@ static int memory_stat_show(struct seq_file *m, void *v) seq_printf(m, "file %llu\n", (u64)stat[MEM_CGROUP_STAT_CACHE] * PAGE_SIZE); seq_printf(m, "kernel_stack %llu\n", - (u64)stat[MEMCG_KERNEL_STACK] * PAGE_SIZE); + (u64)stat[MEMCG_KERNEL_STACK_KB] * 1024); seq_printf(m, "slab %llu\n", (u64)(stat[MEMCG_SLAB_RECLAIMABLE] + stat[MEMCG_SLAB_UNRECLAIMABLE]) * PAGE_SIZE);