From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f52.google.com (mail-pa0-f52.google.com [209.85.220.52]) by kanga.kvack.org (Postfix) with ESMTP id 40F016B0253 for ; Wed, 26 Aug 2015 08:18:31 -0400 (EDT) Received: by pacti10 with SMTP id ti10so86836451pac.0 for ; Wed, 26 Aug 2015 05:18:31 -0700 (PDT) Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [2001:e42:101:1:202:181:97:72]) by mx.google.com with ESMTPS id ad8si38345597pad.109.2015.08.26.05.18.29 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 26 Aug 2015 05:18:30 -0700 (PDT) Subject: [PATCH 1/2] android, lmk: Protect task->comm with task_lock. From: Tetsuo Handa Message-Id: <201508262117.FAH43726.tOFMVJSLQOFHFO@I-love.SAKURA.ne.jp> Date: Wed, 26 Aug 2015 21:17:54 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: gregkh@linuxfoundation.org, arve@android.com, riandrews@android.com Cc: devel@driverdev.osuosl.org, linux-mm@kvack.org, mhocko@kernel.org, rientjes@google.com, hannes@cmpxchg.org Hello. Next patch is mm-related but this patch is not. Via which tree should these patches go? ---------------------------------------- >>From 48c1b457eb32d7a029e9a078ee0a67974ada9261 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Wed, 26 Aug 2015 20:49:17 +0900 Subject: [PATCH 1/2] android, lmk: Protect task->comm with task_lock. Passing task->comm to printk() wants task_lock() protection in order to avoid potentially emitting garbage bytes. Signed-off-by: Tetsuo Handa --- drivers/staging/android/lowmemorykiller.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c index 872bd60..d5d25e4 100644 --- a/drivers/staging/android/lowmemorykiller.c +++ b/drivers/staging/android/lowmemorykiller.c @@ -134,26 +134,25 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc) return 0; } oom_score_adj = p->signal->oom_score_adj; - if (oom_score_adj < min_score_adj) { - task_unlock(p); - continue; - } + if (oom_score_adj < min_score_adj) + goto next; tasksize = get_mm_rss(p->mm); - task_unlock(p); if (tasksize <= 0) - continue; + goto next; if (selected) { if (oom_score_adj < selected_oom_score_adj) - continue; + goto next; if (oom_score_adj == selected_oom_score_adj && tasksize <= selected_tasksize) - continue; + goto next; } selected = p; selected_tasksize = tasksize; selected_oom_score_adj = oom_score_adj; lowmem_print(2, "select %d (%s), adj %hd, size %d, to kill\n", p->pid, p->comm, oom_score_adj, tasksize); +next: + task_unlock(p); } if (selected) { task_lock(selected); @@ -168,10 +167,10 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc) * task should have access to the memory reserves. */ mark_oom_victim(selected); - task_unlock(selected); lowmem_print(1, "send sigkill to %d (%s), adj %hd, size %d\n", selected->pid, selected->comm, selected_oom_score_adj, selected_tasksize); + task_unlock(selected); lowmem_deathpending_timeout = jiffies + HZ; send_sig(SIGKILL, selected, 0); rem += selected_tasksize; -- 1.8.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org