From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zps36.corp.google.com (zps36.corp.google.com [172.25.146.36]) by smtp-out.google.com with ESMTP id l56Ixs4p022002 for ; Wed, 6 Jun 2007 11:59:55 -0700 Message-ID: <46670411.1060901@google.com> Date: Wed, 06 Jun 2007 11:59:29 -0700 From: Ethan Solomita MIME-Version: 1.0 Subject: [PATCH 1/1] oom: stop allocating user memory if TIF_MEMDIE is set Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton , linux-mm@kvack.org List-ID: get_user_pages() can try to allocate a nearly unlimited amount of memory on behalf of a user process, even if that process has been OOM killed. The OOM kill occurs upon return to user space via a SIGKILL, but get_user_pages() will try allocate all its memory before returning. Change get_user_pages() to check for TIF_MEMDIE, and if set then return immediately. Signed-off-by: Ethan Solomita --- diff -uprN -X orig/Documentation/dontdiff orig/mm/memory.c new/mm/memory.c --- orig/mm/memory.c 2007-06-05 19:01:46.000000000 -0700 +++ new/mm/memory.c 2007-06-05 19:07:15.000000000 -0700 @@ -1084,6 +1084,15 @@ int get_user_pages(struct task_struct *t do { struct page *page; + /* + * If tsk is ooming, cut off its access to large memory + * allocations. It has a pending SIGKILL, but it can't + * be processed until returning to user space. + */ + + if (unlikely(test_tsk_thread_flag(tsk, TIF_MEMDIE))) + return -ENOMEM; + if (write) foll_flags |= FOLL_WRITE; -- 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