From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 5884C6B0023 for ; Thu, 5 May 2011 18:06:11 -0400 (EDT) Date: Thu, 5 May 2011 15:06:01 -0700 From: Andrew Morton Subject: Re: [PATCH 1/1] coredump: use task comm instead of (unknown) Message-Id: <20110505150601.a4457970.akpm@linux-foundation.org> In-Reply-To: <1304494354-21487-1-git-send-email-jslaby@suse.cz> References: <4DC0FFAB.1000805@gmail.com> <1304494354-21487-1-git-send-email-jslaby@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Jiri Slaby Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, jirislaby@gmail.com, Alan Cox , Al Viro , Andi Kleen , John Stultz On Wed, 4 May 2011 09:32:34 +0200 Jiri Slaby wrote: > If we don't know the file corresponding to the binary (i.e. exe_file > is unknown), use "task->comm (path unknown)" instead of simple > "(unknown)" as suggested by ak. > > The fallback is the same as %e except it will append "(path unknown)". > > Signed-off-by: Jiri Slaby > Cc: Alan Cox > Cc: Al Viro > Cc: Andi Kleen > --- > fs/exec.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/fs/exec.c b/fs/exec.c > index 5ee7562..0a4d281 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -1555,7 +1555,7 @@ static int cn_print_exe_file(struct core_name *cn) > > exe_file = get_mm_exe_file(current->mm); > if (!exe_file) > - return cn_printf(cn, "(unknown)"); > + return cn_printf(cn, "%s (path unknown)", current->comm); > > pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY); > if (!pathbuf) { Direct access to current->comm is racy since we added prctl(PR_SET_NAME). Hopefully John Stultz will soon be presenting us with a %p modifier for displaying task_struct.comm. But we should get this settled pretty promptly as this is a form of userspace-visible API. Use get_task_comm() for now. Also, there's nothing which prevents userspace from rewriting task->comm to something which contains slashes (this seems bad). If that is done, your patch will do Bad Things - it should be modified to use cn_print_exe_file()'s slash-overwriting codepath. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org