From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933041AbaDBTFk (ORCPT ); Wed, 2 Apr 2014 15:05:40 -0400 Received: from mail.skyhub.de ([78.46.96.112]:41585 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932850AbaDBTFh (ORCPT ); Wed, 2 Apr 2014 15:05:37 -0400 Date: Wed, 2 Apr 2014 21:05:20 +0200 From: Borislav Petkov To: Andrew Morton Cc: Steven Rostedt , LKML , Linus Torvalds , Thomas Gleixner , "H. Peter Anvin" , Ingo Molnar , Mel Gorman , Kay Sievers Subject: Re: [RFC PATCH] cmdline: Hide "debug" from /proc/cmdline Message-ID: <20140402190520.GC21167@pd.tnic> References: <20140402144219.4cafbe37@gandalf.local.home> <20140402120440.1644d6a6486c554a33e584bc@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20140402120440.1644d6a6486c554a33e584bc@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 02, 2014 at 12:04:40PM -0700, Andrew Morton wrote: > On Wed, 2 Apr 2014 14:42:19 -0400 Steven Rostedt wrote: > > > It has come to our attention that a system running a specific user > > space init program will not boot if you add "debug" to the kernel > > command line. What happens is that the user space tool parses the > > kernel command line, and if it sees "debug" it will spit out so much > > information that the system fails to boot. This basically renders the > > "debug" option for the kernel useless. > > > > This bug has been reported to the developers of said tool > > here: > > > > https://bugs.freedesktop.org/show_bug.cgi?id=76935 > > > > The response is: > > > > "Generic terms are generic, not the first user owns them." > > > > That is, the "debug" statement on the *kernel* command line is not > > owned by the kernel just because it was the first user of it, and > > they refuse to fix their bug. > > > > Well, my response is, we OWN the kernel command line, and as such, we > > can keep the users from seeing stuff on it if we so choose. And with > > that, I propose this patch, which hides "debug" from /proc/cmdline, > > such that we don't have to worry about tools parsing for it and causing > > hardship for those trying to debug the kernel. > > > > I had to check the date on this but surprisingly, it's all post > April 1. > > --- a/fs/read_write.c~a > +++ a/fs/read_write.c > @@ -513,6 +513,8 @@ SYSCALL_DEFINE3(read, unsigned int, fd, > struct fd f = fdget_pos(fd); > ssize_t ret = -EBADF; > > + BUG_ON(!strcmp(current->comm, "systemd")); > + > if (f.file) { > loff_t pos = file_pos_read(f.file); > ret = vfs_read(f.file, buf, count, &pos); ACK! -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --