Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933168AbaDBUFP (ORCPT ); Wed, 2 Apr 2014 16:05:15 -0400 Received: from mail-vc0-f171.google.com ([209.85.220.171]:39505 "EHLO mail-vc0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932324AbaDBUFN (ORCPT ); Wed, 2 Apr 2014 16:05:13 -0400 MIME-Version: 1.0 In-Reply-To: References: <20140402144219.4cafbe37@gandalf.local.home> <20140402120440.1644d6a6486c554a33e584bc@linux-foundation.org> Date: Wed, 2 Apr 2014 22:05:12 +0200 Message-ID: Subject: Re: [RFC PATCH] cmdline: Hide "debug" from /proc/cmdline From: Richard Weinberger To: Thomas Gleixner Cc: Andrew Morton , Steven Rostedt , LKML , Linus Torvalds , "H. Peter Anvin" , Borislav Petkov , Ingo Molnar , Mel Gorman , Kay Sievers Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 2, 2014 at 9:50 PM, Thomas Gleixner wrote: > On Wed, 2 Apr 2014, 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")); > > Can we make that strncmp(current->comm, "systemd", 7) please? So we > catch the systemd-xxx stuff as well! > > Otherwise Acked-by-me > > tglx > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ While we are here, can we please also talk about the !cgroup situation? https://bugs.freedesktop.org/show_bug.cgi?id=74589 A segfaulting systemd on CONFIG_CGROUPS=n is no fun. -- Thanks, //richard -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/