From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752719Ab3FZQ7O (ORCPT ); Wed, 26 Jun 2013 12:59:14 -0400 Received: from eddie.linux-mips.org ([78.24.191.182]:54046 "EHLO cvs.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752322Ab3FZQ7M (ORCPT ); Wed, 26 Jun 2013 12:59:12 -0400 Date: Wed, 26 Jun 2013 18:59:00 +0200 From: Ralf Baechle To: Oleg Nesterov Cc: James Hogan , Andrew Morton , David Daney , David Daney , LKML , Al Viro , Kees Cook , David Daney , "Paul E. McKenney" , David Howells , Dave Jones , linux-mips@linux-mips.org, stable@vger.kernel.org Subject: Re: [PATCH v3] kernel/signal.c: fix BUG_ON with SIG128 (MIPS) Message-ID: <20130626165900.GF7171@linux-mips.org> References: <1371821962-9151-1-git-send-email-james.hogan@imgtec.com> <51C47864.9030200@gmail.com> <20130621202244.GA16610@redhat.com> <51C4BB86.1020004@caviumnetworks.com> <20130622190940.GA14150@redhat.com> <51C80CF0.4070608@imgtec.com> <20130625144015.1e4e70a0ac888f4ccf5c6a8f@linux-foundation.org> <51CACB80.5020706@imgtec.com> <20130626161452.GA2888@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130626161452.GA2888@redhat.com> 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, Jun 26, 2013 at 06:14:52PM +0200, Oleg Nesterov wrote: > Or simply remove the BUG_ON(), this can equally confuse wait(status). > 128 & 0x7f == 0. > > Still I think it would be better to change _NSIG on mips. If it was that easy. That's going to outright break binary compatibility, see kernel/signal.c: SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset, sigset_t __user *, oset, size_t, sigsetsize) { sigset_t old_set, new_set; int error; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(sigset_t)) return -EINVAL; There are several more more syscalls performing tests like the above. So at least the kernel sigset_t will have to remain constant, maybe something like below, totally untested patch which I'm sure is going to open a few 20 foot containers full of worms such as NSIG being defined by glibc to 128 and fixing the kernel won't magically change installed libc headers or binaries incorporating NSIG. Ralf arch/mips/include/uapi/asm/signal.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/mips/include/uapi/asm/signal.h b/arch/mips/include/uapi/asm/signal.h index addb9f5..8bba323 100644 --- a/arch/mips/include/uapi/asm/signal.h +++ b/arch/mips/include/uapi/asm/signal.h @@ -11,12 +11,13 @@ #include -#define _NSIG 128 +#define _NSIG 64 #define _NSIG_BPW (sizeof(unsigned long) * 8) #define _NSIG_WORDS (_NSIG / _NSIG_BPW) typedef struct { unsigned long sig[_NSIG_WORDS]; + unsigned long __fill[_NSIG_WORDS]; } sigset_t; typedef unsigned long old_sigset_t; /* at least 32 bits */