From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757600AbZKROwI (ORCPT ); Wed, 18 Nov 2009 09:52:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755314AbZKROwG (ORCPT ); Wed, 18 Nov 2009 09:52:06 -0500 Received: from server1.wserver.cz ([82.113.45.157]:51260 "EHLO server1.wserver.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753032AbZKROv7 (ORCPT ); Wed, 18 Nov 2009 09:51:59 -0500 From: Jiri Slaby To: jirislaby@gmail.com Cc: mingo@elte.hu, nhorman@tuxdriver.com, sfr@canb.auug.org.au, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, marcin.slusarz@gmail.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, torvalds@linux-foundation.org, Jiri Slaby , James Morris , Heiko Carstens , x86@kernel.org Subject: [PATCH 07/16] X86: use ACCESS_ONCE for rlimits Date: Wed, 18 Nov 2009 15:51:53 +0100 Message-Id: <1258555922-2064-7-git-send-email-jslaby@novell.com> X-Mailer: git-send-email 1.6.4.2 In-Reply-To: <4B040A03.2020508@gmail.com> References: <4B040A03.2020508@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make sure compiler won't do weird things with limits. E.g. fetching them twice may return 2 different values after writable limits are implemented. Signed-off-by: Jiri Slaby Cc: James Morris Cc: Heiko Carstens Cc: Andrew Morton Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: x86@kernel.org --- arch/x86/ia32/ia32_aout.c | 2 +- arch/x86/mm/mmap.c | 6 ++++-- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c index 2a4d073..239071b 100644 --- a/arch/x86/ia32/ia32_aout.c +++ b/arch/x86/ia32/ia32_aout.c @@ -297,7 +297,7 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs) * size limits imposed on them by creating programs with large * arrays in the data or bss. */ - rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; + rlim = ACCESS_ONCE(current->signal->rlim[RLIMIT_DATA].rlim_cur); if (rlim >= RLIM_INFINITY) rlim = ~0; if (ex.a_data + ex.a_bss > rlim) diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index c8191de..5578c84 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -71,7 +71,8 @@ static int mmap_is_legacy(void) if (current->personality & ADDR_COMPAT_LAYOUT) return 1; - if (current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY) + if (ACCESS_ONCE(current->signal->rlim[RLIMIT_STACK].rlim_cur) + == RLIM_INFINITY) return 1; return sysctl_legacy_va_layout; @@ -96,7 +97,8 @@ static unsigned long mmap_rnd(void) static unsigned long mmap_base(void) { - unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur; + unsigned long gap = + ACCESS_ONCE(current->signal->rlim[RLIMIT_STACK].rlim_cur); if (gap < MIN_GAP) gap = MIN_GAP; -- 1.6.4.2