From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754106AbaKCUtR (ORCPT ); Mon, 3 Nov 2014 15:49:17 -0500 Received: from terminus.zytor.com ([198.137.202.10]:51889 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754076AbaKCUtJ (ORCPT ); Mon, 3 Nov 2014 15:49:09 -0500 Date: Mon, 3 Nov 2014 12:48:33 -0800 From: tip-bot for Andy Lutomirski Message-ID: Cc: konrad.wilk@oracle.com, hpa@zytor.com, luto@amacapital.net, mingo@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, josh@joshtriplett.org Reply-To: linux-kernel@vger.kernel.org, josh@joshtriplett.org, mingo@kernel.org, konrad.wilk@oracle.com, luto@amacapital.net, hpa@zytor.com, tglx@linutronix.de In-Reply-To: <0dddbadc1d4e3bfbaf887938ff42afc97a7cc1f2.1414618407.git.luto@amacapital.net> References: <0dddbadc1d4e3bfbaf887938ff42afc97a7cc1f2.1414618407.git.luto@amacapital.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/vdso] x86_64, vsyscall: Turn vsyscalls all the way off when vsyscall==none Git-Commit-ID: 87983c66bc02c9cd8e4a42e7924435145d52bb13 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 87983c66bc02c9cd8e4a42e7924435145d52bb13 Gitweb: http://git.kernel.org/tip/87983c66bc02c9cd8e4a42e7924435145d52bb13 Author: Andy Lutomirski AuthorDate: Wed, 29 Oct 2014 14:33:45 -0700 Committer: Thomas Gleixner CommitDate: Mon, 3 Nov 2014 21:44:57 +0100 x86_64, vsyscall: Turn vsyscalls all the way off when vsyscall==none I see no point in having an unusable read-only page sitting at 0xffffffffff600000 when vsyscall=none. Instead, skip mapping it and remove it from /proc/PID/maps. I kept the ratelimited warning when programs try to use a vsyscall in this mode, since it may help admins avoid confusion. Signed-off-by: Andy Lutomirski Reviewed-by: Josh Triplett Cc: Konrad Rzeszutek Wilk Link: http://lkml.kernel.org/r/0dddbadc1d4e3bfbaf887938ff42afc97a7cc1f2.1414618407.git.luto@amacapital.net Signed-off-by: Thomas Gleixner --- arch/x86/kernel/vsyscall_64.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 419e83b..2d91262 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -307,6 +307,8 @@ struct vm_area_struct *get_gate_vma(struct mm_struct *mm) if (!mm || mm->context.ia32_compat) return NULL; #endif + if (vsyscall_mode == NONE) + return NULL; return &gate_vma; } @@ -327,7 +329,7 @@ int in_gate_area(struct mm_struct *mm, unsigned long addr) */ int in_gate_area_no_mm(unsigned long addr) { - return (addr & PAGE_MASK) == VSYSCALL_ADDR; + return vsyscall_mode != NONE && (addr & PAGE_MASK) == VSYSCALL_ADDR; } void __init map_vsyscall(void) @@ -335,10 +337,12 @@ void __init map_vsyscall(void) extern char __vsyscall_page; unsigned long physaddr_vsyscall = __pa_symbol(&__vsyscall_page); - __set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall, - vsyscall_mode == NATIVE - ? PAGE_KERNEL_VSYSCALL - : PAGE_KERNEL_VVAR); + if (vsyscall_mode != NONE) + __set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall, + vsyscall_mode == NATIVE + ? PAGE_KERNEL_VSYSCALL + : PAGE_KERNEL_VVAR); + BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) != (unsigned long)VSYSCALL_ADDR); }