From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755757AbcETKOF (ORCPT ); Fri, 20 May 2016 06:14:05 -0400 Received: from terminus.zytor.com ([198.137.202.10]:54240 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754409AbcETKOC (ORCPT ); Fri, 20 May 2016 06:14:02 -0400 Date: Fri, 20 May 2016 03:13:05 -0700 From: tip-bot for Andy Lutomirski Message-ID: Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, hpa@zytor.com, tglx@linutronix.de, luto@amacapital.net, dvlasenk@redhat.com, mingo@kernel.org, brgerst@gmail.com, luto@kernel.org, peterz@infradead.org, bp@alien8.de Reply-To: tglx@linutronix.de, torvalds@linux-foundation.org, hpa@zytor.com, linux-kernel@vger.kernel.org, bp@alien8.de, luto@kernel.org, peterz@infradead.org, brgerst@gmail.com, mingo@kernel.org, dvlasenk@redhat.com, luto@amacapital.net In-Reply-To: <5357f2fe0f103eabf005773b70722451eab09a89.1462897104.git.luto@kernel.org> References: <5357f2fe0f103eabf005773b70722451eab09a89.1462897104.git.luto@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/fsgsbase/64: Use TASK_SIZE_MAX for FSBASE/GSBASE upper limits Git-Commit-ID: d696ca016d579d43fc043f28ba656d9305fba651 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: d696ca016d579d43fc043f28ba656d9305fba651 Gitweb: http://git.kernel.org/tip/d696ca016d579d43fc043f28ba656d9305fba651 Author: Andy Lutomirski AuthorDate: Tue, 10 May 2016 09:18:46 -0700 Committer: Ingo Molnar CommitDate: Fri, 20 May 2016 09:10:03 +0200 x86/fsgsbase/64: Use TASK_SIZE_MAX for FSBASE/GSBASE upper limits The GSBASE upper limit exists to prevent user code from confusing the paranoid idtentry path. The FSBASE upper limit is just for consistency. There's no need to enforce a smaller limit for 32-bit tasks. Just use TASK_SIZE_MAX. This simplifies the logic and will save a few bytes of code. Signed-off-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/5357f2fe0f103eabf005773b70722451eab09a89.1462897104.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/process_64.c | 4 ++-- arch/x86/kernel/ptrace.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 6b16c36..6e789ca 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -532,7 +532,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) switch (code) { case ARCH_SET_GS: - if (addr >= TASK_SIZE_OF(task)) + if (addr >= TASK_SIZE_MAX) return -EPERM; cpu = get_cpu(); task->thread.gsindex = 0; @@ -546,7 +546,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) case ARCH_SET_FS: /* Not strictly needed for fs, but do it for symmetry with gs */ - if (addr >= TASK_SIZE_OF(task)) + if (addr >= TASK_SIZE_MAX) return -EPERM; cpu = get_cpu(); task->thread.fsindex = 0; diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index e60ef91..600edd2 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -392,7 +392,7 @@ static int putreg(struct task_struct *child, #ifdef CONFIG_X86_64 case offsetof(struct user_regs_struct,fs_base): - if (value >= TASK_SIZE_OF(child)) + if (value >= TASK_SIZE_MAX) return -EIO; /* * When changing the segment base, use do_arch_prctl @@ -406,7 +406,7 @@ static int putreg(struct task_struct *child, /* * Exactly the same here as the %fs handling above. */ - if (value >= TASK_SIZE_OF(child)) + if (value >= TASK_SIZE_MAX) return -EIO; if (child->thread.gsbase != value) return do_arch_prctl(child, ARCH_SET_GS, value);