From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753917AbbKXJfm (ORCPT ); Tue, 24 Nov 2015 04:35:42 -0500 Received: from terminus.zytor.com ([198.137.202.10]:55417 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753670AbbKXJfi (ORCPT ); Tue, 24 Nov 2015 04:35:38 -0500 Date: Tue, 24 Nov 2015 01:34:32 -0800 From: tip-bot for Borislav Petkov Message-ID: Cc: oleg@redhat.com, tglx@linutronix.de, luto@amacapital.net, riel@redhat.com, hpa@zytor.com, brgerst@gmail.com, bp@suse.de, fenghua.yu@intel.com, peterz@infradead.org, linux-kernel@vger.kernel.org, dvlasenk@redhat.com, quentin.casasnovas@oracle.com, torvalds@linux-foundation.org, bp@alien8.de, mingo@kernel.org, dave.hansen@linux.intel.com Reply-To: fenghua.yu@intel.com, brgerst@gmail.com, bp@suse.de, quentin.casasnovas@oracle.com, dvlasenk@redhat.com, torvalds@linux-foundation.org, mingo@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, peterz@infradead.org, linux-kernel@vger.kernel.org, luto@amacapital.net, riel@redhat.com, oleg@redhat.com, tglx@linutronix.de, hpa@zytor.com In-Reply-To: <1447932326-4371-2-git-send-email-bp@alien8.de> References: <1447932326-4371-2-git-send-email-bp@alien8.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/fpu] x86/fpu: Add an XSTATE_OP() macro Git-Commit-ID: b74a0cf1b3db30173eefa00c411775d2b1697700 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: b74a0cf1b3db30173eefa00c411775d2b1697700 Gitweb: http://git.kernel.org/tip/b74a0cf1b3db30173eefa00c411775d2b1697700 Author: Borislav Petkov AuthorDate: Thu, 19 Nov 2015 12:25:25 +0100 Committer: Ingo Molnar CommitDate: Tue, 24 Nov 2015 09:52:52 +0100 x86/fpu: Add an XSTATE_OP() macro Add an XSTATE_OP() macro which contains the XSAVE* fault handling and replace all non-alternatives users of xstate_fault() with it. This fixes also the buglet in copy_xregs_to_user() and copy_user_to_xregs() where the inline asm didn't have @xstate as memory reference and thus potentially causing unwanted reordering of accesses to the extended state. Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Quentin Casasnovas Cc: Rik van Riel Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1447932326-4371-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar --- arch/x86/include/asm/fpu/internal.h | 68 +++++++++++++++++-------------------- 1 file changed, 31 insertions(+), 37 deletions(-) diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 3c3550c..709a3df 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -237,6 +237,20 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu) _ASM_EXTABLE(1b, 3b) \ : [_err] "=r" (__err) +#define XSTATE_OP(op, st, lmask, hmask, err) \ + asm volatile("1:" op "\n\t" \ + "xor %[err], %[err]\n" \ + "2:\n\t" \ + ".pushsection .fixup,\"ax\"\n\t" \ + "3: movl $-2,%[err]\n\t" \ + "jmp 2b\n\t" \ + ".popsection\n\t" \ + _ASM_EXTABLE(1b, 3b) \ + : [err] "=r" (err) \ + : "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \ + : "memory") + + /* * This function is called only during boot time when x86 caps are not set * up and alternative can not be used yet. @@ -246,22 +260,14 @@ static inline void copy_xregs_to_kernel_booting(struct xregs_state *xstate) u64 mask = -1; u32 lmask = mask; u32 hmask = mask >> 32; - int err = 0; + int err; WARN_ON(system_state != SYSTEM_BOOTING); - if (boot_cpu_has(X86_FEATURE_XSAVES)) - asm volatile("1:"XSAVES"\n\t" - "2:\n\t" - xstate_fault(err) - : "D" (xstate), "m" (*xstate), "a" (lmask), "d" (hmask), "0" (err) - : "memory"); + if (static_cpu_has_safe(X86_FEATURE_XSAVES)) + XSTATE_OP(XSAVES, xstate, lmask, hmask, err); else - asm volatile("1:"XSAVE"\n\t" - "2:\n\t" - xstate_fault(err) - : "D" (xstate), "m" (*xstate), "a" (lmask), "d" (hmask), "0" (err) - : "memory"); + XSTATE_OP(XSAVE, xstate, lmask, hmask, err); /* We should never fault when copying to a kernel buffer: */ WARN_ON_FPU(err); @@ -276,22 +282,14 @@ static inline void copy_kernel_to_xregs_booting(struct xregs_state *xstate) u64 mask = -1; u32 lmask = mask; u32 hmask = mask >> 32; - int err = 0; + int err; WARN_ON(system_state != SYSTEM_BOOTING); - if (boot_cpu_has(X86_FEATURE_XSAVES)) - asm volatile("1:"XRSTORS"\n\t" - "2:\n\t" - xstate_fault(err) - : "D" (xstate), "m" (*xstate), "a" (lmask), "d" (hmask), "0" (err) - : "memory"); + if (static_cpu_has_safe(X86_FEATURE_XSAVES)) + XSTATE_OP(XRSTORS, xstate, lmask, hmask, err); else - asm volatile("1:"XRSTOR"\n\t" - "2:\n\t" - xstate_fault(err) - : "D" (xstate), "m" (*xstate), "a" (lmask), "d" (hmask), "0" (err) - : "memory"); + XSTATE_OP(XRSTOR, xstate, lmask, hmask, err); /* We should never fault when copying from a kernel buffer: */ WARN_ON_FPU(err); @@ -388,12 +386,10 @@ static inline int copy_xregs_to_user(struct xregs_state __user *buf) if (unlikely(err)) return -EFAULT; - __asm__ __volatile__(ASM_STAC "\n" - "1:"XSAVE"\n" - "2: " ASM_CLAC "\n" - xstate_fault(err) - : "D" (buf), "a" (-1), "d" (-1), "0" (err) - : "memory"); + stac(); + XSTATE_OP(XSAVE, buf, -1, -1, err); + clac(); + return err; } @@ -405,14 +401,12 @@ static inline int copy_user_to_xregs(struct xregs_state __user *buf, u64 mask) struct xregs_state *xstate = ((__force struct xregs_state *)buf); u32 lmask = mask; u32 hmask = mask >> 32; - int err = 0; + int err; + + stac(); + XSTATE_OP(XRSTOR, xstate, lmask, hmask, err); + clac(); - __asm__ __volatile__(ASM_STAC "\n" - "1:"XRSTOR"\n" - "2: " ASM_CLAC "\n" - xstate_fault(err) - : "D" (xstate), "a" (lmask), "d" (hmask), "0" (err) - : "memory"); /* memory required? */ return err; }