From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x227oAiP/6SaCReRL7on3gCYp9aw0vusFZ++dNlJvQk4UNypNnVN0WSX/9RRTUTK5CifrvLAo ARC-Seal: i=1; a=rsa-sha256; t=1519218030; cv=none; d=google.com; s=arc-20160816; b=frvWE71INvDLMqVlf+hYwdRLG60yUimbT/AuDekXDCK6Z2tlbfcXOAc+F6qC9jNmpa QIlRNEA27erulsI3F4KB+b9Xn4JTs6RxBD9+JO2bZjyC38UhI/hvK6ZPEu6gy13HXrNa tDnHhHglbUpgppdZQWlhaLDjpkIfI0uHbJ6ilwtWgmNbIzhfvp8m8fhPOHPXeYwd40he mAFZCbUbgTgJ/MDY8e9lAzjnkQu80ck7G4+n7aEr8umVrFEiiG68cBQpt+kuuaSzf3Sl Z+Me4MdPA+1c7Pn3gBdccTA4i9H0dgg90vFXKaHqvxHO9x3oAI2Y+IKX8SOZFuoulE7N 5gUQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=FDoFqTiw9p4SAYkr1nAfEG26vGSq63pDiJQa/kNL8G0=; b=VcQQob/Ys/Rv6xi5ct/yveDccUHfHroZDNtQx+PglloSPXPTLXkvO+1GlIDk7ab6LS mDLsSbq85YtmT+a9VRzAVYWPFE0Lfj78t4yoGi3kzyjHB5yqwmRl/k41KkCd5vR9DERv eF6AzEeFEIAnchpUuCN3jjFtxNUxZuXo5WiZ2HAtmeJQfodz4xI4J3GxWMhG1nScaoUS uh4i3WY83gtHV21p8p17He15tgwldG2/s5H/QDHIiowJEXuZAufHem4zeeAwONfwPSUm J1ftuSUpC2Um83P+2DQaldluX3wzqXZsB8TUp/6AywKp/kL2NZfNBQLoZ/nFhnkWSLw1 sFQQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Torvalds , Dominik Brodowski , Andy Lutomirski , Borislav Petkov , Brian Gerst , Denys Vlasenko , "H. Peter Anvin" , Josh Poimboeuf , Peter Zijlstra , Thomas Gleixner , dan.j.williams@intel.com, Ingo Molnar Subject: [PATCH 4.14 062/167] x86/entry/64: Use PUSH_AND_CLEAN_REGS in more cases Date: Wed, 21 Feb 2018 13:47:53 +0100 Message-Id: <20180221124527.894424371@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180221124524.639039577@linuxfoundation.org> References: <20180221124524.639039577@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1593015566176751887?= X-GMAIL-MSGID: =?utf-8?q?1593015566176751887?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dominik Brodowski commit 30907fd13bb593202574bb20af58d67c70a1ee14 upstream. entry_SYSCALL_64_after_hwframe() and nmi() can be converted to use PUSH_AND_CLEAN_REGS instead of opencoded variants thereof. Due to the interleaving, the additional XOR-based clearing of R8 and R9 in entry_SYSCALL_64_after_hwframe() should not have any noticeable negative implications. Suggested-by: Linus Torvalds Signed-off-by: Dominik Brodowski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: dan.j.williams@intel.com Link: http://lkml.kernel.org/r/20180211104949.12992-6-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/entry/calling.h | 6 ++-- arch/x86/entry/entry_64.S | 65 ++-------------------------------------------- 2 files changed, 6 insertions(+), 65 deletions(-) --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -137,7 +137,7 @@ For 32-bit we have the following convent UNWIND_HINT_REGS offset=\offset .endm - .macro PUSH_AND_CLEAR_REGS + .macro PUSH_AND_CLEAR_REGS rdx=%rdx rax=%rax /* * Push registers and sanitize registers of values that a * speculation attack might otherwise want to exploit. The @@ -147,9 +147,9 @@ For 32-bit we have the following convent */ pushq %rdi /* pt_regs->di */ pushq %rsi /* pt_regs->si */ - pushq %rdx /* pt_regs->dx */ + pushq \rdx /* pt_regs->dx */ pushq %rcx /* pt_regs->cx */ - pushq %rax /* pt_regs->ax */ + pushq \rax /* pt_regs->ax */ pushq %r8 /* pt_regs->r8 */ xorq %r8, %r8 /* nospec r8 */ pushq %r9 /* pt_regs->r9 */ --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -223,35 +223,8 @@ ENTRY(entry_SYSCALL_64) pushq %rcx /* pt_regs->ip */ GLOBAL(entry_SYSCALL_64_after_hwframe) pushq %rax /* pt_regs->orig_ax */ - pushq %rdi /* pt_regs->di */ - pushq %rsi /* pt_regs->si */ - pushq %rdx /* pt_regs->dx */ - pushq %rcx /* pt_regs->cx */ - pushq $-ENOSYS /* pt_regs->ax */ - pushq %r8 /* pt_regs->r8 */ - pushq %r9 /* pt_regs->r9 */ - pushq %r10 /* pt_regs->r10 */ - /* - * Clear extra registers that a speculation attack might - * otherwise want to exploit. Interleave XOR with PUSH - * for better uop scheduling: - */ - xorq %r10, %r10 /* nospec r10 */ - pushq %r11 /* pt_regs->r11 */ - xorq %r11, %r11 /* nospec r11 */ - pushq %rbx /* pt_regs->rbx */ - xorl %ebx, %ebx /* nospec rbx */ - pushq %rbp /* pt_regs->rbp */ - xorl %ebp, %ebp /* nospec rbp */ - pushq %r12 /* pt_regs->r12 */ - xorq %r12, %r12 /* nospec r12 */ - pushq %r13 /* pt_regs->r13 */ - xorq %r13, %r13 /* nospec r13 */ - pushq %r14 /* pt_regs->r14 */ - xorq %r14, %r14 /* nospec r14 */ - pushq %r15 /* pt_regs->r15 */ - xorq %r15, %r15 /* nospec r15 */ - UNWIND_HINT_REGS + + PUSH_AND_CLEAR_REGS rax=$-ENOSYS TRACE_IRQS_OFF @@ -1382,39 +1355,7 @@ ENTRY(nmi) pushq 1*8(%rdx) /* pt_regs->rip */ UNWIND_HINT_IRET_REGS pushq $-1 /* pt_regs->orig_ax */ - pushq %rdi /* pt_regs->di */ - pushq %rsi /* pt_regs->si */ - pushq (%rdx) /* pt_regs->dx */ - pushq %rcx /* pt_regs->cx */ - pushq %rax /* pt_regs->ax */ - /* - * Sanitize registers of values that a speculation attack - * might otherwise want to exploit. The lower registers are - * likely clobbered well before they could be put to use in - * a speculative execution gadget. Interleave XOR with PUSH - * for better uop scheduling: - */ - pushq %r8 /* pt_regs->r8 */ - xorq %r8, %r8 /* nospec r8 */ - pushq %r9 /* pt_regs->r9 */ - xorq %r9, %r9 /* nospec r9 */ - pushq %r10 /* pt_regs->r10 */ - xorq %r10, %r10 /* nospec r10 */ - pushq %r11 /* pt_regs->r11 */ - xorq %r11, %r11 /* nospec r11*/ - pushq %rbx /* pt_regs->rbx */ - xorl %ebx, %ebx /* nospec rbx*/ - pushq %rbp /* pt_regs->rbp */ - xorl %ebp, %ebp /* nospec rbp*/ - pushq %r12 /* pt_regs->r12 */ - xorq %r12, %r12 /* nospec r12*/ - pushq %r13 /* pt_regs->r13 */ - xorq %r13, %r13 /* nospec r13*/ - pushq %r14 /* pt_regs->r14 */ - xorq %r14, %r14 /* nospec r14*/ - pushq %r15 /* pt_regs->r15 */ - xorq %r15, %r15 /* nospec r15*/ - UNWIND_HINT_REGS + PUSH_AND_CLEAR_REGS rdx=(%rdx) ENCODE_FRAME_POINTER /*