From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x227zO5qpmxZjVA1HcF4Su6+/XWFIhBSrL06lPv+K6eVz067ZGRrvSrQoDX8WY0CSxy32dUtf ARC-Seal: i=1; a=rsa-sha256; t=1517855021; cv=none; d=google.com; s=arc-20160816; b=0C42qtfibJdeG4r0iaHGTsJ370okb9Dhn3tZ027zYAx6rX7vF5HHg5tHj/woaMbtmF jETSbVCyy3db32ererhv9H8Awx180YIxSkcs3/6HfW5xIpv2GMnT3CjmYeKza4B9Mbyn K5CR0XEemmp/tH8icq/a4kWLzEFaRcqW3V2039aFyfAom6p5GJf7OXWvNW2mdUStSPtL 0nRpqw4ZVzfROTQJiSMBNFUDuakY+Pcb17WtVaBz1XDIFJ/SCpJdZMM9PNP/44MWT913 M3/cThYD1F+0lMhtNaKgGG8WGl36GX12DR+ThmOjgH4yw+D5tejeN+47mUh4SIwJobp2 48Mw== 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=K8C5dbJGgNhofRHtxH/ria+/2JNN52WI6srAH1+OyA4=; b=pIhh/vYXUlSGPMhp9fnIPEBU4QLM5uiG4yRi0+NNsP5o6TFTNgJsWbQN4LAi4UtUeS m5GfldLFWGZwdN15SZCXJB5JaW1QeEZx3hpibasVPdmujGTs7UKsKDK+EorFNmXBeX9a JNULVMOCLkF39UiX5hIRQlZJjSG3sJtaezJVodR0EqVT6H8YzWKnrShh8rRrFAMlf73l SMh/+ij7KnvXRDYrD8dLSYlBIl1Sd7+lPid3r8FHJWsiMsmKSKnRr/0YnLj1imhLcApi MxW8n3nrQ/SHVscU9IzTPmJFd24khJPn1gF7Ysqb+A7bXBdweuSvZw+/cIZRFV3b7ddR aFuA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 104.132.1.108 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 104.132.1.108 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, Borislav Petkov , David Woodhouse , Thomas Gleixner , ak@linux.intel.com, dave.hansen@intel.com, karahmed@amazon.de, arjan@linux.intel.com, torvalds@linux-foundation.org, peterz@infradead.org, bp@alien8.de, pbonzini@redhat.com, tim.c.chen@linux.intel.com, gregkh@linux-foundation.org Subject: [PATCH 4.14 21/64] x86/speculation: Simplify indirect_branch_prediction_barrier() Date: Mon, 5 Feb 2018 10:22:40 -0800 Message-Id: <20180205182139.433019011@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180205182138.571333346@linuxfoundation.org> References: <20180205182138.571333346@linuxfoundation.org> User-Agent: quilt/0.65 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?1591586347373832119?= X-GMAIL-MSGID: =?utf-8?q?1591586347373832119?= 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: Borislav Petkov bp@suse.de commit 64e16720ea0879f8ab4547e3b9758936d483909b Make it all a function which does the WRMSR instead of having a hairy inline asm. [dwmw2: export it, fix CONFIG_RETPOLINE issues] Signed-off-by: Borislav Petkov Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner Cc: ak@linux.intel.com Cc: dave.hansen@intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1517070274-12128-4-git-send-email-dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/nospec-branch.h | 13 ++++--------- arch/x86/include/asm/processor.h | 3 +++ arch/x86/kernel/cpu/bugs.c | 6 ++++++ 3 files changed, 13 insertions(+), 9 deletions(-) --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -164,15 +164,10 @@ static inline void vmexit_fill_RSB(void) static inline void indirect_branch_prediction_barrier(void) { - asm volatile(ALTERNATIVE("", - "movl %[msr], %%ecx\n\t" - "movl %[val], %%eax\n\t" - "movl $0, %%edx\n\t" - "wrmsr", - X86_FEATURE_USE_IBPB) - : : [msr] "i" (MSR_IA32_PRED_CMD), - [val] "i" (PRED_CMD_IBPB) - : "eax", "ecx", "edx", "memory"); + alternative_input("", + "call __ibp_barrier", + X86_FEATURE_USE_IBPB, + ASM_NO_INPUT_CLOBBER("eax", "ecx", "edx", "memory")); } #endif /* __ASSEMBLY__ */ --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -970,4 +970,7 @@ bool xen_set_default_idle(void); void stop_this_cpu(void *dummy); void df_debug(struct pt_regs *regs, long error_code); + +void __ibp_barrier(void); + #endif /* _ASM_X86_PROCESSOR_H */ --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -311,3 +311,9 @@ ssize_t cpu_show_spectre_v2(struct devic spectre_v2_module_string()); } #endif + +void __ibp_barrier(void) +{ + __wrmsr(MSR_IA32_PRED_CMD, PRED_CMD_IBPB, 0); +} +EXPORT_SYMBOL_GPL(__ibp_barrier);