From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x224x+tMyAKY00/14eJ4920rjWvSrnAiztXKZJT+XLyT6TDeSjuC6RaZ2ztOwLoDNYj82+xnc ARC-Seal: i=1; a=rsa-sha256; t=1517855148; cv=none; d=google.com; s=arc-20160816; b=Y0gdGQvNCv5f/zmRZGzhf/SZgpGxu0kCiWZW6X0G7tMcluTHuMH7H7MqoxaUi7ReRg a0HyHNuN5PhyHZJYAXD/7pURzsdfgDAJRaRzaqvk7lLp5pcGVVlN2xOcn6aXUfdJFyzM AL/pzGm5NumhPZqGcYAZkcqFpuFOWYcuUgjtUrq4r+1gNsGn23Iq5Do1zY9Gqka7GY4I w8WDAODp2rXBcBTukN6nkkYF+3h1FD2Dcwu4pgrq4ocfS1e1krUq6bs2zpVD0hmWEsP+ a/ZjCvY7Spty1WNqbGKBeJIrQzrBpMxZUvz+fyEU5ESUuhF8viTX/coYxS+HF5TGOS0a L/gA== 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=5Mssj9LRNZfsnjBCsEwQbGOX3qBc0x1rWsQizdmxsns=; b=XpLGn6zCrI9hfK5Ga5qOAN4JdTdLyUxU9LdxJCOAT9UKEm4oyL7pbus6ZIw4x9fGir /2l8g1x+M2d6xAGrDQLwSURtfydDRDf+N6yGrLK8rJn4BoPsOWm3W28YJUZv2Z9/ROnW O7c6L0OSfYXivA6t/Vf8L6tk88OsJSY+8GZqtmgAS72w4I4bdGIls9wI2ZTA0iS2XNy/ ddXWubgsDoZPyg6i6nseJBLlh5Y9prhprr5F/34VKpmNOVnGoH2PyQTzbxAbbFkhmGUG fTisDHuL+2i54mPGIPUSOAv1lbnRVfiEYFpxQPj5SnhD5UcDVwduOLnQt4RCigIvvtZM WE+g== 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 4.15 17/60] x86/speculation: Simplify indirect_branch_prediction_barrier() Date: Mon, 5 Feb 2018 10:22:50 -0800 Message-Id: <20180205182214.630922743@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180205182213.902626065@linuxfoundation.org> References: <20180205182213.902626065@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?1591586480167120712?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-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 @@ -971,4 +971,7 @@ 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);