From patchwork Tue Apr 8 21:47:30 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Poimboeuf X-Patchwork-Id: 14043729 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 24B53255222; Tue, 8 Apr 2025 21:48:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744148883; cv=none; b=FwCZb6YHkH1iFnE69cRj3TvDb3y7+2k7+Illl7jWFADvWM8Yec2Dl80xVCIc2YS+JL59NNv9xMOYLRU3X7eN+ZiuEZptp067CIcMDwePeh9uerJwhJMIOyL0Gr41XQ+w7rW50yKnJeLqXzAZuLfTSj/noebfNg9ZKvxXpggKNUs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744148883; c=relaxed/simple; bh=c/oFWdmB8Lm8up00opCo8sX9e64iLhaPQi3f/44+TMo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kkSmrNPdNqX3CwwBPFSn9MqT9IXDTtL7QtS38/HZ9ppoB3QjMviA+jUq9YNo2PTzgb1XklOgvAx2cXd6b4NZzwoV8ZPLSSAby8frXEhEBobH0vQASHlgEdprBGJbeS3mFzcD0atOv1QyVadA5lQFsPBU2PhDw6Q+mJWGrrDeaEI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DycNW4I2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DycNW4I2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4B66C4CEE9; Tue, 8 Apr 2025 21:48:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744148882; bh=c/oFWdmB8Lm8up00opCo8sX9e64iLhaPQi3f/44+TMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DycNW4I27oUvHux/3AtaeQZ656n2bxpehgi+ND2/cT96e00TG1j8+Do39+ikTo2lY 9lW9OPV4stRSWzof6xuIn2XyNtjyvtH94yFGEuvOczwjpVhgd/hYSnRj8qiiNlAaJj tltgqxeaupweaZn90211gqDwFmMJM4ScLY8IL0xZxC056lHfqEfoow9FvJ1X+dZ/XM KuCLc3FtESuj5ptPvHlXKWZ7nofoQHeo+MX5L+5xMAwphUU+yexCe0GKUHm0j2pckP 9QqgalpIsYlvGHq4+cwbBvhC3QvI9AsRrZMd5khj3k8QZgcgcZU0q5dXMWv+ewykrd f4+TVQyUsBRjA== From: Josh Poimboeuf To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, amit@kernel.org, kvm@vger.kernel.org, amit.shah@amd.com, thomas.lendacky@amd.com, bp@alien8.de, tglx@linutronix.de, peterz@infradead.org, pawan.kumar.gupta@linux.intel.com, corbet@lwn.net, mingo@redhat.com, dave.hansen@linux.intel.com, hpa@zytor.com, seanjc@google.com, pbonzini@redhat.com, daniel.sneddon@linux.intel.com, kai.huang@intel.com, sandipan.das@amd.com, boris.ostrovsky@oracle.com, Babu.Moger@amd.com, david.kaplan@amd.com, dwmw@amazon.co.uk, andrew.cooper3@citrix.comm, nik.borisov@suse.com Subject: [PATCH v4 1/6] x86/bugs: Rename entry_ibpb() to write_ibpb() Date: Tue, 8 Apr 2025 14:47:30 -0700 Message-ID: <1e54ace131e79b760de3fe828264e26d0896e3ac.1744148254.git.jpoimboe@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 There's nothing entry-specific about entry_ibpb(). In preparation for calling it from elsewhere, rename it to write_ibpb(). Signed-off-by: Josh Poimboeuf --- arch/x86/entry/entry.S | 7 ++++--- arch/x86/include/asm/nospec-branch.h | 6 +++--- arch/x86/kernel/cpu/bugs.c | 6 +++--- 3 files changed, 10 insertions(+), 9 deletions(-) diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S index d3caa31240ed..cabe65ac8379 100644 --- a/arch/x86/entry/entry.S +++ b/arch/x86/entry/entry.S @@ -17,7 +17,8 @@ .pushsection .noinstr.text, "ax" -SYM_FUNC_START(entry_ibpb) +/* Clobbers AX, CX, DX */ +SYM_FUNC_START(write_ibpb) ANNOTATE_NOENDBR movl $MSR_IA32_PRED_CMD, %ecx movl $PRED_CMD_IBPB, %eax @@ -27,9 +28,9 @@ SYM_FUNC_START(entry_ibpb) /* Make sure IBPB clears return stack preductions too. */ FILL_RETURN_BUFFER %rax, RSB_CLEAR_LOOPS, X86_BUG_IBPB_NO_RET RET -SYM_FUNC_END(entry_ibpb) +SYM_FUNC_END(write_ibpb) /* For KVM */ -EXPORT_SYMBOL_GPL(entry_ibpb); +EXPORT_SYMBOL_GPL(write_ibpb); .popsection diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index 8a5cc8e70439..591d1dbca60a 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -269,7 +269,7 @@ * typically has NO_MELTDOWN). * * While retbleed_untrain_ret() doesn't clobber anything but requires stack, - * entry_ibpb() will clobber AX, CX, DX. + * write_ibpb() will clobber AX, CX, DX. * * As such, this must be placed after every *SWITCH_TO_KERNEL_CR3 at a point * where we have a stack but before any RET instruction. @@ -279,7 +279,7 @@ VALIDATE_UNRET_END CALL_UNTRAIN_RET ALTERNATIVE_2 "", \ - "call entry_ibpb", \ibpb_feature, \ + "call write_ibpb", \ibpb_feature, \ __stringify(\call_depth_insns), X86_FEATURE_CALL_DEPTH #endif .endm @@ -368,7 +368,7 @@ extern void srso_return_thunk(void); extern void srso_alias_return_thunk(void); extern void entry_untrain_ret(void); -extern void entry_ibpb(void); +extern void write_ibpb(void); #ifdef CONFIG_X86_64 extern void clear_bhb_loop(void); diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 4386aa6c69e1..608bbe6cf730 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1142,7 +1142,7 @@ static void __init retbleed_select_mitigation(void) setup_clear_cpu_cap(X86_FEATURE_RETHUNK); /* - * There is no need for RSB filling: entry_ibpb() ensures + * There is no need for RSB filling: write_ibpb() ensures * all predictions, including the RSB, are invalidated, * regardless of IBPB implementation. */ @@ -2676,7 +2676,7 @@ static void __init srso_select_mitigation(void) setup_clear_cpu_cap(X86_FEATURE_RETHUNK); /* - * There is no need for RSB filling: entry_ibpb() ensures + * There is no need for RSB filling: write_ibpb() ensures * all predictions, including the RSB, are invalidated, * regardless of IBPB implementation. */ @@ -2701,7 +2701,7 @@ static void __init srso_select_mitigation(void) srso_mitigation = SRSO_MITIGATION_IBPB_ON_VMEXIT; /* - * There is no need for RSB filling: entry_ibpb() ensures + * There is no need for RSB filling: write_ibpb() ensures * all predictions, including the RSB, are invalidated, * regardless of IBPB implementation. */