From mboxrd@z Thu Jan 1 00:00:00 1970 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 318D52DDD03; Mon, 14 Apr 2025 13:32:18 +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=1744637538; cv=none; b=bJNEtU0UY/q6noKkJiJhR3Le/NX4+WEZ56DaJlTqFguKEkcFpRfV2f5+3iMW1VzuE4ba8cgPXJ80r7KHC17Sp4tGJgFVQhYsOsokZCSF3nibHzc1TId1jJGfGtsazqakpIUzuKVTKcVwEjjsQPkvxzu0D22YNKtu886kaJDiX2s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744637538; c=relaxed/simple; bh=p1YNscPHnD9q0ry9tfgRP1Fu8zOjJ1pcXTSkJrt5How=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Zjvftr02p6WLydN277AiH3qXMJjoPCl0mNS6dCPAufBizAxwZVZ5QNZ1JRAPO3nYX7NTBKPjq8Xr/Sc+L6TBnbVaEHPjmoDQ9/5piVN9oKdm5sA94GtzK7TjU/5N+xfV0L+cp7HmlOA0yg20pjfJQ2b0mLasgDnC9WkDJMH0WPw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DZDdBtWu; 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="DZDdBtWu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 853C1C4CEE2; Mon, 14 Apr 2025 13:32:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744637538; bh=p1YNscPHnD9q0ry9tfgRP1Fu8zOjJ1pcXTSkJrt5How=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DZDdBtWuIQ6eqjfxVsyWlW2JzXiiC+NAdO1ZEewYTK3qhew4x89eIZRy+LA+QKpMy BNUp9u4JVsi/3H91bNnoN6lJLxvt87M00cBX83zoW2Y1c8sOW59zQ6TCxsMUEAlv6v OQ0987TbGRXdGD98kO3RjnRLpInNKwK1LfbJhvcaDbMSISR5abGyuPd9GXPVZ8gMz8 WgbhFuoz353aYtmSXNsXIvjyCPZWfIn0vj2BYE/hwysGDYCGBJMQGM3KKcbEhldD05 Qhu6bHSZiYo08ZGbmlXL7GLFkCfAlk/YSfOue7r0SnbesbbJsb/hW1LqVQKiI5jw4T MvROL6OprnVoQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Josh Poimboeuf , Ingo Molnar , Sasha Levin , luto@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org Subject: [PATCH AUTOSEL 5.10 09/11] x86/bugs: Use SBPB in write_ibpb() if applicable Date: Mon, 14 Apr 2025 09:31:56 -0400 Message-Id: <20250414133158.681045-9-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250414133158.681045-1-sashal@kernel.org> References: <20250414133158.681045-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.236 Content-Transfer-Encoding: 8bit From: Josh Poimboeuf [ Upstream commit fc9fd3f98423367c79e0bd85a9515df26dc1b3cc ] write_ibpb() does IBPB, which (among other things) flushes branch type predictions on AMD. If the CPU has SRSO_NO, or if the SRSO mitigation has been disabled, branch type flushing isn't needed, in which case the lighter-weight SBPB can be used. The 'x86_pred_cmd' variable already keeps track of whether IBPB or SBPB should be used. Use that instead of hardcoding IBPB. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/17c5dcd14b29199b75199d67ff7758de9d9a4928.1744148254.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin --- arch/x86/entry/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S index f4419afc7147d..bda217961172b 100644 --- a/arch/x86/entry/entry.S +++ b/arch/x86/entry/entry.S @@ -16,7 +16,7 @@ SYM_FUNC_START(entry_ibpb) movl $MSR_IA32_PRED_CMD, %ecx - movl $PRED_CMD_IBPB, %eax + movl _ASM_RIP(x86_pred_cmd), %eax xorl %edx, %edx wrmsr -- 2.39.5