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 704D0224222; Tue, 29 Apr 2025 18:00:23 +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=1745949623; cv=none; b=ujFQSeXz1pf54hmgX45uzfTC4d6Sqn5O1+WYCQUsn56GemlOPJKLJ1cO8a+ZQ5E7lPQLr1hDhCATeSpQopwFObucoGR3cUAKFfgUzoTk8cD9K+1HPJ5nF5qrfhCFaXq57sOSuPB1SmY2W6JB9xi7VbqequkV3WkDMEgPNTddlrQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745949623; c=relaxed/simple; bh=tkgVveGJzSANGzGMXb45gQlVZ4aEdrqYu0GKZ3Z5hDA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f0kWKon6/QALMLk+VTrfgKccG4OEphq9JU/tzSuNwsUPr42y0HehhGYTL4jqb1off/nzjVNnUg0H329eltynxikUo90h/a7mwlX/r6r47/rXVFT8BDW/Zqz/eBoVd0pkJ8z+MgZNldntVrO0btXu8rT3hpukWYVJ8wiPShcjKGw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BML+BkYz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="BML+BkYz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA1F7C4CEE3; Tue, 29 Apr 2025 18:00:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745949623; bh=tkgVveGJzSANGzGMXb45gQlVZ4aEdrqYu0GKZ3Z5hDA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BML+BkYzPS06/8YCdKq9Dbe7tMo1kYxJ8ekr7x+3arRR+zYcnxG4RzKx7C2i2/Nkr +9vif9y8XNppBPnmEAz4onLwzQsrP7SQIBN1UkQq/l83SjwDjUlbyRbutNKLPkPJWI 2eZbLV0ZQdpdhWUvHw6sa3s3jf3oTnprFzq+Yf04= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josh Poimboeuf , Ingo Molnar , Sasha Levin Subject: [PATCH 5.15 349/373] x86/bugs: Use SBPB in write_ibpb() if applicable Date: Tue, 29 Apr 2025 18:43:46 +0200 Message-ID: <20250429161137.483849619@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250429161123.119104857@linuxfoundation.org> References: <20250429161123.119104857@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ 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