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 F1F832517B3; Wed, 5 Mar 2025 18:03:57 +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=1741197838; cv=none; b=Cv6fVFD73HXbfZcsbqt4/9KjInTKKkwVTlOft+5QjpsI0RAWDbvBhDyPgmThn0fqqxRnO2dWdOhAk2H/HlosaY3oqsnAmae2AcJ8nYjaplz66+19gxR7HHML2IJ9qPDG/CVwjRLk7MEnHWYCrR/+zw4KiVOmijqQ0t2NoybU9ig= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741197838; c=relaxed/simple; bh=V8MbGjj1ecHFGg0QeLNsSbULT7I6lJJZ8gVhEDCEuqA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NOkwEt8SBesPFSDixde8L7E910Hnitl/wv2kUpov/4pzA8KqWCkSaBbjNHd6kY4Bz3b6PdJ4S21tKauOCKs7qzWyugolOEpH5rVB9YoTL0xIdar3Tg90foTLoEPRyw7zZd4NehisOJJO2ZVi3/ZRnNnW0YPmLbDkd8zQ8+LcbBk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=f8Wbd6Vu; 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="f8Wbd6Vu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 788FDC4CED1; Wed, 5 Mar 2025 18:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741197837; bh=V8MbGjj1ecHFGg0QeLNsSbULT7I6lJJZ8gVhEDCEuqA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f8Wbd6VuS2oKLWLcLyILgNU0DW1XsZTgttVMZshPxWk66/UwkSTyxRIctlcyuNzOs ZWEl9xGLYVKr3SWkgJ4uUKbtCGSG/mvt/paPtlZUtA1EDH8FUxnlEdnPY+MinckT1N +SwKK/5Ih4y8kV7+U0D0mPF2TclVutyG8ZRWslQk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thomas Gleixner , "Borislav Petkov (AMD)" , Nikolay Borisov Subject: [PATCH 6.6 118/142] x86/microcode: Clarify the late load logic Date: Wed, 5 Mar 2025 18:48:57 +0100 Message-ID: <20250305174505.071514472@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250305174500.327985489@linuxfoundation.org> References: <20250305174500.327985489@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit 6f059e634dcd0d725854514c94c114bbdd83950d upstream reload_store() is way too complicated. Split the inner workings out and make the following enhancements: - Taint the kernel only when the microcode was actually updated. If. e.g. the rendezvous fails, then nothing happened and there is no reason for tainting. - Return useful error codes Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Nikolay Borisov Link: https://lore.kernel.org/r/20231002115903.145048840@linutronix.de Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/microcode/core.c | 41 ++++++++++++++++------------------- 1 file changed, 19 insertions(+), 22 deletions(-) --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -362,11 +362,11 @@ static int microcode_reload_late(void) pr_info("Reload succeeded, microcode revision: 0x%x -> 0x%x\n", old, boot_cpu_data.microcode); microcode_check(&prev_info); + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); } else { pr_info("Reload failed, current microcode revision: 0x%x\n", boot_cpu_data.microcode); } - return ret; } @@ -399,40 +399,37 @@ static bool ensure_cpus_are_online(void) return true; } +static int ucode_load_late_locked(void) +{ + if (!ensure_cpus_are_online()) + return -EBUSY; + + switch (microcode_ops->request_microcode_fw(0, µcode_pdev->dev)) { + case UCODE_NEW: + return microcode_reload_late(); + case UCODE_NFOUND: + return -ENOENT; + default: + return -EBADFD; + } +} + static ssize_t reload_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { - enum ucode_state tmp_ret = UCODE_OK; - int bsp = boot_cpu_data.cpu_index; unsigned long val; - ssize_t ret = 0; + ssize_t ret; ret = kstrtoul(buf, 0, &val); if (ret || val != 1) return -EINVAL; cpus_read_lock(); - - if (!ensure_cpus_are_online()) { - ret = -EBUSY; - goto put; - } - - tmp_ret = microcode_ops->request_microcode_fw(bsp, µcode_pdev->dev); - if (tmp_ret != UCODE_NEW) - goto put; - - ret = microcode_reload_late(); -put: + ret = ucode_load_late_locked(); cpus_read_unlock(); - if (ret == 0) - ret = size; - - add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); - - return ret; + return ret ? : size; } static DEVICE_ATTR_WO(reload);