From patchwork Wed Jun 22 17:09:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Luck X-Patchwork-Id: 583886 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68FF7C433EF for ; Wed, 22 Jun 2022 17:10:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377080AbiFVRKR (ORCPT ); Wed, 22 Jun 2022 13:10:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377163AbiFVRKE (ORCPT ); Wed, 22 Jun 2022 13:10:04 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CABA041F91; Wed, 22 Jun 2022 10:09:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655917752; x=1687453752; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=GuhujeoTeqcnmWPVCbag/SuSIX6nu8OxcQUPGZZah2E=; b=NvxdOht+KONCsIYJrsOb4xikuq1b8c35EPdrp5drTN1H6v67mIC1dHXY pxAmDshbaJOlFx23mbMpLi9MZoYl6jSriKTGIv2f9nuS5KaVPeHWZROdB ySIbJDVRWIxTGfBennRivR01t9kHHvqj3KPyDccZMUm+yvFz4HAo1oHjc tyTiq9DweDDd1dVbY77wq/eYMCbYTFXjQLMwqkZ6OeamwZHkR0JKPVD43 I7ypNOPA5/y1A+tFoIB/4z0RymjUD4k0ReOv1IvuQnN7WRmDnjYlrRR3j LU1x8hJasge8AeovYbN+Ygs/YcH6GwaDKkIfpQYxujs9rqk2ZXtXkdgbR w==; X-IronPort-AV: E=McAfee;i="6400,9594,10386"; a="278026643" X-IronPort-AV: E=Sophos;i="5.92,212,1650956400"; d="scan'208";a="278026643" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jun 2022 10:09:12 -0700 X-IronPort-AV: E=Sophos;i="5.92,212,1650956400"; d="scan'208";a="644296730" Received: from agluck-desk3.sc.intel.com ([172.25.222.78]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jun 2022 10:09:12 -0700 From: Tony Luck To: "Rafael J. Wysocki" Cc: Darren Hart , LKML , Linux ACPI , Len Brown , James Morse , Borislav Petkov , Doug Rady , Tony Luck Subject: [PATCH] ACPI/APEI: Better fix to avoid spamming the console with old error logs Date: Wed, 22 Jun 2022 10:09:06 -0700 Message-Id: <20220622170906.33759-1-tony.luck@intel.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org The fix in commit 3f8dec116210 ("ACPI/APEI: Limit printable size of BERT table data") does not work as intended on systems where the BIOS has a fixed size block of memory for the BERT table, relying on s/w to quit when it finds a record with estatus->block_status == 0. On these systems all errors are suppressed because the check: if (region_len < ACPI_BERT_PRINT_MAX_LEN) always fails. New scheme skips individual CPER records that are too large, and also limits the total number of records that will be printed to 5. Fixes: 3f8dec116210 ("ACPI/APEI: Limit printable size of BERT table data") Cc: stable@vger.kernel.org Signed-off-by: Tony Luck --- Now in PATCH format with a real commit comment. This version fixes the issues seen by Intel's validation team. drivers/acpi/apei/bert.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/apei/bert.c b/drivers/acpi/apei/bert.c index 598fd19b65fa..45973aa6e06d 100644 --- a/drivers/acpi/apei/bert.c +++ b/drivers/acpi/apei/bert.c @@ -29,16 +29,26 @@ #undef pr_fmt #define pr_fmt(fmt) "BERT: " fmt + +#define ACPI_BERT_PRINT_MAX_RECORDS 5 #define ACPI_BERT_PRINT_MAX_LEN 1024 static int bert_disable; +/* + * Print "all" the error records in the BERT table, but avoid huge spam to + * the console if the BIOS included oversize records, or too many records. + * Skipping some records here does not lose anything because the full + * data is available to user tools in: + * /sys/firmware/acpi/tables/data/BERT + */ static void __init bert_print_all(struct acpi_bert_region *region, unsigned int region_len) { struct acpi_hest_generic_status *estatus = (struct acpi_hest_generic_status *)region; int remain = region_len; + int printed = 0, skipped = 0; u32 estatus_len; while (remain >= sizeof(struct acpi_bert_region)) { @@ -46,24 +56,26 @@ static void __init bert_print_all(struct acpi_bert_region *region, if (remain < estatus_len) { pr_err(FW_BUG "Truncated status block (length: %u).\n", estatus_len); - return; + break; } /* No more error records. */ if (!estatus->block_status) - return; + break; if (cper_estatus_check(estatus)) { pr_err(FW_BUG "Invalid error record.\n"); - return; + break; } - pr_info_once("Error records from previous boot:\n"); - if (region_len < ACPI_BERT_PRINT_MAX_LEN) + if (estatus_len < ACPI_BERT_PRINT_MAX_LEN && + printed < ACPI_BERT_PRINT_MAX_RECORDS) { + pr_info_once("Error records from previous boot:\n"); cper_estatus_print(KERN_INFO HW_ERR, estatus); - else - pr_info_once("Max print length exceeded, table data is available at:\n" - "/sys/firmware/acpi/tables/data/BERT"); + printed++; + } else { + skipped++; + } /* * Because the boot error source is "one-time polled" type, @@ -75,6 +87,9 @@ static void __init bert_print_all(struct acpi_bert_region *region, estatus = (void *)estatus + estatus_len; remain -= estatus_len; } + + if (skipped) + pr_info(HW_ERR "Skipped %d error records\n", skipped); } static int __init setup_bert_disable(char *str)