Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759193Ab2JYByO (ORCPT ); Wed, 24 Oct 2012 21:54:14 -0400 Received: from usindpps05.hds.com ([207.126.252.18]:54112 "EHLO usindpps05.hds.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759111Ab2JYByM convert rfc822-to-8bit (ORCPT ); Wed, 24 Oct 2012 21:54:12 -0400 From: Seiji Aguchi To: "linux-kernel@vger.kernel.org" , "linux-efi@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "mikew@google.com" , "Luck, Tony (tony.luck@intel.com)" , "Matthew Garrett (mjg@redhat.com)" , "dzickus@redhat.com" CC: "dle-develop@lists.sourceforge.net" , Satoru Moriya Subject: [PATCH v2 3/5] efi_pstore: Remove a logic erasing entries from a write callback to hold multiple logs Thread-Topic: [PATCH v2 3/5] efi_pstore: Remove a logic erasing entries from a write callback to hold multiple logs Thread-Index: Ac2yU45Umwbisi8ERWqdMazeX7tkNw== Date: Thu, 25 Oct 2012 01:54:00 +0000 Message-ID: Accept-Language: ja-JP, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.74.43.113] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.7.7855,1.0.431,0.0.0000 definitions=2012-10-24_09:2012-10-24,2012-10-24,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_policy_notspam policy=outbound_policy score=0 spamscore=0 ipscore=0 suspectscore=1 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=6.0.2-1203120001 definitions=main-1210240326 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3032 Lines: 99 [Issue] Currently, efi_pstore driver simply overwrites existing panic messages in NVRAM. So, in the following scenario, we will lose 1st panic messages. 1. kernel panics. 2. efi_pstore is kicked and writes panic messages to NVRAM. 3. system reboots. 4. kernel panics again before a user checks the 1st panic messages in NVRAM. [Solution] A reasonable solution to fix the issue is just holding multiple logs without erasing existing entries. This patch removes a logic erasing existing entries in a write callback because the logic is not needed in the write callback to support holding multiple logs. Signed-off-by: Seiji Aguchi --- drivers/firmware/efivars.c | 39 ++------------------------------------- 1 files changed, 2 insertions(+), 37 deletions(-) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index bee14cc..fbe9202 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -701,18 +701,13 @@ static int efi_pstore_write(enum pstore_type_id type, unsigned int part, size_t size, struct pstore_info *psi) { char name[DUMP_NAME_LEN]; - char stub_name[DUMP_NAME_LEN]; efi_char16_t efi_name[DUMP_NAME_LEN]; efi_guid_t vendor = LINUX_EFI_CRASH_GUID; struct efivars *efivars = psi->data; - struct efivar_entry *entry, *found = NULL; int i, ret = 0; u64 storage_space, remaining_space, max_variable_size; efi_status_t status = EFI_NOT_FOUND; - sprintf(stub_name, "dump-type%u-%u-", type, part); - sprintf(name, "%s%lu", stub_name, get_seconds()); - spin_lock(&efivars->lock); /* @@ -730,35 +725,8 @@ static int efi_pstore_write(enum pstore_type_id type, return -ENOSPC; } - for (i = 0; i < DUMP_NAME_LEN; i++) - efi_name[i] = stub_name[i]; - - /* - * Clean up any entries with the same name - */ - - list_for_each_entry(entry, &efivars->list, list) { - get_var_data_locked(efivars, &entry->var); - - if (efi_guidcmp(entry->var.VendorGuid, vendor)) - continue; - if (utf16_strncmp(entry->var.VariableName, efi_name, - utf16_strlen(efi_name))) - continue; - /* Needs to be a prefix */ - if (entry->var.VariableName[utf16_strlen(efi_name)] == 0) - continue; - - /* found */ - found = entry; - efivars->ops->set_variable(entry->var.VariableName, - &entry->var.VendorGuid, - PSTORE_EFI_ATTRIBUTES, - 0, NULL); - } - - if (found) - list_del(&found->list); + sprintf(name, "dump-type%u-%u-%lu", type, part, + get_seconds()); for (i = 0; i < DUMP_NAME_LEN; i++) efi_name[i] = name[i]; @@ -768,9 +736,6 @@ static int efi_pstore_write(enum pstore_type_id type, spin_unlock(&efivars->lock); - if (found) - efivar_unregister(found); - if (size) ret = efivar_create_sysfs_entry(efivars, utf16_strsize(efi_name, -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/