Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934175Ab2JZVkw (ORCPT ); Fri, 26 Oct 2012 17:40:52 -0400 Received: from usindpps06.hds.com ([207.126.252.19]:40534 "EHLO usindpps06.hds.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933923Ab2JZVkt convert rfc822-to-8bit (ORCPT ); Fri, 26 Oct 2012 17:40:49 -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 v3 2/7] efi_pstore: Add a logic erasing entries to an erase callback Thread-Topic: [PATCH v3 2/7] efi_pstore: Add a logic erasing entries to an erase callback Thread-Index: Ac2zwoMAW3Sb3ZKQQt6P5vGbJvdQVA== Date: Fri, 26 Oct 2012 21:40:39 +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=2012-10-26_06:2012-10-26,2012-10-26,1970-01-01 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-1210260270 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2667 Lines: 88 [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 freshly adds a logic erasing existing entries, which shared with a write callback, to an erase callback. To support holding multiple logs, the write callback doesn't need to erase any entries and it will be removed in a subsequent patch. Signed-off-by: Seiji Aguchi --- drivers/firmware/efivars.c | 46 +++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 45 insertions(+), 1 deletions(-) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 37ac21a..bee14cc 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -784,7 +784,51 @@ static int efi_pstore_write(enum pstore_type_id type, static int efi_pstore_erase(enum pstore_type_id type, u64 id, struct pstore_info *psi) { - efi_pstore_write(type, 0, &id, (unsigned int)id, 0, psi); + 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; + + sprintf(stub_name, "dump-type%u-%u-", type, (unsigned int)id); + + spin_lock(&efivars->lock); + + 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); + + spin_unlock(&efivars->lock); + + if (found) + efivar_unregister(found); return 0; } -- 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/