Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759137Ab2JYBvl (ORCPT ); Wed, 24 Oct 2012 21:51:41 -0400 Received: from usindpps05.hds.com ([207.126.252.18]:53068 "EHLO usindpps05.hds.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759010Ab2JYBvj convert rfc822-to-8bit (ORCPT ); Wed, 24 Oct 2012 21:51:39 -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 1/5] efi_pstore: Check remaining space with QueryVariableInfo() before writing data Thread-Topic: [PATCH v2 1/5] efi_pstore: Check remaining space with QueryVariableInfo() before writing data Thread-Index: Ac2yUzWAAGu/E7YYTt6SMLfP+tNyfA== Date: Thu, 25 Oct 2012 01:51:25 +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=11 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=6.0.2-1203120001 definitions=main-1210240325 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2773 Lines: 80 [Issue] As discussed in a thread below, Running out of space in EFI isn't a well-tested scenario. And we wouldn't expect all firmware to handle it gracefully. http://marc.info/?l=linux-kernel&m=134305325801789&w=2 On the other hand, current efi_pstore doesn't check a remaining space of storage at writing time. Therefore, efi_pstore may not work if it tries to write a large amount of data. [Patch Description] To avoid handling the situation above, this patch checks if there is a space enough to log with QueryVariableInfo() before writing data. Signed-off-by: Seiji Aguchi --- drivers/firmware/efivars.c | 18 ++++++++++++++++++ include/linux/efi.h | 1 + 2 files changed, 19 insertions(+), 0 deletions(-) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index d10c987..37ac21a 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -707,12 +707,29 @@ static int efi_pstore_write(enum pstore_type_id type, 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); + /* + * Check if there is a space enough to log. + * size: a size of logging data + * DUMP_NAME_LEN * 2: a maximum size of variable name + */ + status = efivars->ops->query_variable_info(PSTORE_EFI_ATTRIBUTES, + &storage_space, + &remaining_space, + &max_variable_size); + if (status || remaining_space < size + DUMP_NAME_LEN * 2) { + spin_unlock(&efivars->lock); + *id = part; + return -ENOSPC; + } + for (i = 0; i < DUMP_NAME_LEN; i++) efi_name[i] = stub_name[i]; @@ -1237,6 +1254,7 @@ efivars_init(void) ops.get_variable = efi.get_variable; ops.set_variable = efi.set_variable; ops.get_next_variable = efi.get_next_variable; + ops.query_variable_info = efi.query_variable_info; error = register_efivars(&__efivars, &ops, efi_kobj); if (error) goto err_put; diff --git a/include/linux/efi.h b/include/linux/efi.h index 8670eb1..c47ec36 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -643,6 +643,7 @@ struct efivar_operations { efi_get_variable_t *get_variable; efi_get_next_variable_t *get_next_variable; efi_set_variable_t *set_variable; + efi_query_variable_info_t *query_variable_info; }; struct efivars { -- 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/