Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758028Ab3HAW2M (ORCPT ); Thu, 1 Aug 2013 18:28:12 -0400 Received: from g1t0027.austin.hp.com ([15.216.28.34]:14604 "EHLO g1t0027.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755118Ab3HAW2I (ORCPT ); Thu, 1 Aug 2013 18:28:08 -0400 Message-ID: <1375396019.10300.32.camel@misato.fc.hp.com> Subject: Re: [PATCH v2 04/18] acpi: Introduce acpi_invalid_table() to check if a table is invalid. From: Toshi Kani To: Tang Chen Cc: rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org, tj@kernel.org, trenn@suse.de, yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org, mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, riel@redhat.com, jweiner@redhat.com, prarit@redhat.com, zhangyanfei@cn.fujitsu.com, yanghy@cn.fujitsu.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org Date: Thu, 01 Aug 2013 16:26:59 -0600 In-Reply-To: <1375340800-19332-5-git-send-email-tangchen@cn.fujitsu.com> References: <1375340800-19332-1-git-send-email-tangchen@cn.fujitsu.com> <1375340800-19332-5-git-send-email-tangchen@cn.fujitsu.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4 (3.6.4-3.fc18) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4693 Lines: 140 On Thu, 2013-08-01 at 15:06 +0800, Tang Chen wrote: > In acpi_initrd_override(), it checks several things to ensure the > table it found is valid. In later patches, we need to do these check > somewhere else. So this patch introduces a common function > acpi_invalid_table() to do all these checks, and reuse it in different > places. The function will be used in the subsequent patches. > > Signed-off-by: Tang Chen > Reviewed-by: Zhang Yanfei > --- > drivers/acpi/osl.c | 86 +++++++++++++++++++++++++++++++++++++--------------- > 1 files changed, 61 insertions(+), 25 deletions(-) > > diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c > index 91d9f54..8df8a93 100644 > --- a/drivers/acpi/osl.c > +++ b/drivers/acpi/osl.c > @@ -572,9 +572,68 @@ static const char * const table_sigs[] = { > /* Must not increase 10 or needs code modification below */ > #define ACPI_OVERRIDE_TABLES 10 > > +/******************************************************************************* > + * > + * FUNCTION: acpi_invalid_table > + * > + * PARAMETERS: File - The initrd file > + * Path - Path to acpi overriding tables in cpio file > + * Signature - Signature of the table > + * > + * RETURN: 0 if it passes all the checks, -EINVAL if any check fails. > + * > + * DESCRIPTION: Check if an acpi table found in initrd is invalid. > + * @signature can be NULL. If it is NULL, the function will check > + * if the table signature matches any signature in table_sigs[]. > + * > + ******************************************************************************/ > +int __init acpi_invalid_table(struct cpio_data *file, > + const char *path, const char *signature) Since this function verifies a given acpi table in initrd (not that the table is invalid), I'd suggest to rename it something like acpi_verify_initrd(). Otherwise, it looks good to me. Acked-by: Toshi Kani Thanks, -Toshi > +{ > + int idx; > + struct acpi_table_header *table = file->data; > + > + if (file->size < sizeof(struct acpi_table_header)) { > + INVALID_TABLE("Table smaller than ACPI header", > + path, file->name); > + return -EINVAL; > + } > + > + if (signature) { > + if (memcmp(table->signature, signature, 4)) { > + INVALID_TABLE("Table signature does not match", > + path, file->name); > + return -EINVAL; > + } > + } else { > + for (idx = 0; table_sigs[idx]; idx++) > + if (!memcmp(table->signature, table_sigs[idx], 4)) > + break; > + > + if (!table_sigs[idx]) { > + INVALID_TABLE("Unknown signature", path, file->name); > + return -EINVAL; > + } > + } > + > + if (file->size != table->length) { > + INVALID_TABLE("File length does not match table length", > + path, file->name); > + return -EINVAL; > + } > + > + if (acpi_table_checksum(file->data, table->length)) { > + INVALID_TABLE("Bad table checksum", > + path, file->name); > + return -EINVAL; > + } > + > + return 0; > +} > + > void __init acpi_initrd_override(void *data, size_t size) > { > - int sig, no, table_nr = 0, total_offset = 0; > + int no, table_nr = 0, total_offset = 0; > long offset = 0; > struct acpi_table_header *table; > char cpio_path[32] = "kernel/firmware/acpi/"; > @@ -593,33 +652,10 @@ void __init acpi_initrd_override(void *data, size_t size) > data += offset; > size -= offset; > > - if (file.size < sizeof(struct acpi_table_header)) { > - INVALID_TABLE("Table smaller than ACPI header", > - cpio_path, file.name); > - continue; > - } > - > table = file.data; > > - for (sig = 0; table_sigs[sig]; sig++) > - if (!memcmp(table->signature, table_sigs[sig], 4)) > - break; > - > - if (!table_sigs[sig]) { > - INVALID_TABLE("Unknown signature", > - cpio_path, file.name); > + if (acpi_invalid_table(&file, cpio_path, NULL)) > continue; > - } > - if (file.size != table->length) { > - INVALID_TABLE("File length does not match table length", > - cpio_path, file.name); > - continue; > - } > - if (acpi_table_checksum(file.data, table->length)) { > - INVALID_TABLE("Bad table checksum", > - cpio_path, file.name); > - continue; > - } > > pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n", > table->signature, cpio_path, file.name, table->length); -- 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/