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authorLin Ming <ming.m.lin@intel.com>2010-04-01 06:47:56 +0400
committerLen Brown <len.brown@intel.com>2010-04-20 18:43:16 +0400
commit729df0f848daf2f17d02107199fa92efe909d995 (patch)
treed4ece34a277019368999fd36a0bf15a39eeaa742 /drivers/acpi/acpica/tbxface.c
parentc1637e9c649a0eb72c467041d78275aabdd48a41 (diff)
downloadlinux-729df0f848daf2f17d02107199fa92efe909d995.tar.xz
ACPICA: Add detection of corrupted/replaced DSDT
This change adds support to detect a DSDT that has been corrupted and/or replaced from outside the OS (by firmware). This is typically catastrophic for the system, but has been seen on some machines. https://bugzilla.kernel.org/show_bug.cgi?id=14679 Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/acpica/tbxface.c')
-rw-r--r--drivers/acpi/acpica/tbxface.c32
1 files changed, 12 insertions, 20 deletions
diff --git a/drivers/acpi/acpica/tbxface.c b/drivers/acpi/acpica/tbxface.c
index 684614d0d327..30565100b94c 100644
--- a/drivers/acpi/acpica/tbxface.c
+++ b/drivers/acpi/acpica/tbxface.c
@@ -518,33 +518,25 @@ static acpi_status acpi_tb_load_namespace(void)
(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
+ acpi_gbl_DSDT = &acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT];
+
/*
- * Load the namespace. The DSDT is required, but any SSDT and PSDT tables
- * are optional.
+ * Load the namespace. The DSDT is required, but any SSDT and
+ * PSDT tables are optional. Verify the DSDT.
*/
if (!acpi_gbl_root_table_list.count ||
- !ACPI_COMPARE_NAME(&
- (acpi_gbl_root_table_list.
- tables[ACPI_TABLE_INDEX_DSDT].signature),
- ACPI_SIG_DSDT)
- ||
- ACPI_FAILURE(acpi_tb_verify_table
- (&acpi_gbl_root_table_list.
- tables[ACPI_TABLE_INDEX_DSDT]))) {
+ !ACPI_COMPARE_NAME(&acpi_gbl_DSDT->signature, ACPI_SIG_DSDT) ||
+ ACPI_FAILURE(acpi_tb_verify_table(acpi_gbl_DSDT))) {
status = AE_NO_ACPI_TABLES;
goto unlock_and_exit;
}
- /* A valid DSDT is required */
-
- status =
- acpi_tb_verify_table(&acpi_gbl_root_table_list.
- tables[ACPI_TABLE_INDEX_DSDT]);
- if (ACPI_FAILURE(status)) {
-
- status = AE_NO_ACPI_TABLES;
- goto unlock_and_exit;
- }
+ /*
+ * Save the original DSDT header for detection of table corruption
+ * and/or replacement of the DSDT from outside the OS.
+ */
+ ACPI_MEMCPY(&acpi_gbl_original_dsdt_header, acpi_gbl_DSDT->pointer,
+ sizeof(struct acpi_table_header));
(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);