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[1/5] ACPICA: AML parser: attempt to continue loading table after error

Message ID 20190315050418.7788-2-aaron.ma@canonical.com
State New
Headers show
Series iommu: add kernel dma protection | expand

Commit Message

Aaron Ma March 15, 2019, 5:04 a.m. UTC 
From: Erik Schmauss <erik.schmauss@intel.com>

BugLink: https://bugs.launchpad.net/bugs/1820153

This change alters the parser so that the table load does not abort
upon an error.

Notable changes:

If there is an error while parsing an element of the termlist, we
will skip parsing the current termlist element and continue parsing
to the next opcode in the termlist.

If we get an error while parsing the conditional of If/Else/While or
the device name of Scope, we will skip the body of the statement all
together and pop the parser_state.

If we get an error while parsing the base offset and length of an
operation region declaration, we will remove the operation region
from the namespace.

Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(backported from commit 5088814a6e931350e5bd29f5d59fa40c6dbbdf10)
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
---
 drivers/acpi/acpica/psloop.c   | 51 +++++++++++++++++++++++++++++++++-
 drivers/acpi/acpica/psobject.c | 30 ++++++++++++++++++++
 2 files changed, 80 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/acpi/acpica/psloop.c b/drivers/acpi/acpica/psloop.c
index bb04dec168ad..f437c3d54086 100644
--- a/drivers/acpi/acpica/psloop.c
+++ b/drivers/acpi/acpica/psloop.c
@@ -531,6 +531,22 @@  acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
 				if (ACPI_FAILURE(status)) {
 					return_ACPI_STATUS(status);
 				}
+				if (walk_state->opcode == AML_SCOPE_OP) {
+					/*
+					 * If the scope op fails to parse, skip the body of the
+					 * scope op because the parse failure indicates that the
+					 * device may not exist.
+					 */
+					walk_state->parser_state.aml =
+					    walk_state->aml + 1;
+					walk_state->parser_state.aml =
+					    acpi_ps_get_next_package_end
+					    (&walk_state->parser_state);
+					walk_state->aml =
+					    walk_state->parser_state.aml;
+					ACPI_ERROR((AE_INFO,
+						    "Skipping Scope block"));
+				}
 
 				continue;
 			}
@@ -573,7 +589,40 @@  acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
 				if (ACPI_FAILURE(status)) {
 					return_ACPI_STATUS(status);
 				}
-
+				if ((walk_state->control_state) &&
+				    ((walk_state->control_state->control.
+				      opcode == AML_IF_OP)
+				     || (walk_state->control_state->control.
+					 opcode == AML_WHILE_OP))) {
+					/*
+					 * If the if/while op fails to parse, we will skip parsing
+					 * the body of the op.
+					 */
+					parser_state->aml =
+					    walk_state->control_state->control.
+					    aml_predicate_start + 1;
+					parser_state->aml =
+					    acpi_ps_get_next_package_end
+					    (parser_state);
+					walk_state->aml = parser_state->aml;
+
+					ACPI_ERROR((AE_INFO,
+						    "Skipping While/If block"));
+					if (*walk_state->aml == AML_ELSE_OP) {
+						ACPI_ERROR((AE_INFO,
+							    "Skipping Else block"));
+						walk_state->parser_state.aml =
+						    walk_state->aml + 1;
+						walk_state->parser_state.aml =
+						    acpi_ps_get_next_package_end
+						    (parser_state);
+						walk_state->aml =
+						    parser_state->aml;
+					}
+					ACPI_FREE(acpi_ut_pop_generic_state
+						  (&walk_state->control_state));
+				}
+				op = NULL;
 				continue;
 			}
 		}
diff --git a/drivers/acpi/acpica/psobject.c b/drivers/acpi/acpica/psobject.c
index 0bef6df71bba..9e9d56597e6b 100644
--- a/drivers/acpi/acpica/psobject.c
+++ b/drivers/acpi/acpica/psobject.c
@@ -46,6 +46,7 @@ 
 #include "acparser.h"
 #include "amlcode.h"
 #include "acconvert.h"
+#include "acnamesp.h"
 
 #define _COMPONENT          ACPI_PARSER
 ACPI_MODULE_NAME("psobject")
@@ -587,6 +588,21 @@  acpi_ps_complete_op(struct acpi_walk_state *walk_state,
 
 		do {
 			if (*op) {
+				/*
+				 * These Opcodes need to be removed from the namespace because they
+				 * get created even if these opcodes cannot be created due to
+				 * errors.
+				 */
+				if (((*op)->common.aml_opcode == AML_REGION_OP)
+				    || ((*op)->common.aml_opcode ==
+					AML_DATA_REGION_OP)) {
+					acpi_ns_delete_children((*op)->common.
+								node);
+					acpi_ns_remove_node((*op)->common.node);
+					(*op)->common.node = NULL;
+					acpi_ps_delete_parse_tree(*op);
+				}
+
 				status2 =
 				    acpi_ps_complete_this_op(walk_state, *op);
 				if (ACPI_FAILURE(status2)) {
@@ -612,6 +628,20 @@  acpi_ps_complete_op(struct acpi_walk_state *walk_state,
 #endif
 		walk_state->prev_op = NULL;
 		walk_state->prev_arg_types = walk_state->arg_types;
+
+		if (walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL) {
+			/*
+			 * There was something that went wrong while executing code at the
+			 * module-level. We need to skip parsing whatever caused the
+			 * error and keep going. One runtime error during the table load
+			 * should not cause the entire table to not be loaded. This is
+			 * because there could be correct AML beyond the parts that caused
+			 * the runtime error.
+			 */
+			ACPI_ERROR((AE_INFO,
+				    "Ignore error and continue table load"));
+			return_ACPI_STATUS(AE_OK);
+		}
 		return_ACPI_STATUS(status);
 	}