ACPICA: AML parser: attempt to continue loading table after error

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>

3 files changed, 85 insertions, 6 deletions

diff --git a/drivers/acpi/acpica/psloop.c b/drivers/acpi/acpica/psloop.c
index 68422af..bc5f059 100644
--- a/drivers/acpi/acpica/psloop.c
+++ b/drivers/acpi/acpica/psloop.c
@@ -515,6 +515,22 @@ 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;
 			}
@@ -557,7 +573,40 @@ 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 7d9d015..3138e7a 100644
--- a/drivers/acpi/acpica/psobject.c
+++ b/drivers/acpi/acpica/psobject.c
@@ -12,6 +12,7 @@
 #include "acparser.h"
 #include "amlcode.h"
 #include "acconvert.h"
+#include "acnamesp.h"
 
 #define _COMPONENT          ACPI_PARSER
 ACPI_MODULE_NAME("psobject")
@@ -549,6 +550,21 @@ 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)) {
@@ -574,6 +590,20 @@ 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);
 	}
 
diff --git a/drivers/acpi/acpica/uterror.c b/drivers/acpi/acpica/uterror.c
index 12d4a0f..5a64dda 100644
--- a/drivers/acpi/acpica/uterror.c
+++ b/drivers/acpi/acpica/uterror.c
@@ -182,20 +182,20 @@ acpi_ut_prefixed_namespace_error(const char *module_name,
 	switch (lookup_status) {
 	case AE_ALREADY_EXISTS:
 
-		acpi_os_printf(ACPI_MSG_BIOS_ERROR);
+		acpi_os_printf("\n" ACPI_MSG_BIOS_ERROR);
 		message = "Failure creating";
 		break;
 
 	case AE_NOT_FOUND:
 
-		acpi_os_printf(ACPI_MSG_BIOS_ERROR);
-		message = "Failure looking up";
+		acpi_os_printf("\n" ACPI_MSG_BIOS_ERROR);
+		message = "Could not resolve";
 		break;
 
 	default:
 
-		acpi_os_printf(ACPI_MSG_ERROR);
-		message = "Failure looking up";
+		acpi_os_printf("\n" ACPI_MSG_ERROR);
+		message = "Failure resolving";
 		break;
 	}