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>

1 files changed, 50 insertions, 1 deletions

diff --git a/drivers/acpi/acpica/psloop.c b/drivers/acpi/acpica/psloop.c
index 68422afc365f..bc5f05906bd1 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;
 			}
 		}