Commit c64baa3a authored by Erik Schmauss's avatar Erik Schmauss Committed by Rafael J. Wysocki
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ACPICA: AML Parser: fix parse loop to correctly skip erroneous extended opcodes 



AML opcodes come in two lengths: 1-byte opcodes and 2-byte, extended opcodes.
If an error occurs due to illegal opcodes during table load, the AML parser
needs to continue loading the table. In order to do this, it needs to skip
parsing of the offending opcode and operands associated with that opcode.

This change fixes the AML parse loop to correctly skip parsing of incorrect
extended opcodes. Previously, only the short opcodes were skipped correctly.

Signed-off-by: default avatarErik Schmauss <erik.schmauss@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 4abb951b

drivers/acpi/acpica/psloop.c

+13 −1
Original line number Original line Diff line number Diff line
@@ -417,6 +417,7 @@ acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state) 
	union acpi_parse_object *op = NULL;	/* current op */

	union acpi_parse_object *op = NULL;	/* current op */

	struct acpi_parse_state *parser_state;

	struct acpi_parse_state *parser_state;

	u8 *aml_op_start = NULL;

	u8 *aml_op_start = NULL;

	u8 opcode_length;





	ACPI_FUNCTION_TRACE_PTR(ps_parse_loop, walk_state);

	ACPI_FUNCTION_TRACE_PTR(ps_parse_loop, walk_state);
@@ -540,8 +541,19 @@ acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state) 
						    "Skip parsing opcode %s",

						    "Skip parsing opcode %s",

						    acpi_ps_get_opcode_name

						    acpi_ps_get_opcode_name

						    (walk_state->opcode)));

						    (walk_state->opcode)));



					/*

					 * Determine the opcode length before skipping the opcode.

					 * An opcode can be 1 byte or 2 bytes in length.

					 */

					opcode_length = 1;

					if ((walk_state->opcode & 0xFF00) ==

					    AML_EXTENDED_OPCODE) {

						opcode_length = 2;

					}

					walk_state->parser_state.aml =

					walk_state->parser_state.aml =

					    walk_state->aml + 1;

					    walk_state->aml + opcode_length;



					walk_state->parser_state.aml =

					walk_state->parser_state.aml =

					    acpi_ps_get_next_package_end

					    acpi_ps_get_next_package_end

					    (&walk_state->parser_state);

					    (&walk_state->parser_state);

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