[ACPI] ACPICA 20051117

Fixed a problem in the AML parser where the method thread
count could be decremented below zero if any errors
occurred during the method parse phase. This should
eliminate AE_AML_METHOD_LIMIT exceptions seen on some
machines. This also fixed a related regression with the
mechanism that detects and corrects methods that cannot
properly handle reentrancy (related to the deployment of
the new OwnerId mechanism.)

Eliminated the pre-parsing of control methods (to detect
errors) during table load. Related to the problem above,
this was causing unwind issues if any errors occurred
during the parse, and it seemed to be overkill. A table
load should not be aborted if there are problems with
any single control method, thus rendering this feature
rather pointless.

Fixed a problem with the new table-driven resource manager
where an internal buffer overflow could occur for small
resource templates.

Implemented a new external interface, acpi_get_vendor_resource()
This interface will find and return a vendor-defined
resource descriptor within a _CRS or _PRS
method via an ACPI 3.0 UUID match. (from Bjorn Helgaas)

Removed the length limit (200) on string objects as
per the upcoming ACPI 3.0A specification. This affects
the following areas of the interpreter: 1) any implicit
conversion of a Buffer to a String, 2) a String object
result of the ASL Concatentate operator, 3) the String
object result of the ASL ToString operator.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 94 insertions, 95 deletions

diff --git a/drivers/acpi/parser/psargs.c b/drivers/acpi/parser/psargs.c
index 562d0f822ab1..6eae35febccd 100644
--- a/drivers/acpi/parser/psargs.c
+++ b/drivers/acpi/parser/psargs.c
@@ -62,61 +62,51 @@ static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
  *
  * PARAMETERS:  parser_state        - Current parser state object
  *
- * RETURN:      Decoded package length.  On completion, the AML pointer points
+ * RETURN:      Decoded package length. On completion, the AML pointer points
  *              past the length byte or bytes.
  *
- * DESCRIPTION: Decode and return a package length field
+ * DESCRIPTION: Decode and return a package length field.
+ *              Note: Largest package length is 28 bits, from ACPI specification
  *
  ******************************************************************************/
 
 static u32
 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
 {
-	u32 encoded_length;
-	u32 length = 0;
+	u8 *aml = parser_state->aml;
+	u32 package_length = 0;
+	acpi_native_uint byte_count;
+	u8 byte_zero_mask = 0x3F;	/* Default [0:5] */
 
 	ACPI_FUNCTION_TRACE("ps_get_next_package_length");
 
-	encoded_length = (u32) ACPI_GET8(parser_state->aml);
-	parser_state->aml++;
-
-	switch (encoded_length >> 6) {	/* bits 6-7 contain encoding scheme */
-	case 0:		/* 1-byte encoding (bits 0-5) */
-
-		length = (encoded_length & 0x3F);
-		break;
-
-	case 1:		/* 2-byte encoding (next byte + bits 0-3) */
-
-		length = ((ACPI_GET8(parser_state->aml) << 04) |
-			  (encoded_length & 0x0F));
-		parser_state->aml++;
-		break;
-
-	case 2:		/* 3-byte encoding (next 2 bytes + bits 0-3) */
-
-		length = ((ACPI_GET8(parser_state->aml + 1) << 12) |
-			  (ACPI_GET8(parser_state->aml) << 04) |
-			  (encoded_length & 0x0F));
-		parser_state->aml += 2;
-		break;
-
-	case 3:		/* 4-byte encoding (next 3 bytes + bits 0-3) */
+	/*
+	 * Byte 0 bits [6:7] contain the number of additional bytes
+	 * used to encode the package length, either 0,1,2, or 3
+	 */
+	byte_count = (aml[0] >> 6);
+	parser_state->aml += (byte_count + 1);
 
-		length = ((ACPI_GET8(parser_state->aml + 2) << 20) |
-			  (ACPI_GET8(parser_state->aml + 1) << 12) |
-			  (ACPI_GET8(parser_state->aml) << 04) |
-			  (encoded_length & 0x0F));
-		parser_state->aml += 3;
-		break;
+	/* Get bytes 3, 2, 1 as needed */
 
-	default:
+	while (byte_count) {
+		/*
+		 * Final bit positions for the package length bytes:
+		 *      Byte3->[20:27]
+		 *      Byte2->[12:19]
+		 *      Byte1->[04:11]
+		 *      Byte0->[00:03]
+		 */
+		package_length |= (aml[byte_count] << ((byte_count << 3) - 4));
 
-		/* Can't get here, only 2 bits / 4 cases */
-		break;
+		byte_zero_mask = 0x0F;	/* Use bits [0:3] of byte 0 */
+		byte_count--;
 	}
 
-	return_UINT32(length);
+	/* Byte 0 is a special case, either bits [0:3] or [0:5] are used */
+
+	package_length |= (aml[0] & byte_zero_mask);
+	return_UINT32(package_length);
 }
 
 /*******************************************************************************
@@ -135,16 +125,15 @@ acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
 u8 *acpi_ps_get_next_package_end(struct acpi_parse_state *parser_state)
 {
 	u8 *start = parser_state->aml;
-	acpi_native_uint length;
+	u32 package_length;
 
 	ACPI_FUNCTION_TRACE("ps_get_next_package_end");
 
-	/* Function below changes parser_state->Aml */
+	/* Function below updates parser_state->Aml */
 
-	length =
-	    (acpi_native_uint) acpi_ps_get_next_package_length(parser_state);
+	package_length = acpi_ps_get_next_package_length(parser_state);
 
-	return_PTR(start + length);	/* end of package */
+	return_PTR(start + package_length);	/* end of package */
 }
 
 /*******************************************************************************
@@ -169,17 +158,15 @@ char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
 
 	ACPI_FUNCTION_TRACE("ps_get_next_namestring");
 
-	/* Handle multiple prefix characters */
-
-	while (acpi_ps_is_prefix_char(ACPI_GET8(end))) {
-		/* Include prefix '\\' or '^' */
+	/* Point past any namestring prefix characters (backslash or carat) */
 
+	while (acpi_ps_is_prefix_char(*end)) {
 		end++;
 	}
 
-	/* Decode the path */
+	/* Decode the path prefix character */
 
-	switch (ACPI_GET8(end)) {
+	switch (*end) {
 	case 0:
 
 		/* null_name */
@@ -199,9 +186,9 @@ char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
 
 	case AML_MULTI_NAME_PREFIX_OP:
 
-		/* Multiple name segments, 4 chars each */
+		/* Multiple name segments, 4 chars each, count in next byte */
 
-		end += 2 + ((acpi_size) ACPI_GET8(end + 1) * ACPI_NAME_SIZE);
+		end += 2 + (*(end + 1) * ACPI_NAME_SIZE);
 		break;
 
 	default:
@@ -212,7 +199,7 @@ char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
 		break;
 	}
 
-	parser_state->aml = (u8 *) end;
+	parser_state->aml = end;
 	return_PTR((char *)start);
 }
 
@@ -342,7 +329,6 @@ acpi_ps_get_next_namepath(struct acpi_walk_state *walk_state,
 				    ("search_node %p start_node %p return_node %p\n",
 				     scope_info.scope.node,
 				     parser_state->start_node, node);
-
 			} else {
 				/*
 				 * We got a NOT_FOUND during table load or we encountered
@@ -382,59 +368,63 @@ void
 acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
 			    u32 arg_type, union acpi_parse_object *arg)
 {
+	u32 length;
+	u16 opcode;
+	u8 *aml = parser_state->aml;
 
 	ACPI_FUNCTION_TRACE_U32("ps_get_next_simple_arg", arg_type);
 
 	switch (arg_type) {
 	case ARGP_BYTEDATA:
 
-		acpi_ps_init_op(arg, AML_BYTE_OP);
-		arg->common.value.integer = (u32) ACPI_GET8(parser_state->aml);
-		parser_state->aml++;
+		/* Get 1 byte from the AML stream */
+
+		opcode = AML_BYTE_OP;
+		arg->common.value.integer = (acpi_integer) * aml;
+		length = 1;
 		break;
 
 	case ARGP_WORDDATA:
 
-		acpi_ps_init_op(arg, AML_WORD_OP);
-
 		/* Get 2 bytes from the AML stream */
 
-		ACPI_MOVE_16_TO_32(&arg->common.value.integer,
-				   parser_state->aml);
-		parser_state->aml += 2;
+		opcode = AML_WORD_OP;
+		ACPI_MOVE_16_TO_64(&arg->common.value.integer, aml);
+		length = 2;
 		break;
 
 	case ARGP_DWORDDATA:
 
-		acpi_ps_init_op(arg, AML_DWORD_OP);
-
 		/* Get 4 bytes from the AML stream */
 
-		ACPI_MOVE_32_TO_32(&arg->common.value.integer,
-				   parser_state->aml);
-		parser_state->aml += 4;
+		opcode = AML_DWORD_OP;
+		ACPI_MOVE_32_TO_64(&arg->common.value.integer, aml);
+		length = 4;
 		break;
 
 	case ARGP_QWORDDATA:
 
-		acpi_ps_init_op(arg, AML_QWORD_OP);
-
 		/* Get 8 bytes from the AML stream */
 
-		ACPI_MOVE_64_TO_64(&arg->common.value.integer,
-				   parser_state->aml);
-		parser_state->aml += 8;
+		opcode = AML_QWORD_OP;
+		ACPI_MOVE_64_TO_64(&arg->common.value.integer, aml);
+		length = 8;
 		break;
 
 	case ARGP_CHARLIST:
 
-		acpi_ps_init_op(arg, AML_STRING_OP);
-		arg->common.value.string = (char *)parser_state->aml;
+		/* Get a pointer to the string, point past the string */
+
+		opcode = AML_STRING_OP;
+		arg->common.value.string = ACPI_CAST_PTR(char, aml);
 
-		while (ACPI_GET8(parser_state->aml) != '\0') {
-			parser_state->aml++;
+		/* Find the null terminator */
+
+		length = 0;
+		while (aml[length]) {
+			length++;
 		}
-		parser_state->aml++;
+		length++;
 		break;
 
 	case ARGP_NAME:
@@ -443,14 +433,16 @@ acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
 		acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
 		arg->common.value.name =
 		    acpi_ps_get_next_namestring(parser_state);
-		break;
+		return_VOID;
 
 	default:
 
 		ACPI_REPORT_ERROR(("Invalid arg_type %X\n", arg_type));
-		break;
+		return_VOID;
 	}
 
+	acpi_ps_init_op(arg, opcode);
+	parser_state->aml += length;
 	return_VOID;
 }
 
@@ -540,7 +532,7 @@ static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
 		 * access_type is first operand, access_attribute is second
 		 */
 		field->common.value.integer =
-		    (ACPI_GET8(parser_state->aml) << 8);
+		    (((u32) ACPI_GET8(parser_state->aml) << 8));
 		parser_state->aml++;
 		field->common.value.integer |= ACPI_GET8(parser_state->aml);
 		parser_state->aml++;
diff --git a/drivers/acpi/parser/psparse.c b/drivers/acpi/parser/psparse.c
index 76d4d640d83c..7cfa7eb0dfc7 100644
--- a/drivers/acpi/parser/psparse.c
+++ b/drivers/acpi/parser/psparse.c
@@ -503,22 +503,23 @@ acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
 		} else if (status == AE_CTRL_TERMINATE) {
 			status = AE_OK;
 		} else if ((status != AE_OK) && (walk_state->method_desc)) {
-			ACPI_REPORT_METHOD_ERROR("Method execution failed",
-						 walk_state->method_node, NULL,
-						 status);
+			/* Either the method parse or actual execution failed */
 
-			/* Ensure proper cleanup */
-
-			walk_state->parse_flags |= ACPI_PARSE_EXECUTE;
+			ACPI_REPORT_METHOD_ERROR
+			    ("Method parse/execution failed",
+			     walk_state->method_node, NULL, status);
 
 			/* Check for possible multi-thread reentrancy problem */
 
 			if ((status == AE_ALREADY_EXISTS) &&
 			    (!walk_state->method_desc->method.semaphore)) {
 				/*
-				 * This method is marked not_serialized, but it tried to create
+				 * Method tried to create an object twice. The probable cause is
+				 * that the method cannot handle reentrancy.
+				 *
+				 * The method is marked not_serialized, but it tried to create
 				 * a named object, causing the second thread entrance to fail.
-				 * We will workaround this by marking the method permanently
+				 * Workaround this problem by marking the method permanently
 				 * as Serialized.
 				 */
 				walk_state->method_desc->method.method_flags |=
@@ -536,15 +537,22 @@ acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
 		acpi_ds_scope_stack_clear(walk_state);
 
 		/*
-		 * If we just returned from the execution of a control method,
-		 * there's lots of cleanup to do
+		 * If we just returned from the execution of a control method or if we
+		 * encountered an error during the method parse phase, there's lots of
+		 * cleanup to do
 		 */
-		if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
-		    ACPI_PARSE_EXECUTE) {
+		if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
+		     ACPI_PARSE_EXECUTE) || (ACPI_FAILURE(status))) {
 			if (walk_state->method_desc) {
 				/* Decrement the thread count on the method parse tree */
 
-				walk_state->method_desc->method.thread_count--;
+				if (walk_state->method_desc->method.
+				    thread_count) {
+					walk_state->method_desc->method.
+					    thread_count--;
+				} else {
+					ACPI_REPORT_ERROR(("Invalid zero thread count in method\n"));
+				}
 			}
 
 			acpi_ds_terminate_control_method(walk_state);
@@ -553,7 +561,6 @@ acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
 		/* Delete this walk state and all linked control states */
 
 		acpi_ps_cleanup_scope(&walk_state->parser_state);
-
 		previous_walk_state = walk_state;
 
 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
diff --git a/drivers/acpi/parser/psxface.c b/drivers/acpi/parser/psxface.c
index 4c426f4c6af6..14d544d60867 100644
--- a/drivers/acpi/parser/psxface.c
+++ b/drivers/acpi/parser/psxface.c
@@ -87,7 +87,7 @@ acpi_debug_trace(char *name, u32 debug_level, u32 debug_layer, u32 flags)
 
 	/* TBDs: Validate name, allow full path or just nameseg */
 
-	acpi_gbl_trace_method_name = *(u32 *) name;
+	acpi_gbl_trace_method_name = *ACPI_CAST_PTR(u32, name);
 	acpi_gbl_trace_flags = flags;
 
 	if (debug_level) {