1 files changed, 20 insertions, 12 deletions

diff --git a/drivers/acpi/executer/exconvrt.c b/drivers/acpi/executer/exconvrt.c
index 261d97516d9b..1d1f35adddde 100644
--- a/drivers/acpi/executer/exconvrt.c
+++ b/drivers/acpi/executer/exconvrt.c
@@ -57,7 +57,7 @@ acpi_ex_convert_to_ascii(acpi_integer integer,
  *
  * FUNCTION:    acpi_ex_convert_to_integer
  *
- * PARAMETERS:  obj_desc        - Object to be converted.  Must be an
+ * PARAMETERS:  obj_desc        - Object to be converted. Must be an
  *                                Integer, Buffer, or String
  *              result_desc     - Where the new Integer object is returned
  *              Flags           - Used for string conversion
@@ -103,7 +103,7 @@ acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
         }
 
         /*
-         * Convert the buffer/string to an integer.  Note that both buffers and
+         * Convert the buffer/string to an integer. Note that both buffers and
          * strings are treated as raw data - we don't convert ascii to hex for
          * strings.
          *
@@ -120,7 +120,7 @@ acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
 
                 /*
                  * Convert string to an integer - for most cases, the string must be
-                 * hexadecimal as per the ACPI specification.  The only exception (as
+                 * hexadecimal as per the ACPI specification. The only exception (as
                  * of ACPI 3.0) is that the to_integer() operator allows both decimal
                  * and hexadecimal strings (hex prefixed with "0x").
                  */
@@ -159,6 +159,7 @@ acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
                 break;
 
         default:
+
                 /* No other types can get here */
                 break;
         }
@@ -185,7 +186,7 @@ acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
  *
  * FUNCTION:    acpi_ex_convert_to_buffer
  *
- * PARAMETERS:  obj_desc        - Object to be converted.  Must be an
+ * PARAMETERS:  obj_desc        - Object to be converted. Must be an
  *                                Integer, Buffer, or String
  *              result_desc     - Where the new buffer object is returned
  *
@@ -365,7 +366,7 @@ acpi_ex_convert_to_ascii(acpi_integer integer,
         }
 
         /*
-         * Since leading zeros are supressed, we must check for the case where
+         * Since leading zeros are suppressed, we must check for the case where
          * the integer equals 0
          *
          * Finally, null terminate the string and return the length
@@ -383,7 +384,7 @@ acpi_ex_convert_to_ascii(acpi_integer integer,
  *
  * FUNCTION:    acpi_ex_convert_to_string
  *
- * PARAMETERS:  obj_desc        - Object to be converted.  Must be an
+ * PARAMETERS:  obj_desc        - Object to be converted. Must be an
  *                                Integer, Buffer, or String
  *              result_desc     - Where the string object is returned
  *              Type            - String flags (base and conversion type)
@@ -472,7 +473,7 @@ acpi_ex_convert_to_string(union acpi_operand_object * obj_desc,
                         base = 10;
 
                         /*
-                         * Calculate the final string length.  Individual string values
+                         * Calculate the final string length. Individual string values
                          * are variable length (include separator for each)
                          */
                         for (i = 0; i < obj_desc->buffer.length; i++) {
@@ -511,9 +512,14 @@ acpi_ex_convert_to_string(union acpi_operand_object * obj_desc,
                 /*
                  * Create a new string object and string buffer
                  * (-1 because of extra separator included in string_length from above)
+                 * Allow creation of zero-length strings from zero-length buffers.
                  */
+                if (string_length) {
+                        string_length--;
+                }
+
                 return_desc = acpi_ut_create_string_object((acpi_size)
-                                                           (string_length - 1));
+                                                           string_length);
                 if (!return_desc) {
                         return_ACPI_STATUS(AE_NO_MEMORY);
                 }
@@ -536,7 +542,9 @@ acpi_ex_convert_to_string(union acpi_operand_object * obj_desc,
                  * Null terminate the string
                  * (overwrites final comma/space from above)
                  */
-                new_buf--;
+                if (obj_desc->buffer.length) {
+                        new_buf--;
+                }
                 *new_buf = 0;
                 break;
 
@@ -617,7 +625,7 @@ acpi_ex_convert_to_target_type(acpi_object_type destination_type,
                 case ACPI_TYPE_LOCAL_BANK_FIELD:
                 case ACPI_TYPE_LOCAL_INDEX_FIELD:
                         /*
-                         * These types require an Integer operand.  We can convert
+                         * These types require an Integer operand. We can convert
                          * a Buffer or a String to an Integer if necessary.
                          */
                         status =
@@ -627,7 +635,7 @@ acpi_ex_convert_to_target_type(acpi_object_type destination_type,
 
                 case ACPI_TYPE_STRING:
                         /*
-                         * The operand must be a String.  We can convert an
+                         * The operand must be a String. We can convert an
                          * Integer or Buffer if necessary
                          */
                         status =
@@ -637,7 +645,7 @@ acpi_ex_convert_to_target_type(acpi_object_type destination_type,
 
                 case ACPI_TYPE_BUFFER:
                         /*
-                         * The operand must be a Buffer.  We can convert an
+                         * The operand must be a Buffer. We can convert an
                          * Integer or String if necessary
                          */
                         status =