vendor/acpica/20160930

1 files changed, 63 insertions, 5 deletions

diff --git a/source/components/disassembler/dmbuffer.c b/source/components/disassembler/dmbuffer.c
index 79c37e2e3ea8..42920500ba2d 100644
--- a/source/components/disassembler/dmbuffer.c
+++ b/source/components/disassembler/dmbuffer.c
@@ -529,7 +529,8 @@ AcpiDmIsStringBuffer (
  *
  * PARAMETERS:  Op                  - Buffer Object to be examined
  *
- * RETURN:      TRUE if buffer contains a ASCII string, FALSE otherwise
+ * RETURN:      TRUE if buffer appears to contain data produced via the
+ *              ToPLD macro, FALSE otherwise
  *
  * DESCRIPTION: Determine if a buffer Op contains a _PLD structure
  *
@@ -541,12 +542,60 @@ AcpiDmIsPldBuffer (
 {
     ACPI_NAMESPACE_NODE     *Node;
     ACPI_PARSE_OBJECT       *SizeOp;
+    ACPI_PARSE_OBJECT       *ByteListOp;
     ACPI_PARSE_OBJECT       *ParentOp;
+    UINT64                  BufferSize;
+    UINT64                  InitializerSize;
 
 
-    /* Buffer size is the buffer argument */
-
+    /*
+     * Get the BufferSize argument - Buffer(BufferSize)
+     * If the buffer was generated by the ToPld macro, it must
+     * be a BYTE constant.
+     */
     SizeOp = Op->Common.Value.Arg;
+    if (SizeOp->Common.AmlOpcode != AML_BYTE_OP)
+    {
+        return (FALSE);
+    }
+
+    /* Check the declared BufferSize, two possibilities */
+
+    BufferSize = SizeOp->Common.Value.Integer;
+    if ((BufferSize != ACPI_PLD_REV1_BUFFER_SIZE) &&
+        (BufferSize != ACPI_PLD_REV2_BUFFER_SIZE))
+    {
+        return (FALSE);
+    }
+
+    /*
+     * Check the initializer list length. This is the actual
+     * number of bytes in the buffer as counted by the AML parser.
+     * The declared BufferSize can be larger than the actual length.
+     * However, for the ToPLD macro, the BufferSize will be the same
+     * as the initializer list length.
+     */
+    ByteListOp = SizeOp->Common.Next;
+    if (!ByteListOp)
+    {
+        return (FALSE); /* Zero-length buffer case */
+    }
+
+    InitializerSize = ByteListOp->Common.Value.Integer;
+    if ((InitializerSize != ACPI_PLD_REV1_BUFFER_SIZE) &&
+        (InitializerSize != ACPI_PLD_REV2_BUFFER_SIZE))
+    {
+        return (FALSE);
+    }
+
+    /* Final size check */
+
+    if (BufferSize != InitializerSize)
+    {
+        return (FALSE);
+    }
+
+    /* Now examine the buffer parent */
 
     ParentOp = Op->Common.Parent;
     if (!ParentOp)
@@ -571,8 +620,17 @@ AcpiDmIsPldBuffer (
         return (FALSE);
     }
 
-    /* Check for proper form: Name(_PLD, Package() {Buffer() {}}) */
-
+    /*
+     * Check for proper form: Name(_PLD, Package() {ToPLD()})
+     *
+     * Note: All other forms such as
+     *      Return (Package() {ToPLD()})
+     *      Local0 = ToPLD()
+     * etc. are not converted back to the ToPLD macro, because
+     * there is really no deterministic way to disassemble the buffer
+     * back to the ToPLD macro, other than trying to find the "_PLD"
+     * name
+     */
     if (ParentOp->Common.AmlOpcode == AML_PACKAGE_OP)
     {
         ParentOp = ParentOp->Common.Parent;