ACPICA: Add a mechanism to escape infinite AML While() loops

Add a loop counter to force exit from AML While loops if the
count becomes too large. This can occur in poorly written AML
when the hardware does not respond within a while loop and the
loop does not implement a timeout. The maximum loop count is
configurable. A new exception code is returned when a loop is
broken, AE_AML_INFINITE_LOOP.  Bob Moore, Alexey Starikovskiy.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/acpi/acconfig.h b/include/acpi/acconfig.h
index 29feee27f0ea..e50fe7157463 100644
--- a/include/acpi/acconfig.h
+++ b/include/acpi/acconfig.h
@@ -119,6 +119,10 @@
 
 #define ACPI_ROOT_TABLE_SIZE_INCREMENT  4
 
+/* Maximum number of While() loop iterations before forced abort */
+
+#define ACPI_MAX_LOOP_ITERATIONS        0xFFFF
+
 /******************************************************************************
  *
  * ACPI Specification constants (Do not change unless the specification changes)