From fc37445733aeae4fd1a20385850620354263b1d5 Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Wed, 12 Nov 2008 15:15:29 +0800 Subject: 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 Signed-off-by: Lin Ming Signed-off-by: Len Brown --- include/acpi/acconfig.h | 4 ++++ include/acpi/acexcep.h | 4 +++- include/acpi/aclocal.h | 1 + 3 files changed, 8 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/acpi/acconfig.h b/include/acpi/acconfig.h index 29feee2..e50fe71 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) diff --git a/include/acpi/acexcep.h b/include/acpi/acexcep.h index 84f5cb2..a1ae105 100644 --- a/include/acpi/acexcep.h +++ b/include/acpi/acexcep.h @@ -153,8 +153,9 @@ #define AE_AML_CIRCULAR_REFERENCE (acpi_status) (0x001E | AE_CODE_AML) #define AE_AML_BAD_RESOURCE_LENGTH (acpi_status) (0x001F | AE_CODE_AML) #define AE_AML_ILLEGAL_ADDRESS (acpi_status) (0x0020 | AE_CODE_AML) +#define AE_AML_INFINITE_LOOP (acpi_status) (0x0021 | AE_CODE_AML) -#define AE_CODE_AML_MAX 0x0020 +#define AE_CODE_AML_MAX 0x0021 /* * Internal exceptions used for control @@ -267,6 +268,7 @@ char const *acpi_gbl_exception_names_aml[] = { "AE_AML_CIRCULAR_REFERENCE", "AE_AML_BAD_RESOURCE_LENGTH", "AE_AML_ILLEGAL_ADDRESS", + "AE_AML_INFINITE_LOOP" }; char const *acpi_gbl_exception_names_ctrl[] = { diff --git a/include/acpi/aclocal.h b/include/acpi/aclocal.h index ecab527..0323fa9 100644 --- a/include/acpi/aclocal.h +++ b/include/acpi/aclocal.h @@ -566,6 +566,7 @@ struct acpi_control_state { union acpi_parse_object *predicate_op; u8 *aml_predicate_start; /* Start of if/while predicate */ u8 *package_end; /* End of if/while block */ + u32 loop_count; /* While() loop counter */ }; /* -- cgit v1.1