From d5caf1cdc41c311cb5d4d2c010f90809f319c7dd Mon Sep 17 00:00:00 2001 From: Lv Zheng Date: Wed, 30 Apr 2014 10:04:42 +0800 Subject: [PATCH] ACPICA: OSL: Add configurability for memory allocation macros. OSPMs like Linux trend to include all header files but leave empty stub macros for a feature that is not configured during build. For macros defined without other symbols referencesd it is safe to leave them without protections. By investigation, there are only the following internal/external symbols referenced by the ACPICA macros: 1. C library symbols, including string, ctype, stdarg APIs. Since such symbols are always accessbile in the kernel source tree, it is safe to leave macros referencing them without protected for Linux. 2. ACPICA OSL symbols, such symbols are designed to be used only by ACPICA internal APIs. And there are macros directly referencing mutex and memory allocation OSL symbols. We need to examine the external usages of such macros. For macros referencing the mutex OSL symbols, fortunately, there is no external user directly invoking such macros. ======================================================================== !! IMPORTANT !! ======================================================================== For macros referencing memory allocation OSL symbols - 1. 'free' - ACPI_FREE 2. 'alloc' - ACPI_ALLOCATE, ACPI_ALLOCATE_ZEROED, ACPI_ALLOCATE_BUFFER, ACPI_ALLOCATE_LOCAL_BUFFER there are external users directly invoking 'alloc' macros. And the more complicated situation is the reversals of such macros are not ACPI_FREE but acpi_os_free (or kfree) in Linux. Though we can define such macros into no-op, we in fact cannot define their reversals into no-op. This patch adds mechanism to protect ACPICA memory allocation APIs for Linux so that acpi_os_free (or kfree) invoked in Linux can have a zero address returned by 'alloc' macros to free. In this way, acpi_os_free (or kfree) can be converted into no-op. ======================================================================== 3. ACPI_OFFSET and other macros that would access structure members, we need to check if such structure members are not accessible under a specific configuration. Fortunately, currently Linux doesn't use such structure members when CONFIG_ACPI is disabled. This patch thus only adds mechanism useful for implementing stubs for ACPICA provided macros - the configurability of memory allocation APIs. This patch doesn't include code for Linux to use this new mechanism, thus no functional changes. Lv Zheng. Signed-off-by: Lv Zheng Signed-off-by: Bob Moore Signed-off-by: Rafael J. Wysocki --- include/acpi/actypes.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index e76356574374..19b26bb69a70 100644 --- a/include/acpi/actypes.h +++ b/include/acpi/actypes.h @@ -329,6 +329,15 @@ typedef u32 acpi_physical_address; * ******************************************************************************/ +#ifdef ACPI_NO_MEM_ALLOCATIONS + +#define ACPI_ALLOCATE(a) NULL +#define ACPI_ALLOCATE_ZEROED(a) NULL +#define ACPI_FREE(a) +#define ACPI_MEM_TRACKING(a) + +#else /* ACPI_NO_MEM_ALLOCATIONS */ + #ifdef ACPI_DBG_TRACK_ALLOCATIONS /* * Memory allocation tracking (used by acpi_exec to detect memory leaks) @@ -350,6 +359,8 @@ typedef u32 acpi_physical_address; #endif /* ACPI_DBG_TRACK_ALLOCATIONS */ +#endif /* ACPI_NO_MEM_ALLOCATIONS */ + /****************************************************************************** * * ACPI Specification constants (Do not change unless the specification changes) @@ -928,9 +939,19 @@ struct acpi_object_list { * Miscellaneous common Data Structures used by the interfaces */ #define ACPI_NO_BUFFER 0 + +#ifdef ACPI_NO_MEM_ALLOCATIONS + +#define ACPI_ALLOCATE_BUFFER (acpi_size) (0) +#define ACPI_ALLOCATE_LOCAL_BUFFER (acpi_size) (0) + +#else /* ACPI_NO_MEM_ALLOCATIONS */ + #define ACPI_ALLOCATE_BUFFER (acpi_size) (-1) /* Let ACPICA allocate buffer */ #define ACPI_ALLOCATE_LOCAL_BUFFER (acpi_size) (-2) /* For internal use only (enables tracking) */ +#endif /* ACPI_NO_MEM_ALLOCATIONS */ + struct acpi_buffer { acpi_size length; /* Length in bytes of the buffer */ void *pointer; /* pointer to buffer */