The patch titled
ARRAY_SIZE: check for type
has been added to the -mm tree. Its filename is
array_size-check-for-type.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: ARRAY_SIZE: check for type
From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
We can use a gcc extension to ensure that ARRAY_SIZE() is handed an array,
not a pointer. This is especially important when code is changed from a
fixed array to a pointer. I assume the Intel compiler doesn't support
__builtin_types_compatible_p.
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/compiler-gcc.h | 3 +++
include/linux/compiler-intel.h | 3 +++
include/linux/kernel.h | 3 ++-
3 files changed, 8 insertions(+), 1 deletion(-)
diff -puN include/linux/compiler-gcc.h~array_size-check-for-type include/linux/compiler-gcc.h
--- a/include/linux/compiler-gcc.h~array_size-check-for-type
+++ a/include/linux/compiler-gcc.h
@@ -22,6 +22,9 @@
__asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
(typeof(ptr)) (__ptr + (off)); })
+/* &a[0] degrades to a pointer: a different type from an array */
+#define __must_be_array(a) \
+ BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
#define inline inline __attribute__((always_inline))
#define __inline__ __inline__ __attribute__((always_inline))
diff -puN include/linux/compiler-intel.h~array_size-check-for-type include/linux/compiler-intel.h
--- a/include/linux/compiler-intel.h~array_size-check-for-type
+++ a/include/linux/compiler-intel.h
@@ -21,4 +21,7 @@
__ptr = (unsigned long) (ptr); \
(typeof(ptr)) (__ptr + (off)); })
+/* Intel ECC compiler doesn't support __builtin_types_compatible_p() */
+#define __must_be_array(a) 0
+
#endif
diff -puN include/linux/kernel.h~array_size-check-for-type include/linux/kernel.h
--- a/include/linux/kernel.h~array_size-check-for-type
+++ a/include/linux/kernel.h
@@ -35,7 +35,8 @@ extern const char linux_proc_banner[];
#define ALIGN(x,a) __ALIGN_MASK(x,(typeof(x))(a)-1)
#define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask))
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
+
#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
_
Patches currently in -mm which might be from rusty@xxxxxxxxxxxxxxx are
futex-restartable-futex_wait.patch
i386-vdso_prelink-warning-fix.patch
cleanup-initialize-esp0-properly-all-the-time.patch
lguest-preparation-export_symbol_gpl-5-functions.patch
lguest-preparation-expose-futex-infrastructure.patch
lguest-kconfig-and-headers.patch
lguest-the-host-code-lgko.patch
lguest-guest-code.patch
lguest-makefile.patch
lguest-trivial-guest-network-driver.patch
lguest-trivial-guest-console-driver.patch
lguest-trivial-guest-block-driver.patch
lguest-documentatation-and-example-launcher.patch
module-use-krealloc.patch
extend-print_symbol-capability.patch
array_size-check-for-type.patch
____call_usermodehelper-dont-flush_signals.patch
add-ability-to-keep-track-of-callers-of-symbol_getput.patch
add-ability-to-keep-track-of-callers-of-symbol_getput-tidy.patch
update-mtd-use-of-symbol_getput.patch
update-dvb-use-of-symbol_getput.patch
-
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