The patch titled
ARRAY_SIZE: check for type
has been removed from the -mm tree. Its filename was
array_size-check-for-type.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
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.
[jdike@xxxxxxxxxxx: uml: update UML definition of ARRAY_SIZE]
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/um/include/user_util.h | 15 +++++++++++++--
include/linux/compiler-gcc.h | 3 +++
include/linux/compiler-intel.h | 3 +++
include/linux/kernel.h | 3 ++-
4 files changed, 21 insertions(+), 3 deletions(-)
diff -puN arch/um/include/user_util.h~array_size-check-for-type arch/um/include/user_util.h
--- a/arch/um/include/user_util.h~array_size-check-for-type
+++ a/arch/um/include/user_util.h
@@ -8,8 +8,19 @@
#include "sysdep/ptrace.h"
-/* Copied from kernel.h */
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+/* Copied from kernel.h and compiler-gcc.h */
+
+/* Force a compilation error if condition is true, but also produce a
+ result (of value 0 and type size_t), so the expression can be used
+ e.g. in a structure initializer (or where-ever else comma expressions
+ aren't permitted). */
+#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
+
+/* &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 ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
#define CATCH_EINTR(expr) while ((errno = 0, ((expr) < 0)) && (errno == EINTR))
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
@@ -21,6 +21,9 @@
__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
#define uninitialized_var(x) x
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
origin.patch
xfs-clean-up-shrinker-games.patch
mm-clean-up-and-kernelify-shrinker-registration.patch
module-use-krealloc.patch
get_futex_key-get_key_refs-and-drop_key_refs.patch
futex-restartable-futex_wait.patch
add-ability-to-keep-track-of-callers-of-symbol_getput.patch
update-mtd-use-of-symbol_getput.patch
update-dvb-use-of-symbol_getput.patch
simplify-module_get_kallsym-by-dropping-length-arg.patch
fix-race-between-rmmod-and-cat-proc-kallsyms.patch
simplify-kallsyms_lookup.patch
fix-race-between-cat-proc-wchan-and-rmmod-et-al.patch
fix-race-between-cat-proc-slab_allocators-and-rmmod.patch
____call_usermodehelper-dont-flush_signals.patch
wait_for_helper-remove-unneeded-do_sigaction.patch
futex-new-private-futexes.patch
lguest-export-symbols-for-lguest-as-a-module.patch
lguest-the-guest-code.patch
lguest-vs-x86_64-mm-use-per-cpu-variables-for-gdt-pda.patch
lguest-vs-x86_64-mm-use-per-cpu-variables-for-gdt-pda-lguest-2621-mm1-update.patch
lguest-the-guest-code-update-lguests-patch-code-for-new-paravirt-patch.patch
lguest-the-guest-code-handle-new-paravirt-lazy-mode-fix-userspace.patch
lguest-the-guest-code-dont-use-paravirt_probe-its-dying.patch
lguest-the-host-code.patch
lguest-the-host-code-vs-x86_64-mm-i386-separate-hardware-defined-tss-from-linux-additions.patch
lguest-the-host-code-fix-lguest-oops-when-guest-dies-while-receiving-i-o.patch
lguest-the-host-code-simplification-dont-pin-guest-trap-handlers.patch
lguest-the-host-code-properly-kill-guest-userspace-programs-accessing-kernel-mem.patch
lguest-the-host-code-remove-put_user-etc-warnings-add-bloat.patch
lguest-the-host-code-fix-obscure-but-nasty-cow-bug.patch
lguest-the-host-code-lguest-use-standard-bootloader-format-fix-badly-sized.patch
lguest-the-asm-offsets.patch
lguest-the-makefile-and-kconfig.patch
lguest-the-console-driver.patch
lguest-the-net-driver.patch
lguest-the-net-driver-lguest-2621-mm1-update-lguest-net-stats-inlinepatch.patch
lguest-the-block-driver.patch
lguest-the-documentation-example-launcher.patch
lguest-the-documentation-example-launcher-fix-lguest-documentation-error.patch
lguest-documentation-and-example-updates.patch
lguest-the-documentation-example-launcher-dont-use-paravirt_probe-its-dying-doc.patch
lguest-use-standard-bootloader-format-fix-badly-sized-doc.patch
lguest-the-host-code-vs-futex-new-private-futexes.patch
compiler-introduce-__used-and-__maybe_unused.patch
mm-clean-up-and-kernelify-shrinker-registration-reiser4.patch
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