| Message ID | 20230811120814.169952-2-przemyslaw.kitszel@intel.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | introduce DEFINE_FLEX() macro | expand |
Hi Przemek,
kernel test robot noticed the following build errors:
[auto build test ERROR on 6a1ed1430daa2ccf8ac457e0db93fb0925b801ca]
url: https://github.com/intel-lab-lkp/linux/commits/Przemek-Kitszel/overflow-add-DEFINE_FLEX-for-on-stack-allocs/20230811-201509
base: 6a1ed1430daa2ccf8ac457e0db93fb0925b801ca
patch link: https://lore.kernel.org/r/20230811120814.169952-2-przemyslaw.kitszel%40intel.com
patch subject: [PATCH net-next v2 1/7] overflow: add DEFINE_FLEX() for on-stack allocs
config: m68k-randconfig-r024-20230811 (https://download.01.org/0day-ci/archive/20230811/202308112122.OuF0YZqL-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230811/202308112122.OuF0YZqL-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308112122.OuF0YZqL-lkp@intel.com/
All error/warnings (new ones prefixed by >>):
In file included from include/linux/compiler.h:5,
from include/linux/export.h:5,
from include/asm-generic/export.h:9,
from ./arch/m68k/include/generated/asm/export.h:1,
from arch/m68k/lib/mulsi3.S:35:
>> include/linux/compiler_types.h:331:5: warning: "__has_builtin" is not defined, evaluates to 0 [-Wundef]
331 | #if __has_builtin(__builtin_dynamic_object_size)
| ^~~~~~~~~~~~~
>> include/linux/compiler_types.h:331:18: error: missing binary operator before token "("
331 | #if __has_builtin(__builtin_dynamic_object_size)
| ^
vim +331 include/linux/compiler_types.h
326
327 /*
328 * When the size of an allocated object is needed, use the best available
329 * mechanism to find it. (For cases where sizeof() cannot be used.)
330 */
> 331 #if __has_builtin(__builtin_dynamic_object_size)
332 #define __struct_size(p) __builtin_dynamic_object_size(p, 0)
333 #define __member_size(p) __builtin_dynamic_object_size(p, 1)
334 #else
335 #define __struct_size(p) __builtin_object_size(p, 0)
336 #define __member_size(p) __builtin_object_size(p, 1)
337 #endif
338
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 547ea1ff806e..d880c1180de2 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -324,6 +324,18 @@ struct ftrace_likely_data { # define __realloc_size(x, ...) #endif +/* + * When the size of an allocated object is needed, use the best available + * mechanism to find it. (For cases where sizeof() cannot be used.) + */ +#if __has_builtin(__builtin_dynamic_object_size) +#define __struct_size(p) __builtin_dynamic_object_size(p, 0) +#define __member_size(p) __builtin_dynamic_object_size(p, 1) +#else +#define __struct_size(p) __builtin_object_size(p, 0) +#define __member_size(p) __builtin_object_size(p, 1) +#endif + #ifndef asm_volatile_goto #define asm_volatile_goto(x...) asm goto(x) #endif diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h index da51a83b2829..1e7711185ec6 100644 --- a/include/linux/fortify-string.h +++ b/include/linux/fortify-string.h @@ -93,13 +93,9 @@ extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) #if __has_builtin(__builtin_dynamic_object_size) #define POS __pass_dynamic_object_size(1) #define POS0 __pass_dynamic_object_size(0) -#define __struct_size(p) __builtin_dynamic_object_size(p, 0) -#define __member_size(p) __builtin_dynamic_object_size(p, 1) #else #define POS __pass_object_size(1) #define POS0 __pass_object_size(0) -#define __struct_size(p) __builtin_object_size(p, 0) -#define __member_size(p) __builtin_object_size(p, 1) #endif #define __compiletime_lessthan(bounds, length) ( \ diff --git a/include/linux/overflow.h b/include/linux/overflow.h index f9b60313eaea..21a4410799eb 100644 --- a/include/linux/overflow.h +++ b/include/linux/overflow.h @@ -309,4 +309,31 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend) #define struct_size_t(type, member, count) \ struct_size((type *)NULL, member, count) +/** + * DEFINE_FLEX() - Define a zeroed, on-stack, instance of @type structure with + * a trailing flexible array member. + * + * @type: structure type name, including "struct" keyword. + * @name: Name for a variable to define. + * @member: Name of the array member. + * @count: Number of elements in the array; must be compile-time const. + */ +#define DEFINE_FLEX(type, name, member, count) \ + union { \ + u8 bytes[struct_size_t(type, member, count)]; \ + type obj; \ + } name##_u __aligned(_Alignof(type)) = {}; \ + type *name = (type *)&name##_u + +/** + * const_flex_size() - Get size of on-stack instance of structure with + * a trailing flexible array member. + * + * @name: Name of the variable, the one defined by DEFINE_FLEX() macro above. + * + * Get size of @name, which is equivalent to struct_size(name, array, count), + * but does not require (repeating) last two arguments. + */ +#define const_flex_size(name) __builtin_object_size(name, 1) + #endif /* __LINUX_OVERFLOW_H */