Adding part of the kernel's <linux/err.h> interface: inline void * __must_check ERR_PTR(long error); inline long __must_check PTR_ERR(__force const void *ptr); inline bool __must_check IS_ERR(__force const void *ptr);
it will be used to propagate error through pointers in following patches. Link: http://lkml.kernel.org/n/tip-ufgnyf683uab69anmmrab...@git.kernel.org Signed-off-by: Jiri Olsa <jo...@kernel.org> --- tools/include/linux/err.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 tools/include/linux/err.h diff --git a/tools/include/linux/err.h b/tools/include/linux/err.h new file mode 100644 index 000000000000..c9ada48f5156 --- /dev/null +++ b/tools/include/linux/err.h @@ -0,0 +1,49 @@ +#ifndef __TOOLS_LINUX_ERR_H +#define __TOOLS_LINUX_ERR_H + +#include <linux/compiler.h> +#include <linux/types.h> + +#include <asm/errno.h> + +/* + * Original kernel header comment: + * + * Kernel pointers have redundant information, so we can use a + * scheme where we can return either an error code or a normal + * pointer with the same return value. + * + * This should be a per-architecture thing, to allow different + * error and pointer decisions. + * + * Userspace note: + * The same principle works for userspace, because 'error' pointers + * fall down to the unused hole far from user space, as described + * in Documentation/x86/x86_64/mm.txt for x86_64 arch: + * + * 0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm hole caused by [48:63] sign extension + * ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole + * + * It should be the same case for other architectures, because + * this code is used in generic kernel code. + */ +#define MAX_ERRNO 4095 + +#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO) + +static inline void * __must_check ERR_PTR(long error) +{ + return (void *) error; +} + +static inline long __must_check PTR_ERR(__force const void *ptr) +{ + return (long) ptr; +} + +static inline bool __must_check IS_ERR(__force const void *ptr) +{ + return IS_ERR_VALUE((unsigned long)ptr); +} + +#endif /* _LINUX_ERR_H */ -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
