2015-09-07 4:38 GMT-04:00 Jiri Olsa <jo...@kernel.org>: > 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
Perhaps a dumb question, but it seems the code is exactly the same as in linux/err.h besides the part of the comment you added. Why not using that file directly in the other patches then? -- 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/
