alistair23-linux/include/linux/string.h
Rasmus Villemoes 48a270554a include/linux: apply __malloc attribute
Attach the malloc attribute to a few allocation functions.  This helps
gcc generate better code by telling it that the return value doesn't
alias any existing pointers (which is even more valuable given the
pessimizations implied by -fno-strict-aliasing).

A simple example of what this allows gcc to do can be seen by looking at
the last part of drm_atomic_helper_plane_reset:

	plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);

	if (plane->state) {
		plane->state->plane = plane;
		plane->state->rotation = BIT(DRM_ROTATE_0);
	}

which compiles to

    e8 99 bf d6 ff          callq  ffffffff8116d540 <kmem_cache_alloc_trace>
    48 85 c0                test   %rax,%rax
    48 89 83 40 02 00 00    mov    %rax,0x240(%rbx)
    74 11                   je     ffffffff814015c4 <drm_atomic_helper_plane_reset+0x64>
    48 89 18                mov    %rbx,(%rax)
    48 8b 83 40 02 00 00    mov    0x240(%rbx),%rax [*]
    c7 40 40 01 00 00 00    movl   $0x1,0x40(%rax)

With this patch applied, the instruction at [*] is elided, since the
store to plane->state->plane is known to not alter the value of
plane->state.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-19 19:12:14 -07:00

173 lines
4.8 KiB
C

#ifndef _LINUX_STRING_H_
#define _LINUX_STRING_H_
#include <linux/compiler.h> /* for inline */
#include <linux/types.h> /* for size_t */
#include <linux/stddef.h> /* for NULL */
#include <stdarg.h>
#include <uapi/linux/string.h>
extern char *strndup_user(const char __user *, long);
extern void *memdup_user(const void __user *, size_t);
extern void *memdup_user_nul(const void __user *, size_t);
/*
* Include machine specific inline routines
*/
#include <asm/string.h>
#ifndef __HAVE_ARCH_STRCPY
extern char * strcpy(char *,const char *);
#endif
#ifndef __HAVE_ARCH_STRNCPY
extern char * strncpy(char *,const char *, __kernel_size_t);
#endif
#ifndef __HAVE_ARCH_STRLCPY
size_t strlcpy(char *, const char *, size_t);
#endif
#ifndef __HAVE_ARCH_STRSCPY
ssize_t __must_check strscpy(char *, const char *, size_t);
#endif
#ifndef __HAVE_ARCH_STRCAT
extern char * strcat(char *, const char *);
#endif
#ifndef __HAVE_ARCH_STRNCAT
extern char * strncat(char *, const char *, __kernel_size_t);
#endif
#ifndef __HAVE_ARCH_STRLCAT
extern size_t strlcat(char *, const char *, __kernel_size_t);
#endif
#ifndef __HAVE_ARCH_STRCMP
extern int strcmp(const char *,const char *);
#endif
#ifndef __HAVE_ARCH_STRNCMP
extern int strncmp(const char *,const char *,__kernel_size_t);
#endif
#ifndef __HAVE_ARCH_STRCASECMP
extern int strcasecmp(const char *s1, const char *s2);
#endif
#ifndef __HAVE_ARCH_STRNCASECMP
extern int strncasecmp(const char *s1, const char *s2, size_t n);
#endif
#ifndef __HAVE_ARCH_STRCHR
extern char * strchr(const char *,int);
#endif
#ifndef __HAVE_ARCH_STRCHRNUL
extern char * strchrnul(const char *,int);
#endif
#ifndef __HAVE_ARCH_STRNCHR
extern char * strnchr(const char *, size_t, int);
#endif
#ifndef __HAVE_ARCH_STRRCHR
extern char * strrchr(const char *,int);
#endif
extern char * __must_check skip_spaces(const char *);
extern char *strim(char *);
static inline __must_check char *strstrip(char *str)
{
return strim(str);
}
#ifndef __HAVE_ARCH_STRSTR
extern char * strstr(const char *, const char *);
#endif
#ifndef __HAVE_ARCH_STRNSTR
extern char * strnstr(const char *, const char *, size_t);
#endif
#ifndef __HAVE_ARCH_STRLEN
extern __kernel_size_t strlen(const char *);
#endif
#ifndef __HAVE_ARCH_STRNLEN
extern __kernel_size_t strnlen(const char *,__kernel_size_t);
#endif
#ifndef __HAVE_ARCH_STRPBRK
extern char * strpbrk(const char *,const char *);
#endif
#ifndef __HAVE_ARCH_STRSEP
extern char * strsep(char **,const char *);
#endif
#ifndef __HAVE_ARCH_STRSPN
extern __kernel_size_t strspn(const char *,const char *);
#endif
#ifndef __HAVE_ARCH_STRCSPN
extern __kernel_size_t strcspn(const char *,const char *);
#endif
#ifndef __HAVE_ARCH_MEMSET
extern void * memset(void *,int,__kernel_size_t);
#endif
#ifndef __HAVE_ARCH_MEMCPY
extern void * memcpy(void *,const void *,__kernel_size_t);
#endif
#ifndef __HAVE_ARCH_MEMMOVE
extern void * memmove(void *,const void *,__kernel_size_t);
#endif
#ifndef __HAVE_ARCH_MEMSCAN
extern void * memscan(void *,int,__kernel_size_t);
#endif
#ifndef __HAVE_ARCH_MEMCMP
extern int memcmp(const void *,const void *,__kernel_size_t);
#endif
#ifndef __HAVE_ARCH_MEMCHR
extern void * memchr(const void *,int,__kernel_size_t);
#endif
void *memchr_inv(const void *s, int c, size_t n);
char *strreplace(char *s, char old, char new);
extern void kfree_const(const void *x);
extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
extern const char *kstrdup_const(const char *s, gfp_t gfp);
extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
extern void argv_free(char **argv);
extern bool sysfs_streq(const char *s1, const char *s2);
extern int kstrtobool(const char *s, bool *res);
static inline int strtobool(const char *s, bool *res)
{
return kstrtobool(s, res);
}
int match_string(const char * const *array, size_t n, const char *string);
#ifdef CONFIG_BINARY_PRINTF
int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
#endif
extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
const void *from, size_t available);
/**
* strstarts - does @str start with @prefix?
* @str: string to examine
* @prefix: prefix to look for.
*/
static inline bool strstarts(const char *str, const char *prefix)
{
return strncmp(str, prefix, strlen(prefix)) == 0;
}
size_t memweight(const void *ptr, size_t bytes);
void memzero_explicit(void *s, size_t count);
/**
* kbasename - return the last part of a pathname.
*
* @path: path to extract the filename from.
*/
static inline const char *kbasename(const char *path)
{
const char *tail = strrchr(path, '/');
return tail ? tail + 1 : path;
}
#endif /* _LINUX_STRING_H_ */