tools/nolibc: clean up mmap() routine

Do several cleanups together:

- Since all supported architectures have my_syscall6() now, remove the
  #ifdef check.

- Move the mmap() related macros to tools/include/nolibc/types.h and
  reuse most of them from <linux/mman.h>

- Apply the new generic __sysret() to convert the calling of sys_map()
  to oneline code

Note, since MAP_FAILED is -1 on Linux, so we can use the generic
__sysret() which returns -1 upon error and still satisfy user land that
checks for MAP_FAILED.

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230702192347.GJ16233@1wt.eu/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
This commit is contained in:
Zhangjin Wu 2023-07-07 22:58:20 +08:00 committed by Willy Tarreau
parent 6591be4a73
commit 924e9539ae
2 changed files with 12 additions and 23 deletions

View File

@ -636,26 +636,11 @@ int mknod(const char *path, mode_t mode, dev_t dev)
return __sysret(sys_mknod(path, mode, dev)); return __sysret(sys_mknod(path, mode, dev));
} }
#ifndef MAP_SHARED
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#endif
#ifndef MAP_FAILED
#define MAP_FAILED ((void *)-1)
#endif
#ifndef sys_mmap #ifndef sys_mmap
static __attribute__((unused)) static __attribute__((unused))
void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
off_t offset) off_t offset)
{ {
#ifndef my_syscall6
/* Function not implemented. */
return (void *)-ENOSYS;
#else
int n; int n;
#if defined(__NR_mmap2) #if defined(__NR_mmap2)
@ -666,20 +651,18 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
#endif #endif
return (void *)my_syscall6(n, addr, length, prot, flags, fd, offset); return (void *)my_syscall6(n, addr, length, prot, flags, fd, offset);
#endif
} }
#endif #endif
/* Note that on Linux, MAP_FAILED is -1 so we can use the generic __sysret()
* which returns -1 upon error and still satisfy user land that checks for
* MAP_FAILED.
*/
static __attribute__((unused)) static __attribute__((unused))
void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)
{ {
void *ret = sys_mmap(addr, length, prot, flags, fd, offset); return (void *)__sysret((unsigned long)sys_mmap(addr, length, prot, flags, fd, offset));
if ((unsigned long)ret >= -4095UL) {
SET_ERRNO(-(long)ret);
ret = MAP_FAILED;
}
return ret;
} }
static __attribute__((unused)) static __attribute__((unused))

View File

@ -8,6 +8,7 @@
#define _NOLIBC_TYPES_H #define _NOLIBC_TYPES_H
#include "std.h" #include "std.h"
#include <linux/mman.h>
#include <linux/time.h> #include <linux/time.h>
#include <linux/stat.h> #include <linux/stat.h>
@ -81,6 +82,11 @@
#define MAXPATHLEN (PATH_MAX) #define MAXPATHLEN (PATH_MAX)
#endif #endif
/* flags for mmap */
#ifndef MAP_FAILED
#define MAP_FAILED ((void *)-1)
#endif
/* whence values for lseek() */ /* whence values for lseek() */
#define SEEK_SET 0 #define SEEK_SET 0
#define SEEK_CUR 1 #define SEEK_CUR 1