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/*
* mmap.c
*/
#include <stdint.h>
#include <errno.h>
#include <sys/syscall.h>
#include <sys/mman.h>
#include <asm/page.h> /* For PAGE_SHIFT */
#if defined(__sparc__)
# define MMAP2_SHIFT 12 /* Fixed by syscall definition */
#else
# define MMAP2_SHIFT PAGE_SHIFT
#endif
#define MMAP2_MASK ((1UL << MMAP2_SHIFT)-1)
/*
* Prefer mmap2() over mmap(), except on the architectures listed
*/
#if defined(__NR_mmap2) && !defined(__sparc__) && !defined(__ia64__) && !defined(__powerpc__) && !defined(__powerpc64__)
/* This architecture uses mmap2() */
static inline _syscall6(void *,mmap2,void *,start,size_t,length,int,prot,int,flags,int,fd,off_t,offset);
/* The Linux mmap2() system call takes a page offset as the offset argument.
We need to make sure we have the proper conversion in place. */
void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
if ( offset & MMAP2_MASK ) {
errno = EINVAL;
return MAP_FAILED;
}
return mmap2(start, length, prot, flags, fd, (size_t)offset >> MMAP2_SHIFT);
}
#else
/* This architecture uses a plain mmap() system call */
/* Only use this for architectures where mmap() is a real 6-argument system call! */
_syscall6(void *,mmap,void *,start,size_t,length,int,prot,int,flags,int,fd,off_t,offset)
#endif
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