fusl/src/mman/mmap.c

#include <unistd.h>
#include <sys/mman.h>
#include <errno.h>
#include <stdint.h>
#include <limits.h>
#include "syscall.h"
#include "libc.h"

static void dummy(void) {}
weak_alias(dummy, __vm_wait);

#define UNIT SYSCALL_MMAP2_UNIT
#define OFF_MASK ((-0x2000ULL << (8 * sizeof(long) - 1)) | (UNIT - 1))

void* __mmap(void* start, size_t len, int prot, int flags, int fd, off_t off) {
  if (off & OFF_MASK) {
    errno = EINVAL;
    return MAP_FAILED;
  }
  if (len >= PTRDIFF_MAX) {
    errno = ENOMEM;
    return MAP_FAILED;
  }
  if (flags & MAP_FIXED) {
    __vm_wait();
  }
#ifdef SYS_mmap2
  return (void*)syscall(SYS_mmap2, start, len, prot, flags, fd, off / UNIT);
#else
  return (void*)syscall(SYS_mmap, start, len, prot, flags, fd, off);
#endif
}

weak_alias(__mmap, mmap);

weak_alias(__mmap, mmap64);