text: #include <unistd.h>
  #include <sys/mman.h>
  #include <errno.h>
  #include <stdint.h>
  #include <limits.h>
  #include "syscall.h"
  
  static void dummy(void) { }
  weak_alias(dummy, __vm_wait);
  
  #define UNIT SYSCALL_MMAP2_UNIT
  #define OFF_MASK ((-0x2000ULL << (8*sizeof(syscall_arg_t)-1)) | (UNIT-1))
  
  void *__mmap(void *start, size_t len, int prot, int flags, int fd, off_t off)
  {
  	long ret;
  	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
  	ret = __syscall(SYS_mmap2, start, len, prot, flags, fd, off/UNIT);
  #else
  	ret = __syscall(SYS_mmap, start, len, prot, flags, fd, off);
  #endif
  	/* Fixup incorrect EPERM from kernel. */
  	if (ret == -EPERM && !start && (flags&MAP_ANON) && !(flags&MAP_FIXED))
  		ret = -ENOMEM;
  	return (void *)__syscall_ret(ret);
  }
  
  // Ensure high-level vwasm intercept
  //weak_alias(__mmap, mmap);
  //
  //weak_alias(mmap, mmap64);
  