From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5)
Gecko/20041107 Firefox/1.0

Description of problem:
  
Problem:  mmap() system call can return Nil 
  
 The manual page states that a Nil return is not possible: 
  
------------ Cut Here -------- Cut Here 

 MMAP(2)                    Linux Programmer's Manual                
  MMAP(2) 
  
 NAME 
        mmap, munmap - map or unmap files or devices into memory 
  
 SYNOPSIS 
        #include <sys/mman.h> 
  
        void  *  mmap(void *start, size_t length, int prot , int
flags, int fd, 
        off_t offset); 
  
        int munmap(void *start, size_t length); 
  
 DESCRIPTION 
        The mmap function asks to map length bytes starting  at 
offset  offset 
        from  the  file  (or  other object) specified by the file
descriptor fd 
        into memory, preferably at address start.  This  latter 
address  is  a 
        hint  only,  and is usually specified as 0.  The actual place
where the 
        object is mapped is returned by mmap, and is never 0. 
  
        ... 
  
------------ Cut Here -------- Cut Here 
  
  
 Note the last line:  "... returned by mmap, and is never 0." 
  
 Allowing mmap() to return Nil causes all sorts of problems. 
 Not the least of which de-referencing Nil no longer causes a SEGV. 
 Not a happy state of affairs. 



Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Sample program is attached to reproduce the problem
2.
3.
    

Expected Results:  mmap should not return 0 because it never
places a memory mapping at address 0.
mmap returns -1 (the value of the MAP_FAILED
macro) on failure.

Additional info: