RE: bootstrap/3163

["John Hughes" <john@Calva.COM>]

The following reply was made to PR bootstrap/3163; it has been noted by GNATS.

From: "John Hughes" <john@Calva.COM>
To: "Robert Lipe" <robertlipe@usa.net>, <gcc-gnats@gcc.gnu.org>,
   <gcc-prs@gcc.gnu.org>, <gcc-bugs@gcc.gnu.org>, <nobody@gcc.gnu.org>
Cc:  
Subject: RE: bootstrap/3163
Date: Thu, 14 Jun 2001 09:28:32 +0200

 >> http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view&pr=3163&database=gcc
 >> No OS has yet been observed to be so perverse as to leave unmapped
 >> space between consecutive calls to mmap. */
 >>
 >> Well, UnixWare 7.1.1 is that perverse system. It seems to leave
 >> one page between each mapping.
 
 > This is actually documented behaviour.   From the mmap man page:
 >
 >   References to pages in a mapped region which are beyond the
 >   page containing the end of a file will result in the delivery of a
 >   SIGBUS signal.
 
 No, that paragraph says that if I mmap 10 pages from a 5 page file
 access to the 5 pages beyond eof get a SIGBUS (note: not SIGSEGV).
 
 It says nothing about memory OUTSIDE the mmaped region.