Messages in this thread | | | From | Kyle Moffett <> | Subject | Re: mmap specification - was: ... select specification | Date | Thu, 7 Oct 2004 18:32:43 -0400 |
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On Oct 07, 2004, at 17:58, Andries Brouwer wrote: > On Thu, Oct 07, 2004 at 03:50:31PM +0100, Alan Cox wrote: >> "References >> within the address range starting at pa and continuing for len bytes >> to >> whole pages following the end of an object shall result in delivery >> of a >> SIGBUS signal." > > [I read this as follows: If you mmap a file with MAP_SHARED and modify > the memory at an address so far beyond EOF that it is not in a page > containing stuff from the file, then you get a SIGBUS. -- Linux does > this. > Also, that if you modify the memory at an address beyond EOF, then > the file is not modified. -- Again Linux does this.]
The last bit of the SuS text means:
pa <-- len --> eof <-> page boundary
Anywhere from pa to page boundary will generate SIGBUS. This is a rather useless definition no? I think what they meant is:
"References within the address range starting on the first whole page at least len bytes after pa shall result in delivery of a SIGBUS signal."
(I am assuming, of course, that pa is the result of the mmap call. If I'm wrong please tell me, thanks!)
Cheers, Kyle Moffett
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