Messages in this thread | | | Date | Thu, 7 Oct 2004 23:58:34 +0200 | From | Andries Brouwer <> | Subject | mmap specification - was: ... select specification |
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On Thu, Oct 07, 2004 at 03:50:31PM +0100, Alan Cox wrote:
> I'll quote SuSv3 to illustrate the danger of "specifications" > > "The system shall always zero-fill any partial page at the end of an > object. Further, the system shall never write out any modified portions > of the last page of an object which are beyond its end. 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." > > Its a mistake, its not apparent if its actually meant something entirely > different or someone forgot a "not", or what is going on.
What precisely are you thinking of? You seem to think this is ridiculous. The way I read this, Linux is compliant, I think.
[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.]
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