Re: mmap bug?

From: Joseph Koshy <joseph.koshy_at_gmail.com> Date: Sun, 31 Jul 2005 23:45:19 +0530 · This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:40 UTC

gk> That's something I didn't test.  No, the 'extra' data 
gk> disappears.

So the 'extra' data isn't reaching the FS and is probably
being served up from a cached VM data the second time your
test program ran.

This is still a bug though: the mmap(2) manual page
says:
    ...
    If len is not a multiple of
    the page-size, the mapped region may extend past the 
    specified range.  Any such extension beyond the end of the 
    mapped object will be zero-filled.
    ...

We are clearly not doing the zero-filling.

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