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Date: Sun, 27 Nov 2005 14:06:52 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
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Subject: Re: mmap() on 64K aligned address fails
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On Nov 26 18:41, Ren? Berber wrote:
> René Berber wrote:
> [snip]
> > mmap() is returning an error code, probably EINVAL I just ddisn't care to look
>                                                             didn't
> > what was it because there shouldn't be an error.
> 
> Yes, using perror I get "Invalid argument", so the implementation considers
> mmap(0x470000, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED, fd, 0L)
> somehow an invalid invocation.

I didn't inspect the testcase all too closely since it's annoyingly long
for such a simple test.  But what exactly do you expect when trying to
mmap an arbitrary memory address in the virtual address space which you
know nothing about?  The code is making invalid assumptions about the
usage of the underlying memory layout.

Don't use MAP_FIXED unless you know what you're doing.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat, Inc.

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