mmap(2) with MAP_ANON honouring offset although it shouldn't

[Alexander Best]

Alan Cox schrieb am 2009-11-04:
> Ed Schouten wrote:
> >* Alan Cox <alc at cs.rice.edu> wrote:

> For what it's worth, I believe that Solaris does the exact opposite.
> >>They provide MAP_ANONYMOUS for compatibility.  It seems like a good
> >>idea for us to do the same.


> >Something like this?

> >Index: mman.h
> >===================================================================
> >--- mman.h      (revision 198919)
> >+++ mman.h      (working copy)
> >@@ -82,6 +82,9 @@
> > */
> >#define        MAP_FILE         0x0000 /* map from file (default) */
> >#define        MAP_ANON         0x1000 /* allocated from memory,
> >swap space */
> >+#ifndef _KERNEL
> >+#define        MAP_ANONYMOUS    MAP_ANON /* For compatibility. */
> >+#endif /* !_KERNEL */
> > /*
> > * Extended flags



> Yes.  If no one objects in the next day or so, then please commit
> this change.

> Alan

should this compatibility addition be documented in the mmap(2) manual?

any thoughts on the previous change request so mmap fails with MAP_ANON and
pos=0?

alex