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Date: Wed, 02 Jun 2010 10:20:50 -0700
From: Richard Henderson <rth@twiddle.net>
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Subject: [Qemu-devel] Unposted reserved_va patch
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To: Paul Brook <paul@codesourcery.com>
Cc: qemu-devel@nongnu.org

Re: 68a1c816868b3e35a1da698af412b29e61b1948a

In general, I like the idea (especially since I've proposed it before.  ;-)

However:

+        if (have_guest_base) {
+            flags |= MAP_FIXED;
+        }

I think this is broken.  If the user specifies -G n -R m they're hoping
or guessing that the range [n,n+m) is free.  What they're not expecting
is for the qemu application or any of the required shared libraries to
get forcibly unmapped.

I think instead you should simply adjust the error reporting after the
mmap attempt without MAP_FIXED.



r~