Re: [Qemu-devel] [PATCH] PPC: Fix linker scripts on ppc hosts

[Peter Maydell]

On 14 December 2011 12:04, Paul Brook <address@hidden> wrote:
>> The proper solution would be to rewrite mmap.c to be smarter (perhaps
>> by looking at /proc/self/maps and reserving a lot of space with PROT_NONE
>> mappings at startup and then managing it itself), but so far nobody's
>> done that
>
> Yes they have. That's what -R does.

-R doesn't happen by default, it requires you to specify how much you
want, and it insists that the space all be in one chunk.

> We used to try and parse /proc/self/maps.  This caused more problems than it
> solved.  It doesn't cover things like mmap_min_addr, and you have to re-parse
> it before every allocation in case the host libc allocated something new in
> between.

If you've used a PROT_NONE mapping to claim the space at startup, host libc
doesn't override that mapping, does it?

-- PMM