[Qemu-devel] Re: [PATCH] linux-user, x86: use target_mmap() to allocate idt, gdt and ldt tables

[Jan Kiszka <jan.kiszka@web.de>]

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Kirill A. Shutemov wrote:
> On Sat, Nov 01, 2008 at 10:33:07AM +0100, Jan Kiszka wrote:
>> Kirill A. Shutemov wrote:
>>> env->*dt.base should fits target address space, so we should use
>>> target_mmap to allocate it.
>> I just noticed that this bug is still unfixed upstream, was about to
>> repost my corresponding patch [1], but then found this even nicer
>> approach. Could someone please finally merge a fix?
>>
>> Kirill, do you also have a patch for the problem [2] addresses in your
>> queue?
> 
> No, I don't. But we also can use target_mmap(with my mmap_find_vma()) for
> it, I guess. Can you provide any testcase to reproduce the bug?

I don't have a testcase for this. I just came across it at the time this
h2g usage caused a compiler warning. Laster on, this warning was papered
over, but the bug remained though I reminded people a few times.

We don't need special allocation here (that's what I originally thought
as well), we just need a robust way of detecting the guest-host address
conflict:

http://article.gmane.org/gmane.comp.emulators.qemu/28381

Maybe you can go through my old series and pick up the bits that still
make sense. The user emulation is not on my daily radar, so these things
could be forgotten again if I have to track them. :-]

Jan


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