* [Qemu-devel] Wrong Exception - should have GPF instead of PF for NULL selector
@ 2004-06-12 14:34 Antony T Curtis
2004-06-12 16:28 ` malc
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Antony T Curtis @ 2004-06-12 14:34 UTC (permalink / raw)
To: qemu-devel
I have been looking at why OS/2 Warp Connect fails to start Presentation
Manager under QEMU and I have found the following...
We get a Page Fault when QEMU encounters the following instruction
0xfe0a9971: mov %es:(%si),%ebx
Where ES=0x0000 and ESI=0xabde0000
This should generate a General Protection exception as we are accessing
memory using a NULL selector
I don't know if it would fix OS/2 but it is definitely behaviour which
is 'not correct'.
--
Antony T Curtis <antony.t.curtis@ntlworld.com>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [Qemu-devel] Wrong Exception - should have GPF instead of PF for NULL selector
2004-06-12 14:34 [Qemu-devel] Wrong Exception - should have GPF instead of PF for NULL selector Antony T Curtis
@ 2004-06-12 16:28 ` malc
2004-06-13 13:22 ` Fabrice Bellard
2004-06-13 15:22 ` Fabrice Bellard
2 siblings, 0 replies; 4+ messages in thread
From: malc @ 2004-06-12 16:28 UTC (permalink / raw)
To: qemu-devel
On Sat, 12 Jun 2004, Antony T Curtis wrote:
> I have been looking at why OS/2 Warp Connect fails to start Presentation
> Manager under QEMU and I have found the following...
>
> We get a Page Fault when QEMU encounters the following instruction
>
> 0xfe0a9971: mov %es:(%si),%ebx
>
> Where ES=0x0000 and ESI=0xabde0000
>
> This should generate a General Protection exception as we are accessing
> memory using a NULL selector
>
> I don't know if it would fix OS/2 but it is definitely behaviour which
> is 'not correct'.
Not necessarily, for instance if es was loaded in real mode and cached
descriptor is valid.
--
mailto:malc@pulsesoft.com
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] Wrong Exception - should have GPF instead of PF for NULL selector
2004-06-12 14:34 [Qemu-devel] Wrong Exception - should have GPF instead of PF for NULL selector Antony T Curtis
2004-06-12 16:28 ` malc
@ 2004-06-13 13:22 ` Fabrice Bellard
2004-06-13 15:22 ` Fabrice Bellard
2 siblings, 0 replies; 4+ messages in thread
From: Fabrice Bellard @ 2004-06-13 13:22 UTC (permalink / raw)
To: qemu-devel
Antony T Curtis wrote:
> I have been looking at why OS/2 Warp Connect fails to start Presentation
> Manager under QEMU and I have found the following...
>
> We get a Page Fault when QEMU encounters the following instruction
>
> 0xfe0a9971: mov %es:(%si),%ebx
>
> Where ES=0x0000 and ESI=0xabde0000
>
> This should generate a General Protection exception as we are accessing
> memory using a NULL selector
>
> I don't know if it would fix OS/2 but it is definitely behaviour which
> is 'not correct'.
OK, it is not correct, but it is not the cause of the problem: I tried
to generate a GPF and I have the same bug. Moreover, I looked at the
code before and %es is really set to zero...
Fabrice.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] Wrong Exception - should have GPF instead of PF for NULL selector
2004-06-12 14:34 [Qemu-devel] Wrong Exception - should have GPF instead of PF for NULL selector Antony T Curtis
2004-06-12 16:28 ` malc
2004-06-13 13:22 ` Fabrice Bellard
@ 2004-06-13 15:22 ` Fabrice Bellard
2 siblings, 0 replies; 4+ messages in thread
From: Fabrice Bellard @ 2004-06-13 15:22 UTC (permalink / raw)
To: qemu-devel
Antony T Curtis wrote:
> I have been looking at why OS/2 Warp Connect fails to start Presentation
> Manager under QEMU and I have found the following...
Fixed :-)
Tell me if OS/2 Wrap works correctly now.
Fabrice.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2004-06-13 15:21 UTC | newest]
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2004-06-12 14:34 [Qemu-devel] Wrong Exception - should have GPF instead of PF for NULL selector Antony T Curtis
2004-06-12 16:28 ` malc
2004-06-13 13:22 ` Fabrice Bellard
2004-06-13 15:22 ` Fabrice Bellard
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