From: Richard Henderson <rth@twiddle.net>
To: Peter Maydell <peter.maydell@linaro.org>,
QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [Bug 1810545] Re: [alpha] Strange exception address reported
Date: Tue, 8 Jan 2019 08:17:00 +1000 [thread overview]
Message-ID: <2de32a5f-2002-13ef-bded-4ab6cccb20ba@twiddle.net> (raw)
In-Reply-To: <CAFEAcA9DRhok9WigB_r9a_DGoC+_FNbtxDvz3k1dBHGkFniy5Q@mail.gmail.com>
On 1/8/19 5:00 AM, Peter Maydell wrote:
> On Mon, 7 Jan 2019 at 18:10, Peter Maydell <peter.maydell@linaro.org> wrote:
> (re: https://bugs.launchpad.net/bugs/1810545)
>
>> The problem seems to be that the PC we report for an OPCDEC
>> is first selected by gen_invalid()/gen_excp() in
>> target/alpha/translate.c, which uses pc_next (ie the insn's
>> address plus 4). But that is then handed through to our custom
>> PALcode (https://git.qemu.org/?p=qemu-palcode.git;a=blob;f=pal.S;h=1781c4b415700ca3a68af07fdae90ae43e722501;hb=HEAD) which does
>> addq p6, 4, p1 // increment past the faulting insn
>> resulting in insn + 8.
>>
>> That is, the palcode and the QEMU code have a disagreement about what
>> the (private) API between them is. I'm not sure which side is wrong and
>> should be corrected. I think the linux-user code assumes the same thing
>> that translate.c is doing, so perhaps the palcode.
>
> Richard -- any suggestions for which side of this API we should
> be changing?
Probably the palcode side. I'll take care of it.
r~
next prev parent reply other threads:[~2019-01-07 22:17 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-04 18:21 [Qemu-devel] [Bug 1810545] [NEW] [alpha] Strange exception address reported Stefan Ring
2019-01-04 19:05 ` [Qemu-devel] [Bug 1810545] " Peter Maydell
2019-01-07 17:57 ` Peter Maydell
2019-01-07 19:00 ` Peter Maydell
2019-01-07 22:17 ` Richard Henderson [this message]
2019-01-08 11:47 ` Peter Maydell
2019-01-08 21:13 ` Stefan Ring
2019-04-24 5:28 ` Thomas Huth
2019-04-24 5:28 ` Thomas Huth
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