From: Andreas Schwab <schwab@linux-m68k.org>
To: Matthias Reis <matthias.reis@hu-berlin.de>
Cc: linux-m68k@lists.linux-m68k.org
Subject: Re: Crash in entry.S:resume on Atari ST
Date: Fri, 16 Sep 2016 16:23:05 +0200 [thread overview]
Message-ID: <87y42rx6t2.fsf@linux-m68k.org> (raw)
In-Reply-To: <8132f924080d98f2bbe149d35352507d@hu-berlin.de> (Matthias Reis's message of "Fri, 16 Sep 2016 00:35:53 +0200")
On Sep 16 2016, Matthias Reis <matthias.reis@hu-berlin.de> wrote:
> === objdump -D vmlinux output:
> 000048cc <resume>:
> 48cc: 2208 movel %a0,%d1
> 48ce: 40e8 0320 movew %sr,%a0@(800)
> 48d2: 48e7 031e moveml %d6-%d7/%a3-%fp,%sp@-
> 48d6: 214f 0318 movel %sp,%a0@(792)
> 48da: 4e6b movel %usp,%a3
> 48dc: 214b 031c movel %a3,%a0@(796)
> 48e0: 2669 031c moveal %a1@(796),%a3
> 48e4: 4e63 movel %a3,%usp
> 48e6: 2e69 0318 moveal %a1@(792),%sp
> 48ea: 4cdf 78c0 moveml %sp@+,%d6-%d7/%a3-%fp
> 48ee: 46e9 0320 movew %a1@(800),%sr
> 48f2: 4e75 rtsp
> ===
>
> It can be seen from the register dump given by the hatari debugger, that
> USP contains 0x0 and the superuser bit (indicated by "S=0") is not set:
>
> === hatari emulator output:
> CPU=$48f2, VBL=6379, FrameCycles=86856, HBL=387, LineCycles=168, DSP=N/A
> $000048f2 : 4e75 rts
> r
> D0 00000008 D1 00002200 D2 00005401 D3 00961EC8
> D4 00000000 D5 00940020 D6 602E0206 D7 00E00030
> A0 00865B68 A1 00961EEC A2 0080E000 A3 000026E4
> A4 000045C0 A5 000045E4 A6 00004794 A7 00000000
> USP 00000000 ISP 00000018
> T=00 S=0 M=0 X=0 N=0 Z=0 V=0 C=0 IMASK=2 STP=0
Given the value of SSP and the values loaded into D6/D7 (which match the
ROM shadow at address 0), it is clear that SP was 0 at $48ea. So it
looks like A1 is just pointing at a block of zeros, not at a valid task
struct.
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
next prev parent reply other threads:[~2016-09-16 14:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-15 22:35 Crash in entry.S:resume on Atari ST Matthias Reis
2016-09-16 6:39 ` Greg Ungerer
2016-09-16 13:53 ` Matthias Reis
2016-09-16 9:29 ` Andreas Schwab
2016-09-16 14:23 ` Andreas Schwab [this message]
2016-09-16 14:47 ` Matthias Reis
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87y42rx6t2.fsf@linux-m68k.org \
--to=schwab@linux-m68k.org \
--cc=linux-m68k@lists.linux-m68k.org \
--cc=matthias.reis@hu-berlin.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox