NetBSD Problem Report #57337
From www@netbsd.org Sun Apr 9 14:01:50 2023
Return-Path: <www@netbsd.org>
Received: from mail.netbsd.org (mail.netbsd.org [199.233.217.200])
(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits))
(Client CN "mail.NetBSD.org", Issuer "mail.NetBSD.org CA" (not verified))
by mollari.NetBSD.org (Postfix) with ESMTPS id 880761A9239
for <gnats-bugs@gnats.NetBSD.org>; Sun, 9 Apr 2023 14:01:50 +0000 (UTC)
Message-Id: <20230409140148.F1F6B1A923A@mollari.NetBSD.org>
Date: Sun, 9 Apr 2023 14:01:48 +0000 (UTC)
From: uwe@stderr.spb.ru
Reply-To: uwe@stderr.spb.ru
To: gnats-bugs@NetBSD.org
Subject: gdb completely broken on sparc
X-Send-Pr-Version: www-1.0
>Number: 57337
>Category: port-sparc
>Synopsis: gdb completely broken on sparc
>Confidential: no
>Severity: critical
>Priority: medium
>Responsible: port-sparc-maintainer
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Sun Apr 09 14:05:00 +0000 2023
>Last-Modified: Mon Sep 04 09:15:01 +0000 2023
>Originator: Valery Ushakov
>Release: NetBSD 10
>Organization:
>Environment:
NetBSD krups 10.99.2 NetBSD 10.99.2 (KRUPS) #0: Wed Dec 28 02:08:31 MSK 2022 uwe@majava:/home/uwe/work/netbsd/cvs/src/sys/arch/sparc/compile/KRUPS sparc
>Description:
Gdb seems to be completely broken in current. Unable to get
debuggee registers.
>How-To-Repeat:
$ gdb -q ./hello
Reading symbols from ./hello...
(gdb) b main
Breakpoint 1 at 0x10748: file hello.c, line 6.
(gdb) r
Starting program: /root/hello
Breakpoint 1, main (
argc=<error reading variable: Cannot access memory at address 0xf50b1044>,
argv=<error reading variable: Cannot access memory at address 0xf50b1048>)
at hello.c:6
6 printf("%d\n", argc);
(gdb) l
1 #include <stdio.h>
2
3 int
4 main(int argc, char **argv)
5 {
6 printf("%d\n", argc);
7 return 0;
8 }
(gdb) i r
...
l0 0x65e5e8 6677992
l1 0x65e5e8 6677992
l2 0x65e5e8 6677992
l3 0x65e5e8 6677992
l4 0x65e5e8 6677992
l5 0x65e5e8 6677992
l6 0x65e5e8 6677992
l7 0x65e5e8 6677992
i0 0x65e5e8 6677992
i1 0x65e5e8 6677992
i2 0x65e5e8 6677992
i3 0x65e5e8 6677992
i4 0x65e5e8 6677992
i5 0x65e5e8 6677992
fp 0x65e5e8 0x65e5e8
i7 0x65e5e8 6677992
...
>Fix:
>Audit-Trail:
From: matthew green <mrg@eterna.com.au>
To: gnats-bugs@netbsd.org
Cc: port-sparc-maintainer@netbsd.org, gnats-admin@netbsd.org,
netbsd-bugs@netbsd.org
Subject: re: port-sparc/57337: gdb completely broken on sparc
Date: Mon, 10 Apr 2023 12:38:42 +1000
weird. i have different failure mode.
(gdb) b main
Breakpoint 1 at 0x10740: file hello.c, line 3.
(gdb) run
Starting program: /home/mrg/a.out
Breakpoint 1, main () at hello.c:3
3 printf("hello world\n");
(gdb) i r
g0 0x0 0
g1 0x64 100
g2 0x1 1
g3 0x0 0
g4 0xede3a47c -303848324
g5 0xeded4aa8 -303215960
g6 0x0 0
g7 0xedec8048 -303267768
[ ... ]
psr 0x1e400081 [ S ]
wim <unavailable>
tbr <unavailable>
pc 0x10740 0x10740 <main+4>
npc 0x10744 0x10744 <main+8>
fsr 0x0 [ ]
so i am seeming to get more than you, but then:
(gdb) step
Program received signal SIGBUS, Bus error.
0xeded13b4 in _rtld_bind () from /usr/libexec/ld.elf_so
(gdb) bt
#0 0xeded13b4 in _rtld_bind () from /usr/libexec/ld.elf_so
#1 0x00000012 in ?? ()
a static binary seems to work differently wrong:
(gdb) b main
Breakpoint 2 at 0x1042c: file hello.c, line 3.
(gdb) r
Starting program: /home/mrg/a.out
Breakpoint 2, main () at hello.c:3
3 printf("hello world\n");
(gdb) step
0x00017104 in puts ()
(gdb) bt
#0 0x00017104 in puts ()
#1 0x00010438 in main () at hello.c:3
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb) next
Single stepping until exit from function puts,
which has no line number information.
0x000198d0 in strlen ()
.mrg.
From: Valery Ushakov <uwe@stderr.spb.ru>
To: gnats-bugs@netbsd.org
Cc: matthew green <mrg@eterna.com.au>
Subject: Re: port-sparc/57337: gdb completely broken on sparc
Date: Mon, 10 Apr 2023 14:52:55 +0300
Ah, we quote different parts of "info reg". I also get
(gdb) i r
g0 0x0 0
g1 0x64 100
g2 0x1 1
g3 0x0 0
g4 0xe5ea4acc -437630260
g5 0xe5ed4a90 -437433712
g6 0x0 0
g7 0xe5ec6b58 -437490856
...
for the inital breakpoint, but, significantly, it's the locals and
inputs that are all messed up. The static example you quote most
likely fails for the very same reason, b/c you get junk instead of
saved return address in %i7 (after window rotation), so it cannot do
the proper backtrace.
-uwe
From: Valery Ushakov <uwe@stderr.spb.ru>
To: gnats-bugs@netbsd.org
Cc:
Subject: Re: port-sparc/57337: gdb completely broken on sparc
Date: Tue, 29 Aug 2023 16:10:46 +0300
Import of the new gdb seems to have helped somewhat. I haven't yet
tried any heavy duty debugging, but at least the basics seem to work
again.
/usr/bin/gdb ./hello
GNU gdb (GDB) 13.2
Copyright (C) 2023 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "sparc--netbsdelf".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./hello...
(gdb) b main
Breakpoint 1 at 0x10748: file hello.c, line 6.
(gdb) r
Starting program: /home/uwe/hello
Breakpoint 1, main (argc=1, argv=0xe7fff574) at hello.c:6
6 printf("%d\n", argc);
(gdb) i r
g0 0x0 0
g1 0x64 100
g2 0x1 1
g3 0x0 0
g4 0xe5ea3b7c -437634180
g5 0xe5ed87d4 -437418028
g6 0x0 0
g7 0xe5ea6b58 -437621928
o0 0x0 0
o1 0x344 836
o2 0xe5e00b48 -438301880
o3 0x3400 13312
o4 0xf0b86a30 -256349648
o5 0x209f0 133616
sp 0xe7fff458 0xe7fff458
o7 0x103f8 66552
l0 0x4400087 71303303
l1 0xe5e00b48 -438301880
l2 0xe5e00b4c -438301876
l3 0xfc1 4033
l4 0x1 1
l5 0x2 2
l6 0xf50d5000 -183676928
--Type <RET> for more, q to quit, c to continue without paging--
l7 0xe5ea3b78 -437634184
i0 0x1 1
i1 0xe7fff574 -402655884
i2 0xe7fff57c -402655876
i3 0x1 1
i4 0x0 0
i5 0xe5ea3b5c -437634212
fp 0xe7fff4b8 0xe7fff4b8
i7 0x106d4 67284
y 0x0 0
psr 0x4400086 [ S ]
wim <unavailable>
tbr <unavailable>
pc 0x10748 0x10748 <main+12>
npc 0x1074c 0x1074c <main+16>
fsr 0x0 [ ]
csr <unavailable>
(gdb) p argv[0]
$1 = 0xe7fffa7c "/home/uwe/hello"
But then stepping into libc:
(gdb) s
Program received signal SIGBUS, Bus error.
0xe5ed13a4 in _rtld_bind () from /usr/libexec/ld.elf_so
(gdb)
-uwe
From: Rin Okuyama <rokuyama.rk@gmail.com>
To: gnats-bugs@netbsd.org, port-sparc-maintainer@netbsd.org,
gnats-admin@netbsd.org, netbsd-bugs@netbsd.org, uwe@stderr.spb.ru
Cc:
Subject: Re: port-sparc/57337: gdb completely broken on sparc
Date: Mon, 4 Sep 2023 18:10:55 +0900
On 2023/08/29 22:15, Valery Ushakov wrote:
> Import of the new gdb seems to have helped somewhat. I haven't yet
> tried any heavy duty debugging, but at least the basics seem to work
> again.
Good to know this!
> But then stepping into libc:
>
> (gdb) s
>
> Program received signal SIGBUS, Bus error.
> 0xe5ed13a4 in _rtld_bind () from /usr/libexec/ld.elf_so
> (gdb)
Hmm. It seems like nbsd_skip_resolver() fails for some reasons.
I will examine later...
# Another good news for me is recent version of QEMU/sparc works
# much better than previous versions I remember!
Thanks,
rin
(Contact us)
$NetBSD: query-full-pr,v 1.47 2022/09/11 19:34:41 kim Exp $
$NetBSD: gnats_config.sh,v 1.9 2014/08/02 14:16:04 spz Exp $
Copyright © 1994-2023
The NetBSD Foundation, Inc. ALL RIGHTS RESERVED.
Home