Date: Fri, 3 Jan 2003 09:13:44 -0600 From: ryan beasley <ryanb@goddamnbastard.org> To: freebsd-current@freebsd.org Subject: current/stable remote gdb interoperability Message-ID: <20030103151344.GA50346@goddamnbastard.org>
next in thread | raw e-mail | index | archive | help
--bp/iNruPH9dso1Pn
Content-Type: text/plain; charset=unknown-8bit
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
I'm running -CURRENT from around Dec 28th, 2002, 04:00 -0600, on a
testing machine. While debugging a 3rd party module, I occasionally
find myself in situations where I can't obtain a core dump. (e.g., a
panic related to a lock assertion occurs just before the dump routine
begins.) To get around this, I decided I'd use my other RELENG_4_7 box
as a remote GDB master.
The serial port on the -CURRENT machine is compiled at 38400. FYI,
jesper =3D=3D 4.7R-p2 debugging box, and fredrik =3D=3D 5.0 panic box. =
This
instance of gdb was compiled from source w/ the patches found in the
devel/gdb52 port. (I don't have room for the ports tree locally.)
The problem I'm running into is primarily erratic behavior. The trace
trap shown below occurs frequently, and while it's only a minor
annoyance, my main concern is gdb randomly freezing when attempting to
get a backtrace. (Sometimes it'll run to completion, others will hang
between frames.)
Is this a case of user error? (I've never had a problem w/ serial rates
>9600 bps between similarly configured RELENG_4 boxes.) Is cross-
release debugging taboo? What do the experts recommend I do?
TIA!
Session output is included below:
ryanb@jesper ~/FREDRIK_DP_INV> gdb52 --baud 38400
GNU gdb 5.2 (FreeBSD)
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain
conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-unknown-freebsd4.7".
(gdb) target remote /dev/cuaa0
Remote debugging using /dev/cuaa0
0xc02a5aba in ?? ()
(gdb) add-symbol-file kernel.debug
add symbol table from file "kernel.debug" at
(y or n) y
Reading symbols from kernel.debug...done.
(gdb) dir sys
Source directories searched: /home/ryanb/FREDRIK_DP_INV/sys:$cdir:$cwd
(gdb) dir ipfilter
Source directories searched:
/home/ryanb/FREDRIK_DP_INV/ipfilter:/home/ryanb/FREDRIK_DP_INV/sys:$cdir:$c=
wd
(gdb) c
Continuing.
Program received signal SIGTRAP, Trace/breakpoint trap.
Debugger (msg=3D0x19 <Address 0x19 out of bounds>) at atomic.h:260
260 atomic.h: No such file or directory.
in atomic.h
(gdb) bt
#0 Debugger (msg=3D0x19 <Address 0x19 out of bounds>) at atomic.h:260
#1 0xc01bc5c7 in witness_lock (lock=3D0xc1264734, flags=3D8,
file=3D0xc02d9e6d "/usr/src/sys/kern/kern_descrip.c", line=3D2108)
at /usr/src/sys/kern/subr_witness.c:720
#2 0xc0190441 in _mtx_lock_flags (m=3D0x0, opts=3D0,
file=3D0xc1264734 " \0170=C0U\230-=C0U\230-=C0", line=3D-1070255508)
at /usr/src/sys/kern/kern_mutex.c:328
#3 0xc017eba3 in sysctl_kern_file (oidp=3D0xc02fdfe0, arg1=3D0x0, arg2=3D0,
req=3D0xc5f47c0c) at /usr/src/sys/kern/kern_descrip.c:2108
#4 0xc01a279b in sysctl_root (oidp=3D0x0, arg1=3D0xc5f47ca8, arg2=3D2,
req=3D0xc5f47c0c) at /usr/src/sys/kern/kern_sysctl.c:1150
(Session just dies here.)
ryanb@jesper ~> ps auxww | grep gdb
ryanb 50317 0.0 5.4 22272 21160 p4 S+ 7:35AM 0:01.87 gdb52 --baud
38400
Its current wait channel is (surprise!) ttyin.
--=20
ryan beasley <ryanb@goddamnbastard.org>
GPG ID: 0x16EFBD48 http://www.goddamnbastard.org =09
--bp/iNruPH9dso1Pn
Content-Type: application/pgp-signature
Content-Disposition: inline
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (FreeBSD)
iD8DBQE+FaioskfdOxbvvUgRAl0uAJ4o7+1Pxtht0zsDYmmfE7faBXPAogCeNtjY
MizDHkGl2zKdMLZ7drOlmmI=
=y6G+
-----END PGP SIGNATURE-----
--bp/iNruPH9dso1Pn--
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030103151344.GA50346>