Date: Mon, 10 Mar 2003 10:28:31 +0100 From: Dag-Erling Smorgrav <des@ofug.org> To: Jun Su <JunSu@gmx.net> Cc: freebsd-current@freebsd.org Subject: Re: GDB kernel debug new command Message-ID: <xzpllznbmf4.fsf@flood.ping.uio.no> In-Reply-To: <200303081224.53273.JunSu@gmx.net> (Jun Su's message of "Sat, 8 Mar 2003 12:24:53 %2B0800") References: <200303081224.53273.JunSu@gmx.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Jun Su <JunSu@gmx.net> writes:
> To help myself more easily check the kernel dump, I added two new command. One
> is ps, the other is kldstat. I know we can print the kernel data manually to
> get the same information. I still think this is useful. This can help the
> newbies to get the information without many knowledge about the kernel. This
> also can help the experienced user to get the data more quickly.
>
> Here is the new file. Just put it in /usr/src/gnu/usr.bin/binutils/gdb. And
> add the file to Makefile. Please give me some comments if this is garbage. :)
This is pointless as it won't work unless gdb is in synch with the
kernel (since it depends on knowing the layout of struct proc and
struct linker_file). Both of these commands can be implemented as
macros, which will not depend on gdb being in synch with the kernel.
Greg Lehey wrote this ps macro:
define ps
set $nproc = nprocs
set $aproc = allproc.lh_first
set $proc = allproc.lh_first
printf " pid proc addr uid ppid pgrp flag stat comm wchan\n"
while (--$nproc >= 0)
set $pptr = $proc.p_pptr
if ($pptr == 0)
set $pptr = $proc
end
if ($proc.p_stat)
printf "%5d %08x %08x %4d %5d %5d %06x %d %-10s ", \
$proc.p_pid, $aproc, \
$proc.p_addr, $proc.p_cred->p_ruid, $pptr->p_pid, \
$proc.p_pgrp->pg_id, $proc.p_flag, $proc.p_stat, \
&$proc.p_comm[0]
if ($proc.p_wchan)
if ($proc.p_wmesg)
printf "%s ", $proc.p_wmesg
end
printf "%x", $proc.p_wchan
end
printf "\n"
end
set $aproc = $proc.p_list.le_next
if ($aproc == 0 && $nproc > 0)
set $aproc = zombproc
end
set $proc = $aproc
end
end
document ps
"ps" -- when kernel debugging, type out a ps-like listing of active processes.
end
and I've written two variants of kldstat myself, plus a kldload:
end
document kldstat
Lists the modules that were loaded when the kernel crashed.
end
define kldstat-v
set $kld = linker_files.tqh_first
printf "Id Refs Address Size Name\n"
while ($kld != 0)
printf "%2d %4d 0x%08x %-8x %s\n", \
$kld->id, $kld->refs, $kld->address, $kld->size, $kld->filename
printf " Contains modules:\n"
printf " Id Name\n"
set $module = $kld->modules.tqh_first
while ($module != 0)
printf " %2d %s\n", $module->id, $module->name
set $module = $module->link.tqe_next
end
set $kld = $kld->link.tqe_next
end
end
document kldstat-v
Lists modules with full information.
end
define kldload
set $kld = linker_files.tqh_first
set $done = 0
while ($kld != 0 && $done == 0)
if ($kld->filename == $arg0)
set $done = 1
else
set $kld = $kld->link.tqe_next
end
end
if ($done == 1)
shell /usr/bin/objdump -h $arg0 | \
awk '/ .text/ { print "set \$offset = 0x" $6 }' > .kgdb.temp
source .kgdb.temp
add-symbol-file $arg0 $kld->address + $offset
end
end
document kldload
Loads a module. Arguments are module name and offset of text section.
end
Note that for kldload to work, you need to know the offset of the text
section for the module you wish to load (objdump -h will tell you)
Note also that I haven't used any of these macros in a long time, so
there may be some issues related to KSE or whatnot.
DES
--
Dag-Erling Smorgrav - des@ofug.org
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?xzpllznbmf4.fsf>