RE: kgdb on EM64T

From: Wilkerson, Bryan P
Date: Fri Aug 26 2005 - 18:42:41 EST




George Anzinger [mailto:george@xxxxxxxxxx] wrote:
>
>Well, I checked, it is "int $3". Why then the panic? If you try the
>boot with kgdb (i.e. wait) and the do:
>(gdb) disass gdb_interrupt
>What do you find at +75?

Below is the console from the session it is interesting that gdb is not
able to access the memory. I let it continue and then ctrl-c broke it
later in the boot cycle and tried disass again with the same result.

Feel free to flog me if this is stupid but I have just one EM64T machine
(test) and I'm using a regular P4 machine as dev. I build the test
kernel on the EM64T machine and then copy the updated sources, object
files, and images via NFS to the dev machine. I believe I read in the
kgdb doc that it was possible to use to different architecture machines
for test and dev although there wasn't any information about how to do
it. This is probably the source of the OS/ABI warning. I can probably
get the mothership to send me another EM64T machine if need be.

vincent:/home/bwilkers/proj/linux-2.6.13-rc4-mm1 # gdb vmlinux
GNU gdb 6.3
Copyright 2004 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 "i586-suse-linux"...
warning: A handler for the OS ABI "GNU/Linux" is not built into this
configuration
of GDB. Attempting to continue with the default i386:x86-64 settings.

Using host libthread_db library "/lib/tls/libthread_db.so.1".

(gdb) target remote /dev/ttyS0
Remote debugging using /dev/ttyS0
0x80503b50 in ?? ()
warning: no shared library support for this OS / ABI
(gdb) disass gdb_interrupt
Dump of assembler code for function gdb_interrupt:
0xffffffff80247009 <gdb_interrupt+0>: Cannot access memory at address
0x80247009
(gdb) c
Continuing.
Bootdata ok (command line is root=/dev/sda2 kgdb console=kgdb)
Linux version 2.6.13-rc4-mm1-perfmon-em64t (bwilkers@jules) (gcc version
3.3.5 20050117 (prerelease) (SUSE Linux)) #43 SMP Sat Aug 27 15:56:14
MDT 2005
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000e6000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 000000003fe2f800 (usable)
BIOS-e820: 000000003fe2f800 - 000000003fe3f832 (ACPI NVS)
BIOS-e820: 000000003ff10000 - 000000003ff30000 (reserved)
BIOS-e820: 000000003ff30000 - 000000003ff40000 (ACPI data)
BIOS-e820: 000000003ff40000 - 000000003fff0000 (ACPI NVS)
BIOS-e820: 000000003fff0000 - 0000000040000000 (reserved)
BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved)
BIOS-e820: 00000000fed13000 - 00000000fed1a000 (reserved)
BIOS-e820: 00000000fed1c000 - 00000000feda0000 (reserved)
ACPI: PM-Timer IO Port: 0x408
ACPI: LAPIC (acpi_id[0x01] lapic_id[0x00] enabled)


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