Date: Wed, 24 Jan 2007 11:25:41 -0800 From: "Rao, Nikhil" <nikhil.rao@intel.com> To: <freebsd-amd64@freebsd.org> Subject: Issue with using KGDB for remote debug over serial port Message-ID: <12A5C15467D5B94F8E0FF265D9498ADDE516F5@orsmsx419.amr.corp.intel.com>
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I am trying to debug an AMD64 kernel over a serial connection. Both the
host and the target are running AMD64 6.1 release kernels.
Target platform - Dell Precision Workstation 690, (Dual Quad core system
with Intel Xeon 1.86 Ghz CPU)
Host - XPS 600 Dell - Intel Pentium D 3.00 Ghz CPU
The target platform boots a 6.1 release GENERIC AMD64 kernel with
makeoptions DEBUG=-g, KDB and GDB options enabled and has a serial
connection with the host. In device.hints I have set
hint.sio0.flags=0x80
I am able to enter kgdb using the -d boot option, next I can break on a
breakpoint. However when I try to step the debugger, the target gets a
page fault in kernel mode. I have attached a log of the kgdb output
below. Please let me know if any other info. would be useful to resolve
this problem.
<cut>
[GDB will not be able to debug user-mode threads:
/usr/lib/libthread_db.so: Undefined symbol "ps_pglobal_lookup"]
<cut>
0xffffffff803ecf8f in kdb_enter (msg=0x0) at cpufunc.h:63
63 __asm __volatile("int $3");
Unread portion of the kernel message buffer:
Cannot access memory at address 0xf000a8ece001a840
(kgdb) break pmap_pinit0
Breakpoint 1 at 0xffffffff805c4d10: file
/usr/src/sys/amd64/amd64/pmap.c, line 1059.
(kgdb) c
Continuing.
[New Thread 0]
Program received signal SIGQUIT, Quit.
[Switching to Thread 0]
pmap_pinit0 (pmap=0xffffff0000049d00) at
/usr/src/sys/amd64/amd64/pmap.c:1061
1061 PMAP_LOCK_INIT(pmap);
(kgdb) break 1066
Breakpoint 2 at 0xffffffff805c4d70: file
/usr/src/sys/amd64/amd64/pmap.c, line 1066.
(kgdb) c
Continuing.
Program received signal SIGSYS, Bad system call.
0x0000000000000000 in ?? ()
(kgdb) bt
#0 0x0000000000000000 in ?? ()
#1 0x0000000000000000 in ?? ()
(kgdb)
help
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