[Crash-utility] [PATCH] bt for i386 xen-dom0
Hi,
I found the problem that the subcommand "bt" cannot display the stack
of "bash" process on i386 xen-dom0 like the following:
crash> bt
PID: 3954 TASK: e502aaa0 CPU: 0 COMMAND: "bash"
crash>
This problem happens if running "bt" for "swapper" process too:
crash> bt
PID: 0 TASK: c7ca5550 CPU: 1 COMMAND: "swapper"
crash>
The cause is that bt->stackbase is overwritten in get_netdump_regs_x86()
even if the symbol "crash_kexec" is found. This patch fixes the overwritten
problem, and the result is the following:
crash> bt
PID: 3954 TASK: e502aaa0 CPU: 0 COMMAND: "bash"
#0 [eb30ef34] crash_kexec at c043852a
#1 [eb30ef78] write_sysrq_trigger at c0498b75
#2 [eb30ef84] vfs_write at c0467a6d
#3 [eb30ef9c] sys_write at c046805c
#4 [eb30efb8] system_call at c0405348
EAX: ffffffda EBX: 00000001 ECX: b7c5d000 EDX: 00000002
DS: 007b ESI: 00000002 ES: 007b EDI: b7c5d000
SS: 007b ESP: bfdb5eb8 EBP: bfdb5ed8
CS: 0073 EIP: 00295402 ERR: 00000004 EFLAGS: 00000246
crash>
crash> bt
PID: 0 TASK: c7ca5550 CPU: 1 COMMAND: "swapper"
#0 [c10fdfac] xen_idle at c040321a
#1 [c10fdfac] cpu_idle at c0403334
crash>
Thanks
Ken'ichi Ohmichi
Signed-off-by: Ken'ichi Ohmichi <oomichi(a)mxs.nes.nec.co.jp>
---
diff -rpuN crash-4.0-4.13.org/netdump.c crash-4.0-4.13/netdump.c
--- crash-4.0-4.13.org/netdump.c 2008-01-15 19:24:09.000000000 +0900
+++ crash-4.0-4.13/netdump.c 2008-01-15 19:31:52.000000000 +0900
@@ -2039,6 +2039,12 @@ next_sysrq:
return;
}
+ if (halt_eip && halt_esp) {
+ *eip = halt_eip;
+ *esp = halt_esp;
+ return;
+ }
+
if (panic)
return;
@@ -2064,12 +2070,6 @@ next_sysrq:
goto retry;
}
- if (halt_eip && halt_esp) {
- *eip = halt_eip;
- *esp = halt_esp;
- return;
- }
-
if (CRASHDEBUG(1))
error(INFO,
"get_netdump_regs_x86: cannot find anything useful (task: %lx)\n",
bt->task);
_