[Crash-utility] [RFC] display function param and local value for backtrace

[Lei Wen]

Hi Rabin,

> -----Original Message-----
> From: crash-utility-bounces at redhat.com
> [mailto:crash-utility-bounces at redhat.com] On Behalf Of Rabin Vincent
> Sent: Thursday, October 18, 2012 4:22 PM
> To: Dave Anderson
> Cc: Discussion list for crash utility usage, maintenance and development
> Subject: Re: [Crash-utility] [RFC] display function param and local value for
> backtrace
> 
> 2012/10/17 Dave Anderson <anderson at redhat.com>:
> > BTW, what happens when you run it against a task that has taken a
> > kernel-mode exception or kernel-mode interrupt?
> 
> The backtrace stops at the exception point:
> 
> crash> bt
> PID: 0      TASK: c0998778  CPU: 0   COMMAND: "swapper"
>  #0 [<c0320fb8>] (touch_softlockup_watchdog) from [<c0290030>]
>  #1 [<c0290030>] (asm_do_IRQ) from [<c029124c>]
>     pc : [<c02a1e60>]    lr : [<c02a1e5c>]    psr: 60000013
>     sp : c0983f18  ip : 00000002  fp : 000021ce
>     r10: a83a0af5  r9 : 0000289c  r8 : c09ead48
>     r7 : 00000008  r6 : a7979c2b  r5 : 00000001  r4 : 00000003
>     r3 : 00000000  r2 : 00000001  r1 : 80000093  r0 : c09ead8c
>     Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM
>  #2 [<c029124c>] (__irq_svc) from [<c02a1e5c>]
>  #3 [<c02a1e60>] (cpuidle_enter) from [<c05dfa3c>]
>  #4 [<c05dfa3c>] (cpuidle_idle_call) from [<c0292c98>]
>  #5 [<c0292c98>] (cpu_idle) from [<c0008cb0>]
>  #6 [<c0008cb0>] (start_kernel) from [<00008080>]
> crash> gdb bt
> #0  0xc0320fb8 in touch_softlockup_watchdog () at
> /tmp/kernel/kernel/softlockup.c:77
> #1  0xc0290030 in asm_do_IRQ (irq=80, regs=0x0) at
> /tmp/kernel/arch/arm/kernel/irq.c:109
> #2  0xc029124c in __irq_svc () at
> /tmp/kernel/arch/arm/kernel/entry-armv.S:229
> Register 25 is not available
> gdb: gdb request failed: bt

Your patch still work well in 6.0.9. Good job!
While I am trying to do similar thing in my patch, exacting the registers from thread_info, instead of crash_note for those not running task, I just could get the first unwind function, then it failed. Do you have any idea for why?
The unwind goes normally for the panic task.

Also I see your "gdb bt" would always fails at below message, is there method to provide the cpsr for the not running task?
> Register 25 is not available

Thanks,
Lei