[Crash-utility] crash tool fail to analyze the image

[Dave Anderson]

----- Original Message -----
> 
> 
> Hi
> 
> 
> 
> I just use the crash tool get from crash-utility.git for arm64 kernel panic
> analyze, we found that the crash tool fails to analyze, so what is the
> status of crash support for arm64? 

Very interesting.  The support of arm64 is completely theoretical -- I wrote
it all based upon kernel sources with absolutely no testing whatsoever.  I
have been waiting for full access to arm64 hardware, and it appears I should
have that access within a few weeks. 

> And could you please help to check the log in attachment? I have deleted
> more than 100,000 lines of “WARNING: arm64_verify_symbol: function not 
> implemented” in attachment. Thanks

Right -- that warning is a placeholder.  You could comment out that warning
message for now.

The "read error" messages indicate that the physical addresses that were
calculated from the virtual addresses were not found in any of the PT_LOAD
segments in the ELF header.  I'm guessing that the "phys_offset" calculation
returned by arm64_calc_phys_offset() is maybe causing the arm64 VTOP() to 
come up with bogus values:

#define VTOP(X) \
        ((unsigned long)(X)-(machdep->kvbase)+(machdep->machspec->phys_offset))

  machdep_init(PRE_GDB)
    arm64_init(PRE_GDB)
      arm64_calc_phys_offset()
         arm64_kdump_phys_base()
            arm_kdump_phys_base()
            

But again, that's just a guess.  If you turn on debugging with "crash -d<number> ...",
you might see more useful information.  
 
> I used command “./crash vmlinux emmd003 at Mar-18-2014” to analyze.

Right -- try "crash -d1 ..." or "crash -d8 ..." for more info.  The larger the
number, the more verbose the debug output will be.

But the first question is: how did you create the vmcore?  Are you working on
implementing support for arm64 kexec/kdump support in the kernel?
 
> Due to crash and vmlinux is too big in the mail loop, so I didn’t attach
> them. if you need them, you can give me a space, I can share it to you,
> thanks.

Yes, I would be very interested if you could make the vmlinux/vmcore pair
available to me.  I will send you information on how to do that offline.

Thanks,
  Dave