Re: error to run systemtap in an ARM platform

[fche at redhat dot com (Frank Ch. Eigler)]

I wrote:

>> semantic error: failed to retrieve return value location for vfs_write
>> (/build/tegra2_seaboard/tmp/portage/sys-kernel/chromeos-kernel-9999/work/chromeos-kernel-9999/fs/read_write.c):
>> identifier '$return' at read-write.stp:7:6
>>         source: 	if ($return > 0) {
>>                 	    ^ 
>> [...]
>> Any ideas how to debug the problem?
>
> In this case, I might try focusing the debugger on the function
> arm_return_value_location(), probably in elfutils' libebl_arm.so.

For example, you could use a debugger.  Or, with a native
user-space-capable kernel, run stap on stap:

stap .../examples/general/varwatch.stp \
     'process("/usr/lib*/elfutils/libebl_*.so").statement("*return_value*@*:*")' \
      '$$vars$' \
      -c 'stap -p2 read-write.stp'

- FChE