Re: cannot trace user-level code in cross compilation environment

[Zhiwei Ying <zhiwei.ying@gmail.com>]

Hi Josh,

You are correct. The problem is caused that two files are not in the same path.
I used a soft link to the binary on the host pc side, so in the script
they looks in the same directory, but actually they are not. Systemtap
will expand the softlink into real directory.

Thanks again,
Zhiwei

On Tue, Apr 5, 2011 at 6:56 AM, Josh Stone <jistone@redhat.com> wrote:
> On 04/01/2011 05:52 PM, Zhiwei Ying wrote:
>> Yes, the binary in in the same path. if the binary is different,
>> staprun will complain "build-id mismatch"
>>
>> Here is the detail for my cross-compilation:
>> cd systemtap-1.4
>> mkdir runtimebuild
>> cd runtimebuild
>> ../runtime/staprun/configure --host=/crosstarget --prefix=
>> make
>> make install DESTDIR=/xxx
>>
>> cd runtime/uprobes
>> #change KDIR in Makefile to crosstarget
>> make
>>
>> cp staprun, stapio and uprobes to the board
>>
>> on the board
>> # staprun -v traceauto.ko -b 3 -u -c ./hello.
>> stapio:main:33 Using a buffer of 3 MB.
>> stapio:start_cmd:200 block briefly
>> stapio:stp_main_loop:636 detaching pid 2289
>> stapio:start_cmd:219 execing target_cmd ./hello
>> hello world
>> stapio:cleanup_and_exit:403 detach=0
>> end of tracing
>> stapio:cleanup_and_exit:420 closing control channel
>> staprun:remove_module:213 Module traceauto removed
>>
>> Any help is great appreciated!
>
> Please try these three options for stap, when compiling the ko:
>  -DDEBUG_UPROBES -DDEBUG_TASK_FINDER -DDEBUG_TASK_FINDER_VMA
>
> This should give much more debugging output to find the problem.
>
> Josh
>