Re: Recent review of SystemTap test results on ARM running Fedora 15 hard float.

[William Cohen <wcohen at redhat dot com>]

On 02/25/2012 02:39 PM, Mark Wielaard wrote:

> A simpler test would be running this:
> 
> stap -e 'probe syscall.clock_gettime, syscall.getuidr
>          { if (pid() == target()) printf("%s 0x%x in %s\n", name, uaddr(),
>                                          umodname(uaddr())) }' \
>      -c testsuite/vma_vdso-m64.exe
> 
> Which on x86_64 gives:
> 
> clock_gettime 0x7fff689ff9cf in vdso
> getuid 0x3c5c0ed819 in /usr/lib64/libc-2.15.so
> getuid 0x3c5c0bb007 in /usr/lib64/libc-2.15.so
> 
> Does that fail for all invocations on ARM?
> 
> If it is the vdso tracker then you want to take a look at
> runtime/vma.c _stp_vma_match_vdso will give some debug output
> with stap -DDEBUG_TASK_FINDER_VMA
> 
> Cheers,
> 
> Mark

Hi Mark,

Does this this test need the uprobes support for this test to work?

Below is the output for 2.6.42.3-2.fc15.armv7hl.tegra kernel which doesn't have uprobes support:

$ stap -e 'probe syscall.clock_gettime, syscall.getuid 
      { if (pid() == target()) printf("%s 0x%x in %s\n", name, uaddr(),
                                       umodname(uaddr())) }' -c testsuite/vma_vdsodefault.exe
clock_gettime 0x4010d6ec in <unknown>
getuid 0x40258e10 in <unknown>
getuid 0x40225f5c in <unknown>

-Will