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

[William Cohen <wcohen@redhat.com>]

On 02/23/2012 03:54 PM, David Smith wrote:
> On 02/23/2012 01:06 PM, William Cohen wrote:

Hi David,

Thanks for the comments/questions.

> 
>> I reviewed the SystemTap testsuite failures for Fedora 15 hard float running on ARM.  You can see the recent ARM test results in dejazilla at:
>>
>> http://web.elastic.org/~dejazilla/viewsummary.php?_offset=0&_limit=40&_sort=1A&summary=&age=&rg=&tool=&variant=%3D%27armv7l-unknown-linux-gnu%27&versions=&pass=&fail=&kpass=&kfail=&xpass=&xfail=&untested=&unresolved=&unsupported=&warning=&error=
> 
> 
> Here are some notes on certain tests:
> 
>> FAIL: ipaddr_IPv4_recvmsg find 'nc'
>>       doesn't seem to find /usr/bin/nc, but nc rpm has been installed on machine

I need to pay attention to editing. I installed nc on the machine after I realized why the test was failing, but didn't write things correctly after trying stuff.  The test passes after installing the nc rpm.

> 
> 
> That's odd.  That test tries to find nc by running "which nc".  If that
> succeeds, it assumes nc is there.  Does "which nc" find /usr/bin/nc and
> return a 0 exit code?
> 
>> FAIL: vma_vdsodefault
>>       vma_vdso.stp uses uaddr() which didn't work on arm.
> 
> 
> Hmm, can you tell in systemtap.log what part of 'uaddr()' didn't work?

The log wasn't too helpful. When running the test by hand.  Looks like umodename(uaddrr()) == "<unknown>", so getting from

	  printf("%s@%x unknown\n", name, uaddr());

>>
> 
>> FAIL: uprobeslibgcc-O3default-prelink-debug prelink ./libuprobeslibgcc-O3default-prelink-debug.so
>> FAIL: uprobeslibgcc-O3default-prelink-sep-debug prelink ./libuprobeslibgcc-O3default-prelink-sep-debug.so
>> FAIL: uprobeslibgcc-O3default-prelink-sep-debug-after prelink ./libuprobeslibgcc-O3default-prelink-sep-debug-after.so
>>       uprobes not available on arm
> 
> 
> This is odd.  I would have thought the testsuite would have realized
> this platform didn't have uprobes, and not run the test at all.  Which
> .exp is this, exelib.exp?

Yes, it appears to be running:

systemtap.exelib/exelib.exp ...


> 
>> FAIL: buildok/syscalls-arch-detailed.stp
>>       unable to probe syscall.sigaltstack.return
>>       ARM doesn't have a sys_sigaltstack() function in the kernel.
> 
> 
> That's PR13480.
> 
>> FAIL: buildok/tcp-all-probes.stp
>> FAIL: buildok/tcp-detailed.stp
>>       unable to get identifier '$optname' tapset/tcp.stp:369:27
> 
> 
> Hmm, this one looks like a debuginfo problem.  Could you show me the
> output of:
> 
> # stap -L 'kernel.function("tcp_setsockopt")

$ ../install/bin/stap -L 'kernel.function("tcp_setsockopt")'
kernel.function("tcp_setsockopt@net/ipv4/tcp.c:2406") $optlen:unsigned int $sk:struct sock*

> 
>> FAIL: buildok/twentyeightprime.stp
>>       CONFIG_UTRACE not available (seems like that should be UNTESTED)
> 
> 
> Actually it should be KFAIL.  I'll fix this.
> 
>>
>> FAIL: semok/thirtynine.stp
>>       can't access identifier '$prev' at .../semok/thirtynine.stp:6:40
> 
> 
> I'd guess this is a debuginfo problem.
> 
>> FAIL: systemtap.stress/current.stp compilation
>>       can't probe kernel.function("__switch_to").call
>>       need to adapt for arm
> 
> 
> File a PR on this one.


Looks very similar to PR4331 - systemtap.stress/current.stp need to be updated for s390x
Made clone: PR13734 - systemtap.stress/current.stp need to be updated for arm

> 
>> FAIL: unprivileged embedded C: no embedded C: --unprivileged: inet_get_ip_source(long)
>> FAIL: unprivileged embedded C: no embedded C: --unprivileged: get_ip(long)
> 
> 
> I've always been fuzzy on what exactly these errors mean.

I wasn't too clear on the last two, so I didn't comment on them either. :/

-Will