Re: Improving SystemTap ARM Architecture Support

[William Cohen <wcohen at redhat dot com>]

On 07/20/2011 04:35 AM, Mark Wielaard wrote:
> On Tue, 2011-07-19 at 17:48 -0400, William Cohen wrote:
>> Reviewing early test results and the code the following is an
>> incomplete list of improvements:
>>
>> -created aux_syscalls.stp (FIXED)
>>   "make installcheck" uses debuginfo smoke test
>>   needs _arch_ptrace_argstr(), aux_syscalls.stp
>> -map arm variants (armv7l and armv5tel) to arm (PR4186)
>> -provide tapset/arm/registers.stp
>>   -map register name to/from sruct
>>   -functions for nd probe argument access
>> -add any arm specific syscalls in tapset/arm/syscalls.stp
>> -provide high-resolution timer for gettimeofday_ns()
>>   -this may be complicated by the variety of arm high-res timer mechanisms
> 
> For sdt probes one also needs a fixed binutils with the following fix in
> it: http://sourceware.org/ml/binutils/2011-07/msg00118.html
> Fedora already has source packages, but I don't know if they have been
> build for arm yet:
> http://koji.fedoraproject.org/koji/buildinfo?buildID=253553

There is a similar but separate koji system for arm:

http://arm.koji.fedoraproject.org/

Looks like the newest binutils rpms for arm, still don't have that:
.
http://arm.koji.fedoraproject.org/koji/packageinfo?packageID=702

> For user space probing one needs some general kernel cleanups, utrace
> and uprobes fixes as described in this thread:
> https://www.redhat.com/archives/utrace-devel/2011-April/msg00005.html

Right now the arm machine isn't running a fedora kernel. It is running a locally built kernel from sources at:

git://gitorious.org/efikamx/linux-kernel.git

I haven't moved over to the fedora kernels yet, because I am afraid that is going to take some time to find the appropriate settings for the config file (every ARM seems to be special) and there appears to be some patches in the current efika mx git tree that might be needed.

-Will