exercising current aarch64 kprobe support with systemtap

[William Cohen]

On 08/03/2016 09:13 AM, Pratyush Anand wrote:
> On 07/07/2016:03:58:37 PM, Frank Ch. Eigler wrote:
>> David Long <dave.long@linaro.org> writes:
>>
>>> [...]
>>>> - bug_handler() calls report_bug() which calls __warn()
>>>> - __warn() does lot of pr_warn()  which invokes print_worker_info()
>>>> where we have a kprobe instrumented.
>>>> - Therefore, we are encountering this issue.
> 
> Hi Will,
> 
> Can you please cross-check if following branch works perfectly with
> kprobes_onthefly.exp and other systemtap tests.
> 
> https://github.com/pratyushanand/linux/tree/uprobe/upstream_arm64_devel_v1.1
> 
> Following patch in above branch should solve this issue.
> https://github.com/pratyushanand/linux/commit/d0dcc6477f1279ab0bd99aefc30efdecb16c586e
> 
> However, I am not yet sure that above modification could be the best solution,
> so discussing at arm kernel list.
> 
> ~Pratyush
> 

I have an AMD seattle machine set up Fedora24, the upstream_arm64_devel_v1.1 branch kernel locally built, and a locally built checkout of systemtap (systemtap rpm in fc24 doesn't generate models for linux 4.6 and newer kernels).  Tried to run the systemtap tests with:

 make installcheck RUNTESTFLAGS="--debug systemtap.onthefly/kprobes_onthefly.exp"

However at some point the kernel starts having problems:

http://paste.stg.fedoraproject.org/5375/


-Will