[RFC] Probes don't hit in an already running process

[Torsten Polle]

Hi,

I've made the observation that probes sometimes don't hit when I start
staprun after the process (where the probes should hit) started.  After
some tests, I found out that only multi-thread processes were affected
under a certain condition.

The patch below fixes the issue for me. But I've no clue about possible
side effects. In my first attempt to fix the issue, I also included the
calls to __stp_call_callbacks() into the guarded area. My probes hit,
but calls to usymname(uaddr()) in the probe body only printed the
address instead of the symbol of the probed function.

Any advice of how I can improve the patch is appreciated.

Kind Regards,
Torsten

-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-Fix-uprobes-don-t-hit-in-multi-threaded-processes.patch
Type: text/x-patch
Size: 3496 bytes
Desc: 0001-Fix-uprobes-don-t-hit-in-multi-threaded-processes.patch
URL: <http://sourceware.org/pipermail/systemtap/attachments/20140307/1e0b78e2/attachment.bin>