(Was: ptrace() hangs on attempt to seize/attach stopped & frozen task)
Get series with b4
b4 am [email protected]Versions newest first
- v1 Latest2 patches 2 repliesIn review
Patches in v1 No applies recorded yet
| # | Subject and files | Size | Replies | Applied |
|---|---|---|---|---|
| 1/2 | ptrace: make wait_on_bit(JOBCTL_TRAPPING_BIT) in ptrace_attach() killablekernel/ | +8 | 1 reply | |
| 2/2 | ptrace: task_stopped_code(ptrace => true) can't see TASK_STOPPED taskkernel/ | +1 | 1 reply |
Reviews trailers per patch
All 2 patches have a Reviewed-by or Acked-by.
| Patch | Tejun Heo |
|---|---|
| 1/2 | A-b |
| 2/2 | A-b |
Trailers given in replies are filled; those carried in the patches from earlier versions are outlined with dashes.
Cover letter [PATCH 0/2] (Was: ptrace() hangs on attempt to seize/attach stopped & frozen task)
Quoted 2 lines · Andrey Ryabinin
So, the
ptrace()hangs if we try to attach to stopped task from freezing cgroup.
OK, lets make it killable at least, TASK_KILLABLE looks better in any case.
I am starting to think again that we should remove JOBCTL_TRAPPING, but this needs a bit more discussion and probably testing.
Anyway I agree with Tejun, the freezer doesn't look nice too.
Hmm. I need to re-check but it seems we have another problem... ptrace_stop() does task_participate_group_stop() and this (in particular) clears JOBCTL_STOP_PENDING. This is only correct if the task is still traced, but this is not necessarily true and we can in fact clear JOBCTL_STOP_PENDING set by __ptrace_unlink() called by the exiting tracer.
Oleg.