diff options
| -rw-r--r-- | runtime/ChangeLog | 7 | ||||
| -rw-r--r-- | runtime/task_finder.c | 24 |
2 files changed, 31 insertions, 0 deletions
diff --git a/runtime/ChangeLog b/runtime/ChangeLog index 5cdcec81..da66ca0b 100644 --- a/runtime/ChangeLog +++ b/runtime/ChangeLog @@ -1,3 +1,10 @@ +2009-02-10 David Smith <dsmith@redhat.com> + + * task_finder.c (stap_utrace_detach): Ignores kernel threads by + checking task's flags for PF_KTHREAD. + (stap_utrace_detach_ops): Ditto. + (__stp_utrace_attach): Ditto. + 2009-02-06 Frank Ch. Eigler <fche@elastic.org> * autoconf-procfs-owner.c: New test. diff --git a/runtime/task_finder.c b/runtime/task_finder.c index d9a4cedb..af606356 100644 --- a/runtime/task_finder.c +++ b/runtime/task_finder.c @@ -220,6 +220,14 @@ stap_utrace_detach(struct task_struct *tsk, if (tsk == NULL || tsk->pid <= 1) return 0; +#ifdef PF_KTHREAD + // Ignore kernel threads. On systems without PF_KTHREAD, + // we're ok, since kernel threads won't be matched by the + // utrace_attach_task() call below. + if (tsk->flags & PF_KTHREAD) + return 0; +#endif + // Notice we're not calling get_task_mm() here. Normally we // avoid tasks with no mm, because those are kernel threads. // So, why is this function different? When a thread is in @@ -292,6 +300,14 @@ stap_utrace_detach_ops(struct utrace_engine_ops *ops) rcu_read_lock(); do_each_thread(grp, tsk) { +#ifdef PF_KTHREAD + // Ignore kernel threads. On systems without + // PF_KTHREAD, we're ok, since kernel threads won't be + // matched by the stap_utrace_detach() call. + if (task->flags & PF_KTHREAD) + continue; +#endif + rc = stap_utrace_detach(tsk, ops); if (rc != 0) goto udo_err; @@ -397,18 +413,26 @@ __stp_utrace_attach(struct task_struct *tsk, enum utrace_resume_action action) { struct utrace_attached_engine *engine; +#ifndef PF_KTHREAD struct mm_struct *mm; +#endif int rc = 0; // Ignore init if (tsk == NULL || tsk->pid <= 1) return EPERM; +#ifdef PF_KTHREAD + // Ignore kernel threads + if (task->flags & PF_KTHREAD) + return EPERM; +#else // Ignore threads with no mm (which are kernel threads). mm = get_task_mm(tsk); if (! mm) return EPERM; mmput(mm); +#endif engine = utrace_attach_task(tsk, UTRACE_ATTACH_CREATE, ops, data); if (IS_ERR(engine)) { |