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| author | David Smith <dsmith@redhat.com> | 2009-02-10 06:54:12 -0600 |
|---|---|---|
| committer | David Smith <dsmith@redhat.com> | 2009-02-10 06:54:12 -0600 |
| commit | 7c657805a80358ce2429415af931ca1546c2c2d2 (patch) | |
| tree | b31f8ffb20d9537e1b5828ccd9bdc7c0a736def9 /runtime/task_finder.c | |
| parent | 066e0c0154fd18b9fb4fa880474adb98f27bd091 (diff) | |
| download | systemtap-steved-7c657805a80358ce2429415af931ca1546c2c2d2.tar.gz systemtap-steved-7c657805a80358ce2429415af931ca1546c2c2d2.tar.xz systemtap-steved-7c657805a80358ce2429415af931ca1546c2c2d2.zip | |
Ignores kernel threads (by checking for PF_KTHREAD).
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.
Diffstat (limited to 'runtime/task_finder.c')
| -rw-r--r-- | runtime/task_finder.c | 24 |
1 files changed, 24 insertions, 0 deletions
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)) { |