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-rw-r--r--runtime/ChangeLog11
-rw-r--r--runtime/task_finder.c139
2 files changed, 85 insertions, 65 deletions
diff --git a/runtime/ChangeLog b/runtime/ChangeLog
index e8b9aaf2..f5ae91fb 100644
--- a/runtime/ChangeLog
+++ b/runtime/ChangeLog
@@ -1,3 +1,14 @@
+2008-05-05 David Smith <dsmith@redhat.com>
+
+ * task_finder.c (stap_utrace_detach_ops): Make sure we ignore
+ /sbin/init.
+ (__stp_utrace_attach): Added function to handle details of
+ attaching a utrace engine.
+ (__stp_utrace_task_finder_report_clone): Calls
+ __stp_utrace_attach.
+ (__stp_utrace_task_finder_report_exec): Ditto.
+ (stap_start_task_finder): Ditto.
+
2008-04-30 Masami Hiramatsu <mhiramat@redhat.com>
PR 5648
diff --git a/runtime/task_finder.c b/runtime/task_finder.c
index 915925a3..6d79c98a 100644
--- a/runtime/task_finder.c
+++ b/runtime/task_finder.c
@@ -93,6 +93,10 @@ stap_utrace_detach_ops(struct utrace_engine_ops *ops)
rcu_read_lock();
for_each_process(tsk) {
struct mm_struct *mm;
+
+ if (tsk->pid <= 1)
+ continue;
+
mm = get_task_mm(tsk);
if (mm) {
mmput(mm);
@@ -188,6 +192,45 @@ __stp_get_mm_path(struct mm_struct *mm, char *buf, int buflen)
#define __STP_UTRACE_ATTACHED_TASK_EVENTS (UTRACE_EVENT(DEATH))
+static int
+__stp_utrace_attach(struct task_struct *tsk,
+ const struct utrace_engine_ops *ops, void *data,
+ unsigned long event_flags)
+{
+ struct utrace_attached_engine *engine;
+ struct mm_struct *mm;
+ int rc = 0;
+
+ // Ignore init
+ if (tsk->pid <= 1)
+ return EPERM;
+
+ // Ignore threads with no mm (which are kernel threads).
+ mm = get_task_mm(tsk);
+ if (! mm)
+ return EPERM;
+ mmput(mm);
+
+ engine = utrace_attach(tsk, UTRACE_ATTACH_CREATE, ops, data);
+ if (IS_ERR(engine)) {
+ int error = -PTR_ERR(engine);
+ if (error != ENOENT) {
+ _stp_error("utrace_attach returned error %d on pid %d",
+ error, (int)tsk->pid);
+ rc = error;
+ }
+ }
+ else if (unlikely(engine == NULL)) {
+ _stp_error("utrace_attach returned NULL on pid %d",
+ (int)tsk->pid);
+ rc = EFAULT;
+ }
+ else {
+ utrace_set_flags(tsk, engine, event_flags);
+ }
+ return rc;
+}
+
static u32
__stp_utrace_task_finder_report_clone(struct utrace_attached_engine *engine,
struct task_struct *parent,
@@ -200,21 +243,9 @@ __stp_utrace_task_finder_report_clone(struct utrace_attached_engine *engine,
if (atomic_read(&__stp_task_finder_state) != __STP_TF_RUNNING)
return UTRACE_ACTION_RESUME;
- // On clone, attach to the child. Ignore threads with no mm
- // (which are kernel threads).
- mm = get_task_mm(child);
- if (mm) {
- mmput(mm);
- child_engine = utrace_attach(child, UTRACE_ATTACH_CREATE,
- engine->ops, 0);
- if (IS_ERR(child_engine))
- _stp_error("attach to clone child %d failed: %ld",
- (int)child->pid, PTR_ERR(child_engine));
- else {
- utrace_set_flags(child, child_engine,
- __STP_UTRACE_TASK_FINDER_EVENTS);
- }
- }
+ // On clone, attach to the child.
+ (void) __stp_utrace_attach(child, engine->ops, 0,
+ __STP_UTRACE_TASK_FINDER_EVENTS);
return UTRACE_ACTION_RESUME;
}
@@ -253,6 +284,8 @@ __stp_utrace_task_finder_report_exec(struct utrace_attached_engine *engine,
struct list_head *cb_node;
list_for_each(cb_node, &tgt->callback_list_head) {
struct stap_task_finder_target *cb_tgt;
+ int rc;
+
cb_tgt = list_entry(cb_node,
struct stap_task_finder_target,
callback_list);
@@ -269,19 +302,11 @@ __stp_utrace_task_finder_report_exec(struct utrace_attached_engine *engine,
}
// Set up thread death notification.
- engine = utrace_attach(tsk,
- UTRACE_ATTACH_CREATE,
- &cb_tgt->ops, cb_tgt);
- if (IS_ERR(engine)) {
- _stp_error("attach to exec'ed %d failed: %ld",
- (int)tsk->pid,
- PTR_ERR(engine));
- }
- else {
- utrace_set_flags(tsk, engine,
+ rc = __stp_utrace_attach(tsk, &cb_tgt->ops, cb_tgt,
__STP_UTRACE_ATTACHED_TASK_EVENTS);
- cb_tgt->engine_attached = 1;
- }
+ if (rc != 0 && rc != EPERM)
+ break;
+ cb_tgt->engine_attached = 1;
}
}
return UTRACE_ACTION_RESUME;
@@ -346,46 +371,35 @@ stap_start_task_finder(void)
}
atomic_set(&__stp_task_finder_state, __STP_TF_RUNNING);
- printk(KERN_ERR "SYSTEMTAP: in RUNNING state\n");
rcu_read_lock();
for_each_process(tsk) {
- struct utrace_attached_engine *engine;
struct mm_struct *mm;
char *mmpath;
size_t mmpathlen;
struct list_head *tgt_node;
+ /* Attach to the thread */
+ rc = __stp_utrace_attach(tsk, &__stp_utrace_task_finder_ops, 0,
+ __STP_UTRACE_TASK_FINDER_EVENTS);
+ if (rc == EPERM) {
+ /* Ignore EPERM errors, which mean this wasn't
+ * a thread we can attach to. */
+ rc = 0;
+ continue;
+ }
+ else if (rc != 0) {
+ /* If we get a real error, quit. */
+ break;
+ }
+
+ /* Grab the path associated with this task. */
mm = get_task_mm(tsk);
if (! mm) {
/* If the thread doesn't have a mm_struct, it is
* a kernel thread which we need to skip. */
continue;
}
-
- /* Attach to the thread */
- engine = utrace_attach(tsk, UTRACE_ATTACH_CREATE,
- &__stp_utrace_task_finder_ops, 0);
- if (IS_ERR(engine)) {
- int error = -PTR_ERR(engine);
- if (error != ENOENT) {
- mmput(mm);
- _stp_error("utrace_attach returned error %d on pid %d",
- error, (int)tsk->pid);
- rc = error;
- break;
- }
- }
- else if (unlikely(engine == NULL)) {
- mmput(mm);
- _stp_error("utrace_attach returned NULL on pid %d",
- (int)tsk->pid);
- rc = EFAULT;
- break;
- }
- utrace_set_flags(tsk, engine, __STP_UTRACE_TASK_FINDER_EVENTS);
-
- /* Check the thread's exe's path/pid against our list. */
mmpath = __stp_get_mm_path(mm, mmpath_buf, PATH_MAX);
mmput(mm); /* We're done with mm */
if (IS_ERR(mmpath)) {
@@ -395,6 +409,7 @@ stap_start_task_finder(void)
break;
}
+ /* Check the thread's exe's path/pid against our list. */
mmpathlen = strlen(mmpath);
list_for_each(tgt_node, &__stp_task_finder_list) {
struct stap_task_finder_target *tgt;
@@ -430,23 +445,17 @@ stap_start_task_finder(void)
}
// Set up thread death notification.
- engine = utrace_attach(tsk,
- UTRACE_ATTACH_CREATE,
- &cb_tgt->ops, cb_tgt);
- if (IS_ERR(engine)) {
- _stp_error("attach to %d failed: %ld",
- (int)tsk->pid,
- PTR_ERR(engine));
- }
- else {
- utrace_set_flags(tsk, engine,
+ rc = __stp_utrace_attach(tsk, &cb_tgt->ops,
+ cb_tgt,
__STP_UTRACE_ATTACHED_TASK_EVENTS);
- cb_tgt->engine_attached = 1;
- }
+ if (rc != 0 && rc != EPERM)
+ break;
+ cb_tgt->engine_attached = 1;
}
}
}
rcu_read_unlock();
+
_stp_kfree(mmpath_buf);
return rc;
}
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