#include <linux/compiler.h> /* For unlikely. */
#include <linux/sched.h> /* For struct task_struct. */
+#include <linux/pid_namespace.h> /* For task_active_pid_ns. */
extern long arch_ptrace(struct task_struct *child, long request,
}
}
+/**
+ * ptrace_event_pid - possibly stop for a ptrace event notification
+ * @event: %PTRACE_EVENT_* value to report
+ * @pid: process identifier for %PTRACE_GETEVENTMSG to return
+ *
+ * Check whether @event is enabled and, if so, report @event and @pid
+ * to the ptrace parent. @pid is reported as the pid_t seen from the
+ * the ptrace parent's pid namespace.
+ *
+ * Called without locks.
+ */
+static inline void ptrace_event_pid(int event, struct pid *pid)
+{
+ /*
+ * FIXME: There's a potential race if a ptracer in a different pid
+ * namespace than parent attaches between computing message below and
+ * when we acquire tasklist_lock in ptrace_stop(). If this happens,
+ * the ptracer will get a bogus pid from PTRACE_GETEVENTMSG.
+ */
+ unsigned long message = 0;
+ struct pid_namespace *ns;
+
+ rcu_read_lock();
+ ns = task_active_pid_ns(rcu_dereference(current->parent));
+ if (ns)
+ message = pid_nr_ns(pid, ns);
+ rcu_read_unlock();
+
+ ptrace_event(event, message);
+}
+
/**
* ptrace_init_task - initialize ptrace state for a new child
* @child: new child task