[PATCH] pid: add do_each_pid_task
To avoid pid rollover confusion the kernel needs to work with struct pid *
instead of pid_t. Currently there is not an iterator that walks through all
of the tasks of a given pid type starting with a struct pid. This prevents us
replacing some pid_t instances with struct pid. So this patch adds
do_each_pid_task which walks through the set of task for a given pid type
starting with a struct pid.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 3591210..8cf9b11 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -119,4 +119,17 @@
1; }) ); \
}
+#define do_each_pid_task(pid, type, task) \
+ if ((task = pid_task(pid, type))) { \
+ prefetch(pid_next(task, type)); \
+ do {
+
+#define while_each_pid_task(pid, type, task) \
+ } while (pid_next(task, type) && ({ \
+ task = pid_next_task(task, type); \
+ rcu_dereference(task); \
+ prefetch(pid_next(task, type)); \
+ 1; }) ); \
+ }
+
#endif /* _LINUX_PID_H */