From: "Eric W. Biederman" 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 Signed-off-by: Andrew Morton --- include/linux/pid.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff -puN include/linux/pid.h~pid-add-do_each_pid_task include/linux/pid.h --- a/include/linux/pid.h~pid-add-do_each_pid_task +++ a/include/linux/pid.h @@ -118,4 +118,17 @@ extern void FASTCALL(free_pid(struct pid 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 */ _