Re: [PATCH] pid: change task_struct::pid to read-only

On 12/16, Richard Guy Briggs wrote: > > task->pid is only ever assigned once (well ok, twice). For system health and > secure logging confidence, make it const to make it much more intentional when > it is being changed. Hmm. I am a bit suprized you decided to constify task->pid, but OK. And we can do the same with task->signal, this can actually help to generate a better code, probably. > if (!thread_group_leader(tsk)) { > struct task_struct *leader = tsk->group_leader; > + /* tast_struct::pid is const pid_t, hence the ugly cast */ > + pid_t *pid_p = (pid_t*)&(tsk->pid); > > sig->notify_count = -1; /* for exit_notify() */ > for (;;) { > @@ -950,7 +952,7 @@ static int de_thread(struct task_struct *tsk) > * Note: The old leader also uses this pid until release_task > * is called. Odd but simple and correct. > */ > - tsk->pid = leader->pid; > + *pid_p = leader->pid; Well, imho this (and de_thread) looks a bit ugly. Perhaps we should add something like #define ASSIGN_CONST(l, r) (*(typeof(r) *)&(l) = (r)) into compiler.h ?