[PATCH 3/7] pid: use the CONST_CAST macro instead to write to const task_struct::pid

The CONST_CAST macro is a cleaner and more reliable way to write to the const task_struct::pid. Cc: Oleg Nesterov <oleg(a)redhat.com&gt; Cc: Peter Zijlstra <peterz(a)infradead.org&gt; Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; --- fs/exec.c | 4 +--- kernel/fork.c | 5 +---- 2 files changed, 2 insertions(+), 7 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index a6b585e..1d2369d 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -906,8 +906,6 @@ static int de_thread(struct task_struct *tsk) */ 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 +948,7 @@ 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. */ - *pid_p = leader->pid; + CONST_CAST(pid_t, tsk->pid) = leader->pid; change_pid(tsk, PIDTYPE_PID, task_pid(leader)); transfer_pid(leader, tsk, PIDTYPE_PGID); transfer_pid(leader, tsk, PIDTYPE_SID); diff --git a/kernel/fork.c b/kernel/fork.c index 296e564..207c543 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1135,7 +1135,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, { int retval; struct task_struct *p; - pid_t *pid_p; if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS)) return ERR_PTR(-EINVAL); @@ -1391,9 +1390,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, /* ok, now we should be set up.. */ - /* tast_struct::pid is const pid_t, hence the ugly cast */ - pid_p = (pid_t*)&(p->pid); - *pid_p = pid_nr(pid); + CONST_CAST(pid_t, p->pid) = pid_nr(pid); if (clone_flags & CLONE_THREAD) { p->exit_signal = -1; p->group_leader = current->group_leader; -- 1.7.1