From 6883f81aac6f44e7df70a6af189b3689ff52cbfb Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 4 Jun 2017 04:32:13 -0500 Subject: pid: Implement PIDTYPE_TGID Everywhere except in the pid array we distinguish between a tasks pid and a tasks tgid (thread group id). Even in the enumeration we want that distinction sometimes so we have added __PIDTYPE_TGID. With leader_pid we almost have an implementation of PIDTYPE_TGID in struct signal_struct. Add PIDTYPE_TGID as a first class member of the pid_type enumeration and into the pids array. Then remove the __PIDTYPE_TGID special case and the leader_pid in signal_struct. The net size increase is just an extra pointer added to struct pid and an extra pair of pointers of an hlist_node added to task_struct. The effect on code maintenance is the removal of a number of special cases today and the potential to remove many more special cases as PIDTYPE_TGID gets used to it's fullest. The long term potential is allowing zombie thread group leaders to exit, which will remove a lot more special cases in the code. Signed-off-by: "Eric W. Biederman" --- kernel/time/itimer.c | 5 +++-- kernel/time/posix-cpu-timers.c | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c index f26acef5d7b4..9a65713c8309 100644 --- a/kernel/time/itimer.c +++ b/kernel/time/itimer.c @@ -139,9 +139,10 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer) { struct signal_struct *sig = container_of(timer, struct signal_struct, real_timer); + struct pid *leader_pid = sig->pids[PIDTYPE_TGID]; - trace_itimer_expire(ITIMER_REAL, sig->leader_pid, 0); - kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid); + trace_itimer_expire(ITIMER_REAL, leader_pid, 0); + kill_pid_info(SIGALRM, SEND_SIG_PRIV, leader_pid); return HRTIMER_NORESTART; } diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 5a6251ac6f7a..40e6fae46cec 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -895,7 +895,7 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, trace_itimer_expire(signo == SIGPROF ? ITIMER_PROF : ITIMER_VIRTUAL, - tsk->signal->leader_pid, cur_time); + task_tgid(tsk), cur_time); __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); } -- cgit v1.2.3