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| author |   Eric W. Biederman <ebiederm@xmission.com> | 2017-06-04 04:32:13 -0500 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2018-07-21 10:43:12 -0500 |
| commit | 6883f81aac6f44e7df70a6af189b3689ff52cbfb (patch) | |
| tree | 184e376d23aa5ea7321e22f23dd78a3c77c74a63 /include/linux | |
| parent | pids: Move the pgrp and session pid pointers from task_struct to signal_struct (diff) | |
| download | linux-dev-6883f81aac6f44e7df70a6af189b3689ff52cbfb.tar.xz linux-dev-6883f81aac6f44e7df70a6af189b3689ff52cbfb.zip | |
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" <ebiederm@xmission.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/pid.h | 3 | ||||
| -rw-r--r-- | include/linux/sched.h | 4 | ||||
| -rw-r--r-- | include/linux/sched/signal.h | 5 |
3 files changed, 5 insertions, 7 deletions
diff --git a/include/linux/pid.h b/include/linux/pid.h index 3d4c504dcc8c..14a9a39da9c7 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -7,11 +7,10 @@ enum pid_type { PIDTYPE_PID, + PIDTYPE_TGID, PIDTYPE_PGID, PIDTYPE_SID, PIDTYPE_MAX, - /* only valid to __task_pid_nr_ns() */ - __PIDTYPE_TGID }; /* diff --git a/include/linux/sched.h b/include/linux/sched.h index 445bdf5b1f64..06b4e3bda93a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1275,12 +1275,12 @@ static inline pid_t task_session_vnr(struct task_struct *tsk) static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) { - return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, ns); + return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns); } static inline pid_t task_tgid_vnr(struct task_struct *tsk) { - return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, NULL); + return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL); } static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 2dcded16eb1e..ee30a5ba475f 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -147,7 +147,6 @@ struct signal_struct { #endif /* PID/PID hash table linkage. */ - struct pid *leader_pid; struct pid *pids[PIDTYPE_MAX]; #ifdef CONFIG_NO_HZ_FULL @@ -571,7 +570,7 @@ struct pid *task_pid_type(struct task_struct *task, enum pid_type type) static inline struct pid *task_tgid(struct task_struct *task) { - return task->signal->leader_pid; + return task->signal->pids[PIDTYPE_TGID]; } /* @@ -607,7 +606,7 @@ static inline bool thread_group_leader(struct task_struct *p) */ static inline bool has_group_leader_pid(struct task_struct *p) { - return task_pid(p) == p->signal->leader_pid; + return task_pid(p) == task_tgid(p); } static inline |