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| author | Eric W. Biederman <ebiederm@xmission.com> | 2017-06-04 11:32:13 +0200 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2018-07-21 17:43:12 +0200 |
| commit | 6883f81aac6f44e7df70a6af189b3689ff52cbfb (patch) | |
| tree | 184e376d23aa5ea7321e22f23dd78a3c77c74a63 /kernel/fork.c | |
| parent | pids: Move the pgrp and session pid pointers from task_struct to signal_struct (diff) | |
| download | linux-6883f81aac6f44e7df70a6af189b3689ff52cbfb.tar.xz linux-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 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index d2952162399b..cc5be0d01ce6 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1946,6 +1946,7 @@ static __latent_entropy struct task_struct *copy_process( init_task_pid(p, PIDTYPE_PID, pid); if (thread_group_leader(p)) { + init_task_pid(p, PIDTYPE_TGID, pid); init_task_pid(p, PIDTYPE_PGID, task_pgrp(current)); init_task_pid(p, PIDTYPE_SID, task_session(current)); @@ -1954,7 +1955,6 @@ static __latent_entropy struct task_struct *copy_process( p->signal->flags |= SIGNAL_UNKILLABLE; } - p->signal->leader_pid = pid; p->signal->tty = tty_kref_get(current->signal->tty); /* * Inherit has_child_subreaper flag under the same @@ -1965,6 +1965,7 @@ static __latent_entropy struct task_struct *copy_process( p->real_parent->signal->is_child_subreaper; list_add_tail(&p->sibling, &p->real_parent->children); list_add_tail_rcu(&p->tasks, &init_task.tasks); + attach_pid(p, PIDTYPE_TGID); attach_pid(p, PIDTYPE_PGID); attach_pid(p, PIDTYPE_SID); __this_cpu_inc(process_counts); |