Merge tag 'pidfd-updates-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/braun...

[sfrench/cifs-2.6.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index fe83343da24ba2c6c36761983ad974e72fcbbf52..187c02ce534c87a955cf93d1d01f9fba57c723e2 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -898,6 +898,8 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
 #ifdef CONFIG_STACKPROTECTOR
        tsk->stack_canary = get_random_canary();
 #endif
+       if (orig->cpus_ptr == &orig->cpus_mask)
+               tsk->cpus_ptr = &tsk->cpus_mask;
 
        /*
         * One for us, one for whoever does the "release_task()" (usually
@@ -1709,8 +1711,34 @@ static void pidfd_show_fdinfo(struct seq_file *m, struct file *f)
 }
 #endif
 
+/*
+ * Poll support for process exit notification.
+ */
+static unsigned int pidfd_poll(struct file *file, struct poll_table_struct *pts)
+{
+       struct task_struct *task;
+       struct pid *pid = file->private_data;
+       int poll_flags = 0;
+
+       poll_wait(file, &pid->wait_pidfd, pts);
+
+       rcu_read_lock();
+       task = pid_task(pid, PIDTYPE_PID);
+       /*
+        * Inform pollers only when the whole thread group exits.
+        * If the thread group leader exits before all other threads in the
+        * group, then poll(2) should block, similar to the wait(2) family.
+        */
+       if (!task || (task->exit_state && thread_group_empty(task)))
+               poll_flags = POLLIN | POLLRDNORM;
+       rcu_read_unlock();
+
+       return poll_flags;
+}
+
 const struct file_operations pidfd_fops = {
        .release = pidfd_release,
+       .poll = pidfd_poll,
 #ifdef CONFIG_PROC_FS
        .show_fdinfo = pidfd_show_fdinfo,
 #endif
@@ -1952,9 +1980,6 @@ static __latent_entropy struct task_struct *copy_process(
        p->pagefault_disabled = 0;
 
 #ifdef CONFIG_LOCKDEP
-       p->lockdep_depth = 0; /* no locks held yet */
-       p->curr_chain_key = 0;
-       p->lockdep_recursion = 0;
        lockdep_init_task(p);
 #endif
 
@@ -2117,7 +2142,7 @@ static __latent_entropy struct task_struct *copy_process(
         */
 
        p->start_time = ktime_get_ns();
-       p->real_start_time = ktime_get_boot_ns();
+       p->real_start_time = ktime_get_boottime_ns();
 
        /*
         * Make it visible to the rest of the system, but dont wake it up yet.