fork: Explicitly set PF_KTHREAD

Instead of implicitly inheriting PF_KTHREAD from the parent process examine arguments in kernel_clone_args to see if PF_KTHREAD should be set. This makes knowledge of which new threads are kernel threads explicit. This also makes it so that init and the user mode helper processes no longer have PF_KTHREAD set. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: "Eric W. Biederman" <[email protected]>
ddstreet · May 7, 2022 · 753550e · 753550e
1 parent 68d85f0
commit 753550e
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/kernel/fork.c b/kernel/fork.c
@@ -2068,6 +2068,9 @@ static __latent_entropy struct task_struct *copy_process(
 	p = dup_task_struct(current, node);
 	if (!p)
 		goto fork_out;
+	p->flags &= ~PF_KTHREAD;
+	if (args->kthread)
+		p->flags |= PF_KTHREAD;
 	if (args->io_thread) {
 		/*
 		 * Mark us an IO worker, and block any signal that isn't