ptrace: ptrace_check_attach() should not do s/STOPPED/TRACED/ (321fb561) · Commits · 戴 / test

After "ptrace: Clean transitions between TASK_STOPPED and TRACED" , ptrace_check_attach() should never see a TASK_STOPPED tracee and s/STOPPED/TRACED/ is no longer legal. Add the warning. Note: ptrace_check_attach() can be greatly simplified, in particular it doesn't need tasklist. But I'd prefer another patch for that. Signed-off-by:

Oleg Nesterov <oleg@redhat.com> Signed-off-by:

Tejun Heo <tj@kernel.org>

kernel/ptrace.c

+3 −5

Original line number	Diff line number	Diff line
		@@ -112,16 +112,14 @@ int ptrace_check_attach(struct task_struct *child, int kill)
		*/
		read_lock(&tasklist_lock);
		if ((child->ptrace & PT_PTRACED) && child->parent == current) {
		ret = 0;
		/*
		* child->sighand can't be NULL, release_task()
		* does ptrace_unlink() before __exit_signal().
		*/
		spin_lock_irq(&child->sighand->siglock);
		if (task_is_stopped(child))
		child->state = TASK_TRACED;
		else if (!task_is_traced(child) && !kill)
		ret = -ESRCH;
		WARN_ON_ONCE(task_is_stopped(child));
		if (task_is_traced(child) \|\| kill)
		ret = 0;
		spin_unlock_irq(&child->sighand->siglock);
		}
		read_unlock(&tasklist_lock);

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