ptrace_init_task: initialize child->jobctl explicitly (6634ae10) · Commits · 戴 / test

new_child->jobctl is not initialized during the fork, it is copied from parent->jobctl. Currently this is harmless, the forking task is running and copy_process() can't succeed if signal_pending() is true, so only JOBCTL_STOP_DEQUEUED can be copied. Still this is a bit fragile, it would be more clean to set ->jobctl = 0 explicitly. Also, check ->ptrace != 0 instead of PT_PTRACED, move the CONFIG_HAVE_HW_BREAKPOINT code up. Signed-off-by:

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

Tejun Heo <tj@kernel.org>

include/linux/ptrace.h

+7 −6

Original line number	Diff line number	Diff line
		@@ -217,16 +217,17 @@ static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
		{
		INIT_LIST_HEAD(&child->ptrace_entry);
		INIT_LIST_HEAD(&child->ptraced);
		child->parent = child->real_parent;
		#ifdef CONFIG_HAVE_HW_BREAKPOINT
		atomic_set(&child->ptrace_bp_refcnt, 1);
		#endif
		child->jobctl = 0;
		child->ptrace = 0;
		if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) {
		child->parent = child->real_parent;

		if (unlikely(ptrace) && current->ptrace) {
		child->ptrace = current->ptrace;
		__ptrace_link(child, current->parent);
		}

		#ifdef CONFIG_HAVE_HW_BREAKPOINT
		atomic_set(&child->ptrace_bp_refcnt, 1);
		#endif
		}

		/**

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