Pull optimize-ptrace-threads into release branch (9590204d) · Commits · e / devices / android_kernel_sony_msm8998

arch/ia64/kernel/ptrace.c

+10 −16

Original line number	Diff line number	Diff line
		@@ -589,6 +589,7 @@ find_thread_for_addr (struct task_struct *child, unsigned long addr)
		{
		struct task_struct g, p;
		struct mm_struct *mm;
		struct list_head this, next;
		int mm_users;

		if (!(mm = get_task_mm(child)))
		@@ -600,28 +601,21 @@ find_thread_for_addr (struct task_struct *child, unsigned long addr)
		goto out; /* not multi-threaded */

		/*
		* First, traverse the child's thread-list. Good for scalability with
		* NPTL-threads.
		* Traverse the current process' children list. Every task that
		* one attaches to becomes a child. And it is only attached children
		* of the debugger that are of interest (ptrace_check_attach checks
		* for this).
		*/
		p = child;
		do {
		if (thread_matches(p, addr)) {
		child = p;
		goto out;
		}
		if (mm_users-- <= 1)
		goto out;
		} while ((p = next_thread(p)) != child);

		do_each_thread(g, p) {
		if (child->mm != mm)
		list_for_each_safe(this, next, &current->children) {
		p = list_entry(this, struct task_struct, sibling);
		if (p->mm != mm)
		continue;

		if (thread_matches(p, addr)) {
		child = p;
		goto out;
		}
		} while_each_thread(g, p);
		}

		out:
		mmput(mm);
		return child;