uprobes: Introduce filter_chain()

	return ret;

}

static bool filter_chain(struct uprobe *uprobe)

{

	/*

	 * TODO:

	 *	for_each_consumer(uc)

	 *		if (uc->filter(...))

	 *			return true;

	 *	return false;

	 */

	return uprobe->consumers != NULL;

}

static int

install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,

			struct vm_area_struct *vma, unsigned long vaddr)

	/*

	 * If probe is being deleted, unregister thread could be done with

	 * the vma-rmap-walk through. Adding a probe now can be fatal since

	 * nobody will be able to cleanup. Also we could be from fork or

	 * mremap path, where the probe might have already been inserted.

	 * Hence behave as if probe already existed.

	 * nobody will be able to cleanup. But in this case filter_chain()

	 * must return false, all consumers have gone away.

	 */

	if (!uprobe->consumers)

	if (!filter_chain(uprobe))

		return 0;

	ret = prepare_uprobe(uprobe, vma->vm_file, mm, vaddr);

static int

remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr)

{

	/* can happen if uprobe_register() fails */

	if (!test_bit(MMF_HAS_UPROBES, &mm->flags))

		return 0;

	if (filter_chain(uprobe))

		return 0;

	set_bit(MMF_RECALC_UPROBES, &mm->flags);

	return set_orig_insn(&uprobe->arch, mm, vaddr);

}

		 * This is not strictly accurate, we can race with

		 * uprobe_unregister() and see the already removed

		 * uprobe if delete_uprobe() was not yet called.

		 * Or this uprobe can be filtered out.

		 */

		if (vma_has_uprobes(vma, vma->vm_start, vma->vm_end))

			return;