uprobes: Kill set_orig_insn()->is_swbp_at_addr() (ed6f6a50) · Commits · 戴 / test

kernel/events/uprobes.c

+23 −9

Original line number	Diff line number	Diff line
		@@ -190,6 +190,25 @@ static void copy_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
		kunmap_atomic(kaddr);
		}

		static int verify_opcode(struct page page, unsigned long vaddr, uprobe_opcode_t new_opcode)
		{
		uprobe_opcode_t old_opcode;
		bool is_swbp;

		copy_opcode(page, vaddr, &old_opcode);
		is_swbp = is_swbp_insn(&old_opcode);

		if (is_swbp_insn(new_opcode)) {
		if (is_swbp) /* register: already installed? */
		return 0;
		} else {
		if (!is_swbp) /* unregister: was it changed by us? */
		return -EINVAL;
		}

		return 1;
		}

		/*
		* NOTE:
		* Expect the breakpoint instruction to be the smallest size instruction for
		@@ -226,6 +245,10 @@ retry:
		if (ret <= 0)
		return ret;

		ret = verify_opcode(old_page, vaddr, &opcode);
		if (ret <= 0)
		goto put_old;

		ret = -ENOMEM;
		new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
		if (!new_page)
		@@ -311,15 +334,6 @@ int __weak set_swbp(struct arch_uprobe auprobe, struct mm_struct mm, unsigned
		int __weak
		set_orig_insn(struct arch_uprobe auprobe, struct mm_struct mm, unsigned long vaddr)
		{
		int result;

		result = is_swbp_at_addr(mm, vaddr);
		if (!result)
		return -EINVAL;

		if (result != 1)
		return result;

		return write_opcode(mm, vaddr, (uprobe_opcode_t )auprobe->insn);
		}