Commit 3bff6b09 authored by Zheng Yejian's avatar Zheng Yejian
Browse files

livepatch/arm64: Adjust instruction replace order for KLP_STACK_OPTIMIZE mode 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9R2TB



--------------------------------

Signed-off-by: default avatarZheng Yejian <zhengyejian1@huawei.com>
parent 8eec24ed

arch/arm64/kernel/livepatch.c

+30 −17
Original line number Diff line number Diff line
@@ -358,6 +358,27 @@ long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func) 
	return ret;

}



static int klp_patch_text(u32 *dst, const u32 *src, int len)

{

	int i;

	int ret;



	if (len <= 0)

		return -EINVAL;

	/* skip breakpoint at first */

	for (i = 1; i < len; i++) {

		ret = aarch64_insn_patch_text_nosync(dst + i, src[i]);

		if (ret)

			return ret;

	}

	/*

	 * Avoid compile optimization, make sure that instructions

	 * except first breakpoint has been patched.

	 */

	barrier();

	return aarch64_insn_patch_text_nosync(dst, src[0]);

}



static int do_patch(unsigned long pc, unsigned long new_addr)

{

	u32 insns[LJMP_INSN_SIZE];
@@ -366,27 +387,23 @@ static int do_patch(unsigned long pc, unsigned long new_addr) 
	if (offset_in_range(pc, new_addr, SZ_128M)) {

		insns[0] = aarch64_insn_gen_branch_imm(pc, new_addr,

						       AARCH64_INSN_BRANCH_NOLINK);

		ret = aarch64_insn_patch_text_nosync((void *)pc, insns[0]);

		ret = klp_patch_text((u32 *)pc, insns, 1);

		if (ret) {

			pr_err("patch instruction small range failed, ret=%d\n", ret);

			return -EPERM;

		}

	} else {

#ifdef CONFIG_ARM64_MODULE_PLTS

		int i;



		insns[0] = 0x92800010 | (((~new_addr) & 0xffff)) << 5;

		insns[1] = 0xf2a00010 | (((new_addr >> 16) & 0xffff)) << 5;

		insns[2] = 0xf2c00010 | (((new_addr >> 32) & 0xffff)) << 5;

		insns[3] = 0xd61f0200;

		for (i = 0; i < LJMP_INSN_SIZE; i++) {

			ret = aarch64_insn_patch_text_nosync(((u32 *)pc) + i, insns[i]);

		ret = klp_patch_text((u32 *)pc, insns, LJMP_INSN_SIZE);

		if (ret) {

				pr_err("patch instruction %d large range failed, ret=%d\n",

				       i, ret);

			pr_err("patch instruction large range failed, ret=%d\n", ret);

			return -EPERM;

		}

		}

#else

		/*

		 * When offset from 'new_addr' to 'pc' is out of SZ_128M range but
@@ -417,21 +434,17 @@ void arch_klp_unpatch_func(struct klp_func *func) 
	struct klp_func_node *func_node;

	struct klp_func *next_func;

	unsigned long pc;

	int i;

	int ret;



	func_node = func->func_node;

	pc = (unsigned long)func_node->old_func;

	list_del_rcu(&func->stack_node);

	if (list_empty(&func_node->func_stack)) {

		for (i = 0; i < LJMP_INSN_SIZE; i++) {

			ret = aarch64_insn_patch_text_nosync(((u32 *)pc) + i,

							     func_node->arch_data.old_insns[i]);

		ret = klp_patch_text((u32 *)pc, func_node->arch_data.old_insns, LJMP_INSN_SIZE);

		if (ret) {

				pr_err("restore instruction %d failed, ret=%d\n", i, ret);

			pr_err("restore instruction failed, ret=%d\n", ret);

			return;

		}

		}

	} else {

		next_func = list_first_or_null_rcu(&func_node->func_stack,

					struct klp_func, stack_node);