Commit 8eec24ed authored by Zheng Yejian's avatar Zheng Yejian
Browse files

livepatch/arm: 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 e1627d21

arch/arm/kernel/livepatch.c

+20 −10
Original line number Diff line number Diff line
@@ -383,14 +383,29 @@ long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func) 
	return ret;

}



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

{

	int i;



	if (len <= 0)

		return;

	/* skip breakpoint at first */

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

		__patch_text(dst + i, src[i]);

	/*

	 * Avoid compile optimization, make sure that instructions

	 * except first breakpoint has been patched.

	 */

	barrier();

	__patch_text(dst, src[0]);

}



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

{

	u32 insns[LJMP_INSN_SIZE];



	if (!offset_in_range(pc, new_addr, SZ_32M)) {

#ifdef CONFIG_ARM_MODULE_PLTS

		int i;



		/*

		 * [0] LDR PC, [PC+8]

		 * [4] nop
@@ -400,8 +415,7 @@ static int do_patch(unsigned long pc, unsigned long new_addr) 
		insns[1] = __opcode_to_mem_arm(0xe320f000);

		insns[2] = new_addr;



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

			__patch_text(((u32 *)pc) + i, insns[i]);

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

#else

		/*

		 * When offset from 'new_addr' to 'pc' is out of SZ_32M range but
@@ -412,7 +426,7 @@ static int do_patch(unsigned long pc, unsigned long new_addr) 
#endif

	} else {

		insns[0] = arm_gen_branch(pc, new_addr);

		__patch_text((void *)pc, insns[0]);

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

	}

	return 0;

}
@@ -440,11 +454,7 @@ void arch_klp_unpatch_func(struct klp_func *func) 
	pc = (unsigned long)func_node->old_func;

	list_del_rcu(&func->stack_node);

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

		int i;



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

			__patch_text(((u32 *)pc) + i, func_node->arch_data.old_insns[i]);

		}

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

	} else {

		next_func = list_first_or_null_rcu(&func_node->func_stack,

					struct klp_func, stack_node);