Commit b980761b authored by Zheng Yejian's avatar Zheng Yejian
Browse files

livepatch/ppc32: 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 3bff6b09

arch/powerpc/include/asm/livepatch.h

+1 −0
Original line number Diff line number Diff line
@@ -147,6 +147,7 @@ void arch_klp_remove_breakpoint(struct arch_klp_data *arch_data, void *old_func) 
long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func);

int arch_klp_module_check_calltrace(void *data);

int klp_unwind_frame(struct task_struct *tsk, struct stackframe *frame);

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



#endif /* CONFIG_LIVEPATCH_FTRACE */

arch/powerpc/kernel/livepatch.c

+22 −0
Original line number Diff line number Diff line
@@ -136,3 +136,25 @@ int klp_unwind_frame(struct task_struct *tsk, struct stackframe *frame) 


	return 0;

}



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 = patch_instruction((struct ppc_inst *)(dst + i),

					ppc_inst(src[i]));

		if (ret)

			return ret;

	}

	/*

	 * Avoid compile optimization, make sure that instructions

	 * except first breakpoint has been patched.

	 */

	barrier();

	return patch_instruction((struct ppc_inst *)dst, ppc_inst(src[0]));

}

arch/powerpc/kernel/livepatch_32.c

+9 −17
Original line number Diff line number Diff line
@@ -379,7 +379,6 @@ long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func) 
static int do_patch(unsigned long pc, unsigned long new_addr)

{

	int ret;

	int i;

	u32 insns[LJMP_INSN_SIZE];



	if (offset_in_range(pc, new_addr, SZ_32M)) {
@@ -403,16 +402,12 @@ static int do_patch(unsigned long pc, unsigned long new_addr) 
		insns[2] = 0x7d8903a6;

		insns[3] = 0x4e800420;



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

			ret = patch_instruction((struct ppc_inst *)(((u32 *)pc) + i),

						ppc_inst(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;

		}

	}

	}

	return 0;

}
@@ -434,21 +429,18 @@ 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 = patch_instruction((struct ppc_inst *)(((u32 *)pc) + i),

						ppc_inst(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);