livepatch: Introduce 'arch_klp_save_old_code'

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4UAQ1

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

Introduce 'arch_klp_save_old_code' preparing for moving func_node
initializing codes out of stop_machine.
Signed-off-by: NZheng Yejian <zhengyejian1@huawei.com>
Reviewed-by: NKuohai Xu <xukuohai@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm/include/asm/livepatch.h

@@ -51,6 +51,8 @@ struct arch_klp_data {
 #endif
 };
 
+long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func);
+
 #endif
 
 #endif /* _ASM_ARM_LIVEPATCH_H */

arch/arm/kernel/livepatch.c

@@ -353,6 +353,23 @@ long arm_insn_read(void *addr, u32 *insnp)
 	return ret;
 }
 
+long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func)
+{
+	long ret;
+#ifdef CONFIG_ARM_MODULE_PLTS
+	int i;
+
+	for (i = 0; i < LJMP_INSN_SIZE; i++) {
+		ret = arm_insn_read((u32 *)old_func + i, &arch_data->old_insns[i]);
+		if (ret)
+			break;
+	}
+#else
+	ret = arm_insn_read(old_func, &arch_data->old_insn);
+#endif
+	return ret;
+}
+
 int arch_klp_patch_func(struct klp_func *func)
 {
 	struct klp_func_node *func_node;
@@ -372,16 +389,7 @@ int arch_klp_patch_func(struct klp_func *func)
 
 		INIT_LIST_HEAD(&func_node->func_stack);
 		func_node->old_func = func->old_func;
-#ifdef CONFIG_ARM_MODULE_PLTS
-		for (i = 0; i < LJMP_INSN_SIZE; i++) {
-			ret = arm_insn_read((u32 *)func->old_func + i,
-					    &func_node->arch_data.old_insns[i]);
-			if (ret)
-				break;
-		}
-#else
-		ret = arm_insn_read(func->old_func, &func_node->arch_data.old_insn);
-#endif
+		ret = arch_klp_save_old_code(&func_node->arch_data, func->old_func);
 		if (ret) {
 			return -EPERM;
 		}

arch/arm64/include/asm/livepatch.h

@@ -61,6 +61,8 @@ struct arch_klp_data {
 #endif
 };
 
+long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func);
+
 #endif
 
 #endif /* _ASM_ARM64_LIVEPATCH_H */

arch/arm64/kernel/livepatch.c

@@ -331,6 +331,24 @@ int klp_check_calltrace(struct klp_patch *patch, int enable)
 }
 #endif
 
+long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func)
+{
+	long ret;
+#ifdef CONFIG_ARM64_MODULE_PLTS
+	int i;
+
+	for (i = 0; i < LJMP_INSN_SIZE; i++) {
+		ret = aarch64_insn_read(((u32 *)old_func) + i,
+					&arch_data->old_insns[i]);
+		if (ret)
+			break;
+	}
+#else
+	ret = aarch64_insn_read(old_func, &arch_data->old_insn);
+#endif
+	return ret;
+}
+
 int arch_klp_patch_func(struct klp_func *func)
 {
 	struct klp_func_node *func_node;
@@ -353,17 +371,7 @@ int arch_klp_patch_func(struct klp_func *func)
 		INIT_LIST_HEAD(&func_node->func_stack);
 		func_node->old_func = func->old_func;
 
-#ifdef CONFIG_ARM64_MODULE_PLTS
-		for (i = 0; i < LJMP_INSN_SIZE; i++) {
-			ret = aarch64_insn_read(((u32 *)func->old_func) + i,
-					&func_node->arch_data.old_insns[i]);
-			if (ret)
-				break;
-		}
-#else
-		ret = aarch64_insn_read((void *)func->old_func,
-					&func_node->arch_data.old_insn);
-#endif
+		ret = arch_klp_save_old_code(&func_node->arch_data, func->old_func);
 		if (ret) {
 			return -EPERM;
 		}

arch/powerpc/include/asm/livepatch.h

@@ -93,6 +93,7 @@ struct arch_klp_data {
 
 #elif defined(CONFIG_PPC32)
 
+#define PPC32_INSN_SIZE	4
 #define LJMP_INSN_SIZE	4
 struct arch_klp_data {
 	u32 old_insns[LJMP_INSN_SIZE];
@@ -100,6 +101,8 @@ struct arch_klp_data {
 
 #endif	/* CONFIG_PPC64 */
 
+long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func);
+
 #endif /* CONFIG_LIVEPATCH_FTRACE */
 
 #ifdef CONFIG_LIVEPATCH_STOP_MACHINE_CONSISTENCY

arch/powerpc/kernel/livepatch_32.c

@@ -378,6 +378,20 @@ static inline bool offset_in_range(unsigned long pc, unsigned long addr,
 	return (offset >= -range && offset < range);
 }
 
+long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func)
+{
+	long ret;
+	int i;
+
+	for (i = 0; i < LJMP_INSN_SIZE; i++) {
+		ret = copy_from_kernel_nofault(&arch_data->old_insns[i],
+			((u32 *)old_func) + i, PPC32_INSN_SIZE);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
 int arch_klp_patch_func(struct klp_func *func)
 {
 	struct klp_func_node *func_node;
@@ -396,13 +410,9 @@ int arch_klp_patch_func(struct klp_func *func)
 		memory_flag = 1;
 		INIT_LIST_HEAD(&func_node->func_stack);
 		func_node->old_func = func->old_func;
-		for (i = 0; i < LJMP_INSN_SIZE; i++) {
-			ret = copy_from_kernel_nofault(&func_node->arch_data.old_insns[i],
-				((u32 *)func->old_func) + i, LJMP_INSN_SIZE);
-			if (ret) {
-				return -EPERM;
-			}
-		}
+		ret = arch_klp_save_old_code(&func_node->arch_data, func->old_func);
+		if (ret)
+			return -EPERM;
 
 		klp_add_func_node(func_node);
 	}

arch/powerpc/kernel/livepatch_64.c

@@ -424,11 +424,25 @@ int klp_check_calltrace(struct klp_patch *patch, int enable)
 #endif
 
 #ifdef CONFIG_LIVEPATCH_WO_FTRACE
+
+long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func)
+{
+	long ret;
+	int i;
+
+	for (i = 0; i < LJMP_INSN_SIZE; i++) {
+		ret = copy_from_kernel_nofault(&arch_data->old_insns[i],
+			((u32 *)old_func) + i, PPC64_INSN_SIZE);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
 int arch_klp_patch_func(struct klp_func *func)
 {
 	struct klp_func_node *func_node;
 	unsigned long pc, new_addr;
-	int i;
 	int memory_flag = 0;
 	long ret;
 
@@ -441,13 +455,9 @@ int arch_klp_patch_func(struct klp_func *func)
 		memory_flag = 1;
 		INIT_LIST_HEAD(&func_node->func_stack);
 		func_node->old_func = func->old_func;
-		for (i = 0; i < LJMP_INSN_SIZE; i++) {
-			ret = copy_from_kernel_nofault(&func_node->arch_data.old_insns[i],
-				((u32 *)func->old_func) + i, 4);
-			if (ret) {
-				return -EPERM;
-			}
-		}
+		ret = arch_klp_save_old_code(&func_node->arch_data, func->old_func);
+		if (ret)
+			return -EPERM;
 		klp_add_func_node(func_node);
 	}
 

arch/x86/include/asm/livepatch.h

@@ -39,6 +39,8 @@ struct arch_klp_data {
 	unsigned char old_code[JMP_E9_INSN_SIZE];
 };
 
+long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func);
+
 #endif
 
 #endif /* _ASM_X86_LIVEPATCH_H */

arch/x86/kernel/livepatch.c

@@ -388,6 +388,12 @@ void arch_klp_code_modify_post_process(void)
 	mutex_unlock(&text_mutex);
 }
 
+long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func)
+{
+	return copy_from_kernel_nofault(arch_data->old_code,
+					old_func, JMP_E9_INSN_SIZE);
+}
+
 int arch_klp_patch_func(struct klp_func *func)
 {
 	struct klp_func_node *func_node;
@@ -404,8 +410,7 @@ int arch_klp_patch_func(struct klp_func *func)
 
 		INIT_LIST_HEAD(&func_node->func_stack);
 		func_node->old_func = func->old_func;
-		ret = copy_from_kernel_nofault(func_node->arch_data.old_code,
-					(void *)ip, JMP_E9_INSN_SIZE);
+		ret = arch_klp_save_old_code(&func_node->arch_data, (void *)ip);
 		if (ret) {
 			return -EPERM;
 		}