添加跳过CFI检查的机制

kernel/core_hook.c

@@ -686,6 +686,10 @@ __maybe_unused int ksu_kprobe_init(void)
 	rc = register_kprobe(&renameat_kp);
 	pr_info("renameat kp: %d\n", rc);
 
+	#ifdef CONFIG_KPM
+	kpm_cfi_bypass_init();
+	#endif
+
 	return rc;
 }
 
@@ -693,6 +697,9 @@ __maybe_unused int ksu_kprobe_exit(void)
 {
 	unregister_kprobe(&prctl_kp);
 	unregister_kprobe(&renameat_kp);
+	#ifdef CONFIG_KPM
+	kpm_cfi_bypass_exit();
+	#endif
 	return 0;
 }
 

kernel/kpm/bypasscfi.c

@@ -0,0 +1,73 @@
+#include <linux/kprobes.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/kallsyms.h>
+
+/* CFI 检查函数符号 */
+#define CFI_CHECK_FUNC "__cfi_check"
+
+/* Kprobe 实例 */
+static struct kprobe cfi_kp;
+
+bool kpm_is_allow_address(unsigned long addr);
+
+/*--------------------- kprobe 处理逻辑 ---------------------*/
+static int handler_pre(struct kprobe *p, struct pt_regs *regs)
+{
+    unsigned long target_addr;
+    
+    /* 从寄存器获取目标地址（架构相关） */
+#if defined(__aarch64__)
+    target_addr = regs->regs[1];    // ARM64: 第二个参数在 X1
+#elif defined(__x86_64__)
+    target_addr = regs->si;         // x86_64: 第二个参数在 RSI
+#else
+    #error "Unsupported architecture"
+#endif
+
+    /* 根据自定义规则放行 */
+    if (kpm_is_allow_address(target_addr)) {
+        printk(KERN_INFO "CFI bypass at 0x%lx\n", target_addr);
+#if defined(__aarch64__)
+        regs->regs[0] = 0;  // 修改返回值：0 表示校验通过
+#elif defined(__x86_64__)
+        regs->ax = 0;        // x86 返回值在 RAX
+#endif
+        return 0; // 跳过原始 CFI 检查
+    }
+    
+    return 0; // 继续执行原始检查
+}
+
+/*--------------------- 模块初始化/卸载 ---------------------*/
+int kpm_cfi_bypass_init(void)
+{
+    unsigned long cfi_check_addr;
+    
+    /* 动态查找 CFI 检查函数 */
+    cfi_check_addr = kallsyms_lookup_name(CFI_CHECK_FUNC);
+    if (!cfi_check_addr) {
+        printk(KERN_ERR "CFI check function not found\n");
+        return -ENOENT;
+    }
+    
+    /* 初始化 kprobe */
+    memset(&cfi_kp, 0, sizeof(cfi_kp));
+    cfi_kp.addr = (kprobe_opcode_t *)cfi_check_addr;
+    cfi_kp.pre_handler = handler_pre;
+    
+    /* 注册 kprobe */
+    if (register_kprobe(&cfi_kp) < 0) {
+        printk(KERN_ERR "Register kprobe failed\n");
+        return -EINVAL;
+    }
+    
+    printk(KERN_INFO "CFI bypass module loaded\n");
+    return 0;
+}
+
+void kpm_cfi_bypass_exit(void)
+{
+    unregister_kprobe(&cfi_kp);
+    printk(KERN_INFO "CFI bypass module unloaded\n");
+}

kernel/kpm/kpm.c

@@ -175,10 +175,10 @@ struct kpm_module {
     unsigned int size;           /* 总大小 */
     unsigned int text_size;
     unsigned int ro_size;
-    int (*init)(const char *args, const char *event, void *__user reserved) __nocfi;
+    int (*init)(const char *args, const char *event, void *__user reserved);
-    void (*exit)(void *__user reserved) __nocfi;
+    void (*exit)(void *__user reserved);
-    int (*ctl0)(const char *ctl_args, char *__user out_msg, int outlen) __nocfi;
+    int (*ctl0)(const char *ctl_args, char *__user out_msg, int outlen);
-    int (*ctl1)(void *a1, void *a2, void *a3) __nocfi;
+    int (*ctl1)(void *a1, void *a2, void *a3);
     struct {
         const char *base;
         const char *name;
@@ -937,6 +937,7 @@ static int kpm_setup_load_info(struct kpm_load_info *info)
  * KPM 模块加载主流程
  *----------------------------------------------------------*/
 /* 注意：接口名称改为 kpm_load_module，避免与内核原有 load_module 冲突 */
+__nocfi
 long kpm_load_module(const void *data, int len, const char *args,
                        const char *event, void *__user reserved)
 {
@@ -1025,6 +1026,7 @@ out:
 }
 
 /* 卸载模块接口，改名为 sukisu_kpm_unload_module */
+__nocfi
 long sukisu_kpm_unload_module(const char *name, void *__user reserved)
 {
     long rc = 0;
@@ -1098,6 +1100,36 @@ free_data:
     return rc;
 }
 
+/*--------------------- 地址过滤逻辑 ---------------------*/
+/**
+ * is_allow_address - 自定义地址放行规则
+ * @addr: 目标函数地址
+ * 
+ * 返回值: true 放行 | false 拦截
+ */
+bool kpm_is_allow_address(unsigned long addr)
+{
+    struct kpm_module *pos;
+    bool allow = false;
+
+    spin_lock(&kpm_module_lock);
+    list_for_each_entry(pos, &kpm_module_list, list) {
+        unsigned long start_address = (unsigned long) pos->start;
+        unsigned long end_address = start_address + pos->size;
+
+        /* 规则1：地址在KPM允许范围内 */
+        if (addr >= allow_start && addr <= allow_end) {
+            allow = true;
+            break;
+        }
+    }
+    spin_unlock(&kpm_module_lock);
+
+    // TODO: 增加Hook跳板放行机制
+
+    return allow;
+}
+
 /*-----------------------------------------------------------
  * 模块管理查询接口
  *----------------------------------------------------------*/

kernel/kpm/kpm.h

@@ -4,6 +4,9 @@
 int sukisu_handle_kpm(unsigned long arg3, unsigned long arg4, unsigned long arg5);
 int sukisu_is_kpm_control_code(unsigned long arg2);
 
+int kpm_cfi_bypass_init(void);
+void kpm_cfi_bypass_exit(void);
+
 // KPM控制代码
 #define CMD_KPM_CONTROL 28
 #define CMD_KPM_CONTROL_MAX 34