kernel: add CONFIG_KSU_DEBUG (#19)

* Kconfig: add KSU_DEBUG

* print alert on debug mode

* allow shell by default

* store signature to var on debug mode

* format

* export as module_param

* rename apk_sign to kernelsu

kernel/Kconfig

@@ -5,3 +5,10 @@ config KSU
 	depends on OVERLAY_FS
 	help
 	This is the KSU privilege driver for android system.
+
+config KSU_DEBUG
+	tristate "KernelSU module debug mode"
+	default n
+	depends on KSU
+	help
+	This enables debug mode for KSU

kernel/Makefile

@@ -1,6 +1,7 @@
 obj-y += ksu.o
 obj-y += allowlist.o
-obj-y += apk_sign.o
+kernelsu-objs := apk_sign.o
+obj-y += kernelsu.o
 obj-y += module_api.o
 obj-y += sucompat.o
 

kernel/allowlist.c

@@ -181,7 +181,16 @@ void do_load_allow_list(struct work_struct *work)
 	fp = filp_open(KERNEL_SU_ALLOWLIST, O_RDONLY, 0);
 
 	if (IS_ERR(fp)) {
+#ifdef CONFIG_KSU_DEBUG
+		int errno = PTR_ERR(fp);
+		if (errno == -ENOENT) {
+			ksu_allow_uid(2000, true); // allow adb shell by default
+		} else {
+			pr_err("load_allow_list open file failed: %d\n", PTR_ERR(fp));
+		}
+#else
 		pr_err("load_allow_list open file failed: %d\n", PTR_ERR(fp));
+#endif
 		return;
 	}
 

kernel/apk_sign.c

@@ -1,9 +1,10 @@
+#include <linux/moduleparam.h>
 #include <linux/fs.h>
 
 #include "apk_sign.h"
 #include "klog.h"
 
-static int check_v2_signature(char *path, unsigned expected_size,
+static __always_inline int check_v2_signature(char *path, unsigned expected_size,
 			      unsigned expected_hash)
 {
 	unsigned char buffer[0x11] = { 0 };
@@ -121,7 +122,25 @@ static int check_v2_signature(char *path, unsigned expected_size,
 	return sign;
 }
 
+#ifdef CONFIG_KSU_DEBUG
+
+unsigned ksu_expected_size = EXPECTED_SIZE;
+unsigned ksu_expected_hash = EXPECTED_HASH;
+
+module_param(ksu_expected_size, uint, S_IRUSR | S_IWUSR);
+module_param(ksu_expected_hash, uint, S_IRUSR | S_IWUSR);
+
+int is_manager_apk(char *path)
+{
+	return check_v2_signature(path, ksu_expected_size, ksu_expected_hash);
+}
+
+#else
+
+
 int is_manager_apk(char *path)
 {
 	return check_v2_signature(path, EXPECTED_SIZE, EXPECTED_HASH);
-}
+}
+
+#endif

kernel/ksu.c

@@ -299,6 +299,10 @@ int kernelsu_init(void)
 {
 	int rc = 0;
 
+#ifdef CONFIG_KSU_DEBUG
+	pr_alert("You are running DEBUG version of KernelSU");
+#endif
+
 	ksu_allowlist_init();
 
 	rc = register_kprobe(&kp);