kernel: precise trigger timing of post-fs-data (#118)

* kernel: add report_event cmd

* ksud: report event

* kernel: trigger on_post_fs_data

* ksud: comment unused code

* [skip ci] run clang-format

Signed-off-by: Ylarod <me@ylarod.cn>

* ci: use custom key to sign official bootimgs

* format ksud

* reject non root

* remove

Signed-off-by: Ylarod <me@ylarod.cn>

userspace/ksud/src/ksu.rs

@@ -0,0 +1,58 @@
+const KERNEL_SU_OPTION: u32 = 0xDEADBEEF;
+
+// const CMD_GRANT_ROOT: u64 = 0;
+// const CMD_BECOME_MANAGER: u64 = 1;
+const CMD_GET_VERSION: u64 = 2;
+// const CMD_ALLOW_SU: u64 = 3;
+// const CMD_DENY_SU: u64 = 4;
+// const CMD_GET_ALLOW_LIST: u64 = 5;
+// const CMD_GET_DENY_LIST: u64 = 6;
+const CMD_REPORT_EVENT: u64 = 7;
+
+const EVENT_POST_FS_DATA: u64 = 1;
+const EVENT_BOOT_COMPLETED: u64 = 2;
+
+
+// pub fn grant_root() -> bool {
+//     let mut result: i32 = 0;
+//     unsafe {
+//         libc::prctl(
+//             KERNEL_SU_OPTION as i32,
+//             CMD_GRANT_ROOT,
+//             0,
+//             0,
+//             &mut result as *mut _ as *mut libc::c_void,
+//         );
+//     }
+//     return result as u32 == KERNEL_SU_OPTION;
+// }
+
+pub fn get_version() -> i32 {
+    let mut result: i32 = 0;
+    unsafe {
+        libc::prctl(
+            KERNEL_SU_OPTION as i32,
+            CMD_GET_VERSION,
+            &mut result as *mut _ as *mut libc::c_void,
+        );
+    }
+    return result;
+}
+
+fn report_event(event: u64){
+    unsafe {
+        libc::prctl(
+            KERNEL_SU_OPTION as i32,
+            CMD_REPORT_EVENT,
+            event,
+        );
+    }
+}
+
+pub fn report_post_fs_data(){
+    report_event(EVENT_POST_FS_DATA);
+}
+
+pub fn report_boot_complete(){
+    report_event(EVENT_BOOT_COMPLETED);
+}