Revert "kernel: throne_tracker: offload to kthread tiann #2632"

This reverts commit 86ccca18eb.

kernel/Kconfig

@@ -59,15 +59,6 @@ config KSU_LSM_SECURITY_HOOKS
 	  Disabling this is mostly only useful for kernel 4.1 and older.
 	  Make sure to implement manual hooks on security/security.c.
 
-config KSU_THRONE_TRACKER_ALWAYS_THREADED
-	bool "Always run throne_tracker in a kthread"
-	default n
-	help
-	  Runs throne_tracker in a separate kthread, including the first run.
-	  Significantly decreases boot time, but can cause crowning failure
-	  on some FDE or FBEv1 setups.
-	  If unsure, say n.
-
 choice
 	prompt "KernelSU hook type"
 	depends on KSU

kernel/apk_sign.c

@@ -19,7 +19,6 @@
 #include "klog.h" // IWYU pragma: keep
 #include "kernel_compat.h"
 #include "manager_sign.h"
-#include "throne_tracker.h"
 
 struct sdesc {
 	struct shash_desc shash;
@@ -266,23 +265,6 @@ check_v2_signature(char *path, bool check_multi_manager, int *signature_index)
 	bool v3_1_signing_exist = false;
 	int matched_index = -1;
 	int i;
-	struct path kpath;
-	if (kern_path(path, 0, &kpath))
-		return false;
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0) 
-	if (inode_is_locked(kpath.dentry->d_inode))
-#else
-	if (mutex_is_locked(&kpath.dentry->d_inode->i_mutex))
-#endif
-	{
-		pr_info("%s: inode is locked for %s\n", __func__, path);
-		path_put(&kpath);
-		return false;
-	}
-
-	path_put(&kpath);
-
 	struct file *fp = ksu_filp_open_compat(path, O_RDONLY, 0);
 	if (IS_ERR(fp)) {
 		pr_err("open %s error.\n", path);
@@ -438,42 +420,10 @@ module_param_cb(ksu_debug_manager_uid, &expected_size_ops,
 
 bool is_manager_apk(char *path)
 {
-	int tries = 0;
-
-	while (tries++ < 10) {
-		if (!is_lock_held(path))
-			break;
-
-		pr_info("%s: waiting for %s\n", __func__, path);
-		msleep(100);
-	}
-
-	// let it go, if retry fails, check_v2_signature will fail to open it anyway
-	if (tries == 10) {
-		pr_info("%s: timeout for %s\n", __func__, path);
-		return false;
-	}
-
 	return check_v2_signature(path, false, NULL);
 }
 
 bool is_dynamic_manager_apk(char *path, int *signature_index)
 {
-	int tries = 0;
-
-	while (tries++ < 10) {
-		if (!is_lock_held(path))
-			break;
-
-		pr_info("%s: waiting for %s\n", __func__, path);
-		msleep(100);
-	}
-
-	// let it go, if retry fails, check_v2_signature will fail to open it anyway
-	if (tries == 10) {
-		pr_info("%s: timeout for %s\n", __func__, path);
-		return false;
-	}
-	
 	return check_v2_signature(path, true, signature_index);
 }

kernel/throne_tracker.c

@@ -17,13 +17,8 @@
 #include "dynamic_manager.h"
 #include "throne_comm.h"
 
-#include <linux/kthread.h>
-#include <linux/sched.h>
-
 uid_t ksu_manager_uid = KSU_INVALID_UID;
 
-static struct task_struct *throne_thread;
-
 #define KSU_UID_LIST_PATH "/data/misc/user_uid/uid_list"
 #define USER_DATA_PATH "/data/user_de/0"
 #define USER_DATA_PATH_LEN 256
@@ -552,7 +547,7 @@ void search_manager(const char *path, int depth, struct list_head *uid_data)
 
 			if (!stop) {
 				file = ksu_filp_open_compat(
-					pos->dirpath, O_RDONLY | O_NOFOLLOW | O_DIRECTORY, 0);
+					pos->dirpath, O_RDONLY | O_NOFOLLOW, 0);
 				if (IS_ERR(file)) {
 					pr_err("Failed to open directory: %s, err: %ld\n",
 					       pos->dirpath, PTR_ERR(file));
@@ -618,7 +613,7 @@ static bool is_uid_exist(uid_t uid, char *package, void *data)
 	return exist;
 }
 
-static void track_throne_function()
+void track_throne(void)
 {
 	struct list_head uid_list;
 	INIT_LIST_HEAD(&uid_list);
@@ -700,37 +695,6 @@ out:
 	}
 }
 
-static int throne_tracker_thread(void *data)
-{
-	pr_info("%s: pid: %d started\n", __func__, current->pid);
-	track_throne_function();
-	throne_thread = NULL;
-	smp_mb();
-	pr_info("%s: pid: %d exit!\n", __func__, current->pid);
-	return 0;
-}
-
-void track_throne(void)
-{
-#ifndef CONFIG_KSU_THRONE_TRACKER_ALWAYS_THREADED
-	static bool throne_tracker_first_run __read_mostly = true;
-	if (unlikely(throne_tracker_first_run)) {
-		track_throne_function();
-		throne_tracker_first_run = false;
-		return;
-	}
-#endif
-	smp_mb();
-	if (throne_thread != NULL) // single instance lock
-		return;
-
-	throne_thread = kthread_run(throne_tracker_thread, NULL, "throne_tracker");
-	if (IS_ERR(throne_thread)) {
-		throne_thread = NULL;
-		return;
-	}
-}
-
 void ksu_throne_tracker_init(void)
 {
 	// nothing to do

kernel/throne_tracker.h

@@ -7,37 +7,4 @@ void ksu_throne_tracker_exit(void);
 
 void track_throne(void);
 
-/*
- * small helper to check if lock is held
- * false - file is stable
- * true - file is being deleted/renamed
- * possibly optional
- *
- */
-static bool is_lock_held(const char *path) 
-{
-	struct path kpath;
-
-	// kern_path returns 0 on success
-	if (kern_path(path, 0, &kpath))
-		return true;
-
-	// just being defensive
-	if (!kpath.dentry) {
-		path_put(&kpath);
-		return true;
-	}
-
-	if (!spin_trylock(&kpath.dentry->d_lock)) {
-		pr_info("%s: lock held, bail out!\n", __func__);
-		path_put(&kpath);
-		return true;
-	}
-	// we hold it ourselves here!
-
-	spin_unlock(&kpath.dentry->d_lock);
-	path_put(&kpath);
-	return false;
-}
-
 #endif