kernelsu: pkg_observer: Add backward compatibility

Co-authored-by: TwinbornPlate75 <[email protected]>
Signed-off-by: Pranav Vashi <[email protected]>

Author: 2 people

drivers/kernelsu/pkg_observer.c

@@ -2,8 +2,9 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/namei.h>
-#include <linux/fsnotify_backend.h>
+#include <linux/fsnotify.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/rculist.h>
 #include <linux/version.h>
 #include "klog.h" // IWYU pragma: keep
@@ -21,42 +22,64 @@ struct watch_dir {
 
 static struct fsnotify_group *g;
 
-static int ksu_handle_inode_event(struct fsnotify_mark *mark, u32 mask,
-				  struct inode *inode, struct inode *dir,
-				  const struct qstr *file_name, u32 cookie)
+#include "pkg_observer_defs.h" // KSU_DECL_FSNOTIFY_OPS
+static KSU_DECL_FSNOTIFY_OPS(ksu_handle_generic_event)
 {
-	if (!file_name)
+	if (!file_name || (mask & FS_ISDIR))
 		return 0;
-	if (mask & FS_ISDIR)
-		return 0;
-	if (file_name->len == 13 &&
-	    !memcmp(file_name->name, "packages.list", 13)) {
+
+	if (ksu_fname_len(file_name) == 13 &&
+	    !memcmp(ksu_fname_arg(file_name), "packages.list", 13)) {
 		pr_info("packages.list detected: %d\n", mask);
 		track_throne();
 	}
 	return 0;
 }
 
 static const struct fsnotify_ops ksu_ops = {
-	.handle_inode_event = ksu_handle_inode_event,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0)
+	.handle_inode_event = ksu_handle_generic_event,
+#else
+	.handle_event = ksu_handle_generic_event,
+#endif
 };
 
+static void __maybe_unused m_free(struct fsnotify_mark *m)
+{
+	if (m) {
+		kfree(m);
+	}
+}
+
 static int add_mark_on_inode(struct inode *inode, u32 mask,
 			     struct fsnotify_mark **out)
 {
 	struct fsnotify_mark *m;
+	int ret;
 
 	m = kzalloc(sizeof(*m), GFP_KERNEL);
 	if (!m)
 		return -ENOMEM;
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 12, 0)
+	fsnotify_init_mark(m, m_free);
+	m->mask = mask;
+	ret = fsnotify_add_mark(m, g, inode, NULL, 0);
+#else
 	fsnotify_init_mark(m, g);
 	m->mask = mask;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 18, 0)
+	ret = fsnotify_add_inode_mark(m, inode, 0);
+#else
+	ret = fsnotify_add_mark(m, inode, NULL, 0);
+#endif
+#endif
 
-	if (fsnotify_add_inode_mark(m, inode, 0)) {
+	if (ret < 0) {
 		fsnotify_put_mark(m);
-		return -EINVAL;
+		return ret;
 	}
+
 	*out = m;
 	return 0;
 }
@@ -116,13 +139,13 @@ int ksu_observer_init(void)
 		return PTR_ERR(g);
 
 	ret = watch_one_dir(&g_watch);
-	pr_info("observer init done\n");
+	pr_info("%s done.\n", __func__);
 	return 0;
 }
 
 void ksu_observer_exit(void)
 {
 	unwatch_one_dir(&g_watch);
 	fsnotify_put_group(g);
-	pr_info("observer exit done\n");
+	pr_info("%s: done.\n", __func__);
 }

drivers/kernelsu/pkg_observer_defs.h

@@ -0,0 +1,42 @@
+// This header should not be used outside of pkg_observer.c!
+
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0)
+typedef const struct qstr *ksu_fname_t;
+#define ksu_fname_len(f) ((f)->len)
+#define ksu_fname_arg(f) ((f)->name)
+#else
+typedef const unsigned char *ksu_fname_t;
+#define ksu_fname_len(f) (strlen(f))
+#define ksu_fname_arg(f) (f)
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0)
+#define KSU_DECL_FSNOTIFY_OPS(name)                                            \
+	int name(struct fsnotify_mark *mark, u32 mask, struct inode *inode,    \
+		 struct inode *dir, const struct qstr *file_name, u32 cookie)
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0)
+#define KSU_DECL_FSNOTIFY_OPS(name)                                            \
+	int name(struct fsnotify_group *group, struct inode *inode, u32 mask,  \
+		 const void *data, int data_type, ksu_fname_t file_name,       \
+		 u32 cookie, struct fsnotify_iter_info *iter_info)
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 18, 0)
+#define KSU_DECL_FSNOTIFY_OPS(name)                                            \
+	int name(struct fsnotify_group *group, struct inode *inode, u32 mask,  \
+		 const void *data, int data_type, ksu_fname_t file_name,       \
+		 u32 cookie, struct fsnotify_iter_info *iter_info)
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
+#define KSU_DECL_FSNOTIFY_OPS(name)                                            \
+	int name(struct fsnotify_group *group, struct inode *inode,            \
+		 struct fsnotify_mark *inode_mark,                             \
+		 struct fsnotify_mark *vfsmount_mark, u32 mask,                \
+		 const void *data, int data_type, ksu_fname_t file_name,       \
+		 u32 cookie, struct fsnotify_iter_info *iter_info)
+#else
+#define KSU_DECL_FSNOTIFY_OPS(name)                                            \
+	int name(struct fsnotify_group *group, struct inode *inode,            \
+		 struct fsnotify_mark *inode_mark,                             \
+		 struct fsnotify_mark *vfsmount_mark, u32 mask, void *data,    \
+		 int data_type, ksu_fname_t file_name, u32 cookie)
+#endif