[Feature] add GA346 baseline version
Change-Id: Ic62933698569507dcf98240cdf5d9931ae34348f
diff --git a/src/kernel/linux/v4.19/fs/notify/fanotify/fanotify.c b/src/kernel/linux/v4.19/fs/notify/fanotify/fanotify.c
new file mode 100644
index 0000000..a18b8d7
--- /dev/null
+++ b/src/kernel/linux/v4.19/fs/notify/fanotify/fanotify.c
@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/fanotify.h>
+#include <linux/fdtable.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h> /* UINT_MAX */
+#include <linux/mount.h>
+#include <linux/sched.h>
+#include <linux/sched/user.h>
+#include <linux/sched/signal.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+#include <linux/audit.h>
+#include <linux/sched/mm.h>
+
+#include "fanotify.h"
+
+static bool should_merge(struct fsnotify_event *old_fsn,
+ struct fsnotify_event *new_fsn)
+{
+ struct fanotify_event_info *old, *new;
+
+ pr_debug("%s: old=%p new=%p\n", __func__, old_fsn, new_fsn);
+ old = FANOTIFY_E(old_fsn);
+ new = FANOTIFY_E(new_fsn);
+
+ if (old_fsn->inode == new_fsn->inode && old->tgid == new->tgid &&
+ old->path.mnt == new->path.mnt &&
+ old->path.dentry == new->path.dentry)
+ return true;
+ return false;
+}
+
+/* and the list better be locked by something too! */
+static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
+{
+ struct fsnotify_event *test_event;
+
+ pr_debug("%s: list=%p event=%p\n", __func__, list, event);
+
+ /*
+ * Don't merge a permission event with any other event so that we know
+ * the event structure we have created in fanotify_handle_event() is the
+ * one we should check for permission response.
+ */
+ if (fanotify_is_perm_event(event->mask))
+ return 0;
+
+ list_for_each_entry_reverse(test_event, list, list) {
+ if (should_merge(test_event, event)) {
+ test_event->mask |= event->mask;
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+static int fanotify_get_response(struct fsnotify_group *group,
+ struct fanotify_perm_event_info *event,
+ struct fsnotify_iter_info *iter_info)
+{
+ int ret;
+
+ pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
+ wait_event(group->fanotify_data.access_waitq, event->response);
+
+ /* userspace responded, convert to something usable */
+ switch (event->response & ~FAN_AUDIT) {
+ case FAN_ALLOW:
+ ret = 0;
+ break;
+ case FAN_DENY:
+ default:
+ ret = -EPERM;
+ }
+
+ /* Check if the response should be audited */
+ if (event->response & FAN_AUDIT)
+ audit_fanotify(event->response & ~FAN_AUDIT);
+
+ event->response = 0;
+
+ pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__,
+ group, event, ret);
+
+ return ret;
+}
+
+static bool fanotify_should_send_event(struct fsnotify_iter_info *iter_info,
+ u32 event_mask, const void *data,
+ int data_type)
+{
+ __u32 marks_mask = 0, marks_ignored_mask = 0;
+ const struct path *path = data;
+ struct fsnotify_mark *mark;
+ int type;
+
+ pr_debug("%s: report_mask=%x mask=%x data=%p data_type=%d\n",
+ __func__, iter_info->report_mask, event_mask, data, data_type);
+
+ /* if we don't have enough info to send an event to userspace say no */
+ if (data_type != FSNOTIFY_EVENT_PATH)
+ return false;
+
+ /* sorry, fanotify only gives a damn about files and dirs */
+ if (!d_is_reg(path->dentry) &&
+ !d_can_lookup(path->dentry))
+ return false;
+
+ fsnotify_foreach_obj_type(type) {
+ if (!fsnotify_iter_should_report_type(iter_info, type))
+ continue;
+ mark = iter_info->marks[type];
+ /*
+ * If the event is for a child and this mark doesn't care about
+ * events on a child, don't send it!
+ */
+ if (event_mask & FS_EVENT_ON_CHILD &&
+ (type != FSNOTIFY_OBJ_TYPE_INODE ||
+ !(mark->mask & FS_EVENT_ON_CHILD)))
+ continue;
+
+ marks_mask |= mark->mask;
+ marks_ignored_mask |= mark->ignored_mask;
+ }
+
+ if (d_is_dir(path->dentry) &&
+ !(marks_mask & FS_ISDIR & ~marks_ignored_mask))
+ return false;
+
+ if (event_mask & FAN_ALL_OUTGOING_EVENTS & marks_mask &
+ ~marks_ignored_mask)
+ return true;
+
+ return false;
+}
+
+struct fanotify_event_info *fanotify_alloc_event(struct fsnotify_group *group,
+ struct inode *inode, u32 mask,
+ const struct path *path)
+{
+ struct fanotify_event_info *event = NULL;
+ gfp_t gfp = GFP_KERNEL_ACCOUNT;
+
+ /*
+ * For queues with unlimited length lost events are not expected and
+ * can possibly have security implications. Avoid losing events when
+ * memory is short. For the limited size queues, avoid OOM killer in the
+ * target monitoring memcg as it may have security repercussion.
+ */
+ if (group->max_events == UINT_MAX)
+ gfp |= __GFP_NOFAIL;
+ else
+ gfp |= __GFP_RETRY_MAYFAIL;
+
+ /* Whoever is interested in the event, pays for the allocation. */
+ memalloc_use_memcg(group->memcg);
+
+ if (fanotify_is_perm_event(mask)) {
+ struct fanotify_perm_event_info *pevent;
+
+ pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp);
+ if (!pevent)
+ goto out;
+ event = &pevent->fae;
+ pevent->response = 0;
+ goto init;
+ }
+ event = kmem_cache_alloc(fanotify_event_cachep, gfp);
+ if (!event)
+ goto out;
+init: __maybe_unused
+ fsnotify_init_event(&event->fse, inode, mask);
+ event->tgid = get_pid(task_tgid(current));
+ if (path) {
+ event->path = *path;
+ path_get(&event->path);
+ } else {
+ event->path.mnt = NULL;
+ event->path.dentry = NULL;
+ }
+out:
+ memalloc_unuse_memcg();
+ return event;
+}
+
+static int fanotify_handle_event(struct fsnotify_group *group,
+ struct inode *inode,
+ u32 mask, const void *data, int data_type,
+ const unsigned char *file_name, u32 cookie,
+ struct fsnotify_iter_info *iter_info)
+{
+ int ret = 0;
+ struct fanotify_event_info *event;
+ struct fsnotify_event *fsn_event;
+
+ BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
+ BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY);
+ BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
+ BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE);
+ BUILD_BUG_ON(FAN_OPEN != FS_OPEN);
+ BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD);
+ BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW);
+ BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM);
+ BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM);
+ BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR);
+
+ if (!fanotify_should_send_event(iter_info, mask, data, data_type))
+ return 0;
+
+ pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode,
+ mask);
+
+ if (fanotify_is_perm_event(mask)) {
+ /*
+ * fsnotify_prepare_user_wait() fails if we race with mark
+ * deletion. Just let the operation pass in that case.
+ */
+ if (!fsnotify_prepare_user_wait(iter_info))
+ return 0;
+ }
+
+ event = fanotify_alloc_event(group, inode, mask, data);
+ ret = -ENOMEM;
+ if (unlikely(!event)) {
+ /*
+ * We don't queue overflow events for permission events as
+ * there the access is denied and so no event is in fact lost.
+ */
+ if (!fanotify_is_perm_event(mask))
+ fsnotify_queue_overflow(group);
+ goto finish;
+ }
+
+ fsn_event = &event->fse;
+ ret = fsnotify_add_event(group, fsn_event, fanotify_merge);
+ if (ret) {
+ /* Permission events shouldn't be merged */
+ BUG_ON(ret == 1 && mask & FAN_ALL_PERM_EVENTS);
+ /* Our event wasn't used in the end. Free it. */
+ fsnotify_destroy_event(group, fsn_event);
+
+ ret = 0;
+ } else if (fanotify_is_perm_event(mask)) {
+ ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event),
+ iter_info);
+ fsnotify_destroy_event(group, fsn_event);
+ }
+finish:
+ if (fanotify_is_perm_event(mask))
+ fsnotify_finish_user_wait(iter_info);
+
+ return ret;
+}
+
+static void fanotify_free_group_priv(struct fsnotify_group *group)
+{
+ struct user_struct *user;
+
+ user = group->fanotify_data.user;
+ atomic_dec(&user->fanotify_listeners);
+ free_uid(user);
+}
+
+static void fanotify_free_event(struct fsnotify_event *fsn_event)
+{
+ struct fanotify_event_info *event;
+
+ event = FANOTIFY_E(fsn_event);
+ path_put(&event->path);
+ put_pid(event->tgid);
+ if (fanotify_is_perm_event(fsn_event->mask)) {
+ kmem_cache_free(fanotify_perm_event_cachep,
+ FANOTIFY_PE(fsn_event));
+ return;
+ }
+ kmem_cache_free(fanotify_event_cachep, event);
+}
+
+static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
+{
+ kmem_cache_free(fanotify_mark_cache, fsn_mark);
+}
+
+const struct fsnotify_ops fanotify_fsnotify_ops = {
+ .handle_event = fanotify_handle_event,
+ .free_group_priv = fanotify_free_group_priv,
+ .free_event = fanotify_free_event,
+ .free_mark = fanotify_free_mark,
+};