#include "fanotify.h"
+static bool fanotify_path_equal(struct path *p1, struct path *p2)
+{
+ return p1->mnt == p2->mnt && p1->dentry == p2->dentry;
+}
+
+static inline bool fanotify_fsid_equal(__kernel_fsid_t *fsid1,
+ __kernel_fsid_t *fsid2)
+{
+ return fsid1->val[0] == fsid1->val[0] && fsid2->val[1] == fsid2->val[1];
+}
+
+static bool fanotify_fh_equal(struct fanotify_fh *fh1,
+ struct fanotify_fh *fh2)
+{
+ if (fh1->type != fh2->type || fh1->len != fh2->len)
+ return false;
+
+ /* Do not merge events if we failed to encode fh */
+ if (fh1->type == FILEID_INVALID)
+ return false;
+
+ return !fh1->len ||
+ !memcmp(fanotify_fh_buf(fh1), fanotify_fh_buf(fh2), fh1->len);
+}
+
static bool should_merge(struct fsnotify_event *old_fsn,
struct fsnotify_event *new_fsn)
{
new = FANOTIFY_E(new_fsn);
if (old_fsn->objectid != new_fsn->objectid || old->pid != new->pid ||
- old->fh_type != new->fh_type || old->fh_len != new->fh_len)
+ old->fh.type != new->fh.type)
return false;
if (fanotify_event_has_path(old)) {
- return old->path.mnt == new->path.mnt &&
- old->path.dentry == new->path.dentry;
+ return fanotify_path_equal(fanotify_event_path(old),
+ fanotify_event_path(new));
} else if (fanotify_event_has_fid(old)) {
/*
* We want to merge many dirent events in the same dir (i.e.
* mask FAN_CREATE|FAN_DELETE|FAN_ONDIR if it describes mkdir+
* unlink pair or rmdir+create pair of events.
*/
- return (old->mask & FS_ISDIR) == (new->mask & FS_ISDIR) &&
- fanotify_fid_equal(&old->fid, &new->fid, old->fh_len);
+ if ((old->mask & FS_ISDIR) != (new->mask & FS_ISDIR))
+ return false;
+
+ return fanotify_fsid_equal(&old->fsid, &new->fsid) &&
+ fanotify_fh_equal(&old->fh, &new->fh);
}
/* Do not merge events if we failed to encode fid */
return test_mask & user_mask;
}
-static int fanotify_encode_fid(struct fanotify_event *event,
- struct inode *inode, gfp_t gfp,
- __kernel_fsid_t *fsid)
+static void fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
+ gfp_t gfp)
{
- struct fanotify_fid *fid = &event->fid;
- int dwords, bytes = 0;
- int err, type;
+ int dwords, type, bytes = 0;
+ char *ext_buf = NULL;
+ void *buf = fh->buf;
+ int err;
- fid->ext_fh = NULL;
dwords = 0;
err = -ENOENT;
type = exportfs_encode_inode_fh(inode, NULL, &dwords, NULL);
if (bytes > FANOTIFY_INLINE_FH_LEN) {
/* Treat failure to allocate fh as failure to allocate event */
err = -ENOMEM;
- fid->ext_fh = kmalloc(bytes, gfp);
- if (!fid->ext_fh)
+ ext_buf = kmalloc(bytes, gfp);
+ if (!ext_buf)
goto out_err;
+
+ *fanotify_fh_ext_buf_ptr(fh) = ext_buf;
+ buf = ext_buf;
}
- type = exportfs_encode_inode_fh(inode, fanotify_fid_fh(fid, bytes),
- &dwords, NULL);
+ type = exportfs_encode_inode_fh(inode, buf, &dwords, NULL);
err = -EINVAL;
if (!type || type == FILEID_INVALID || bytes != dwords << 2)
goto out_err;
- fid->fsid = *fsid;
- event->fh_len = bytes;
+ fh->type = type;
+ fh->len = bytes;
- return type;
+ return;
out_err:
- pr_warn_ratelimited("fanotify: failed to encode fid (fsid=%x.%x, "
- "type=%d, bytes=%d, err=%i)\n",
- fsid->val[0], fsid->val[1], type, bytes, err);
- kfree(fid->ext_fh);
- fid->ext_fh = NULL;
- event->fh_len = 0;
-
- return FILEID_INVALID;
+ pr_warn_ratelimited("fanotify: failed to encode fid (type=%d, len=%d, err=%i)\n",
+ type, bytes, err);
+ kfree(ext_buf);
+ *fanotify_fh_ext_buf_ptr(fh) = NULL;
+ /* Report the event without a file identifier on encode error */
+ fh->type = FILEID_INVALID;
+ fh->len = 0;
}
/*
event->pid = get_pid(task_pid(current));
else
event->pid = get_pid(task_tgid(current));
- event->fh_len = 0;
+ event->fh.len = 0;
if (id && FAN_GROUP_FLAG(group, FAN_REPORT_FID)) {
- /* Report the event without a file identifier on encode error */
- event->fh_type = fanotify_encode_fid(event, id, gfp, fsid);
+ event->fsid = *fsid;
+ if (id)
+ fanotify_encode_fh(&event->fh, id, gfp);
} else if (path) {
- event->fh_type = FILEID_ROOT;
+ event->fh.type = FILEID_ROOT;
event->path = *path;
path_get(path);
} else {
- event->fh_type = FILEID_INVALID;
+ event->fh.type = FILEID_INVALID;
event->path.mnt = NULL;
event->path.dentry = NULL;
}
event = FANOTIFY_E(fsn_event);
if (fanotify_event_has_path(event))
path_put(&event->path);
- else if (fanotify_event_has_ext_fh(event))
- kfree(event->fid.ext_fh);
+ else if (fanotify_fh_has_ext_buf(&event->fh))
+ kfree(fanotify_fh_ext_buf(&event->fh));
put_pid(event->pid);
if (fanotify_is_perm_event(event->mask)) {
kmem_cache_free(fanotify_perm_event_cachep,
/*
* 3 dwords are sufficient for most local fs (64bit ino, 32bit generation).
- * For 32bit arch, fid increases the size of fanotify_event by 12 bytes and
- * fh_* fields increase the size of fanotify_event by another 4 bytes.
- * For 64bit arch, fid increases the size of fanotify_fid by 8 bytes and
- * fh_* fields are packed in a hole after mask.
+ * fh buf should be dword aligned. On 64bit arch, the ext_buf pointer is
+ * stored in either the first or last 2 dwords.
*/
-#if BITS_PER_LONG == 32
#define FANOTIFY_INLINE_FH_LEN (3 << 2)
-#else
-#define FANOTIFY_INLINE_FH_LEN (4 << 2)
-#endif
-struct fanotify_fid {
- __kernel_fsid_t fsid;
- union {
- unsigned char fh[FANOTIFY_INLINE_FH_LEN];
- unsigned char *ext_fh;
- };
-};
+struct fanotify_fh {
+ unsigned char buf[FANOTIFY_INLINE_FH_LEN];
+ u8 type;
+ u8 len;
+} __aligned(4);
+
+static inline bool fanotify_fh_has_ext_buf(struct fanotify_fh *fh)
+{
+ return fh->len > FANOTIFY_INLINE_FH_LEN;
+}
-static inline void *fanotify_fid_fh(struct fanotify_fid *fid,
- unsigned int fh_len)
+static inline char **fanotify_fh_ext_buf_ptr(struct fanotify_fh *fh)
{
- return fh_len <= FANOTIFY_INLINE_FH_LEN ? fid->fh : fid->ext_fh;
+ BUILD_BUG_ON(__alignof__(char *) - 4 + sizeof(char *) >
+ FANOTIFY_INLINE_FH_LEN);
+ return (char **)ALIGN((unsigned long)(fh->buf), __alignof__(char *));
}
-static inline bool fanotify_fid_equal(struct fanotify_fid *fid1,
- struct fanotify_fid *fid2,
- unsigned int fh_len)
+static inline void *fanotify_fh_ext_buf(struct fanotify_fh *fh)
{
- return fid1->fsid.val[0] == fid2->fsid.val[0] &&
- fid1->fsid.val[1] == fid2->fsid.val[1] &&
- !memcmp(fanotify_fid_fh(fid1, fh_len),
- fanotify_fid_fh(fid2, fh_len), fh_len);
+ return *fanotify_fh_ext_buf_ptr(fh);
+}
+
+static inline void *fanotify_fh_buf(struct fanotify_fh *fh)
+{
+ return fanotify_fh_has_ext_buf(fh) ? fanotify_fh_ext_buf(fh) : fh->buf;
}
/*
struct fsnotify_event fse;
u32 mask;
/*
- * Those fields are outside fanotify_fid to pack fanotify_event nicely
- * on 64bit arch and to use fh_type as an indication of whether path
- * or fid are used in the union:
- * FILEID_ROOT (0) for path, > 0 for fid, FILEID_INVALID for neither.
+ * With FAN_REPORT_FID, we do not hold any reference on the
+ * victim object. Instead we store its NFS file handle and its
+ * filesystem's fsid as a unique identifier.
+ */
+ __kernel_fsid_t fsid;
+ struct fanotify_fh fh;
+ /*
+ * We hold ref to this path so it may be dereferenced at any
+ * point during this object's lifetime
*/
- u8 fh_type;
- u8 fh_len;
- u16 pad;
- union {
- /*
- * We hold ref to this path so it may be dereferenced at any
- * point during this object's lifetime
- */
- struct path path;
- /*
- * With FAN_REPORT_FID, we do not hold any reference on the
- * victim object. Instead we store its NFS file handle and its
- * filesystem's fsid as a unique identifier.
- */
- struct fanotify_fid fid;
- };
+ struct path path;
struct pid *pid;
};
static inline bool fanotify_event_has_path(struct fanotify_event *event)
{
- return event->fh_type == FILEID_ROOT;
+ return event->fh.type == FILEID_ROOT;
}
static inline bool fanotify_event_has_fid(struct fanotify_event *event)
{
- return event->fh_type != FILEID_ROOT &&
- event->fh_type != FILEID_INVALID;
+ return event->fh.type != FILEID_ROOT &&
+ event->fh.type != FILEID_INVALID;
}
-static inline bool fanotify_event_has_ext_fh(struct fanotify_event *event)
+static inline __kernel_fsid_t *fanotify_event_fsid(struct fanotify_event *event)
{
- return fanotify_event_has_fid(event) &&
- event->fh_len > FANOTIFY_INLINE_FH_LEN;
+ if (fanotify_event_has_fid(event))
+ return &event->fsid;
+ else
+ return NULL;
}
-static inline void *fanotify_event_fh(struct fanotify_event *event)
+static inline struct fanotify_fh *fanotify_event_object_fh(
+ struct fanotify_event *event)
{
- return fanotify_fid_fh(&event->fid, event->fh_len);
+ if (fanotify_event_has_fid(event))
+ return &event->fh;
+ else
+ return NULL;
+}
+
+static inline int fanotify_event_object_fh_len(struct fanotify_event *event)
+{
+ struct fanotify_fh *fh = fanotify_event_object_fh(event);
+
+ return fh ? fh->len : 0;
}
/*
return container_of(fse, struct fanotify_event, fse);
}
+static inline struct path *fanotify_event_path(struct fanotify_event *event)
+{
+ if (fanotify_event_has_path(event))
+ return &event->path;
+ else
+ return NULL;
+}
+
struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
struct inode *inode, u32 mask,
const void *data, int data_type,
static int fanotify_event_info_len(struct fanotify_event *event)
{
- if (!fanotify_event_has_fid(event))
+ int fh_len = fanotify_event_object_fh_len(event);
+
+ if (!fh_len)
return 0;
return roundup(sizeof(struct fanotify_event_info_fid) +
- sizeof(struct file_handle) + event->fh_len,
+ sizeof(struct file_handle) + fh_len,
FANOTIFY_EVENT_ALIGN);
}
{
struct fanotify_event_info_fid info = { };
struct file_handle handle = { };
- unsigned char bounce[FANOTIFY_INLINE_FH_LEN], *fh;
- size_t fh_len = event->fh_len;
+ unsigned char bounce[FANOTIFY_INLINE_FH_LEN], *fh_buf;
+ struct fanotify_fh *fh = fanotify_event_object_fh(event);
+ size_t fh_len = fh->len;
size_t len = fanotify_event_info_len(event);
if (!len)
/* Copy event info fid header followed by vaiable sized file handle */
info.hdr.info_type = FAN_EVENT_INFO_TYPE_FID;
info.hdr.len = len;
- info.fsid = event->fid.fsid;
+ info.fsid = *fanotify_event_fsid(event);
if (copy_to_user(buf, &info, sizeof(info)))
return -EFAULT;
buf += sizeof(info);
len -= sizeof(info);
- handle.handle_type = event->fh_type;
+ handle.handle_type = fh->type;
handle.handle_bytes = fh_len;
if (copy_to_user(buf, &handle, sizeof(handle)))
return -EFAULT;
* For an inline fh, copy through stack to exclude the copy from
* usercopy hardening protections.
*/
- fh = fanotify_event_fh(event);
+ fh_buf = fanotify_fh_buf(fh);
if (fh_len <= FANOTIFY_INLINE_FH_LEN) {
- memcpy(bounce, fh, fh_len);
- fh = bounce;
+ memcpy(bounce, fh_buf, fh_len);
+ fh_buf = bounce;
}
- if (copy_to_user(buf, fh, fh_len))
+ if (copy_to_user(buf, fh_buf, fh_len))
return -EFAULT;
/* Pad with 0's */
{
struct fanotify_event_metadata metadata;
struct fanotify_event *event;
+ struct path *path;
struct file *f = NULL;
int ret, fd = FAN_NOFD;
pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event);
event = container_of(fsn_event, struct fanotify_event, fse);
+ path = fanotify_event_path(event);
metadata.event_len = FAN_EVENT_METADATA_LEN;
metadata.metadata_len = FAN_EVENT_METADATA_LEN;
metadata.vers = FANOTIFY_METADATA_VERSION;
metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS;
metadata.pid = pid_vnr(event->pid);
- if (fanotify_event_has_path(event)) {
- struct path *path = &event->path;
-
- if (path->mnt && path->dentry) {
- fd = create_fd(group, path, &f);
- if (fd < 0)
- return fd;
- }
- } else if (fanotify_event_has_fid(event)) {
+ if (fanotify_event_has_fid(event)) {
metadata.event_len += fanotify_event_info_len(event);
+ } else if (path && path->mnt && path->dentry) {
+ fd = create_fd(group, path, &f);
+ if (fd < 0)
+ return fd;
}
metadata.fd = fd;
projects / users / dwmw2 / linux.git / commitdiff