unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
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fanotify: open code fill_event_metadata()

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The helper is quite trivial and open coding it will make it easier
to implement copying event fid info to user.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Amir Goldstein 2019-01-10 19:04:33 +02:00 committed by Jan Kara
parent 33913997d5
commit bb2f7b4542
1 changed files with 28 additions and 45 deletions
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73
fs/notify/fanotify/fanotify_user.c
View file

@ -114,36 +114,6 @@ static int create_fd(struct fsnotify_group *group,
return client_fd;
}
static int fill_event_metadata(struct fsnotify_group *group,
struct fanotify_event_metadata *metadata,
struct fsnotify_event *fsn_event,
struct file **file)
{
int ret = 0;
struct fanotify_event *event;
pr_debug("%s: group=%p metadata=%p event=%p\n", __func__,
group, metadata, fsn_event);
*file = NULL;
event = container_of(fsn_event, struct fanotify_event, fse);
metadata->event_len = FAN_EVENT_METADATA_LEN;
metadata->metadata_len = FAN_EVENT_METADATA_LEN;
metadata->vers = FANOTIFY_METADATA_VERSION;
metadata->reserved = 0;
metadata->mask = event->mask & FANOTIFY_OUTGOING_EVENTS;
metadata->pid = pid_vnr(event->pid);
if (unlikely(event->mask & FAN_Q_OVERFLOW))
metadata->fd = FAN_NOFD;
else {
metadata->fd = create_fd(group, event, file);
if (metadata->fd < 0)
ret = metadata->fd;
}
return ret;
}
static struct fanotify_perm_event *dequeue_event(
struct fsnotify_group *group, int fd)
{
@ -205,37 +175,50 @@ static int process_access_response(struct fsnotify_group *group,
}
static ssize_t copy_event_to_user(struct fsnotify_group *group,
struct fsnotify_event *event,
struct fsnotify_event *fsn_event,
char __user *buf, size_t count)
{
struct fanotify_event_metadata fanotify_event_metadata;
struct file *f;
struct fanotify_event_metadata metadata;
struct fanotify_event *event;
struct file *f = NULL;
int fd, ret;
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event);
ret = fill_event_metadata(group, &fanotify_event_metadata, event, &f);
if (ret < 0)
return ret;
event = container_of(fsn_event, struct fanotify_event, fse);
metadata.event_len = FAN_EVENT_METADATA_LEN;
metadata.metadata_len = FAN_EVENT_METADATA_LEN;
metadata.vers = FANOTIFY_METADATA_VERSION;
metadata.reserved = 0;
metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS;
metadata.pid = pid_vnr(event->pid);
if (unlikely(event->mask & FAN_Q_OVERFLOW)) {
fd = FAN_NOFD;
} else {
fd = create_fd(group, event, &f);
if (fd < 0)
return fd;
}
metadata.fd = fd;
fd = fanotify_event_metadata.fd;
ret = -EFAULT;
/*
* Sanity check copy size in case get_one_event() and
* fill_event_metadata() event_len sizes ever get out of sync.
*/
if (WARN_ON_ONCE(fanotify_event_metadata.event_len > count))
goto out_close_fd;
if (copy_to_user(buf, &fanotify_event_metadata,
fanotify_event_metadata.event_len))
if (WARN_ON_ONCE(metadata.event_len > count))
goto out_close_fd;
if (fanotify_is_perm_event(FANOTIFY_E(event)->mask))
FANOTIFY_PE(event)->fd = fd;
if (copy_to_user(buf, &metadata, metadata.event_len))
goto out_close_fd;
if (fanotify_is_perm_event(event->mask))
FANOTIFY_PE(fsn_event)->fd = fd;
if (fd != FAN_NOFD)
fd_install(fd, f);
return fanotify_event_metadata.event_len;
return metadata.event_len;
out_close_fd:
if (fd != FAN_NOFD) {