* - Takes instrumentation source specific arguments.
*/
+#include <linux/module.h>
#include <linux/debugfs.h>
+#include <linux/anon_inodes.h>
+#include <linux/file.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h> /* For vmalloc_sync_all */
+#include "wrapper/ringbuffer/vfs.h"
+#include "ltt-debugfs-abi.h"
#include "ltt-events.h"
/*
static const struct file_operations lttng_fops;
static const struct file_operations lttng_session_fops;
static const struct file_operations lttng_channel_fops;
+static const struct file_operations lttng_metadata_fops;
+static const struct file_operations lttng_event_fops;
-/*
- * LTTng DebugFS ABI structures.
- */
-
-struct lttng_channel {
- int session; /* Session file descriptor */
- int overwrite; /* 1: overwrite, 0: discard */
- u64 subbuf_size;
- u64 num_subbuf;
- unsigned int switch_timer_interval;
- unsigned int read_timer_interval;
-};
-
-struct lttng_event {
- int channel; /* Channel file descriptor */
- enum instrum_type itype;
- char name[];
+enum channel_type {
+ PER_CPU_CHANNEL,
+ GLOBAL_CHANNEL,
+ METADATA_CHANNEL,
};
static
{
struct ltt_session *session;
struct file *session_file;
- int session_fd;
+ int session_fd, ret;
- session = ltt_session_create()
+ session = ltt_session_create();
if (!session)
return -ENOMEM;
- session_fd = get_unused_fd_flags(O_RDWR);
+ session_fd = get_unused_fd();
if (session_fd < 0) {
ret = session_fd;
goto fd_error;
ret = PTR_ERR(session_file);
goto file_error;
}
+ session->file = session_file;
fd_install(session_fd, session_file);
return session_fd;
/**
* lttng_ioctl - lttng syscall through ioctl
*
- * @filp: the file
+ * @file: the file
* @cmd: the command
* @arg: command arg
*
* The returned session will be deleted when its file descriptor is closed.
*/
static
-long lttng_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case LTTNG_SESSION:
}
}
+static const struct file_operations lttng_fops = {
+ .unlocked_ioctl = lttng_ioctl,
#ifdef CONFIG_COMPAT
+ .compat_ioctl = lttng_ioctl,
+#endif
+};
+
+/*
+ * We tolerate no failure in this function (if one happens, we print a dmesg
+ * error, but cannot return any error, because the channel information is
+ * invariant.
+ */
static
-long lttng_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+void lttng_metadata_create_events(struct file *channel_file)
{
- switch (cmd) {
- case LTTNG_SESSION:
- return lttng_abi_create_session();
- default:
- return -ENOIOCTLCMD;
+ struct ltt_channel *channel = channel_file->private_data;
+ char *event_name = "lttng-metadata";
+ struct ltt_event *event;
+ int ret;
+ void *probe;
+
+ probe = ltt_probe_get(event_name);
+ if (!probe) {
+ ret = -ENOENT;
+ goto probe_error;
}
-}
-#endif
+ /*
+ * We tolerate no failure path after event creation. It will stay
+ * invariant for the rest of the session.
+ */
+ event = ltt_event_create(channel, event_name, INSTRUM_TRACEPOINTS,
+ probe, NULL);
+ if (!event) {
+ goto event_error;
+ ret = -EEXIST;
+ }
+ return;
-static const struct file_operations lttng_fops = {
- .unlocked_ioctl = lttng_ioctl,
-#ifdef CONFIG_COMPAT
- .compat_ioctl = lttng_compat_ioctl,
-#endif
+event_error:
+ ltt_probe_put(probe);
+probe_error:
+ WARN_ON(1);
+ return; /* not allowed to return error */
}
-int lttng_abi_create_channel(struct file *session_filp,
- struct lttng_channel __user *uchan_param)
+static
+int lttng_abi_create_channel(struct file *session_file,
+ struct lttng_channel __user *uchan_param,
+ enum channel_type channel_type)
{
- struct ltt_session *session = session_filp->private_data;
+ struct ltt_session *session = session_file->private_data;
+ const struct file_operations *fops;
+ const char *transport_name;
struct ltt_channel *chan;
- struct file *chan_filp;
+ struct file *chan_file;
struct lttng_channel chan_param;
int chan_fd;
int ret = 0;
- if (copy_from_user(&chan_param, ucham_param, sizeof(chan_param)))
+ if (copy_from_user(&chan_param, uchan_param, sizeof(chan_param)))
return -EFAULT;
- chan = ltt_channel_create(session, chan_param->overwrite, NULL,
- chan_param->subbuf_size,
- chan_param->num_subbuf,
- chan_param->switch_timer_interval,
- chan_param->read_timer_interval);
- if (!chan) {
- ret = -ENOMEM;
- goto chan_error;
- }
- chan_fd = get_unused_fd_flags(O_RDWR);
+ chan_fd = get_unused_fd();
if (chan_fd < 0) {
ret = chan_fd;
goto fd_error;
}
- chan_filp = anon_inode_getfile("[lttng_channel]",
+ chan_file = anon_inode_getfile("[lttng_channel]",
<tng_channel_fops,
- chan, O_RDWR);
- if (IS_ERR(chan_filp)) {
- ret = PTR_ERR(chan_filp);
+ NULL, O_RDWR);
+ if (IS_ERR(chan_file)) {
+ ret = PTR_ERR(chan_file);
goto file_error;
}
+ switch (channel_type) {
+ case PER_CPU_CHANNEL:
+ transport_name = chan_param.overwrite ?
+ "relay-overwrite" : "relay-discard";
+ fops = <tng_channel_fops;
+ break;
+ case GLOBAL_CHANNEL:
+ transport_name = chan_param.overwrite ?
+ "global-relay-overwrite" : "global-relay-discard";
+ fops = <tng_channel_fops;
+ break;
+ case METADATA_CHANNEL:
+ transport_name = "global-relay-discard";
+ fops = <tng_metadata_fops;
+ break;
+ default:
+ transport_name = "<unknown>";
+ break;
+ }
+ /*
+ * We tolerate no failure path after channel creation. It will stay
+ * invariant for the rest of the session.
+ */
+ chan = ltt_channel_create(session, transport_name, NULL,
+ chan_param.subbuf_size,
+ chan_param.num_subbuf,
+ chan_param.switch_timer_interval,
+ chan_param.read_timer_interval);
+ if (!chan) {
+ ret = -EINVAL;
+ goto chan_error;
+ }
+ chan->file = chan_file;
+ chan_file->private_data = chan;
+ fd_install(chan_fd, chan_file);
+ if (channel_type == METADATA_CHANNEL)
+ lttng_metadata_create_events(chan_file);
/* The channel created holds a reference on the session */
- atomic_inc(&session_filp->f_count);
+ atomic_long_inc(&session_file->f_count);
return chan_fd;
+chan_error:
+ fput(chan_file);
file_error:
put_unused_fd(chan_fd);
fd_error:
- ltt_channel_destroy(chan);
-chan_error:
return ret;
}
/**
* lttng_session_ioctl - lttng session fd ioctl
*
- * @filp: the file
+ * @file: the file
* @cmd: the command
* @arg: command arg
*
* The returned channel will be deleted when its file descriptor is closed.
*/
static
-long lttng_session_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
+ struct ltt_session *session = file->private_data;
+
switch (cmd) {
case LTTNG_CHANNEL:
- return lttng_abi_create_channel(filp, (struct lttng_channel __user *)arg);
+ return lttng_abi_create_channel(file,
+ (struct lttng_channel __user *)arg,
+ PER_CPU_CHANNEL);
+ case LTTNG_SESSION_START:
+ return ltt_session_start(session);
+ case LTTNG_SESSION_STOP:
+ return ltt_session_stop(session);
+ case LTTNG_METADATA:
+ return lttng_abi_create_channel(file,
+ (struct lttng_channel __user *)arg,
+ METADATA_CHANNEL);
default:
return -ENOIOCTLCMD;
}
}
-#ifdef CONFIG_COMPAT
+/*
+ * Called when the last file reference is dropped.
+ *
+ * Big fat note: channels and events are invariant for the whole session after
+ * their creation. So this session destruction also destroys all channel and
+ * event structures specific to this session (they are not destroyed when their
+ * individual file is released).
+ */
static
-long lttng_session_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+int lttng_session_release(struct inode *inode, struct file *file)
{
- switch (cmd) {
- case LTTNG_CHANNEL:
- return lttng_abi_create_channel(filp, (struct lttng_channel __user *)arg);
- default:
- return -ENOIOCTLCMD;
- }
+ struct ltt_session *session = file->private_data;
+
+ if (session)
+ ltt_session_destroy(session);
+ return 0;
}
-#endif
static const struct file_operations lttng_session_fops = {
+ .release = lttng_session_release,
.unlocked_ioctl = lttng_session_ioctl,
#ifdef CONFIG_COMPAT
- .compat_ioctl = lttng_session_compat_ioctl,
+ .compat_ioctl = lttng_session_ioctl,
#endif
-}
+};
static
-int lttng_abi_open_stream(struct file *channel_filp)
+int lttng_abi_open_stream(struct file *channel_file)
{
- struct ltt_channel *channel = channel_filp->private_data;
+ struct ltt_channel *channel = channel_file->private_data;
struct lib_ring_buffer *buf;
int stream_fd, ret;
+ struct file *stream_file;
- buf = ltt_buffer_read_open(channel->chan);
+ buf = channel->ops->buffer_read_open(channel->chan);
if (!buf)
return -ENOENT;
- stream_fd = get_unused_fd_flags(O_RDWR);
+ stream_fd = get_unused_fd();
if (stream_fd < 0) {
ret = stream_fd;
goto fd_error;
}
- stream_filp = anon_inode_getfile("[lttng_stream]",
- <tng_stream_fops,
+ stream_file = anon_inode_getfile("[lttng_stream]",
+ &lib_ring_buffer_file_operations,
buf, O_RDWR);
- if (IS_ERR(stream_filp)) {
- ret = PTR_ERR(stream_filp);
+ if (IS_ERR(stream_file)) {
+ ret = PTR_ERR(stream_file);
goto file_error;
}
-
- /* The stream holds a reference on the channel */
- atomic_inc(&channel_filp->f_count);
+ /*
+ * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
+ * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
+ * file descriptor, so we set FMODE_PREAD here.
+ */
+ stream_file->f_mode |= FMODE_PREAD;
+ fd_install(stream_fd, stream_file);
+ /*
+ * The stream holds a reference to the channel within the generic ring
+ * buffer library, so no need to hold a refcount on the channel and
+ * session files here.
+ */
return stream_fd;
file_error:
put_unused_fd(stream_fd);
fd_error:
- ltt_buffer_read_close(buf);
+ channel->ops->buffer_read_close(buf);
return ret;
}
+static
+int lttng_abi_create_event(struct file *channel_file,
+ struct lttng_event __user *uevent_param)
+{
+ struct ltt_channel *channel = channel_file->private_data;
+ struct ltt_event *event;
+ char *event_name;
+ struct lttng_event event_param;
+ int event_fd, ret;
+ struct file *event_file;
+ void *probe;
+
+ if (copy_from_user(&event_param, uevent_param, sizeof(event_param)))
+ return -EFAULT;
+ event_name = kmalloc(PATH_MAX, GFP_KERNEL);
+ if (!event_name)
+ return -ENOMEM;
+ if (strncpy_from_user(event_name, uevent_param->name, PATH_MAX) < 0) {
+ ret = -EFAULT;
+ goto name_error;
+ }
+ event_name[PATH_MAX - 1] = '\0';
+
+ probe = ltt_probe_get(event_name);
+ if (!probe) {
+ ret = -ENOENT;
+ goto probe_error;
+ }
+ event_fd = get_unused_fd();
+ if (event_fd < 0) {
+ ret = event_fd;
+ goto fd_error;
+ }
+ event_file = anon_inode_getfile("[lttng_event]",
+ <tng_event_fops,
+ NULL, O_RDWR);
+ if (IS_ERR(event_file)) {
+ ret = PTR_ERR(event_file);
+ goto file_error;
+ }
+ /*
+ * We tolerate no failure path after event creation. It will stay
+ * invariant for the rest of the session.
+ */
+ event = ltt_event_create(channel, event_name, event_param.itype,
+ probe, NULL);
+ if (!event) {
+ goto event_error;
+ ret = -EEXIST;
+ }
+ event_file->private_data = event;
+ fd_install(event_fd, event_file);
+ /* The event holds a reference on the channel */
+ atomic_long_inc(&channel_file->f_count);
+ kfree(event_name);
+ return event_fd;
+
+event_error:
+ fput(event_file);
+file_error:
+ put_unused_fd(event_fd);
+fd_error:
+ ltt_probe_put(probe);
+probe_error:
+name_error:
+ kfree(event_name);
+ return ret;
+}
/**
* lttng_channel_ioctl - lttng syscall through ioctl
*
- * @filp: the file
+ * @file: the file
* @cmd: the command
* @arg: command arg
*
* LTTNG_STREAM
* Returns an event stream file descriptor or failure.
* (typically, one event stream records events from one CPU)
- * LTTNG_STREAM_NOTIFIER
- * Returns a file descriptor that can be used to monitor
- * addition/removal of streams to/from a channel. (e.g. notifier
- * called on CPU hotplug).
* LTTNG_EVENT
* Returns an event file descriptor or failure.
*
- * The returned session will be deleted when its file descriptor is closed.
* Channel and event file descriptors also hold a reference on the session.
*/
static
-long lttng_channel_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case LTTNG_STREAM:
- return lttng_abi_open_stream(filp);
- case LTTNG_STREAM_NOTIFIER:
- return lttng_abi_open_stream_notifier(filp);
+ return lttng_abi_open_stream(file);
case LTTNG_EVENT:
- return lttng_abi_create_event(filp, (struct lttng_event __user *)arg);
+ return lttng_abi_create_event(file, (struct lttng_event __user *)arg);
default:
return -ENOIOCTLCMD;
}
}
-#ifdef CONFIG_COMPAT
+/**
+ * lttng_metadata_ioctl - lttng syscall through ioctl
+ *
+ * @file: the file
+ * @cmd: the command
+ * @arg: command arg
+ *
+ * This ioctl implements lttng commands:
+ * LTTNG_STREAM
+ * Returns an event stream file descriptor or failure.
+ *
+ * Channel and event file descriptors also hold a reference on the session.
+ */
static
-long lttng_channel_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case LTTNG_STREAM:
- return lttng_abi_get_stream(filp);
- case LTTNG_STREAM_NOTIFIER:
- return lttng_abi_get_stream_notifier(filp);
- case LTTNG_EVENT:
- return lttng_abi_create_event(filp, (struct lttng_event __user *)arg);
+ return lttng_abi_open_stream(file);
default:
return -ENOIOCTLCMD;
}
}
-#endif
+
+/* TODO: poll */
+#if 0
+/**
+ * lttng_channel_poll - lttng stream addition/removal monitoring
+ *
+ * @file: the file
+ * @wait: poll table
+ */
+unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
+{
+ struct ltt_channel *channel = file->private_data;
+ unsigned int mask = 0;
+
+ if (file->f_mode & FMODE_READ) {
+ poll_wait_set_exclusive(wait);
+ poll_wait(file, &channel->notify_wait, wait);
+
+ /* TODO: identify when the channel is being finalized. */
+ if (finalized)
+ return POLLHUP;
+ else
+ return POLLIN | POLLRDNORM;
+ }
+ return mask;
+
+}
+#endif //0
+
+static
+int lttng_channel_release(struct inode *inode, struct file *file)
+{
+ struct ltt_channel *channel = file->private_data;
+
+ if (channel)
+ fput(channel->session->file);
+ return 0;
+}
static const struct file_operations lttng_channel_fops = {
+ .release = lttng_channel_release,
+/* TODO */
+#if 0
+ .poll = lttng_channel_poll,
+#endif //0
.unlocked_ioctl = lttng_channel_ioctl,
#ifdef CONFIG_COMPAT
- .compat_ioctl = lttng_channel_compat_ioctl,
+ .compat_ioctl = lttng_channel_ioctl,
#endif
+};
+
+static const struct file_operations lttng_metadata_fops = {
+ .release = lttng_channel_release,
+ .unlocked_ioctl = lttng_metadata_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = lttng_metadata_ioctl,
+#endif
+};
+
+static
+int lttng_event_release(struct inode *inode, struct file *file)
+{
+ struct ltt_event *event = file->private_data;
+
+ if (event)
+ fput(event->chan->file);
+ return 0;
}
-static int __init ltt_debugfs_abi_init(void)
+/* TODO: filter control ioctl */
+static const struct file_operations lttng_event_fops = {
+ .release = lttng_event_release,
+};
+
+int __init ltt_debugfs_abi_init(void)
{
int ret = 0;
- lttng_dentry = debugfs_create_file("lttng", NULL);
- if (IS_ERR(lttng_dentry) || !lttng_dentry)
+ vmalloc_sync_all();
+ lttng_dentry = debugfs_create_file("lttng", S_IWUSR, NULL, NULL,
+ <tng_fops);
+ if (IS_ERR(lttng_dentry) || !lttng_dentry) {
printk(KERN_ERR "Error creating LTTng control file\n");
ret = -ENOMEM;
goto error;
return ret;
}
-static void __exit ltt_debugfs_abi_exit(void)
+void __exit ltt_debugfs_abi_exit(void)
{
- debugfs_remote(lttng_dentry);
+ debugfs_remove(lttng_dentry);
}
projects / lttng-modules.git / blobdiff