* - 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 "wrapper/symbols.h" /* for wrapper_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 overwrite; /* 1: overwrite, 0: discard */
- u64 subbuf_size;
- u64 num_subbuf;
- unsigned int switch_timer_interval;
- unsigned int read_timer_interval;
-};
-
-struct lttng_event {
- 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();
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;
#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
+void lttng_metadata_create_events(struct file *channel_file)
+{
+ 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;
+ }
+ /*
+ * 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;
+
+event_error:
+ ltt_probe_put(probe);
+probe_error:
+ WARN_ON(1);
+ return; /* not allowed to return error */
}
+static
int lttng_abi_create_channel(struct file *session_file,
- struct lttng_channel __user *uchan_param)
+ struct lttng_channel __user *uchan_param,
+ enum channel_type channel_type)
{
struct ltt_session *session = session_file->private_data;
+ const struct file_operations *fops;
+ const char *transport_name;
struct ltt_channel *chan;
struct file *chan_file;
struct lttng_channel chan_param;
if (copy_from_user(&chan_param, uchan_param, sizeof(chan_param)))
return -EFAULT;
- chan_fd = get_unused_fd_flags(O_RDWR);
+ chan_fd = get_unused_fd();
if (chan_fd < 0) {
ret = chan_fd;
goto fd_error;
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, chan_param->overwrite, NULL,
- chan_param->subbuf_size,
- chan_param->num_subbuf,
- chan_param->switch_timer_interval,
- chan_param->read_timer_interval);
+ 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 = -ENOMEM;
+ ret = -EINVAL;
goto chan_error;
}
- channel->file = chan_file;
+ 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_file->f_count);
+ atomic_long_inc(&session_file->f_count);
return chan_fd;
switch (cmd) {
case LTTNG_CHANNEL:
- return lttng_abi_create_channel(file, (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_SESSION_FINALIZE:
- return ltt_session_finalize(session);
+ case LTTNG_METADATA:
+ return lttng_abi_create_channel(file,
+ (struct lttng_channel __user *)arg,
+ METADATA_CHANNEL);
default:
return -ENOIOCTLCMD;
}
int lttng_session_release(struct inode *inode, struct file *file)
{
struct ltt_session *session = file->private_data;
- return ltt_session_destroy(session);
+
+ if (session)
+ ltt_session_destroy(session);
+ return 0;
}
static const struct file_operations lttng_session_fops = {
#ifdef CONFIG_COMPAT
.compat_ioctl = lttng_session_ioctl,
#endif
-}
+};
static
int lttng_abi_open_stream(struct file *channel_file)
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;
ret = PTR_ERR(stream_file);
goto file_error;
}
+ /*
+ * 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 on the channel */
- atomic_inc(&channel_file->f_count);
+ /*
+ * 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;
}
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)) {
+ if (strncpy_from_user(event_name, uevent_param->name, PATH_MAX) < 0) {
ret = -EFAULT;
goto name_error;
}
event_name[PATH_MAX - 1] = '\0';
- event_fd = get_unused_fd_flags(O_RDWR);
+
+ 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;
* We tolerate no failure path after event creation. It will stay
* invariant for the rest of the session.
*/
- event = ltt_event_create(channel, event_param->itype, event_name, NULL);
+ 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_inc(&channel_file->f_count);
+ atomic_long_inc(&channel_file->f_count);
kfree(event_name);
return event_fd;
file_error:
put_unused_fd(event_fd);
fd_error:
+ ltt_probe_put(probe);
+probe_error:
name_error:
kfree(event_name);
return ret;
* 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
}
}
+/**
+ * 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_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+ case LTTNG_STREAM:
+ return lttng_abi_open_stream(file);
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
/* TODO: poll */
#if 0
/**
int lttng_channel_release(struct inode *inode, struct file *file)
{
struct ltt_channel *channel = file->private_data;
- fput(channel->session->file);
+
+ if (channel)
+ fput(channel->session->file);
return 0;
}
#ifdef CONFIG_COMPAT
.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;
- fput(event->chan->file);
+
+ if (event)
+ fput(event->chan->file);
return 0;
}
/* TODO: filter control ioctl */
static const struct file_operations lttng_event_fops = {
.release = lttng_event_release,
-}
+};
-static int __init ltt_debugfs_abi_init(void)
+int __init ltt_debugfs_abi_init(void)
{
int ret = 0;
- lttng_dentry = debugfs_create_file("lttng", NULL);
- if (IS_ERR(lttng_dentry) || !lttng_dentry)
+ wrapper_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);
}