X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=ltt-debugfs-abi.c;h=340f7ddc1d685cdace58f4357eece818398e587b;hb=5dbbdb433f181be8b3c30e8cd03191b5408614ca;hp=a10236134a287a47207825fbb3bd49d831168600;hpb=11b5a3c23711e1119185011f791f599713914d67;p=lttng-modules.git diff --git a/ltt-debugfs-abi.c b/ltt-debugfs-abi.c index a1023613..340f7ddc 100644 --- a/ltt-debugfs-abi.c +++ b/ltt-debugfs-abi.c @@ -41,8 +41,15 @@ static struct dentry *lttng_dentry; 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; +enum channel_type { + PER_CPU_CHANNEL, + GLOBAL_CHANNEL, + METADATA_CHANNEL, +}; + static int lttng_abi_create_session(void) { @@ -53,7 +60,7 @@ int lttng_abi_create_session(void) 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; @@ -107,10 +114,52 @@ static const struct file_operations lttng_fops = { #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; @@ -119,7 +168,7 @@ int lttng_abi_create_channel(struct file *session_file, 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; @@ -131,24 +180,46 @@ int lttng_abi_create_channel(struct file *session_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 = ""; + 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 = 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; } 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; @@ -180,11 +251,17 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 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_METADATA: + return lttng_abi_create_channel(file, + (struct lttng_channel __user *)arg, + METADATA_CHANNEL); default: return -ENOIOCTLCMD; } @@ -202,7 +279,9 @@ static int lttng_session_release(struct inode *inode, struct file *file) { struct ltt_session *session = file->private_data; - ltt_session_destroy(session); + + if (session) + ltt_session_destroy(session); return 0; } @@ -226,7 +305,7 @@ int lttng_abi_open_stream(struct file *channel_file) 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; @@ -238,9 +317,18 @@ int lttng_abi_open_stream(struct file *channel_file) 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: @@ -260,18 +348,25 @@ int lttng_abi_create_event(struct file *channel_file, 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; @@ -288,7 +383,7 @@ int lttng_abi_create_event(struct file *channel_file, * invariant for the rest of the session. */ event = ltt_event_create(channel, event_name, event_param.itype, - NULL, NULL); /* TODO non-null probe */ + probe, NULL); if (!event) { goto event_error; ret = -EEXIST; @@ -296,7 +391,7 @@ int lttng_abi_create_event(struct file *channel_file, 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; @@ -305,6 +400,8 @@ event_error: file_error: put_unused_fd(event_fd); fd_error: + ltt_probe_put(probe); +probe_error: name_error: kfree(event_name); return ret; @@ -324,7 +421,6 @@ name_error: * 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 @@ -340,6 +436,30 @@ long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg) } } +/** + * 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 /** @@ -372,7 +492,9 @@ static 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; } @@ -388,11 +510,21 @@ static const struct file_operations lttng_channel_fops = { #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; } @@ -401,12 +533,12 @@ 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", S_IWUSR, NULL, NULL, - <tng_session_fops); + <tng_fops); if (IS_ERR(lttng_dentry) || !lttng_dentry) { printk(KERN_ERR "Error creating LTTng control file\n"); ret = -ENOMEM; @@ -416,15 +548,7 @@ error: return ret; } -module_init(ltt_debugfs_abi_init); - -static void __exit ltt_debugfs_abi_exit(void) +void __exit ltt_debugfs_abi_exit(void) { debugfs_remove(lttng_dentry); } - -module_exit(ltt_debugfs_abi_exit); - -MODULE_LICENSE("GPL and additional rights"); -MODULE_AUTHOR("Mathieu Desnoyers"); -MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation DebugFS ABI");