detailed syscall tracing (work in progress)
[lttng-modules.git] / ltt-debugfs-abi.c
index ee3ab043b9badf9f10cb58c0b4a292a090ff10ca..86a1720068c49eb96d306f86711f6bb54bd22b65 100644 (file)
  *     - Takes an instrumentation source as parameter
  *       - e.g. tracepoints, dynamic_probes...
  *     - Takes instrumentation source specific arguments.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
  */
 
 #include <linux/module.h>
 #include <linux/debugfs.h>
+#include <linux/proc_fs.h>
 #include <linux/anon_inodes.h>
 #include <linux/file.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 #include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
 #include "wrapper/ringbuffer/vfs.h"
+#include "wrapper/poll.h"
 #include "ltt-debugfs-abi.h"
 #include "ltt-events.h"
 #include "ltt-tracer.h"
  */
 
 static struct dentry *lttng_dentry;
+static struct proc_dir_entry *lttng_proc_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;
 
+/*
+ * Teardown management: opened file descriptors keep a refcount on the module,
+ * so it can only exit when all file descriptors are closed.
+ */
+
 enum channel_type {
        PER_CPU_CHANNEL,
        METADATA_CHANNEL,
@@ -84,6 +94,43 @@ fd_error:
        return ret;
 }
 
+static
+int lttng_abi_tracepoint_list(void)
+{
+       struct file *tracepoint_list_file;
+       int file_fd, ret;
+
+       file_fd = get_unused_fd();
+       if (file_fd < 0) {
+               ret = file_fd;
+               goto fd_error;
+       }
+
+       tracepoint_list_file = anon_inode_getfile("[lttng_session]",
+                                         &lttng_tracepoint_list_fops,
+                                         NULL, O_RDWR);
+       if (IS_ERR(tracepoint_list_file)) {
+               ret = PTR_ERR(tracepoint_list_file);
+               goto file_error;
+       }
+       ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
+       if (ret < 0)
+               goto open_error;
+       fd_install(file_fd, tracepoint_list_file);
+       if (file_fd < 0) {
+               ret = file_fd;
+               goto fd_error;
+       }
+       return file_fd;
+
+open_error:
+       fput(tracepoint_list_file);
+file_error:
+       put_unused_fd(file_fd);
+fd_error:
+       return ret;
+}
+
 static
 long lttng_abi_tracer_version(struct file *file, 
        struct lttng_kernel_tracer_version __user *uversion_param)
@@ -99,6 +146,49 @@ long lttng_abi_tracer_version(struct file *file,
        return 0;
 }
 
+static
+long lttng_abi_add_context(struct file *file,
+       struct lttng_kernel_context __user *ucontext_param,
+       struct lttng_ctx **ctx, struct ltt_session *session)
+{
+       struct lttng_kernel_context context_param;
+
+       if (session->been_active)
+               return -EPERM;
+
+       if (copy_from_user(&context_param, ucontext_param, sizeof(context_param)))
+               return -EFAULT;
+
+       switch (context_param.ctx) {
+       case LTTNG_KERNEL_CONTEXT_PID:
+               return lttng_add_pid_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_PRIO:
+               return lttng_add_prio_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_NICE:
+               return lttng_add_nice_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_VPID:
+               return lttng_add_vpid_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_TID:
+               return lttng_add_tid_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_VTID:
+               return lttng_add_vtid_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_PPID:
+               return lttng_add_ppid_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_VPPID:
+               return lttng_add_vppid_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
+               context_param.u.perf_counter.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
+               return lttng_add_perf_counter_to_ctx(context_param.u.perf_counter.type,
+                               context_param.u.perf_counter.config,
+                               context_param.u.perf_counter.name,
+                               ctx);
+       case LTTNG_KERNEL_CONTEXT_COMM:
+               return lttng_add_comm_to_ctx(ctx);
+       default:
+               return -EINVAL;
+       }
+}
+
 /**
  *     lttng_ioctl - lttng syscall through ioctl
  *
@@ -109,6 +199,12 @@ long lttng_abi_tracer_version(struct file *file,
  *     This ioctl implements lttng commands:
  *     LTTNG_KERNEL_SESSION
  *             Returns a LTTng trace session file descriptor
+ *     LTTNG_KERNEL_TRACER_VERSION
+ *             Returns the LTTng kernel tracer version
+ *     LTTNG_KERNEL_TRACEPOINT_LIST
+ *             Returns a file descriptor listing available tracepoints
+ *     LTTNG_KERNEL_WAIT_QUIESCENT
+ *             Returns after all previously running probes have completed
  *
  * The returned session will be deleted when its file descriptor is closed.
  */
@@ -121,12 +217,32 @@ long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        case LTTNG_KERNEL_TRACER_VERSION:
                return lttng_abi_tracer_version(file,
                                (struct lttng_kernel_tracer_version __user *) arg);
+       case LTTNG_KERNEL_TRACEPOINT_LIST:
+               return lttng_abi_tracepoint_list();
+       case LTTNG_KERNEL_WAIT_QUIESCENT:
+               synchronize_trace();
+               return 0;
+       case LTTNG_KERNEL_CALIBRATE:
+       {
+               struct lttng_kernel_calibrate __user *ucalibrate =
+                       (struct lttng_kernel_calibrate __user *) arg;
+               struct lttng_kernel_calibrate calibrate;
+               int ret;
+
+               if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
+                       return -EFAULT;
+               ret = lttng_calibrate(&calibrate);
+               if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
+                       return -EFAULT;
+               return ret;
+       }
        default:
                return -ENOIOCTLCMD;
        }
 }
 
 static const struct file_operations lttng_fops = {
+       .owner = THIS_MODULE,
        .unlocked_ioctl = lttng_ioctl,
 #ifdef CONFIG_COMPAT
        .compat_ioctl = lttng_ioctl,
@@ -147,16 +263,14 @@ void lttng_metadata_create_events(struct file *channel_file)
                .name = "lttng_metadata",
        };
        struct ltt_event *event;
-       int ret;
 
        /*
         * We tolerate no failure path after event creation. It will stay
         * invariant for the rest of the session.
         */
-       event = ltt_event_create(channel, &metadata_params, NULL);
+       event = ltt_event_create(channel, &metadata_params, NULL, NULL);
        if (!event) {
                goto create_error;
-               ret = -EEXIST;
        }
        return;
 
@@ -171,7 +285,7 @@ int lttng_abi_create_channel(struct file *session_file,
                             enum channel_type channel_type)
 {
        struct ltt_session *session = session_file->private_data;
-       const struct file_operations *fops;
+       const struct file_operations *fops = NULL;
        const char *transport_name;
        struct ltt_channel *chan;
        struct file *chan_file;
@@ -186,8 +300,17 @@ int lttng_abi_create_channel(struct file *session_file,
                ret = chan_fd;
                goto fd_error;
        }
+       switch (channel_type) {
+       case PER_CPU_CHANNEL:
+               fops = &lttng_channel_fops;
+               break;
+       case METADATA_CHANNEL:
+               fops = &lttng_metadata_fops;
+               break;
+       }
+               
        chan_file = anon_inode_getfile("[lttng_channel]",
-                                      &lttng_channel_fops,
+                                      fops,
                                       NULL, O_RDWR);
        if (IS_ERR(chan_file)) {
                ret = PTR_ERR(chan_file);
@@ -195,13 +318,23 @@ int lttng_abi_create_channel(struct file *session_file,
        }
        switch (channel_type) {
        case PER_CPU_CHANNEL:
-               transport_name = chan_param.overwrite ?
-                       "relay-overwrite" : "relay-discard";
-               fops = &lttng_channel_fops;
+               if (chan_param.output == LTTNG_KERNEL_SPLICE) {
+                       transport_name = chan_param.overwrite ?
+                               "relay-overwrite" : "relay-discard";
+               } else if (chan_param.output == LTTNG_KERNEL_MMAP) {
+                       transport_name = chan_param.overwrite ?
+                               "relay-overwrite-mmap" : "relay-discard-mmap";
+               } else {
+                       return -EINVAL;
+               }
                break;
        case METADATA_CHANNEL:
-               transport_name = "relay-metadata";
-               fops = &lttng_metadata_fops;
+               if (chan_param.output == LTTNG_KERNEL_SPLICE)
+                       transport_name = "relay-metadata";
+               else if (chan_param.output == LTTNG_KERNEL_MMAP)
+                       transport_name = "relay-metadata-mmap";
+               else
+                       return -EINVAL;
                break;
        default:
                transport_name = "<unknown>";
@@ -251,6 +384,12 @@ fd_error:
  *     This ioctl implements lttng commands:
  *     LTTNG_KERNEL_CHANNEL
  *             Returns a LTTng channel file descriptor
+ *     LTTNG_KERNEL_ENABLE
+ *             Enables tracing for a session (weak enable)
+ *     LTTNG_KERNEL_DISABLE
+ *             Disables tracing for a session (strong disable)
+ *     LTTNG_KERNEL_METADATA
+ *             Returns a LTTng metadata file descriptor
  *
  * The returned channel will be deleted when its file descriptor is closed.
  */
@@ -265,9 +404,11 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                                (struct lttng_kernel_channel __user *) arg,
                                PER_CPU_CHANNEL);
        case LTTNG_KERNEL_SESSION_START:
-               return ltt_session_start(session);
+       case LTTNG_KERNEL_ENABLE:
+               return ltt_session_enable(session);
        case LTTNG_KERNEL_SESSION_STOP:
-               return ltt_session_stop(session);
+       case LTTNG_KERNEL_DISABLE:
+               return ltt_session_disable(session);
        case LTTNG_KERNEL_METADATA:
                return lttng_abi_create_channel(file,
                                (struct lttng_kernel_channel __user *) arg,
@@ -296,6 +437,7 @@ int lttng_session_release(struct inode *inode, struct file *file)
 }
 
 static const struct file_operations lttng_session_fops = {
+       .owner = THIS_MODULE,
        .release = lttng_session_release,
        .unlocked_ioctl = lttng_session_ioctl,
 #ifdef CONFIG_COMPAT
@@ -362,6 +504,9 @@ int lttng_abi_create_event(struct file *channel_file,
                return -EFAULT;
        event_param.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
        switch (event_param.instrumentation) {
+       case LTTNG_KERNEL_KRETPROBE:
+               event_param.u.kretprobe.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
+               break;
        case LTTNG_KERNEL_KPROBE:
                event_param.u.kprobe.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
                break;
@@ -371,31 +516,41 @@ int lttng_abi_create_event(struct file *channel_file,
        default:
                break;
        }
-       event_fd = get_unused_fd();
-       if (event_fd < 0) {
-               ret = event_fd;
-               goto fd_error;
-       }
-       event_file = anon_inode_getfile("[lttng_event]",
-                                       &lttng_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_param, NULL);
-       if (!event) {
-               ret = -EEXIST;
-               goto event_error;
+       switch (event_param.instrumentation) {
+       default:
+               event_fd = get_unused_fd();
+               if (event_fd < 0) {
+                       ret = event_fd;
+                       goto fd_error;
+               }
+               event_file = anon_inode_getfile("[lttng_event]",
+                                               &lttng_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_param, NULL, NULL);
+               if (!event) {
+                       ret = -EINVAL;
+                       goto event_error;
+               }
+               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);
+               break;
+       case LTTNG_KERNEL_SYSCALLS:
+               ret = lttng_syscalls_register(channel, NULL);
+               if (ret)
+                       goto fd_error;
+               event_fd = 0;
+               break;
        }
-       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);
        return event_fd;
 
 event_error:
@@ -419,17 +574,33 @@ fd_error:
  *              (typically, one event stream records events from one CPU)
  *     LTTNG_KERNEL_EVENT
  *             Returns an event file descriptor or failure.
+ *     LTTNG_KERNEL_CONTEXT
+ *             Prepend a context field to each event in the channel
+ *     LTTNG_KERNEL_ENABLE
+ *             Enable recording for events in this channel (weak enable)
+ *     LTTNG_KERNEL_DISABLE
+ *             Disable recording for events in this channel (strong disable)
  *
  * Channel and event file descriptors also hold a reference on the session.
  */
 static
 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
+       struct ltt_channel *channel = file->private_data;
+
        switch (cmd) {
        case LTTNG_KERNEL_STREAM:
                return lttng_abi_open_stream(file);
        case LTTNG_KERNEL_EVENT:
                return lttng_abi_create_event(file, (struct lttng_kernel_event __user *) arg);
+       case LTTNG_KERNEL_CONTEXT:
+               return lttng_abi_add_context(file,
+                               (struct lttng_kernel_context __user *) arg,
+                               &channel->ctx, channel->session);
+       case LTTNG_KERNEL_ENABLE:
+               return ltt_channel_enable(channel);
+       case LTTNG_KERNEL_DISABLE:
+               return ltt_channel_disable(channel);
        default:
                return -ENOIOCTLCMD;
        }
@@ -459,8 +630,6 @@ long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg
        }
 }
 
-/* TODO: poll */
-#if 0
 /**
  *     lttng_channel_poll - lttng stream addition/removal monitoring
  *
@@ -474,18 +643,20 @@ unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
 
        if (file->f_mode & FMODE_READ) {
                poll_wait_set_exclusive(wait);
-               poll_wait(file, &channel->notify_wait, wait);
+               poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
+                         wait);
 
-               /* TODO: identify when the channel is being finalized. */
-               if (finalized)
+               if (channel->ops->is_disabled(channel->chan))
+                       return POLLERR;
+               if (channel->ops->is_finalized(channel->chan))
                        return POLLHUP;
-               else
+               if (channel->ops->buffer_has_read_closed_stream(channel->chan))
                        return POLLIN | POLLRDNORM;
+               return 0;
        }
        return mask;
 
 }
-#endif //0
 
 static
 int lttng_channel_release(struct inode *inode, struct file *file)
@@ -498,11 +669,9 @@ int lttng_channel_release(struct inode *inode, struct file *file)
 }
 
 static const struct file_operations lttng_channel_fops = {
+       .owner = THIS_MODULE,
        .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_ioctl,
@@ -510,6 +679,7 @@ static const struct file_operations lttng_channel_fops = {
 };
 
 static const struct file_operations lttng_metadata_fops = {
+       .owner = THIS_MODULE,
        .release = lttng_channel_release,
        .unlocked_ioctl = lttng_metadata_ioctl,
 #ifdef CONFIG_COMPAT
@@ -517,6 +687,40 @@ static const struct file_operations lttng_metadata_fops = {
 #endif
 };
 
+/**
+ *     lttng_event_ioctl - lttng syscall through ioctl
+ *
+ *     @file: the file
+ *     @cmd: the command
+ *     @arg: command arg
+ *
+ *     This ioctl implements lttng commands:
+ *     LTTNG_KERNEL_CONTEXT
+ *             Prepend a context field to each record of this event
+ *     LTTNG_KERNEL_ENABLE
+ *             Enable recording for this event (weak enable)
+ *     LTTNG_KERNEL_DISABLE
+ *             Disable recording for this event (strong disable)
+ */
+static
+long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       struct ltt_event *event = file->private_data;
+
+       switch (cmd) {
+       case LTTNG_KERNEL_CONTEXT:
+               return lttng_abi_add_context(file,
+                               (struct lttng_kernel_context __user *) arg,
+                               &event->ctx, event->chan->session);
+       case LTTNG_KERNEL_ENABLE:
+               return ltt_event_enable(event);
+       case LTTNG_KERNEL_DISABLE:
+               return ltt_event_disable(event);
+       default:
+               return -ENOIOCTLCMD;
+       }
+}
+
 static
 int lttng_event_release(struct inode *inode, struct file *file)
 {
@@ -529,7 +733,12 @@ int lttng_event_release(struct inode *inode, struct file *file)
 
 /* TODO: filter control ioctl */
 static const struct file_operations lttng_event_fops = {
+       .owner = THIS_MODULE,
        .release = lttng_event_release,
+       .unlocked_ioctl = lttng_event_ioctl,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl = lttng_event_ioctl,
+#endif
 };
 
 int __init ltt_debugfs_abi_init(void)
@@ -538,8 +747,14 @@ int __init ltt_debugfs_abi_init(void)
 
        wrapper_vmalloc_sync_all();
        lttng_dentry = debugfs_create_file("lttng", S_IWUSR, NULL, NULL,
-                                          &lttng_fops);
-       if (IS_ERR(lttng_dentry) || !lttng_dentry) {
+                                       &lttng_fops);
+       if (IS_ERR(lttng_dentry))
+               lttng_dentry = NULL;
+
+       lttng_proc_dentry = proc_create_data("lttng", S_IWUSR, NULL,
+                                       &lttng_fops, NULL);
+       
+       if (!lttng_dentry && !lttng_proc_dentry) {
                printk(KERN_ERR "Error creating LTTng control file\n");
                ret = -ENOMEM;
                goto error;
@@ -550,5 +765,8 @@ error:
 
 void __exit ltt_debugfs_abi_exit(void)
 {
-       debugfs_remove(lttng_dentry);
+       if (lttng_dentry)
+               debugfs_remove(lttng_dentry);
+       if (lttng_proc_dentry)
+               remove_proc_entry("lttng", NULL);
 }
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