Add CPU hotplug notifier for ltt debugfs ABI, add pollwait exclusive wrapper

[lttng-modules.git] / ltt-debugfs-abi.c

diff --git a/ltt-debugfs-abi.c b/ltt-debugfs-abi.c
index c5ca63253b45575cca7e9e2c1f69b8c5a2b16e8d..fb6c789f1e0da0f4aa32bba7775fb86d439b90f0 100644 (file)
--- a/ltt-debugfs-abi.c
+++ b/ltt-debugfs-abi.c
@@ -20,6 +20,8 @@
  *     - 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>
@@ -30,6 +32,7 @@
 #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"
@@ -95,6 +98,7 @@ int lttng_abi_tracepoint_list(void)
                ret = file_fd;
                goto fd_error;
        }
+
        tracepoint_list_file = anon_inode_getfile("[lttng_session]",
                                          &lttng_tracepoint_list_fops,
                                          NULL, O_RDWR);
@@ -102,9 +106,18 @@ int lttng_abi_tracepoint_list(void)
                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:
@@ -126,6 +139,39 @@ 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_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
  *
@@ -284,6 +330,12 @@ fd_error:
  *     This ioctl implements lttng commands:
  *     LTTNG_KERNEL_CHANNEL
  *             Returns a LTTng channel file descriptor
+ *     LTTNG_KERNEL_SESSION_START
+ *             Starts tracing session
+ *     LTTNG_KERNEL_SESSION_STOP
+ *             Stops tracing session
+ *     LTTNG_KERNEL_METADATA
+ *             Returns a LTTng metadata file descriptor
  *
  * The returned channel will be deleted when its file descriptor is closed.
  */
@@ -452,17 +504,25 @@ 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
  *
  * 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);
        default:
                return -ENOIOCTLCMD;
        }
@@ -492,8 +552,6 @@ 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
  *
@@ -506,11 +564,11 @@ unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
        unsigned int mask = 0;
 
        if (file->f_mode & FMODE_READ) {
-               poll_wait_set_exclusive(wait);
-               poll_wait(file, &channel->notify_wait, wait);
+               init_poll_funcptr(wait, wrapper_pollwait_exclusive);
+               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_finalized(channel->chan))
                        return POLLHUP;
                else
                        return POLLIN | POLLRDNORM;
@@ -518,7 +576,6 @@ unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
        return mask;
 
 }
-#endif //0
 
 static
 int lttng_channel_release(struct inode *inode, struct file *file)
@@ -532,10 +589,7 @@ int lttng_channel_release(struct inode *inode, struct file *file)
 
 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_ioctl,
@@ -550,6 +604,37 @@ 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_STREAM
+ *              Returns an event stream file descriptor or failure.
+ *              (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 record of this event
+ */
+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);
+       default:
+               return -ENOIOCTLCMD;
+       }
+}
+
 static
 int lttng_event_release(struct inode *inode, struct file *file)
 {
@@ -563,6 +648,10 @@ int lttng_event_release(struct inode *inode, struct file *file)
 /* TODO: filter control ioctl */
 static const struct file_operations lttng_event_fops = {
        .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)