Version 2.7.7

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

diff --git a/lttng-abi.c b/lttng-abi.c
index beaad907d072ca5db410d8fc2a23e1feb0d17a25..9400f5374aad7ce1510e7db59bcc423568b50448 100644 (file)
--- a/lttng-abi.c
+++ b/lttng-abi.c
@@ -50,6 +50,7 @@
 #include "wrapper/ringbuffer/frontend.h"
 #include "wrapper/poll.h"
 #include "wrapper/file.h"
+#include "wrapper/kref.h"
 #include "lttng-abi.h"
 #include "lttng-abi-old.h"
 #include "lttng-events.h"
@@ -130,19 +131,56 @@ int lttng_abi_tracepoint_list(void)
        if (ret < 0)
                goto open_error;
        fd_install(file_fd, tracepoint_list_file);
+       return file_fd;
+
+open_error:
+       fput(tracepoint_list_file);
+file_error:
+       put_unused_fd(file_fd);
+fd_error:
+       return ret;
+}
+
+#ifndef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+static inline
+int lttng_abi_syscall_list(void)
+{
+       return -ENOSYS;
+}
+#else
+static
+int lttng_abi_syscall_list(void)
+{
+       struct file *syscall_list_file;
+       int file_fd, ret;
+
+       file_fd = lttng_get_unused_fd();
        if (file_fd < 0) {
                ret = file_fd;
                goto fd_error;
        }
+
+       syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
+                                         &lttng_syscall_list_fops,
+                                         NULL, O_RDWR);
+       if (IS_ERR(syscall_list_file)) {
+               ret = PTR_ERR(syscall_list_file);
+               goto file_error;
+       }
+       ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
+       if (ret < 0)
+               goto open_error;
+       fd_install(file_fd, syscall_list_file);
        return file_fd;
 
 open_error:
-       fput(tracepoint_list_file);
+       fput(syscall_list_file);
 file_error:
        put_unused_fd(file_fd);
 fd_error:
        return ret;
 }
+#endif
 
 static
 void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
@@ -195,6 +233,8 @@ long lttng_abi_add_context(struct file *file,
                return lttng_add_procname_to_ctx(ctx);
        case LTTNG_KERNEL_CONTEXT_HOSTNAME:
                return lttng_add_hostname_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_CPU_ID:
+               return lttng_add_cpu_id_to_ctx(ctx);
        default:
                return -EINVAL;
        }
@@ -378,6 +418,10 @@ int lttng_abi_create_channel(struct file *session_file,
                transport_name = "<unknown>";
                break;
        }
+       if (atomic_long_add_unless(&session_file->f_count,
+               1, INT_MAX) == INT_MAX) {
+               goto refcount_error;
+       }
        /*
         * We tolerate no failure path after channel creation. It will stay
         * invariant for the rest of the session.
@@ -395,11 +439,12 @@ int lttng_abi_create_channel(struct file *session_file,
        chan->file = chan_file;
        chan_file->private_data = chan;
        fd_install(chan_fd, chan_file);
-       atomic_long_inc(&session_file->f_count);
 
        return chan_fd;
 
 chan_error:
+       atomic_long_dec(&session_file->f_count);
+refcount_error:
        fput(chan_file);
 file_error:
        put_unused_fd(chan_fd);
@@ -575,9 +620,11 @@ unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
                if (finalized)
                        mask |= POLLHUP;
 
+               mutex_lock(&stream->metadata_cache->lock);
                if (stream->metadata_cache->metadata_written >
                                stream->metadata_out)
                        mask |= POLLIN;
+               mutex_unlock(&stream->metadata_cache->lock);
        }
 
        return mask;
@@ -637,6 +684,18 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
                        goto err;
                break;
        }
+       case RING_BUFFER_SNAPSHOT:
+       {
+               /*
+                * Force the buffer to quiescent so the ring buffer
+                * don't attempt to perform a SWITCH_FLUSH, which would
+                * desynchronize the client accounting of the amount of
+                * data available in the buffer from the ring buffer
+                * view.
+                */
+               buf->quiescent = true;
+               break;
+       }
        default:
                break;
        }
@@ -692,6 +751,33 @@ long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
                 */
                return -ENOSYS;
        }
+       case RING_BUFFER_FLUSH:
+       {
+               struct lttng_metadata_stream *stream = filp->private_data;
+               struct lib_ring_buffer *buf = stream->priv;
+               struct channel *chan = buf->backend.chan;
+
+               /*
+                * Before doing the actual ring buffer flush, write up to one
+                * packet of metadata in the ring buffer.
+                */
+               ret = lttng_metadata_output_channel(stream, chan);
+               if (ret < 0)
+                       goto err;
+               break;
+       }
+       case RING_BUFFER_SNAPSHOT:
+       {
+               /*
+                * Force the buffer to quiescent so the ring buffer
+                * don't attempt to perform a SWITCH_FLUSH, which would
+                * desynchronize the client accounting of the amount of
+                * data available in the buffer from the ring buffer
+                * view.
+                */
+               buf->quiescent = true;
+               break;
+       }
        default:
                break;
        }
@@ -875,7 +961,6 @@ int lttng_abi_open_metadata_stream(struct file *channel_file)
        metadata_stream->priv = buf;
        stream_priv = metadata_stream;
        metadata_stream->transport = channel->transport;
-       mutex_init(&metadata_stream->lock);
 
        /*
         * Since life-time of metadata cache differs from that of
@@ -887,17 +972,20 @@ int lttng_abi_open_metadata_stream(struct file *channel_file)
                goto notransport;
        }
 
+       if (!lttng_kref_get(&session->metadata_cache->refcount))
+               goto kref_error;
        ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
                        &lttng_metadata_ring_buffer_file_operations);
        if (ret < 0)
                goto fd_error;
 
-       kref_get(&session->metadata_cache->refcount);
        list_add(&metadata_stream->list,
                &session->metadata_cache->metadata_stream);
        return ret;
 
 fd_error:
+       kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
+kref_error:
        module_put(metadata_stream->transport->owner);
 notransport:
        kfree(metadata_stream);
@@ -941,6 +1029,12 @@ int lttng_abi_create_event(struct file *channel_file,
                ret = PTR_ERR(event_file);
                goto file_error;
        }
+       /* The event holds a reference on the channel */
+       if (atomic_long_add_unless(&channel_file->f_count,
+               1, INT_MAX) == INT_MAX) {
+               ret = -EOVERFLOW;
+               goto refcount_error;
+       }
        if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
                        || event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
                struct lttng_enabler *enabler;
@@ -972,11 +1066,11 @@ int lttng_abi_create_event(struct file *channel_file,
        }
        event_file->private_data = priv;
        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:
+       atomic_long_dec(&channel_file->f_count);
+refcount_error:
        fput(event_file);
 file_error:
        put_unused_fd(event_fd);
@@ -1238,8 +1332,8 @@ int lttng_metadata_channel_release(struct inode *inode, struct file *file)
        struct lttng_channel *channel = file->private_data;
 
        if (channel) {
-               lttng_metadata_channel_destroy(channel);
                fput(channel->session->file);
+               lttng_metadata_channel_destroy(channel);
        }
 
        return 0;