Fix: update writeback instrumentation for kernel 4.14
[lttng-modules.git] / lttng-abi.c
index beaad907d072ca5db410d8fc2a23e1feb0d17a25..77e5e9859e7f51099964f4002b932faf98531984 100644 (file)
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 #include <linux/err.h>
-#include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
-#include "wrapper/ringbuffer/vfs.h"
-#include "wrapper/ringbuffer/backend.h"
-#include "wrapper/ringbuffer/frontend.h"
-#include "wrapper/poll.h"
-#include "wrapper/file.h"
-#include "lttng-abi.h"
-#include "lttng-abi-old.h"
-#include "lttng-events.h"
-#include "lttng-tracer.h"
-#include "lib/ringbuffer/frontend_types.h"
+#include <wrapper/vmalloc.h>   /* for wrapper_vmalloc_sync_all() */
+#include <wrapper/ringbuffer/vfs.h>
+#include <wrapper/ringbuffer/backend.h>
+#include <wrapper/ringbuffer/frontend.h>
+#include <wrapper/poll.h>
+#include <wrapper/file.h>
+#include <wrapper/kref.h>
+#include <lttng-string-utils.h>
+#include <lttng-abi.h>
+#include <lttng-abi-old.h>
+#include <lttng-events.h>
+#include <lttng-tracer.h>
+#include <lib/ringbuffer/frontend_types.h>
 
 /*
  * This is LTTng's own personal way to create a system call as an external
@@ -69,6 +71,8 @@ static const struct file_operations lttng_metadata_fops;
 static const struct file_operations lttng_event_fops;
 static struct file_operations lttng_stream_ring_buffer_file_operations;
 
+static int put_u64(uint64_t val, unsigned long arg);
+
 /*
  * Teardown management: opened file descriptors keep a refcount on the module,
  * so it can only exit when all file descriptors are closed.
@@ -130,19 +134,56 @@ 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 +236,16 @@ 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);
+       case LTTNG_KERNEL_CONTEXT_INTERRUPTIBLE:
+               return lttng_add_interruptible_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE:
+               return lttng_add_need_reschedule_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_PREEMPTIBLE:
+               return lttng_add_preemptible_to_ctx(ctx);
+       case LTTNG_KERNEL_CONTEXT_MIGRATABLE:
+               return lttng_add_migratable_to_ctx(ctx);
        default:
                return -EINVAL;
        }
@@ -346,7 +397,7 @@ int lttng_abi_create_channel(struct file *session_file,
                fops = &lttng_metadata_fops;
                break;
        }
-               
+
        chan_file = anon_inode_getfile("[lttng_channel]",
                                       fops,
                                       NULL, O_RDWR);
@@ -378,6 +429,10 @@ 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 +450,12 @@ 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);
@@ -512,6 +568,10 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                return lttng_session_untrack_pid(session, (int) arg);
        case LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS:
                return lttng_session_list_tracker_pids(session);
+       case LTTNG_KERNEL_SESSION_METADATA_REGEN:
+               return lttng_session_metadata_regenerate(session);
+       case LTTNG_KERNEL_SESSION_STATEDUMP:
+               return lttng_session_statedump(session);
        default:
                return -ENOIOCTLCMD;
        }
@@ -575,9 +635,11 @@ 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;
@@ -622,6 +684,7 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
                 */
                return -ENOSYS;
        }
+       case RING_BUFFER_FLUSH_EMPTY:   /* Fall-through. */
        case RING_BUFFER_FLUSH:
        {
                struct lttng_metadata_stream *stream = filp->private_data;
@@ -637,6 +700,12 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
                        goto err;
                break;
        }
+       case RING_BUFFER_GET_METADATA_VERSION:
+       {
+               struct lttng_metadata_stream *stream = filp->private_data;
+
+               return put_u64(stream->version, arg);
+       }
        default:
                break;
        }
@@ -692,6 +761,28 @@ long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
                 */
                return -ENOSYS;
        }
+       case RING_BUFFER_FLUSH_EMPTY:   /* Fall-through. */
+       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_GET_METADATA_VERSION:
+       {
+               struct lttng_metadata_stream *stream = filp->private_data;
+
+               return put_u64(stream->version, arg);
+       }
        default:
                break;
        }
@@ -875,7 +966,6 @@ 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 +977,23 @@ int lttng_abi_open_metadata_stream(struct file *channel_file)
                goto notransport;
        }
 
+       if (!lttng_kref_get(&session->metadata_cache->refcount)) {
+               ret = -EOVERFLOW;
+               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);
@@ -941,12 +1037,22 @@ 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;
 
-               if (event_param->name[strlen(event_param->name) - 1] == '*') {
-                       enabler = lttng_enabler_create(LTTNG_ENABLER_WILDCARD,
+               if (strutils_is_star_glob_pattern(event_param->name)) {
+                       /*
+                        * If the event name is a star globbing pattern,
+                        * we create the special star globbing enabler.
+                        */
+                       enabler = lttng_enabler_create(LTTNG_ENABLER_STAR_GLOB,
                                event_param, channel);
                } else {
                        enabler = lttng_enabler_create(LTTNG_ENABLER_NAME,
@@ -972,11 +1078,11 @@ 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 +1344,8 @@ 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;
@@ -1460,6 +1566,24 @@ static long lttng_stream_ring_buffer_ioctl(struct file *filp,
                        goto error;
                return put_u64(ts, arg);
        }
+       case LTTNG_RING_BUFFER_GET_SEQ_NUM:
+       {
+               uint64_t seq;
+
+               ret = ops->sequence_number(config, buf, &seq);
+               if (ret < 0)
+                       goto error;
+               return put_u64(seq, arg);
+       }
+       case LTTNG_RING_BUFFER_INSTANCE_ID:
+       {
+               uint64_t id;
+
+               ret = ops->instance_id(config, buf, &id);
+               if (ret < 0)
+                       goto error;
+               return put_u64(id, arg);
+       }
        default:
                return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
                                cmd, arg);
@@ -1546,6 +1670,24 @@ static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
                        goto error;
                return put_u64(ts, arg);
        }
+       case LTTNG_RING_BUFFER_COMPAT_GET_SEQ_NUM:
+       {
+               uint64_t seq;
+
+               ret = ops->sequence_number(config, buf, &seq);
+               if (ret < 0)
+                       goto error;
+               return put_u64(seq, arg);
+       }
+       case LTTNG_RING_BUFFER_COMPAT_INSTANCE_ID:
+       {
+               uint64_t id;
+
+               ret = ops->instance_id(config, buf, &id);
+               if (ret < 0)
+                       goto error;
+               return put_u64(id, arg);
+       }
        default:
                return lib_ring_buffer_file_operations.compat_ioctl(filp,
                                cmd, arg);
@@ -1584,23 +1726,27 @@ int __init lttng_abi_init(void)
        int ret = 0;
 
        wrapper_vmalloc_sync_all();
+       lttng_clock_ref();
        lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
                                        &lttng_fops, NULL);
-       
+
        if (!lttng_proc_dentry) {
                printk(KERN_ERR "Error creating LTTng control file\n");
                ret = -ENOMEM;
                goto error;
        }
        lttng_stream_override_ring_buffer_fops();
+       return 0;
 
 error:
+       lttng_clock_unref();
        return ret;
 }
 
 /* No __exit annotation because used by init error path too. */
 void lttng_abi_exit(void)
 {
+       lttng_clock_unref();
        if (lttng_proc_dentry)
                remove_proc_entry("lttng", NULL);
 }
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