Fix: rcu: Fix data-race due to atomic_t copy-by-value (5.5.6, 5.4.22)

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

diff --git a/lttng-abi.c b/lttng-abi.c
index 4dd9273f1eb9a0551d343dfd7706b0893f45fb2d..811becf6fe023d487e95f67cd0db77fedac22cc4 100644 (file)
--- a/lttng-abi.c
+++ b/lttng-abi.c
@@ -51,10 +51,12 @@
 #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 <lttng-tp-mempool.h>
 #include <lib/ringbuffer/frontend_types.h>
 
 /*
@@ -63,7 +65,13 @@
  */
 
 static struct proc_dir_entry *lttng_proc_dentry;
-static const struct file_operations lttng_fops;
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
+static const struct proc_ops lttng_proc_ops;
+#else
+static const struct file_operations lttng_proc_ops;
+#endif
+
 static const struct file_operations lttng_session_fops;
 static const struct file_operations lttng_channel_fops;
 static const struct file_operations lttng_metadata_fops;
@@ -362,13 +370,22 @@ long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        }
 }
 
-static const struct file_operations lttng_fops = {
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
+static const struct proc_ops lttng_proc_ops = {
+       .proc_ioctl = lttng_ioctl,
+#ifdef CONFIG_COMPAT
+       .proc_compat_ioctl = lttng_ioctl,
+#endif /* CONFIG_COMPAT */
+};
+#else
+static const struct file_operations lttng_proc_ops = {
        .owner = THIS_MODULE,
        .unlocked_ioctl = lttng_ioctl,
 #ifdef CONFIG_COMPAT
        .compat_ioctl = lttng_ioctl,
-#endif
+#endif /* CONFIG_COMPAT */
 };
+#endif
 
 static
 int lttng_abi_create_channel(struct file *session_file,
@@ -396,7 +413,7 @@ 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);
@@ -428,8 +445,8 @@ 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) {
+       if (!atomic_long_add_unless(&session_file->f_count, 1, LONG_MAX)) {
+               ret = -EOVERFLOW;
                goto refcount_error;
        }
        /*
@@ -489,13 +506,12 @@ static
 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
        struct lttng_session *session = file->private_data;
+       struct lttng_kernel_channel chan_param;
+       struct lttng_kernel_old_channel old_chan_param;
 
        switch (cmd) {
        case LTTNG_KERNEL_OLD_CHANNEL:
        {
-               struct lttng_kernel_channel chan_param;
-               struct lttng_kernel_old_channel old_chan_param;
-
                if (copy_from_user(&old_chan_param,
                                (struct lttng_kernel_old_channel __user *) arg,
                                sizeof(struct lttng_kernel_old_channel)))
@@ -512,8 +528,6 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        }
        case LTTNG_KERNEL_CHANNEL:
        {
-               struct lttng_kernel_channel chan_param;
-
                if (copy_from_user(&chan_param,
                                (struct lttng_kernel_channel __user *) arg,
                                sizeof(struct lttng_kernel_channel)))
@@ -533,9 +547,6 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                return lttng_session_disable(session);
        case LTTNG_KERNEL_OLD_METADATA:
        {
-               struct lttng_kernel_channel chan_param;
-               struct lttng_kernel_old_channel old_chan_param;
-
                if (copy_from_user(&old_chan_param,
                                (struct lttng_kernel_old_channel __user *) arg,
                                sizeof(struct lttng_kernel_old_channel)))
@@ -552,8 +563,6 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        }
        case LTTNG_KERNEL_METADATA:
        {
-               struct lttng_kernel_channel chan_param;
-
                if (copy_from_user(&chan_param,
                                        (struct lttng_kernel_channel __user *) arg,
                                        sizeof(struct lttng_kernel_channel)))
@@ -569,6 +578,8 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                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;
        }
@@ -681,6 +692,7 @@ 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;
@@ -702,18 +714,6 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 
                return put_u64(stream->version, arg);
        }
-       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;
        }
@@ -769,6 +769,7 @@ 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;
@@ -790,18 +791,6 @@ long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 
                return put_u64(stream->version, arg);
        }
-       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;
        }
@@ -996,8 +985,11 @@ int lttng_abi_open_metadata_stream(struct file *channel_file)
                goto notransport;
        }
 
-       if (!lttng_kref_get(&session->metadata_cache->refcount))
+       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)
@@ -1054,8 +1046,7 @@ int lttng_abi_create_event(struct file *channel_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) {
+       if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
                ret = -EOVERFLOW;
                goto refcount_error;
        }
@@ -1063,8 +1054,12 @@ int lttng_abi_create_event(struct file *channel_file,
                        || 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,
@@ -1739,9 +1734,15 @@ int __init lttng_abi_init(void)
 
        wrapper_vmalloc_sync_all();
        lttng_clock_ref();
+
+       ret = lttng_tp_mempool_init();
+       if (ret) {
+               goto error;
+       }
+
        lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
-                                       &lttng_fops, NULL);
-       
+                                       &lttng_proc_ops, NULL);
+
        if (!lttng_proc_dentry) {
                printk(KERN_ERR "Error creating LTTng control file\n");
                ret = -ENOMEM;
@@ -1751,6 +1752,7 @@ int __init lttng_abi_init(void)
        return 0;
 
 error:
+       lttng_tp_mempool_destroy();
        lttng_clock_unref();
        return ret;
 }
@@ -1758,6 +1760,7 @@ error:
 /* No __exit annotation because used by init error path too. */
 void lttng_abi_exit(void)
 {
+       lttng_tp_mempool_destroy();
        lttng_clock_unref();
        if (lttng_proc_dentry)
                remove_proc_entry("lttng", NULL);