Merge branch 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[sfrench/cifs-2.6.git] / kernel / trace / trace.c

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 77c2d9bcb40f9d75d85a4caa7923906260216fa9..0029fe62b2450361923ebb93346206cded759a09 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -260,16 +260,8 @@ unsigned long long ns2usecs(u64 nsec)
        TRACE_ITER_EVENT_FORK
 
 /*
- * The global_trace is the descriptor that holds the tracing
- * buffers for the live tracing. For each CPU, it contains
- * a link list of pages that will store trace entries. The
- * page descriptor of the pages in the memory is used to hold
- * the link list by linking the lru item in the page descriptor
- * to each of the pages in the buffer per CPU.
- *
- * For each active CPU there is a data field that holds the
- * pages for the buffer for that CPU. Each CPU has the same number
- * of pages allocated for its buffer.
+ * The global_trace is the descriptor that holds the top-level tracing
+ * buffers for the live tracing.
  */
 static struct trace_array global_trace = {
        .trace_flags = TRACE_DEFAULT_FLAGS,
@@ -1193,6 +1185,7 @@ int trace_parser_get_init(struct trace_parser *parser, int size)
 void trace_parser_put(struct trace_parser *parser)
 {
        kfree(parser->buffer);
+       parser->buffer = NULL;
 }
 
 /*
@@ -4348,22 +4341,23 @@ static const char readme_msg[] =
        "\t\t\t  traces\n"
 #endif
 #endif /* CONFIG_STACK_TRACER */
-#ifdef CONFIG_KPROBE_EVENT
+#ifdef CONFIG_KPROBE_EVENTS
        "  kprobe_events\t\t- Add/remove/show the kernel dynamic events\n"
        "\t\t\t  Write into this file to define/undefine new trace events.\n"
 #endif
-#ifdef CONFIG_UPROBE_EVENT
+#ifdef CONFIG_UPROBE_EVENTS
        "  uprobe_events\t\t- Add/remove/show the userspace dynamic events\n"
        "\t\t\t  Write into this file to define/undefine new trace events.\n"
 #endif
-#if defined(CONFIG_KPROBE_EVENT) || defined(CONFIG_UPROBE_EVENT)
+#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
        "\t  accepts: event-definitions (one definition per line)\n"
        "\t   Format: p|r[:[<group>/]<event>] <place> [<args>]\n"
        "\t           -:[<group>/]<event>\n"
-#ifdef CONFIG_KPROBE_EVENT
+#ifdef CONFIG_KPROBE_EVENTS
        "\t    place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
+  "place (kretprobe): [<module>:]<symbol>[+<offset>]|<memaddr>\n"
 #endif
-#ifdef CONFIG_UPROBE_EVENT
+#ifdef CONFIG_UPROBE_EVENTS
        "\t    place: <path>:<offset>\n"
 #endif
        "\t     args: <name>=fetcharg[:type]\n"
@@ -6738,11 +6732,13 @@ ftrace_trace_snapshot_callback(struct ftrace_hash *hash,
                return ret;
 
  out_reg:
-       ret = register_ftrace_function_probe(glob, ops, count);
+       ret = alloc_snapshot(&global_trace);
+       if (ret < 0)
+               goto out;
 
-       if (ret >= 0)
-               alloc_snapshot(&global_trace);
+       ret = register_ftrace_function_probe(glob, ops, count);
 
+ out:
        return ret < 0 ? ret : 0;
 }
 
@@ -7407,6 +7403,7 @@ static int instance_rmdir(const char *name)
 
        tracing_set_nop(tr);
        event_trace_del_tracer(tr);
+       ftrace_clear_pids(tr);
        ftrace_destroy_function_files(tr);
        tracefs_remove_recursive(tr->dir);
        free_trace_buffers(tr);
@@ -7501,7 +7498,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
        ftrace_init_tracefs(tr, d_tracer);
 }
 
-static struct vfsmount *trace_automount(void *ingore)
+static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore)
 {
        struct vfsmount *mnt;
        struct file_system_type *type;
@@ -7514,7 +7511,7 @@ static struct vfsmount *trace_automount(void *ingore)
        type = get_fs_type("tracefs");
        if (!type)
                return NULL;
-       mnt = vfs_kern_mount(type, 0, "tracefs", NULL);
+       mnt = vfs_submount(mntpt, type, "tracefs", NULL);
        put_filesystem(type);
        if (IS_ERR(mnt))
                return NULL;