Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 197 insertions, 0 deletions

diff --git a/include/drm/drm_debugfs.h b/include/drm/drm_debugfs.h
new file mode 100644
index 000000000..eb93512b0
--- /dev/null
+++ b/include/drm/drm_debugfs.h
@@ -0,0 +1,197 @@
+/*
+ * Internal Header for the Direct Rendering Manager
+ *
+ * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
+ * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
+ * Copyright (c) 2009-2010, Code Aurora Forum.
+ * All rights reserved.
+ *
+ * Author: Rickard E. (Rik) Faith <faith@valinux.com>
+ * Author: Gareth Hughes <gareth@valinux.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _DRM_DEBUGFS_H_
+#define _DRM_DEBUGFS_H_
+
+#include <linux/types.h>
+#include <linux/seq_file.h>
+
+#include <drm/drm_gpuvm.h>
+
+/**
+ * DRM_DEBUGFS_GPUVA_INFO - &drm_info_list entry to dump a GPU VA space
+ * @show: the &drm_info_list's show callback
+ * @data: driver private data
+ *
+ * Drivers should use this macro to define a &drm_info_list entry to provide a
+ * debugfs file for dumping the GPU VA space regions and mappings.
+ *
+ * For each DRM GPU VA space drivers should call drm_debugfs_gpuva_info() from
+ * their @show callback.
+ */
+#define DRM_DEBUGFS_GPUVA_INFO(show, data) {"gpuvas", show, 0, data}
+
+/**
+ * struct drm_info_list - debugfs info list entry
+ *
+ * This structure represents a debugfs file to be created by the drm
+ * core.
+ */
+struct drm_info_list {
+	/** @name: file name */
+	const char *name;
+	/**
+	 * @show:
+	 *
+	 * Show callback. &seq_file->private will be set to the &struct
+	 * drm_info_node corresponding to the instance of this info on a given
+	 * &struct drm_minor.
+	 */
+	int (*show)(struct seq_file*, void*);
+	/** @driver_features: Required driver features for this entry */
+	u32 driver_features;
+	/** @data: Driver-private data, should not be device-specific. */
+	void *data;
+};
+
+/**
+ * struct drm_info_node - Per-minor debugfs node structure
+ *
+ * This structure represents a debugfs file, as an instantiation of a &struct
+ * drm_info_list on a &struct drm_minor.
+ *
+ * FIXME:
+ *
+ * No it doesn't make a hole lot of sense that we duplicate debugfs entries for
+ * both the render and the primary nodes, but that's how this has organically
+ * grown. It should probably be fixed, with a compatibility link, if needed.
+ */
+struct drm_info_node {
+	/** @minor: &struct drm_minor for this node. */
+	struct drm_minor *minor;
+	/** @info_ent: template for this node. */
+	const struct drm_info_list *info_ent;
+	/* private: */
+	struct list_head list;
+	struct dentry *dent;
+};
+
+/**
+ * struct drm_debugfs_info - debugfs info list entry
+ *
+ * This structure represents a debugfs file to be created by the drm
+ * core.
+ */
+struct drm_debugfs_info {
+	/** @name: File name */
+	const char *name;
+
+	/**
+	 * @show:
+	 *
+	 * Show callback. &seq_file->private will be set to the &struct
+	 * drm_debugfs_entry corresponding to the instance of this info
+	 * on a given &struct drm_device.
+	 */
+	int (*show)(struct seq_file*, void*);
+
+	/** @driver_features: Required driver features for this entry. */
+	u32 driver_features;
+
+	/** @data: Driver-private data, should not be device-specific. */
+	void *data;
+};
+
+/**
+ * struct drm_debugfs_entry - Per-device debugfs node structure
+ *
+ * This structure represents a debugfs file, as an instantiation of a &struct
+ * drm_debugfs_info on a &struct drm_device.
+ */
+struct drm_debugfs_entry {
+	/** @dev: &struct drm_device for this node. */
+	struct drm_device *dev;
+
+	/** @file: Template for this node. */
+	struct drm_debugfs_info file;
+
+	/** @list: Linked list of all device nodes. */
+	struct list_head list;
+};
+
+#if defined(CONFIG_DEBUG_FS)
+void drm_debugfs_create_files(const struct drm_info_list *files,
+			      int count, struct dentry *root,
+			      struct drm_minor *minor);
+int drm_debugfs_remove_files(const struct drm_info_list *files, int count,
+			     struct dentry *root, struct drm_minor *minor);
+
+void drm_debugfs_add_file(struct drm_device *dev, const char *name,
+			  int (*show)(struct seq_file*, void*), void *data);
+
+void drm_debugfs_add_files(struct drm_device *dev,
+			   const struct drm_debugfs_info *files, int count);
+
+int drm_debugfs_gpuva_info(struct seq_file *m,
+			   struct drm_gpuvm *gpuvm);
+
+void drm_debugfs_clients_add(struct drm_file *file);
+void drm_debugfs_clients_remove(struct drm_file *file);
+#else
+static inline void drm_debugfs_create_files(const struct drm_info_list *files,
+					    int count, struct dentry *root,
+					    struct drm_minor *minor)
+{}
+
+static inline int drm_debugfs_remove_files(const struct drm_info_list *files,
+					   int count, struct dentry *root,
+					   struct drm_minor *minor)
+{
+	return 0;
+}
+
+static inline void drm_debugfs_add_file(struct drm_device *dev, const char *name,
+					int (*show)(struct seq_file*, void*),
+					void *data)
+{}
+
+static inline void drm_debugfs_add_files(struct drm_device *dev,
+					 const struct drm_debugfs_info *files,
+					 int count)
+{}
+
+static inline int drm_debugfs_gpuva_info(struct seq_file *m,
+					 struct drm_gpuvm *gpuvm)
+{
+	return 0;
+}
+
+static inline void drm_debugfs_clients_add(struct drm_file *file)
+{
+}
+
+static inline void drm_debugfs_clients_remove(struct drm_file *file)
+{
+}
+#endif
+
+#endif /* _DRM_DEBUGFS_H_ */