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, 328 insertions, 0 deletions

diff --git a/include/drm/drm_framebuffer.h b/include/drm/drm_framebuffer.h
new file mode 100644
index 000000000..38b24fc89
--- /dev/null
+++ b/include/drm/drm_framebuffer.h
@@ -0,0 +1,328 @@
+/*
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifndef __DRM_FRAMEBUFFER_H__
+#define __DRM_FRAMEBUFFER_H__
+
+#include <linux/bits.h>
+#include <linux/ctype.h>
+#include <linux/list.h>
+#include <linux/sched.h>
+
+#include <drm/drm_fourcc.h>
+#include <drm/drm_mode_object.h>
+
+struct drm_clip_rect;
+struct drm_device;
+struct drm_file;
+struct drm_framebuffer;
+struct drm_gem_object;
+
+/**
+ * struct drm_framebuffer_funcs - framebuffer hooks
+ */
+struct drm_framebuffer_funcs {
+	/**
+	 * @destroy:
+	 *
+	 * Clean up framebuffer resources, specifically also unreference the
+	 * backing storage. The core guarantees to call this function for every
+	 * framebuffer successfully created by calling
+	 * &drm_mode_config_funcs.fb_create. Drivers must also call
+	 * drm_framebuffer_cleanup() to release DRM core resources for this
+	 * framebuffer.
+	 */
+	void (*destroy)(struct drm_framebuffer *framebuffer);
+
+	/**
+	 * @create_handle:
+	 *
+	 * Create a buffer handle in the driver-specific buffer manager (either
+	 * GEM or TTM) valid for the passed-in &struct drm_file. This is used by
+	 * the core to implement the GETFB IOCTL, which returns (for
+	 * sufficiently priviledged user) also a native buffer handle. This can
+	 * be used for seamless transitions between modesetting clients by
+	 * copying the current screen contents to a private buffer and blending
+	 * between that and the new contents.
+	 *
+	 * GEM based drivers should call drm_gem_handle_create() to create the
+	 * handle.
+	 *
+	 * RETURNS:
+	 *
+	 * 0 on success or a negative error code on failure.
+	 */
+	int (*create_handle)(struct drm_framebuffer *fb,
+			     struct drm_file *file_priv,
+			     unsigned int *handle);
+	/**
+	 * @dirty:
+	 *
+	 * Optional callback for the dirty fb IOCTL.
+	 *
+	 * Userspace can notify the driver via this callback that an area of the
+	 * framebuffer has changed and should be flushed to the display
+	 * hardware. This can also be used internally, e.g. by the fbdev
+	 * emulation, though that's not the case currently.
+	 *
+	 * See documentation in drm_mode.h for the struct drm_mode_fb_dirty_cmd
+	 * for more information as all the semantics and arguments have a one to
+	 * one mapping on this function.
+	 *
+	 * Atomic drivers should use drm_atomic_helper_dirtyfb() to implement
+	 * this hook.
+	 *
+	 * RETURNS:
+	 *
+	 * 0 on success or a negative error code on failure.
+	 */
+	int (*dirty)(struct drm_framebuffer *framebuffer,
+		     struct drm_file *file_priv, unsigned flags,
+		     unsigned color, struct drm_clip_rect *clips,
+		     unsigned num_clips);
+};
+
+#define DRM_FRAMEBUFFER_HAS_HANDLE_REF(_i)	BIT(0u + (_i))
+
+/**
+ * struct drm_framebuffer - frame buffer object
+ *
+ * Note that the fb is refcounted for the benefit of driver internals,
+ * for example some hw, disabling a CRTC/plane is asynchronous, and
+ * scanout does not actually complete until the next vblank.  So some
+ * cleanup (like releasing the reference(s) on the backing GEM bo(s))
+ * should be deferred.  In cases like this, the driver would like to
+ * hold a ref to the fb even though it has already been removed from
+ * userspace perspective. See drm_framebuffer_get() and
+ * drm_framebuffer_put().
+ *
+ * The refcount is stored inside the mode object @base.
+ */
+struct drm_framebuffer {
+	/**
+	 * @dev: DRM device this framebuffer belongs to
+	 */
+	struct drm_device *dev;
+	/**
+	 * @head: Place on the &drm_mode_config.fb_list, access protected by
+	 * &drm_mode_config.fb_lock.
+	 */
+	struct list_head head;
+
+	/**
+	 * @base: base modeset object structure, contains the reference count.
+	 */
+	struct drm_mode_object base;
+
+	/**
+	 * @comm: Name of the process allocating the fb, used for fb dumping.
+	 */
+	char comm[TASK_COMM_LEN];
+
+	/**
+	 * @format: framebuffer format information
+	 */
+	const struct drm_format_info *format;
+	/**
+	 * @funcs: framebuffer vfunc table
+	 */
+	const struct drm_framebuffer_funcs *funcs;
+	/**
+	 * @pitches: Line stride per buffer. For userspace created object this
+	 * is copied from drm_mode_fb_cmd2.
+	 */
+	unsigned int pitches[DRM_FORMAT_MAX_PLANES];
+	/**
+	 * @offsets: Offset from buffer start to the actual pixel data in bytes,
+	 * per buffer. For userspace created object this is copied from
+	 * drm_mode_fb_cmd2.
+	 *
+	 * Note that this is a linear offset and does not take into account
+	 * tiling or buffer layout per @modifier. It is meant to be used when
+	 * the actual pixel data for this framebuffer plane starts at an offset,
+	 * e.g. when multiple planes are allocated within the same backing
+	 * storage buffer object. For tiled layouts this generally means its
+	 * @offsets must at least be tile-size aligned, but hardware often has
+	 * stricter requirements.
+	 *
+	 * This should not be used to specifiy x/y pixel offsets into the buffer
+	 * data (even for linear buffers). Specifying an x/y pixel offset is
+	 * instead done through the source rectangle in &struct drm_plane_state.
+	 */
+	unsigned int offsets[DRM_FORMAT_MAX_PLANES];
+	/**
+	 * @modifier: Data layout modifier. This is used to describe
+	 * tiling, or also special layouts (like compression) of auxiliary
+	 * buffers. For userspace created object this is copied from
+	 * drm_mode_fb_cmd2.
+	 */
+	uint64_t modifier;
+	/**
+	 * @width: Logical width of the visible area of the framebuffer, in
+	 * pixels.
+	 */
+	unsigned int width;
+	/**
+	 * @height: Logical height of the visible area of the framebuffer, in
+	 * pixels.
+	 */
+	unsigned int height;
+	/**
+	 * @flags: Framebuffer flags like DRM_MODE_FB_INTERLACED or
+	 * DRM_MODE_FB_MODIFIERS.
+	 */
+	int flags;
+	/**
+	 * @internal_flags: Framebuffer flags like DRM_FRAMEBUFFER_HAS_HANDLE_REF.
+	 */
+	unsigned int internal_flags;
+	/**
+	 * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock.
+	 */
+	struct list_head filp_head;
+	/**
+	 * @obj: GEM objects backing the framebuffer, one per plane (optional).
+	 *
+	 * This is used by the GEM framebuffer helpers, see e.g.
+	 * drm_gem_fb_create().
+	 */
+	struct drm_gem_object *obj[DRM_FORMAT_MAX_PLANES];
+};
+
+#define obj_to_fb(x) container_of(x, struct drm_framebuffer, base)
+
+int drm_framebuffer_init(struct drm_device *dev,
+			 struct drm_framebuffer *fb,
+			 const struct drm_framebuffer_funcs *funcs);
+struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
+					       struct drm_file *file_priv,
+					       uint32_t id);
+void drm_framebuffer_remove(struct drm_framebuffer *fb);
+void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
+void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
+
+/**
+ * drm_framebuffer_get - acquire a framebuffer reference
+ * @fb: DRM framebuffer
+ *
+ * This function increments the framebuffer's reference count.
+ */
+static inline void drm_framebuffer_get(struct drm_framebuffer *fb)
+{
+	drm_mode_object_get(&fb->base);
+}
+
+/**
+ * drm_framebuffer_put - release a framebuffer reference
+ * @fb: DRM framebuffer
+ *
+ * This function decrements the framebuffer's reference count and frees the
+ * framebuffer if the reference count drops to zero.
+ */
+static inline void drm_framebuffer_put(struct drm_framebuffer *fb)
+{
+	drm_mode_object_put(&fb->base);
+}
+
+/**
+ * drm_framebuffer_read_refcount - read the framebuffer reference count.
+ * @fb: framebuffer
+ *
+ * This functions returns the framebuffer's reference count.
+ */
+static inline uint32_t drm_framebuffer_read_refcount(const struct drm_framebuffer *fb)
+{
+	return kref_read(&fb->base.refcount);
+}
+
+/**
+ * drm_framebuffer_assign - store a reference to the fb
+ * @p: location to store framebuffer
+ * @fb: new framebuffer (maybe NULL)
+ *
+ * This functions sets the location to store a reference to the framebuffer,
+ * unreferencing the framebuffer that was previously stored in that location.
+ */
+static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
+					  struct drm_framebuffer *fb)
+{
+	if (fb)
+		drm_framebuffer_get(fb);
+	if (*p)
+		drm_framebuffer_put(*p);
+	*p = fb;
+}
+
+/*
+ * drm_for_each_fb - iterate over all framebuffers
+ * @fb: the loop cursor
+ * @dev: the DRM device
+ *
+ * Iterate over all framebuffers of @dev. User must hold
+ * &drm_mode_config.fb_lock.
+ */
+#define drm_for_each_fb(fb, dev) \
+	for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)),		\
+	     fb = list_first_entry(&(dev)->mode_config.fb_list,	\
+					  struct drm_framebuffer, head);	\
+	     &fb->head != (&(dev)->mode_config.fb_list);			\
+	     fb = list_next_entry(fb, head))
+
+/**
+ * struct drm_afbc_framebuffer - a special afbc frame buffer object
+ *
+ * A derived class of struct drm_framebuffer, dedicated for afbc use cases.
+ */
+struct drm_afbc_framebuffer {
+	/**
+	 * @base: base framebuffer structure.
+	 */
+	struct drm_framebuffer base;
+	/**
+	 * @block_width: width of a single afbc block
+	 */
+	u32 block_width;
+	/**
+	 * @block_height: height of a single afbc block
+	 */
+	u32 block_height;
+	/**
+	 * @aligned_width: aligned frame buffer width
+	 */
+	u32 aligned_width;
+	/**
+	 * @aligned_height: aligned frame buffer height
+	 */
+	u32 aligned_height;
+	/**
+	 * @offset: offset of the first afbc header
+	 */
+	u32 offset;
+	/**
+	 * @afbc_size: minimum size of afbc buffer
+	 */
+	u32 afbc_size;
+};
+
+#define fb_to_afbc_fb(x) container_of(x, struct drm_afbc_framebuffer, base)
+
+#endif