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, 350 insertions, 0 deletions

diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h
new file mode 100644
index 000000000..eded7c344
--- /dev/null
+++ b/include/drm/drm_encoder.h
@@ -0,0 +1,350 @@
+/*
+ * 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_ENCODER_H__
+#define __DRM_ENCODER_H__
+
+#include <linux/list.h>
+#include <linux/ctype.h>
+#include <linux/mutex.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mode.h>
+#include <drm/drm_mode_object.h>
+#include <drm/drm_util.h>
+
+struct drm_encoder;
+
+/**
+ * struct drm_encoder_funcs - encoder controls
+ *
+ * Encoders sit between CRTCs and connectors.
+ */
+struct drm_encoder_funcs {
+	/**
+	 * @reset:
+	 *
+	 * Reset encoder hardware and software state to off. This function isn't
+	 * called by the core directly, only through drm_mode_config_reset().
+	 * It's not a helper hook only for historical reasons.
+	 */
+	void (*reset)(struct drm_encoder *encoder);
+
+	/**
+	 * @destroy:
+	 *
+	 * Clean up encoder resources. This is only called at driver unload time
+	 * through drm_mode_config_cleanup() since an encoder cannot be
+	 * hotplugged in DRM.
+	 */
+	void (*destroy)(struct drm_encoder *encoder);
+
+	/**
+	 * @late_register:
+	 *
+	 * This optional hook can be used to register additional userspace
+	 * interfaces attached to the encoder.
+	 * It is called late in the driver load sequence from drm_dev_register().
+	 * Everything added from this callback should be unregistered in
+	 * the early_unregister callback.
+	 *
+	 * Returns:
+	 *
+	 * 0 on success, or a negative error code on failure.
+	 */
+	int (*late_register)(struct drm_encoder *encoder);
+
+	/**
+	 * @early_unregister:
+	 *
+	 * This optional hook should be used to unregister the additional
+	 * userspace interfaces attached to the encoder from
+	 * @late_register. It is called from drm_dev_unregister(),
+	 * early in the driver unload sequence to disable userspace access
+	 * before data structures are torndown.
+	 */
+	void (*early_unregister)(struct drm_encoder *encoder);
+
+	/**
+	 * @debugfs_init:
+	 *
+	 * Allows encoders to create encoder-specific debugfs files.
+	 */
+	void (*debugfs_init)(struct drm_encoder *encoder, struct dentry *root);
+};
+
+/**
+ * struct drm_encoder - central DRM encoder structure
+ * @dev: parent DRM device
+ * @head: list management
+ * @base: base KMS object
+ * @name: human readable name, can be overwritten by the driver
+ * @funcs: control functions, can be NULL for simple managed encoders
+ * @helper_private: mid-layer private data
+ *
+ * CRTCs drive pixels to encoders, which convert them into signals
+ * appropriate for a given connector or set of connectors.
+ */
+struct drm_encoder {
+	struct drm_device *dev;
+	struct list_head head;
+
+	struct drm_mode_object base;
+	char *name;
+	/**
+	 * @encoder_type:
+	 *
+	 * One of the DRM_MODE_ENCODER_<foo> types in drm_mode.h. The following
+	 * encoder types are defined thus far:
+	 *
+	 * - DRM_MODE_ENCODER_DAC for VGA and analog on DVI-I/DVI-A.
+	 *
+	 * - DRM_MODE_ENCODER_TMDS for DVI, HDMI and (embedded) DisplayPort.
+	 *
+	 * - DRM_MODE_ENCODER_LVDS for display panels, or in general any panel
+	 *   with a proprietary parallel connector.
+	 *
+	 * - DRM_MODE_ENCODER_TVDAC for TV output (Composite, S-Video,
+	 *   Component, SCART).
+	 *
+	 * - DRM_MODE_ENCODER_VIRTUAL for virtual machine displays
+	 *
+	 * - DRM_MODE_ENCODER_DSI for panels connected using the DSI serial bus.
+	 *
+	 * - DRM_MODE_ENCODER_DPI for panels connected using the DPI parallel
+	 *   bus.
+	 *
+	 * - DRM_MODE_ENCODER_DPMST for special fake encoders used to allow
+	 *   mutliple DP MST streams to share one physical encoder.
+	 */
+	int encoder_type;
+
+	/**
+	 * @index: Position inside the mode_config.list, can be used as an array
+	 * index. It is invariant over the lifetime of the encoder.
+	 */
+	unsigned index;
+
+	/**
+	 * @possible_crtcs: Bitmask of potential CRTC bindings, using
+	 * drm_crtc_index() as the index into the bitfield. The driver must set
+	 * the bits for all &drm_crtc objects this encoder can be connected to
+	 * before calling drm_dev_register().
+	 *
+	 * You will get a WARN if you get this wrong in the driver.
+	 *
+	 * Note that since CRTC objects can't be hotplugged the assigned indices
+	 * are stable and hence known before registering all objects.
+	 */
+	uint32_t possible_crtcs;
+
+	/**
+	 * @possible_clones: Bitmask of potential sibling encoders for cloning,
+	 * using drm_encoder_index() as the index into the bitfield. The driver
+	 * must set the bits for all &drm_encoder objects which can clone a
+	 * &drm_crtc together with this encoder before calling
+	 * drm_dev_register(). Drivers should set the bit representing the
+	 * encoder itself, too. Cloning bits should be set such that when two
+	 * encoders can be used in a cloned configuration, they both should have
+	 * each another bits set.
+	 *
+	 * As an exception to the above rule if the driver doesn't implement
+	 * any cloning it can leave @possible_clones set to 0. The core will
+	 * automagically fix this up by setting the bit for the encoder itself.
+	 *
+	 * You will get a WARN if you get this wrong in the driver.
+	 *
+	 * Note that since encoder objects can't be hotplugged the assigned indices
+	 * are stable and hence known before registering all objects.
+	 */
+	uint32_t possible_clones;
+
+	/**
+	 * @crtc: Currently bound CRTC, only really meaningful for non-atomic
+	 * drivers.  Atomic drivers should instead check
+	 * &drm_connector_state.crtc.
+	 */
+	struct drm_crtc *crtc;
+
+	/**
+	 * @bridge_chain: Bridges attached to this encoder. Drivers shall not
+	 * access this field directly.
+	 */
+	struct list_head bridge_chain;
+
+	/** @bridge_chain_mutex: protect bridge_chain from changes while iterating */
+	struct mutex bridge_chain_mutex;
+
+	const struct drm_encoder_funcs *funcs;
+	const struct drm_encoder_helper_funcs *helper_private;
+
+	/**
+	 * @debugfs_entry:
+	 *
+	 * Debugfs directory for this CRTC.
+	 */
+	struct dentry *debugfs_entry;
+};
+
+#define obj_to_encoder(x) container_of(x, struct drm_encoder, base)
+
+__printf(5, 6)
+int drm_encoder_init(struct drm_device *dev,
+		     struct drm_encoder *encoder,
+		     const struct drm_encoder_funcs *funcs,
+		     int encoder_type, const char *name, ...);
+
+__printf(5, 6)
+int drmm_encoder_init(struct drm_device *dev,
+		      struct drm_encoder *encoder,
+		      const struct drm_encoder_funcs *funcs,
+		      int encoder_type, const char *name, ...);
+
+__printf(6, 7)
+void *__drmm_encoder_alloc(struct drm_device *dev,
+			   size_t size, size_t offset,
+			   const struct drm_encoder_funcs *funcs,
+			   int encoder_type,
+			   const char *name, ...);
+
+/**
+ * drmm_encoder_alloc - Allocate and initialize an encoder
+ * @dev: drm device
+ * @type: the type of the struct which contains struct &drm_encoder
+ * @member: the name of the &drm_encoder within @type
+ * @funcs: callbacks for this encoder (optional)
+ * @encoder_type: user visible type of the encoder
+ * @name: printf style format string for the encoder name, or NULL for default name
+ *
+ * Allocates and initializes an encoder. Encoder should be subclassed as part of
+ * driver encoder objects. Cleanup is automatically handled through registering
+ * drm_encoder_cleanup() with drmm_add_action().
+ *
+ * The @drm_encoder_funcs.destroy hook must be NULL.
+ *
+ * Returns:
+ * Pointer to new encoder, or ERR_PTR on failure.
+ */
+#define drmm_encoder_alloc(dev, type, member, funcs, encoder_type, name, ...) \
+	((type *)__drmm_encoder_alloc(dev, sizeof(type), \
+				      offsetof(type, member), funcs, \
+				      encoder_type, name, ##__VA_ARGS__))
+
+/**
+ * drmm_plain_encoder_alloc - Allocate and initialize an encoder
+ * @dev: drm device
+ * @funcs: callbacks for this encoder (optional)
+ * @encoder_type: user visible type of the encoder
+ * @name: printf style format string for the encoder name, or NULL for default name
+ *
+ * This is a simplified version of drmm_encoder_alloc(), which only allocates
+ * and returns a struct drm_encoder instance, with no subclassing.
+ *
+ * Returns:
+ * Pointer to the new drm_encoder struct, or ERR_PTR on failure.
+ */
+#define drmm_plain_encoder_alloc(dev, funcs, encoder_type, name, ...) \
+	((struct drm_encoder *) \
+	 __drmm_encoder_alloc(dev, sizeof(struct drm_encoder), \
+			      0, funcs, encoder_type, name, ##__VA_ARGS__))
+
+/**
+ * drm_encoder_index - find the index of a registered encoder
+ * @encoder: encoder to find index for
+ *
+ * Given a registered encoder, return the index of that encoder within a DRM
+ * device's list of encoders.
+ */
+static inline unsigned int drm_encoder_index(const struct drm_encoder *encoder)
+{
+	return encoder->index;
+}
+
+/**
+ * drm_encoder_mask - find the mask of a registered encoder
+ * @encoder: encoder to find mask for
+ *
+ * Given a registered encoder, return the mask bit of that encoder for an
+ * encoder's possible_clones field.
+ */
+static inline u32 drm_encoder_mask(const struct drm_encoder *encoder)
+{
+	return 1 << drm_encoder_index(encoder);
+}
+
+/**
+ * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
+ * @encoder: encoder to test
+ * @crtc: crtc to test
+ *
+ * Returns false if @encoder can't be driven by @crtc, true otherwise.
+ */
+static inline bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
+				       struct drm_crtc *crtc)
+{
+	return !!(encoder->possible_crtcs & drm_crtc_mask(crtc));
+}
+
+/**
+ * drm_encoder_find - find a &drm_encoder
+ * @dev: DRM device
+ * @file_priv: drm file to check for lease against.
+ * @id: encoder id
+ *
+ * Returns the encoder with @id, NULL if it doesn't exist. Simple wrapper around
+ * drm_mode_object_find().
+ */
+static inline struct drm_encoder *drm_encoder_find(struct drm_device *dev,
+						   struct drm_file *file_priv,
+						   uint32_t id)
+{
+	struct drm_mode_object *mo;
+
+	mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_ENCODER);
+
+	return mo ? obj_to_encoder(mo) : NULL;
+}
+
+void drm_encoder_cleanup(struct drm_encoder *encoder);
+
+/**
+ * drm_for_each_encoder_mask - iterate over encoders specified by bitmask
+ * @encoder: the loop cursor
+ * @dev: the DRM device
+ * @encoder_mask: bitmask of encoder indices
+ *
+ * Iterate over all encoders specified by bitmask.
+ */
+#define drm_for_each_encoder_mask(encoder, dev, encoder_mask) \
+	list_for_each_entry((encoder), &(dev)->mode_config.encoder_list, head) \
+		for_each_if ((encoder_mask) & drm_encoder_mask(encoder))
+
+/**
+ * drm_for_each_encoder - iterate over all encoders
+ * @encoder: the loop cursor
+ * @dev: the DRM device
+ *
+ * Iterate over all encoders of @dev.
+ */
+#define drm_for_each_encoder(encoder, dev) \
+	list_for_each_entry(encoder, &(dev)->mode_config.encoder_list, head)
+
+#endif