Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

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