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, 281 insertions, 0 deletions

diff --git a/include/media/dvb_vb2.h b/include/media/dvb_vb2.h
new file mode 100644
index 000000000..8932396d2
--- /dev/null
+++ b/include/media/dvb_vb2.h
@@ -0,0 +1,281 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0
+ *
+ * dvb-vb2.h - DVB driver helper framework for streaming I/O
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ *
+ * Author: jh1009.sung@samsung.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _DVB_VB2_H
+#define _DVB_VB2_H
+
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/dvb/dmx.h>
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-dma-contig.h>
+#include <media/videobuf2-vmalloc.h>
+
+/**
+ * enum dvb_buf_type - types of Digital TV memory-mapped buffers
+ *
+ * @DVB_BUF_TYPE_CAPTURE: buffer is filled by the Kernel,
+ *			  with a received Digital TV stream
+ */
+enum dvb_buf_type {
+	DVB_BUF_TYPE_CAPTURE        = 1,
+};
+
+/**
+ * enum dvb_vb2_states - states to control VB2 state machine
+ * @DVB_VB2_STATE_NONE:
+ *	VB2 engine not initialized yet, init failed or VB2 was released.
+ * @DVB_VB2_STATE_INIT:
+ *	VB2 engine initialized.
+ * @DVB_VB2_STATE_REQBUFS:
+ *	Buffers were requested
+ * @DVB_VB2_STATE_STREAMON:
+ *	VB2 is streaming. Callers should not check it directly. Instead,
+ *	they should use dvb_vb2_is_streaming().
+ *
+ * Note:
+ *
+ * Callers should not touch at the state machine directly. This
+ * is handled inside dvb_vb2.c.
+ */
+enum dvb_vb2_states {
+	DVB_VB2_STATE_NONE	= 0x0,
+	DVB_VB2_STATE_INIT	= 0x1,
+	DVB_VB2_STATE_REQBUFS	= 0x2,
+	DVB_VB2_STATE_STREAMON	= 0x4,
+};
+
+#define DVB_VB2_NAME_MAX (20)
+
+/**
+ * struct dvb_buffer - video buffer information for v4l2.
+ *
+ * @vb:		embedded struct &vb2_buffer.
+ * @list:	list of &struct dvb_buffer.
+ */
+struct dvb_buffer {
+	struct vb2_buffer	vb;
+	struct list_head	list;
+};
+
+/**
+ * struct dvb_vb2_ctx - control struct for VB2 handler
+ * @vb_q:	pointer to &struct vb2_queue with videobuf2 queue.
+ * @slock:	spin lock used to protect buffer filling at dvb_vb2.c.
+ * @dvb_q:	List of buffers that are not filled yet.
+ * @buf:	Pointer to the buffer that are currently being filled.
+ * @offset:	index to the next position at the @buf to be filled.
+ * @remain:	How many bytes are left to be filled at @buf.
+ * @state:	bitmask of buffer states as defined by &enum dvb_vb2_states.
+ * @buf_siz:	size of each VB2 buffer.
+ * @buf_cnt:	number of VB2 buffers.
+ * @nonblocking:
+ *		If different than zero, device is operating on non-blocking
+ *		mode.
+ * @flags:	buffer flags as defined by &enum dmx_buffer_flags.
+ *		Filled only at &DMX_DQBUF. &DMX_QBUF should zero this field.
+ * @count:	monotonic counter for filled buffers. Helps to identify
+ *		data stream loses. Filled only at &DMX_DQBUF. &DMX_QBUF should
+ *		zero this field.
+ *
+ * @name:	name of the device type. Currently, it can either be
+ *		"dvr" or "demux_filter".
+ */
+struct dvb_vb2_ctx {
+	struct vb2_queue	vb_q;
+	spinlock_t		slock;
+	struct list_head	dvb_q;
+	struct dvb_buffer	*buf;
+	int	offset;
+	int	remain;
+	int	state;
+	int	buf_siz;
+	int	buf_cnt;
+	int	nonblocking;
+
+	enum dmx_buffer_flags flags;
+	u32	count;
+
+	char	name[DVB_VB2_NAME_MAX + 1];
+};
+
+#ifndef CONFIG_DVB_MMAP
+static inline int dvb_vb2_init(struct dvb_vb2_ctx *ctx, const char *name,
+			       struct mutex *mutex, int non_blocking)
+{
+	return 0;
+};
+static inline int dvb_vb2_release(struct dvb_vb2_ctx *ctx)
+{
+	return 0;
+};
+#define dvb_vb2_is_streaming(ctx) (0)
+#define dvb_vb2_fill_buffer(ctx, file, wait, flags, flush) (0)
+
+static inline __poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx,
+				    struct file *file,
+				    poll_table *wait)
+{
+	return 0;
+}
+#else
+/**
+ * dvb_vb2_init - initializes VB2 handler
+ *
+ * @ctx:	control struct for VB2 handler
+ * @name:	name for the VB2 handler
+ * @mutex:	pointer to the mutex that serializes vb2 ioctls
+ * @non_blocking:
+ *		if not zero, it means that the device is at non-blocking mode
+ */
+int dvb_vb2_init(struct dvb_vb2_ctx *ctx, const char *name,
+		 struct mutex *mutex, int non_blocking);
+
+/**
+ * dvb_vb2_release - Releases the VB2 handler allocated resources and
+ *	put @ctx at DVB_VB2_STATE_NONE state.
+ * @ctx:	control struct for VB2 handler
+ */
+int dvb_vb2_release(struct dvb_vb2_ctx *ctx);
+
+/**
+ * dvb_vb2_is_streaming - checks if the VB2 handler is streaming
+ * @ctx:	control struct for VB2 handler
+ *
+ * Return: 0 if not streaming, 1 otherwise.
+ */
+int dvb_vb2_is_streaming(struct dvb_vb2_ctx *ctx);
+
+/**
+ * dvb_vb2_fill_buffer - fills a VB2 buffer
+ * @ctx:	control struct for VB2 handler
+ * @src:	place where the data is stored
+ * @len:	number of bytes to be copied from @src
+ * @buffer_flags:
+ *		pointer to buffer flags as defined by &enum dmx_buffer_flags.
+ *		can be NULL.
+ * @flush:	flush the buffer, even if it isn't full.
+ */
+int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
+			const unsigned char *src, int len,
+			enum dmx_buffer_flags *buffer_flags,
+			bool flush);
+
+/**
+ * dvb_vb2_poll - Wrapper to vb2_core_streamon() for Digital TV
+ *      buffer handling.
+ *
+ * @ctx:	control struct for VB2 handler
+ * @file:	&struct file argument passed to the poll
+ *		file operation handler.
+ * @wait:	&poll_table wait argument passed to the poll
+ *		file operation handler.
+ *
+ * Implements poll syscall() logic.
+ */
+__poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx, struct file *file,
+		      poll_table *wait);
+#endif
+
+/**
+ * dvb_vb2_stream_on() - Wrapper to vb2_core_streamon() for Digital TV
+ *	buffer handling.
+ *
+ * @ctx:	control struct for VB2 handler
+ *
+ * Starts dvb streaming
+ */
+int dvb_vb2_stream_on(struct dvb_vb2_ctx *ctx);
+/**
+ * dvb_vb2_stream_off() - Wrapper to vb2_core_streamoff() for Digital TV
+ *	buffer handling.
+ *
+ * @ctx:	control struct for VB2 handler
+ *
+ * Stops dvb streaming
+ */
+int dvb_vb2_stream_off(struct dvb_vb2_ctx *ctx);
+
+/**
+ * dvb_vb2_reqbufs() - Wrapper to vb2_core_reqbufs() for Digital TV
+ *	buffer handling.
+ *
+ * @ctx:	control struct for VB2 handler
+ * @req:	&struct dmx_requestbuffers passed from userspace in
+ *		order to handle &DMX_REQBUFS.
+ *
+ * Initiate streaming by requesting a number of buffers. Also used to
+ * free previously requested buffers, is ``req->count`` is zero.
+ */
+int dvb_vb2_reqbufs(struct dvb_vb2_ctx *ctx, struct dmx_requestbuffers *req);
+
+/**
+ * dvb_vb2_querybuf() - Wrapper to vb2_core_querybuf() for Digital TV
+ *	buffer handling.
+ *
+ * @ctx:	control struct for VB2 handler
+ * @b:		&struct dmx_buffer passed from userspace in
+ *		order to handle &DMX_QUERYBUF.
+ *
+ *
+ */
+int dvb_vb2_querybuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b);
+
+/**
+ * dvb_vb2_expbuf() - Wrapper to vb2_core_expbuf() for Digital TV
+ *	buffer handling.
+ *
+ * @ctx:	control struct for VB2 handler
+ * @exp:	&struct dmx_exportbuffer passed from userspace in
+ *		order to handle &DMX_EXPBUF.
+ *
+ * Export a buffer as a file descriptor.
+ */
+int dvb_vb2_expbuf(struct dvb_vb2_ctx *ctx, struct dmx_exportbuffer *exp);
+
+/**
+ * dvb_vb2_qbuf() - Wrapper to vb2_core_qbuf() for Digital TV buffer handling.
+ *
+ * @ctx:	control struct for VB2 handler
+ * @b:		&struct dmx_buffer passed from userspace in
+ *		order to handle &DMX_QBUF.
+ *
+ * Queue a Digital TV buffer as requested by userspace
+ */
+int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b);
+
+/**
+ * dvb_vb2_dqbuf() - Wrapper to vb2_core_dqbuf() for Digital TV
+ *	buffer handling.
+ *
+ * @ctx:	control struct for VB2 handler
+ * @b:		&struct dmx_buffer passed from userspace in
+ *		order to handle &DMX_DQBUF.
+ *
+ * Dequeue a Digital TV buffer to the userspace
+ */
+int dvb_vb2_dqbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b);
+
+/**
+ * dvb_vb2_mmap() - Wrapper to vb2_mmap() for Digital TV buffer handling.
+ *
+ * @ctx:	control struct for VB2 handler
+ * @vma:        pointer to &struct vm_area_struct with the vma passed
+ *              to the mmap file operation handler in the driver.
+ *
+ * map Digital TV video buffers into application address space.
+ */
+int dvb_vb2_mmap(struct dvb_vb2_ctx *ctx, struct vm_area_struct *vma);
+
+#endif /* _DVB_VB2_H */