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, 279 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/example-schema.yaml b/Documentation/devicetree/bindings/example-schema.yaml
new file mode 100644
index 000000000..b04f3cc43
--- /dev/null
+++ b/Documentation/devicetree/bindings/example-schema.yaml
@@ -0,0 +1,279 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2018 Linaro Ltd.
+%YAML 1.2
+---
+# All the top-level keys are standard json-schema keywords except for
+# 'maintainers' and 'select'
+
+# $id is a unique identifier based on the filename. There may or may not be a
+# file present at the URL.
+$id: http://devicetree.org/schemas/example-schema.yaml#
+# $schema is the meta-schema this schema should be validated with.
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: An Example Device
+
+maintainers:
+  - Rob Herring <robh@kernel.org>
+
+description: |
+  A more detailed multi-line description of the binding.
+
+  Details about the hardware device and any links to datasheets can go here.
+
+  Literal blocks are marked with the '|' at the beginning. The end is marked by
+  indentation less than the first line of the literal block. Lines also cannot
+  begin with a tab character.
+
+select: false
+  # 'select' is a schema applied to a DT node to determine if this binding
+  # schema should be applied to the node. It is optional and by default the
+  # possible compatible strings are extracted and used to match.
+
+  # In this case, a 'false' schema will never match.
+
+properties:
+  # A dictionary of DT properties for this binding schema
+  compatible:
+    # More complicated schema can use oneOf (XOR), anyOf (OR), or allOf (AND)
+    # to handle different conditions.
+    # In this case, it's needed to handle a variable number of values as there
+    # isn't another way to express a constraint of the last string value.
+    # The boolean schema must be a list of schemas.
+    oneOf:
+      - items:
+          # items is a list of possible values for the property. The number of
+          # values is determined by the number of elements in the list.
+          # Order in lists is significant, order in dicts is not
+          # Must be one of the 1st enums followed by the 2nd enum
+          #
+          # Each element in items should be 'enum' or 'const'
+          - enum:
+              - vendor,soc4-ip
+              - vendor,soc3-ip
+              - vendor,soc2-ip
+          - const: vendor,soc1-ip
+        # additionalItems being false is implied
+        # minItems/maxItems equal to 2 is implied
+      - items:
+          # 'const' is just a special case of an enum with a single possible value
+          - const: vendor,soc1-ip
+
+  reg:
+    # The core schema already checks that reg values are numbers, so device
+    # specific schema don't need to do those checks.
+    # The description of each element defines the order and implicitly defines
+    # the number of reg entries.
+    items:
+      - description: core registers
+      - description: aux registers
+    # minItems/maxItems equal to 2 is implied
+
+  reg-names:
+    # The core schema enforces this (*-names) is a string array
+    items:
+      - const: core
+      - const: aux
+
+  clocks:
+    # Cases that have only a single entry just need to express that with maxItems
+    maxItems: 1
+    description: bus clock. A description is only needed for a single item if
+      there's something unique to add.
+      The items should have a fixed order, so pattern matching names are
+      discouraged.
+
+  clock-names:
+    # For single-entry lists in clocks, resets etc., the xxx-names often do not
+    # bring any value, especially if they copy the IP block name.  In such case
+    # just skip the xxx-names.
+    items:
+      - const: bus
+
+  interrupts:
+    # Either 1 or 2 interrupts can be present
+    minItems: 1
+    items:
+      - description: tx or combined interrupt
+      - description: rx interrupt
+    description:
+      A variable number of interrupts warrants a description of what conditions
+      affect the number of interrupts. Otherwise, descriptions on standard
+      properties are not necessary.
+      The items should have a fixed order, so pattern matching names are
+      discouraged.
+
+  interrupt-names:
+    # minItems must be specified here because the default would be 2
+    minItems: 1
+    items:
+      - const: tx irq
+      - const: rx irq
+
+  # Property names starting with '#' must be quoted
+  '#interrupt-cells':
+    # A simple case where the value must always be '2'.
+    # The core schema handles that this must be a single integer.
+    const: 2
+
+  interrupt-controller: true
+    # The core checks this is a boolean, so just have to list it here to be
+    # valid for this binding.
+
+  clock-frequency:
+    # The type is set in the core schema. Per-device schema only need to set
+    # constraints on the possible values.
+    minimum: 100
+    maximum: 400000
+    # The value that should be used if the property is not present
+    default: 200
+
+  foo-gpios:
+    maxItems: 1
+    description: A connection of the 'foo' gpio line.
+
+  # *-supply is always a single phandle, so nothing more to define.
+  foo-supply: true
+
+  # Vendor-specific properties
+  #
+  # Vendor-specific properties have slightly different schema requirements than
+  # common properties. They must have at least a type definition and
+  # 'description'.
+  vendor,int-property:
+    description: Vendor-specific properties must have a description
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [2, 4, 6, 8, 10]
+
+  vendor,bool-property:
+    description: Vendor-specific properties must have a description. Boolean
+      properties are one case where the json-schema 'type' keyword can be used
+      directly.
+    type: boolean
+
+  vendor,string-array-property:
+    description: Vendor-specific properties should reference a type in the
+      core schema.
+    $ref: /schemas/types.yaml#/definitions/string-array
+    items:
+      - enum: [foo, bar]
+      - enum: [baz, boo]
+
+  vendor,property-in-standard-units-microvolt:
+    description: Vendor-specific properties having a standard unit suffix
+      don't need a type.
+    enum: [ 100, 200, 300 ]
+
+  vendor,int-array-variable-length-and-constrained-values:
+    description: Array might define what type of elements might be used (e.g.
+      their range).
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 2
+    maxItems: 3
+    items:
+      minimum: 0
+      maximum: 8
+
+  child-node:
+    description: Child nodes are just another property from a json-schema
+      perspective.
+    type: object  # DT nodes are json objects
+    # Child nodes also need additionalProperties or unevaluatedProperties, where
+    # 'false' should be used in most cases (see 'child-node-with-own-schema'
+    # below).
+    additionalProperties: false
+    properties:
+      vendor,a-child-node-property:
+        description: Child node properties have all the same schema
+          requirements.
+        type: boolean
+
+    required:
+      - vendor,a-child-node-property
+
+  child-node-with-own-schema:
+    description: |
+      Child node with their own compatible and device schema which ends in
+      'additionalProperties: false' or 'unevaluatedProperties: false' can
+      mention only the compatible and use here 'additionalProperties: true'.
+    type: object
+    additionalProperties: true
+    properties:
+      compatible:
+        const: vendor,sub-device
+
+# Describe the relationship between different properties
+dependencies:
+  # 'vendor,bool-property' is only allowed when 'vendor,string-array-property'
+  # is present
+  vendor,bool-property: [ 'vendor,string-array-property' ]
+  # Expressing 2 properties in both orders means all of the set of properties
+  # must be present or none of them.
+  vendor,string-array-property: [ 'vendor,bool-property' ]
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-controller
+
+# if/then schema can be used to handle conditions on a property affecting
+# another property. A typical case is a specific 'compatible' value changes the
+# constraints on other properties.
+#
+# For multiple 'if' schema, group them under an 'allOf'.
+#
+# If the conditionals become too unwieldy, then it may be better to just split
+# the binding into separate schema documents.
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: vendor,soc2-ip
+    then:
+      required:
+        - foo-supply
+    else:
+      # If otherwise the property is not allowed:
+      properties:
+        foo-supply: false
+  # Altering schema depending on presence of properties is usually done by
+  # dependencies (see above), however some adjustments might require if:
+  - if:
+      required:
+        - vendor,bool-property
+    then:
+      properties:
+        vendor,int-property:
+          enum: [2, 4, 6]
+
+# Ideally, the schema should have this line otherwise any other properties
+# present are allowed. There's a few common properties such as 'status' and
+# 'pinctrl-*' which are added automatically by the tooling.
+#
+# This can't be used in cases where another schema is referenced
+# (i.e. allOf: [{$ref: ...}]).
+# If and only if another schema is referenced and arbitrary children nodes can
+# appear, "unevaluatedProperties: false" could be used.  A typical example is
+# an I2C controller where no name pattern matching for children can be added.
+additionalProperties: false
+
+examples:
+  # Examples are now compiled with dtc and validated against the schemas
+  #
+  # Examples have a default #address-cells and #size-cells value of 1. This can
+  # be overridden or an appropriate parent bus node should be shown (such as on
+  # i2c buses).
+  #
+  # Any includes used have to be explicitly included. Use 4-space indentation.
+  - |
+    node@1000 {
+        compatible = "vendor,soc4-ip", "vendor,soc1-ip";
+        reg = <0x1000 0x80>,
+              <0x3000 0x80>;
+        reg-names = "core", "aux";
+        interrupts = <10>;
+        interrupt-controller;
+        #interrupt-cells = <2>;
+    };