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

7 files changed, 486 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/auxdisplay/arm,versatile-lcd.yaml b/Documentation/devicetree/bindings/auxdisplay/arm,versatile-lcd.yaml
new file mode 100644
index 000000000..51d68a778
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/arm,versatile-lcd.yaml
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/arm,versatile-lcd.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Versatile Character LCD
+
+maintainers:
+  - Linus Walleij <linusw@kernel.org>
+  - Rob Herring <robh@kernel.org>
+
+description:
+  This binding defines the character LCD interface found on ARM Versatile AB
+  and PB reference platforms.
+
+properties:
+  compatible:
+    const: arm,versatile-lcd
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    lcd@10008000 {
+        compatible = "arm,versatile-lcd";
+        reg = <0x10008000 0x1000>;
+    };
diff --git a/Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml b/Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml
new file mode 100644
index 000000000..328954893
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/gpio-7-segment.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: GPIO based LED segment display
+
+maintainers:
+  - Chris Packham <chris.packham@alliedtelesis.co.nz>
+
+properties:
+  compatible:
+    const: gpio-7-segment
+
+  segment-gpios:
+    description: |
+      An array of GPIOs one per segment. The first GPIO corresponds to the A
+      segment, the seventh GPIO corresponds to the G segment. Some LED blocks
+      also have a decimal point which can be specified as an optional eighth
+      segment.
+
+               -a-
+              |   |
+              f   b
+              |   |
+               -g-
+              |   |
+              e   c
+              |   |
+               -d-  dp
+
+    minItems: 7
+    maxItems: 8
+
+required:
+  - segment-gpios
+
+additionalProperties: false
+
+examples:
+  - |
+
+    #include <dt-bindings/gpio/gpio.h>
+
+    led-7seg {
+        compatible = "gpio-7-segment";
+        segment-gpios = <&gpio 0 GPIO_ACTIVE_LOW>,
+                        <&gpio 1 GPIO_ACTIVE_LOW>,
+                        <&gpio 2 GPIO_ACTIVE_LOW>,
+                        <&gpio 3 GPIO_ACTIVE_LOW>,
+                        <&gpio 4 GPIO_ACTIVE_LOW>,
+                        <&gpio 5 GPIO_ACTIVE_LOW>,
+                        <&gpio 6 GPIO_ACTIVE_LOW>;
+    };
diff --git a/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml b/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml
new file mode 100644
index 000000000..3ca0e9863
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml
@@ -0,0 +1,127 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/hit,hd44780.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Hitachi HD44780 Character LCD Controller
+
+maintainers:
+  - Geert Uytterhoeven <geert@linux-m68k.org>
+
+description:
+  The Hitachi HD44780 Character LCD Controller is commonly used on character
+  LCDs that can display one or more lines of text. It exposes an M6800 bus
+  interface, which can be used in either 4-bit or 8-bit mode. By using a
+  GPIO expander it is possible to use the driver with one of the popular I2C
+  expander boards based on the PCF8574 available for these displays. For
+  an example see below.
+
+properties:
+  compatible:
+    const: hit,hd44780
+
+  data-gpios:
+    description:
+      GPIO pins connected to the data signal lines DB0-DB7 (8-bit mode) or
+      DB4-DB7 (4-bit mode) of the LCD Controller's bus interface.
+    oneOf:
+      - maxItems: 4
+      - maxItems: 8
+
+  enable-gpios:
+    description:
+      GPIO pin connected to the "E" (Enable) signal line of the LCD
+      Controller's bus interface.
+    maxItems: 1
+
+  rs-gpios:
+    description:
+      GPIO pin connected to the "RS" (Register Select) signal line of the LCD
+      Controller's bus interface.
+    maxItems: 1
+
+  rw-gpios:
+    description:
+      GPIO pin connected to the "RW" (Read/Write) signal line of the LCD
+      Controller's bus interface.
+    maxItems: 1
+
+  backlight-gpios:
+    description: GPIO pin used for enabling the LCD's backlight.
+    maxItems: 1
+
+  display-height-chars:
+    description: Height of the display, in character cells,
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 4
+
+  display-width-chars:
+    description: Width of the display, in character cells.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 64
+
+  internal-buffer-width:
+    description:
+      Internal buffer width (default is 40 for displays with 1 or 2 lines, and
+      display-width-chars for displays with more than 2 lines).
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 64
+
+required:
+  - compatible
+  - data-gpios
+  - enable-gpios
+  - rs-gpios
+  - display-height-chars
+  - display-width-chars
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    display-controller {
+        compatible = "hit,hd44780";
+
+        data-gpios = <&hc595 0 GPIO_ACTIVE_HIGH>,
+                     <&hc595 1 GPIO_ACTIVE_HIGH>,
+                     <&hc595 2 GPIO_ACTIVE_HIGH>,
+                     <&hc595 3 GPIO_ACTIVE_HIGH>;
+        enable-gpios = <&hc595 4 GPIO_ACTIVE_HIGH>;
+        rs-gpios = <&hc595 5 GPIO_ACTIVE_HIGH>;
+
+        display-height-chars = <2>;
+        display-width-chars = <16>;
+    };
+
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        pcf8574: gpio-expander@27 {
+            compatible = "nxp,pcf8574";
+            reg = <0x27>;
+            gpio-controller;
+            #gpio-cells = <2>;
+        };
+    };
+
+    display-controller {
+        compatible = "hit,hd44780";
+        display-height-chars = <2>;
+        display-width-chars = <16>;
+        data-gpios = <&pcf8574 4 GPIO_ACTIVE_HIGH>,
+                     <&pcf8574 5 GPIO_ACTIVE_HIGH>,
+                     <&pcf8574 6 GPIO_ACTIVE_HIGH>,
+                     <&pcf8574 7 GPIO_ACTIVE_HIGH>;
+        enable-gpios = <&pcf8574 2 GPIO_ACTIVE_HIGH>;
+        rs-gpios = <&pcf8574 0 GPIO_ACTIVE_HIGH>;
+        rw-gpios = <&pcf8574 1 GPIO_ACTIVE_HIGH>;
+        backlight-gpios = <&pcf8574 3 GPIO_ACTIVE_HIGH>;
+    };
diff --git a/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml b/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml
new file mode 100644
index 000000000..1d2e2429b
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/holtek,ht16k33.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Holtek HT16K33 RAM mapping 16*8 LED controller with keyscan
+
+maintainers:
+  - Robin van der Gracht <robin@protonic.nl>
+
+allOf:
+  - $ref: /schemas/input/input.yaml#
+  - $ref: /schemas/input/matrix-keymap.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - adafruit,3108  # 0.56" 4-Digit 7-Segment FeatherWing Display (Red)
+              - adafruit,3130  # 0.54" Quad Alphanumeric FeatherWing Display (Red)
+          - const: holtek,ht16k33
+
+      - const: holtek,ht16k33     # Generic 16*8 LED controller with dot-matrix display
+
+  reg:
+    maxItems: 1
+
+  refresh-rate-hz:
+    maxItems: 1
+    description: Display update interval in Hertz for dot-matrix displays
+
+  interrupts:
+    maxItems: 1
+
+  debounce-delay-ms: true
+
+  linux,keymap: true
+
+  linux,no-autorepeat:
+    type: boolean
+    description: Disable keyrepeat
+
+  default-brightness-level:
+    minimum: 1
+    maximum: 16
+    default: 16
+    description: Initial brightness level
+
+  led:
+    type: object
+    $ref: /schemas/leds/common.yaml#
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+
+if:
+  properties:
+    compatible:
+      const: holtek,ht16k33
+then:
+  required:
+    - refresh-rate-hz
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/input/input.h>
+    #include <dt-bindings/leds/common.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        display-controller@70 {
+            compatible = "holtek,ht16k33";
+            reg = <0x70>;
+            refresh-rate-hz = <20>;
+            interrupt-parent = <&gpio4>;
+            interrupts = <5 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
+            debounce-delay-ms = <50>;
+            linux,keymap = <MATRIX_KEY(2, 0, KEY_F6)>,
+                           <MATRIX_KEY(3, 0, KEY_F8)>,
+                           <MATRIX_KEY(4, 0, KEY_F10)>,
+                           <MATRIX_KEY(5, 0, KEY_F4)>,
+                           <MATRIX_KEY(6, 0, KEY_F2)>,
+                           <MATRIX_KEY(2, 1, KEY_F5)>,
+                           <MATRIX_KEY(3, 1, KEY_F7)>,
+                           <MATRIX_KEY(4, 1, KEY_F9)>,
+                           <MATRIX_KEY(5, 1, KEY_F3)>,
+                           <MATRIX_KEY(6, 1, KEY_F1)>;
+
+            led {
+                color = <LED_COLOR_ID_RED>;
+                function = LED_FUNCTION_BACKLIGHT;
+                linux,default-trigger = "backlight";
+            };
+        };
+    };
diff --git a/Documentation/devicetree/bindings/auxdisplay/img,ascii-lcd.yaml b/Documentation/devicetree/bindings/auxdisplay/img,ascii-lcd.yaml
new file mode 100644
index 000000000..55e9831b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/img,ascii-lcd.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/img,ascii-lcd.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASCII LCD displays on Imagination Technologies boards
+
+maintainers:
+  - Paul Burton <paulburton@kernel.org>
+
+properties:
+  compatible:
+    enum:
+      - img,boston-lcd
+      - mti,malta-lcd
+      - mti,sead3-lcd
+
+  reg:
+    maxItems: 1
+
+  offset:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Offset in bytes to the LCD registers within the system controller
+
+required:
+  - compatible
+
+oneOf:
+  - required:
+      - reg
+  - required:
+      - offset
+
+if:
+  properties:
+    compatible:
+      contains:
+        const: img,boston-lcd
+then:
+  required:
+    - reg
+else:
+  required:
+    - offset
+
+additionalProperties: false
+
+examples:
+  - |
+    lcd: lcd@17fff000 {
+        compatible = "img,boston-lcd";
+        reg = <0x17fff000 0x8>;
+    };
diff --git a/Documentation/devicetree/bindings/auxdisplay/maxim,max6959.yaml b/Documentation/devicetree/bindings/auxdisplay/maxim,max6959.yaml
new file mode 100644
index 000000000..20dd9e8c8
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/maxim,max6959.yaml
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/maxim,max6959.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MAX6958/6959 7-segment LED display controller
+
+maintainers:
+  - Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+
+description:
+  The Maxim MAX6958/6959 7-segment LED display controller provides
+  an I2C interface to up to four 7-segment LED digits. The MAX6959,
+  in comparison to MAX6958, adds input support. Type of the chip can
+  be autodetected via specific register read, and hence the features
+  may be enabled in the driver at run-time, in case they are requested
+  via Device Tree. A given hardware is simple and does not provide
+  any additional pins, such as reset or power enable.
+
+properties:
+  compatible:
+    const: maxim,max6959
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        display-controller@38 {
+            compatible = "maxim,max6959";
+            reg = <0x38>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml b/Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml
new file mode 100644
index 000000000..a1d55a263
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/modtronix,lcd2s.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Modtronix engineering LCD2S Character LCD Display
+
+maintainers:
+  - Lars Poeschel <poeschel@lemonage.de>
+
+description:
+  The LCD2S is a Character LCD Display manufactured by Modtronix Engineering.
+  The display supports a serial I2C and SPI interface. The driver currently
+  only supports the I2C interface.
+
+properties:
+  compatible:
+    const: modtronix,lcd2s
+
+  reg:
+    maxItems: 1
+    description:
+      I2C bus address of the display.
+
+  display-height-chars:
+    description: Height of the display, in character cells.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 4
+
+  display-width-chars:
+    description: Width of the display, in character cells.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 16
+    maximum: 20
+
+required:
+  - compatible
+  - reg
+  - display-height-chars
+  - display-width-chars
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      lcd2s: auxdisplay@28 {
+        compatible = "modtronix,lcd2s";
+        reg = <0x28>;
+        display-height-chars = <4>;
+        display-width-chars = <20>;
+      };
+    };