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

5 files changed, 329 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml b/Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml
new file mode 100644
index 000000000..c34b86bb7
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/brcm,bcm4751.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom BCM4751 family GNSS Receiver
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+  - Linus Walleij <linusw@kernel.org>
+
+description:
+  Broadcom GPS chips can be used over the UART or I2C bus. The UART
+  bus requires CTS/RTS support. The number of the capsule is more
+  elaborate than the compatibles BCM4751 may be printed
+  BCM4751IFBG for example.
+
+allOf:
+  - $ref: gnss-common.yaml#
+  - $ref: /schemas/serial/serial-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - brcm,bcm4751
+      - brcm,bcm4752
+      - brcm,bcm4753
+
+  reg:
+    description:
+      The I2C Address, not required on UART buses.
+
+  vdd-auxin-supply:
+    description:
+      Main voltage supply, pin name VDD_AUXIN, typically connected
+      directly to a battery such as LiIon 3.8V battery or a 2.6V supply.
+
+  vddio-supply:
+    description:
+      IO voltage supply, pin name VDDIO, typically 1.8V
+
+  reset-gpios:
+    maxItems: 1
+    description: An optional active low reset line, should be flagged with
+      GPIO_ACTIVE_LOW.
+
+  enable-gpios:
+    description: Enable GPIO line, connected to pins named REGPU or NSTANDBY.
+      If the line is active low such as NSTANDBY, it should be tagged
+      GPIO_ACTIVE_LOW.
+
+required:
+  - compatible
+  - enable-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    serial {
+        gnss {
+            compatible = "brcm,bcm4751";
+            vdd-auxin-supply = <&vbat>;
+            reset-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>;
+            enable-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+            current-speed = <38400>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/gnss/gnss-common.yaml b/Documentation/devicetree/bindings/gnss/gnss-common.yaml
new file mode 100644
index 000000000..354c05240
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/gnss-common.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/gnss-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common Properties for Global Navigation Satellite Systems (GNSS)
+  receiver devices
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+
+description: |
+  This document defines device tree properties common to Global Navigation
+  Satellite System receivers.
+
+properties:
+  $nodename:
+    pattern: "^gnss(@.*)?$"
+
+  lna-supply:
+    description: A separate regulator supplying power for the Low Noise
+      Amplifier (LNA). This is an amplifier connected between the GNSS
+      device and the receiver antenna.
+
+  enable-gpios:
+    description: A GPIO line that will enable the GNSS receiver when
+      asserted. If this line is active low, the GPIO phandle should
+      consequently be tagged with the GPIO_ACTIVE_LOW flag so the operating
+      system can rely on asserting the line to enable the GNSS device.
+    maxItems: 1
+
+  timepulse-gpios:
+    description: Timepulse signal
+    maxItems: 1
+
+additionalProperties: true
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    serial {
+      gnss {
+        compatible = "u-blox,neo-8";
+        vcc-supply = <&gnss_reg>;
+        timepulse-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+        current-speed = <4800>;
+      };
+    };
diff --git a/Documentation/devicetree/bindings/gnss/mediatek.yaml b/Documentation/devicetree/bindings/gnss/mediatek.yaml
new file mode 100644
index 000000000..2b9e5be4e
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/mediatek.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/mediatek.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mediatek GNSS Receiver
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+
+description:
+  Mediatek chipsets are used in GNSS-receiver modules produced by several
+  vendors and can use a UART interface.
+
+allOf:
+  - $ref: gnss-common.yaml#
+  - $ref: /schemas/serial/serial-peripheral-props.yaml#
+
+properties:
+  compatible:
+    const: globaltop,pa6h
+
+  vcc-supply:
+    description:
+      Main voltage regulator, pin name VCC.
+
+  reset-gpios:
+    maxItems: 1
+    description: An optional reset line, with names such as RESET or NRESET.
+      If the line is active low it should be flagged with GPIO_ACTIVE_LOW.
+
+  timepulse-gpios:
+    description: Comes with pin names such as PPS1 or 1PPS.
+
+  gnss-fix-gpios:
+    maxItems: 1
+    description: GPIO used to determine device position fix state, pin names
+      FIX or 3D_FIX.
+
+  vbackup-supply:
+    description:
+      Regulator providing backup voltage, pin names such as VBAT or VBACKUP.
+
+required:
+  - compatible
+  - vcc-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    serial {
+        gnss {
+            compatible = "globaltop,pa6h";
+            vcc-supply = <&vcc_3v3>;
+            reset-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/gnss/sirfstar.yaml b/Documentation/devicetree/bindings/gnss/sirfstar.yaml
new file mode 100644
index 000000000..7e5da89a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/sirfstar.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/sirfstar.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SiRFstar GNSS Receiver
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+
+description:
+  The SiRFstar GNSS receivers have incarnated over the years in different
+  chips, starting from the SiRFstarIII which was a chip that was introduced in
+  2004 and used in a lot of dedicated GPS devices. In 2009 SiRF was acquired
+  by CSR (Cambridge Silicon Radio) and in 2012 the CSR GPS business was
+  acquired by Samsung, while some products remained with CSR. In 2014 CSR
+  was acquired by Qualcomm who still sell some of the SiRF products.
+
+  SiRF chips can be used over UART, I2C or SPI buses.
+
+allOf:
+  - $ref: gnss-common.yaml#
+  - $ref: /schemas/serial/serial-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - csr,gsd4t
+      - csr,csrg05ta03-icje-r
+      - fastrax,uc430
+      - linx,r4
+      - wi2wi,w2sg0004
+      - wi2wi,w2sg0008i
+      - wi2wi,w2sg0084i
+
+  reg:
+    description:
+      The I2C Address, SPI chip select address. Not required on UART buses.
+
+  vcc-supply:
+    description:
+      Main voltage regulator, pin names such as 3V3_IN, VCC, VDD.
+
+  reset-gpios:
+    maxItems: 1
+    description: An optional active low reset line, should be flagged with
+      GPIO_ACTIVE_LOW.
+
+  sirf,onoff-gpios:
+    maxItems: 1
+    description: GPIO used to power on and off device, pin name ON_OFF.
+
+  sirf,wakeup-gpios:
+    maxItems: 1
+    description: GPIO used to determine device power state, pin names such
+      as RFPWRUP, WAKEUP.
+
+required:
+  - compatible
+  - vcc-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    serial {
+        gnss {
+            compatible = "wi2wi,w2sg0084i";
+            vcc-supply = <&gnss_vcc_reg>;
+            reset-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>;
+            sirf,onoff-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+            sirf,wakeup-gpios = <&gpio0 17 GPIO_ACTIVE_HIGH>;
+            current-speed = <38400>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
new file mode 100644
index 000000000..b349b7bc0
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/u-blox,neo-6m.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: u-blox GNSS receiver
+
+allOf:
+  - $ref: gnss-common.yaml#
+  - $ref: /schemas/serial/serial-peripheral-props.yaml#
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+
+description: >
+  The u-blox GNSS receivers can use UART, DDC (I2C), SPI and USB interfaces.
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - u-blox,neo-6m
+          - u-blox,neo-8
+          - u-blox,neo-m8
+      - items:
+          - const: u-blox,neo-m9
+          - const: u-blox,neo-m8
+
+  reg:
+    description: >
+      The DDC Slave Address, SPI chip select address, the number of the USB hub
+      port or the USB host-controller port to which this device is attached,
+      depending on the bus used. Required for the DDC, SPI or USB busses.
+
+  reset-gpios:
+    maxItems: 1
+
+  safeboot-gpios:
+    maxItems: 1
+
+  vcc-supply:
+    description: >
+      Main voltage regulator
+
+  u-blox,extint-gpios:
+    maxItems: 1
+    description: >
+      GPIO connected to the "external interrupt" input pin
+
+  v-bckp-supply:
+    description: >
+      Backup voltage regulator
+
+required:
+  - compatible
+  - vcc-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    serial {
+        gnss {
+            compatible = "u-blox,neo-8";
+            v-bckp-supply = <&gnss_v_bckp_reg>;
+            vcc-supply = <&gnss_vcc_reg>;
+            reset-gpios = <&gpio 1 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>;
+            safeboot-gpios = <&gpio 2 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>;
+        };
+    };