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

1 files changed, 284 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-vx855.c b/drivers/gpio/gpio-vx855.c
new file mode 100644
index 000000000..84b3a973a
--- /dev/null
+++ b/drivers/gpio/gpio-vx855.c
@@ -0,0 +1,284 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Linux GPIOlib driver for the VIA VX855 integrated southbridge GPIO
+ *
+ * Copyright (C) 2009 VIA Technologies, Inc.
+ * Copyright (C) 2010 One Laptop per Child
+ * Author: Harald Welte <HaraldWelte@viatech.com>
+ * All rights reserved.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio/driver.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+
+#define MODULE_NAME "vx855_gpio"
+
+/* The VX855 south bridge has the following GPIO pins:
+ *	GPI 0...13	General Purpose Input
+ *	GPO 0...12	General Purpose Output
+ *	GPIO 0...14	General Purpose I/O (Open-Drain)
+ */
+
+#define NR_VX855_GPI	14
+#define NR_VX855_GPO	13
+#define NR_VX855_GPIO	15
+
+#define NR_VX855_GPInO	(NR_VX855_GPI + NR_VX855_GPO)
+#define NR_VX855_GP	(NR_VX855_GPI + NR_VX855_GPO + NR_VX855_GPIO)
+
+struct vx855_gpio {
+	struct gpio_chip gpio;
+	spinlock_t lock;
+	u32 io_gpi;
+	u32 io_gpo;
+};
+
+/* resolve a GPIx into the corresponding bit position */
+static inline u_int32_t gpi_i_bit(int i)
+{
+	if (i < 10)
+		return 1 << i;
+	else
+		return 1 << (i + 14);
+}
+
+static inline u_int32_t gpo_o_bit(int i)
+{
+	if (i < 11)
+		return 1 << i;
+	else
+		return 1 << (i + 14);
+}
+
+static inline u_int32_t gpio_i_bit(int i)
+{
+	if (i < 14)
+		return 1 << (i + 10);
+	else
+		return 1 << (i + 14);
+}
+
+static inline u_int32_t gpio_o_bit(int i)
+{
+	if (i < 14)
+		return 1 << (i + 11);
+	else
+		return 1 << (i + 13);
+}
+
+/* Mapping between numeric GPIO ID and the actual GPIO hardware numbering:
+ * 0..13	GPI 0..13
+ * 14..26	GPO 0..12
+ * 27..41	GPIO 0..14
+ */
+
+static int vx855gpio_direction_input(struct gpio_chip *gpio,
+				     unsigned int nr)
+{
+	struct vx855_gpio *vg = gpiochip_get_data(gpio);
+	unsigned long flags;
+	u_int32_t reg_out;
+
+	/* Real GPI bits are always in input direction */
+	if (nr < NR_VX855_GPI)
+		return 0;
+
+	/* Real GPO bits cannot be put in output direction */
+	if (nr < NR_VX855_GPInO)
+		return -EINVAL;
+
+	/* Open Drain GPIO have to be set to one */
+	spin_lock_irqsave(&vg->lock, flags);
+	reg_out = inl(vg->io_gpo);
+	reg_out |= gpio_o_bit(nr - NR_VX855_GPInO);
+	outl(reg_out, vg->io_gpo);
+	spin_unlock_irqrestore(&vg->lock, flags);
+
+	return 0;
+}
+
+static int vx855gpio_get(struct gpio_chip *gpio, unsigned int nr)
+{
+	struct vx855_gpio *vg = gpiochip_get_data(gpio);
+	u_int32_t reg_in;
+	int ret = 0;
+
+	if (nr < NR_VX855_GPI) {
+		reg_in = inl(vg->io_gpi);
+		if (reg_in & gpi_i_bit(nr))
+			ret = 1;
+	} else if (nr < NR_VX855_GPInO) {
+		/* GPO don't have an input bit, we need to read it
+		 * back from the output register */
+		reg_in = inl(vg->io_gpo);
+		if (reg_in & gpo_o_bit(nr - NR_VX855_GPI))
+			ret = 1;
+	} else {
+		reg_in = inl(vg->io_gpi);
+		if (reg_in & gpio_i_bit(nr - NR_VX855_GPInO))
+			ret = 1;
+	}
+
+	return ret;
+}
+
+static int vx855gpio_set(struct gpio_chip *gpio, unsigned int nr, int val)
+{
+	struct vx855_gpio *vg = gpiochip_get_data(gpio);
+	unsigned long flags;
+	u_int32_t reg_out;
+
+	/* True GPI cannot be switched to output mode */
+	if (nr < NR_VX855_GPI)
+		return -EPERM;
+
+	spin_lock_irqsave(&vg->lock, flags);
+	reg_out = inl(vg->io_gpo);
+	if (nr < NR_VX855_GPInO) {
+		if (val)
+			reg_out |= gpo_o_bit(nr - NR_VX855_GPI);
+		else
+			reg_out &= ~gpo_o_bit(nr - NR_VX855_GPI);
+	} else {
+		if (val)
+			reg_out |= gpio_o_bit(nr - NR_VX855_GPInO);
+		else
+			reg_out &= ~gpio_o_bit(nr - NR_VX855_GPInO);
+	}
+	outl(reg_out, vg->io_gpo);
+	spin_unlock_irqrestore(&vg->lock, flags);
+
+	return 0;
+}
+
+static int vx855gpio_direction_output(struct gpio_chip *gpio,
+				      unsigned int nr, int val)
+{
+	/* True GPI cannot be switched to output mode */
+	if (nr < NR_VX855_GPI)
+		return -EINVAL;
+
+	/* True GPO don't need to be switched to output mode,
+	 * and GPIO are open-drain, i.e. also need no switching,
+	 * so all we do is set the level */
+	vx855gpio_set(gpio, nr, val);
+
+	return 0;
+}
+
+static int vx855gpio_set_config(struct gpio_chip *gpio, unsigned int nr,
+				unsigned long config)
+{
+	enum pin_config_param param = pinconf_to_config_param(config);
+
+	/* The GPI cannot be single-ended */
+	if (nr < NR_VX855_GPI)
+		return -EINVAL;
+
+	/* The GPO's are push-pull */
+	if (nr < NR_VX855_GPInO) {
+		if (param != PIN_CONFIG_DRIVE_PUSH_PULL)
+			return -ENOTSUPP;
+		return 0;
+	}
+
+	/* The GPIO's are open drain */
+	if (param != PIN_CONFIG_DRIVE_OPEN_DRAIN)
+		return -ENOTSUPP;
+
+	return 0;
+}
+
+static const char *vx855gpio_names[NR_VX855_GP] = {
+	"VX855_GPI0", "VX855_GPI1", "VX855_GPI2", "VX855_GPI3", "VX855_GPI4",
+	"VX855_GPI5", "VX855_GPI6", "VX855_GPI7", "VX855_GPI8", "VX855_GPI9",
+	"VX855_GPI10", "VX855_GPI11", "VX855_GPI12", "VX855_GPI13",
+	"VX855_GPO0", "VX855_GPO1", "VX855_GPO2", "VX855_GPO3", "VX855_GPO4",
+	"VX855_GPO5", "VX855_GPO6", "VX855_GPO7", "VX855_GPO8", "VX855_GPO9",
+	"VX855_GPO10", "VX855_GPO11", "VX855_GPO12",
+	"VX855_GPIO0", "VX855_GPIO1", "VX855_GPIO2", "VX855_GPIO3",
+	"VX855_GPIO4", "VX855_GPIO5", "VX855_GPIO6", "VX855_GPIO7",
+	"VX855_GPIO8", "VX855_GPIO9", "VX855_GPIO10", "VX855_GPIO11",
+	"VX855_GPIO12", "VX855_GPIO13", "VX855_GPIO14"
+};
+
+static void vx855gpio_gpio_setup(struct vx855_gpio *vg)
+{
+	struct gpio_chip *c = &vg->gpio;
+
+	c->label = "VX855 South Bridge";
+	c->owner = THIS_MODULE;
+	c->direction_input = vx855gpio_direction_input;
+	c->direction_output = vx855gpio_direction_output;
+	c->get = vx855gpio_get;
+	c->set = vx855gpio_set;
+	c->set_config = vx855gpio_set_config;
+	c->dbg_show = NULL;
+	c->base = 0;
+	c->ngpio = NR_VX855_GP;
+	c->can_sleep = false;
+	c->names = vx855gpio_names;
+}
+
+/* This platform device is ordinarily registered by the vx855 mfd driver */
+static int vx855gpio_probe(struct platform_device *pdev)
+{
+	struct resource *res_gpi;
+	struct resource *res_gpo;
+	struct vx855_gpio *vg;
+
+	res_gpi = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	res_gpo = platform_get_resource(pdev, IORESOURCE_IO, 1);
+	if (!res_gpi || !res_gpo)
+		return -EBUSY;
+
+	vg = devm_kzalloc(&pdev->dev, sizeof(*vg), GFP_KERNEL);
+	if (!vg)
+		return -ENOMEM;
+
+	dev_info(&pdev->dev, "found VX855 GPIO controller\n");
+	vg->io_gpi = res_gpi->start;
+	vg->io_gpo = res_gpo->start;
+	spin_lock_init(&vg->lock);
+
+	/*
+	 * A single byte is used to control various GPIO ports on the VX855,
+	 * and in the case of the OLPC XO-1.5, some of those ports are used
+	 * for switches that are interpreted and exposed through ACPI. ACPI
+	 * will have reserved the region, so our own reservation will not
+	 * succeed. Ignore and continue.
+	 */
+
+	if (!devm_request_region(&pdev->dev, res_gpi->start,
+				 resource_size(res_gpi), MODULE_NAME "_gpi"))
+		dev_warn(&pdev->dev,
+			"GPI I/O resource busy, probably claimed by ACPI\n");
+
+	if (!devm_request_region(&pdev->dev, res_gpo->start,
+				 resource_size(res_gpo), MODULE_NAME "_gpo"))
+		dev_warn(&pdev->dev,
+			"GPO I/O resource busy, probably claimed by ACPI\n");
+
+	vx855gpio_gpio_setup(vg);
+
+	return devm_gpiochip_add_data(&pdev->dev, &vg->gpio, vg);
+}
+
+static struct platform_driver vx855gpio_driver = {
+	.driver = {
+		.name	= MODULE_NAME,
+	},
+	.probe		= vx855gpio_probe,
+};
+
+module_platform_driver(vx855gpio_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
+MODULE_DESCRIPTION("GPIO driver for the VIA VX855 chipset");
+MODULE_ALIAS("platform:vx855_gpio");