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, 410 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-it87.c b/drivers/gpio/gpio-it87.c
new file mode 100644
index 000000000..2ad3c2393
--- /dev/null
+++ b/drivers/gpio/gpio-it87.c
@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  GPIO interface for IT87xx Super I/O chips
+ *
+ *  Author: Diego Elio Pettenò <flameeyes@flameeyes.eu>
+ *  Copyright (c) 2017 Google, Inc.
+ *
+ *  Based on it87_wdt.c     by Oliver Schuster
+ *           gpio-it8761e.c by Denis Turischev
+ *           gpio-stmpe.c   by Rabin Vincent
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cleanup.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/gpio/driver.h>
+
+/* Chip Id numbers */
+#define NO_DEV_ID	0xffff
+#define IT8613_ID	0x8613
+#define IT8620_ID	0x8620
+#define IT8628_ID	0x8628
+#define IT8718_ID       0x8718
+#define IT8728_ID	0x8728
+#define IT8732_ID	0x8732
+#define IT8761_ID	0x8761
+#define IT8772_ID	0x8772
+#define IT8786_ID	0x8786
+
+/* IO Ports */
+#define REG		0x2e
+#define VAL		0x2f
+
+/* Logical device Numbers LDN */
+#define GPIO		0x07
+
+/* Configuration Registers and Functions */
+#define LDNREG		0x07
+#define CHIPID		0x20
+#define CHIPREV		0x22
+
+/**
+ * struct it87_gpio - it87-specific GPIO chip
+ * @chip: the underlying gpio_chip structure
+ * @lock: a lock to avoid races between operations
+ * @io_base: base address for gpio ports
+ * @io_size: size of the port rage starting from io_base.
+ * @output_base: Super I/O register address for Output Enable register
+ * @simple_base: Super I/O 'Simple I/O' Enable register
+ * @simple_size: Super IO 'Simple I/O' Enable register size; this is
+ *	required because IT87xx chips might only provide Simple I/O
+ *	switches on a subset of lines, whereas the others keep the
+ *	same status all time.
+ */
+struct it87_gpio {
+	struct gpio_chip chip;
+	spinlock_t lock;
+	u16 io_base;
+	u16 io_size;
+	u8 output_base;
+	u8 simple_base;
+	u8 simple_size;
+};
+
+static struct it87_gpio it87_gpio_chip = {
+	.lock = __SPIN_LOCK_UNLOCKED(it87_gpio_chip.lock),
+};
+
+/* Superio chip access functions; copied from wdt_it87 */
+
+static inline int superio_enter(void)
+{
+	/*
+	 * Try to reserve REG and REG + 1 for exclusive access.
+	 */
+	if (!request_muxed_region(REG, 2, KBUILD_MODNAME))
+		return -EBUSY;
+
+	outb(0x87, REG);
+	outb(0x01, REG);
+	outb(0x55, REG);
+	outb(0x55, REG);
+	return 0;
+}
+
+static inline void superio_exit(void)
+{
+	outb(0x02, REG);
+	outb(0x02, VAL);
+	release_region(REG, 2);
+}
+
+static inline void superio_select(int ldn)
+{
+	outb(LDNREG, REG);
+	outb(ldn, VAL);
+}
+
+static inline int superio_inb(int reg)
+{
+	outb(reg, REG);
+	return inb(VAL);
+}
+
+static inline void superio_outb(int val, int reg)
+{
+	outb(reg, REG);
+	outb(val, VAL);
+}
+
+static inline int superio_inw(int reg)
+{
+	int val;
+
+	outb(reg++, REG);
+	val = inb(VAL) << 8;
+	outb(reg, REG);
+	val |= inb(VAL);
+	return val;
+}
+
+static inline void superio_set_mask(int mask, int reg)
+{
+	u8 curr_val = superio_inb(reg);
+	u8 new_val = curr_val | mask;
+
+	if (curr_val != new_val)
+		superio_outb(new_val, reg);
+}
+
+static inline void superio_clear_mask(int mask, int reg)
+{
+	u8 curr_val = superio_inb(reg);
+	u8 new_val = curr_val & ~mask;
+
+	if (curr_val != new_val)
+		superio_outb(new_val, reg);
+}
+
+static int it87_gpio_request(struct gpio_chip *chip, unsigned gpio_num)
+{
+	u8 mask, group;
+	int rc = 0;
+	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
+
+	mask = 1 << (gpio_num % 8);
+	group = (gpio_num / 8);
+
+	spin_lock(&it87_gpio->lock);
+
+	rc = superio_enter();
+	if (rc)
+		goto exit;
+
+	/* not all the IT87xx chips support Simple I/O and not all of
+	 * them allow all the lines to be set/unset to Simple I/O.
+	 */
+	if (group < it87_gpio->simple_size)
+		superio_set_mask(mask, group + it87_gpio->simple_base);
+
+	/* clear output enable, setting the pin to input, as all the
+	 * newly-exported GPIO interfaces are set to input.
+	 */
+	superio_clear_mask(mask, group + it87_gpio->output_base);
+
+	superio_exit();
+
+exit:
+	spin_unlock(&it87_gpio->lock);
+	return rc;
+}
+
+static int it87_gpio_get(struct gpio_chip *chip, unsigned gpio_num)
+{
+	u16 reg;
+	u8 mask;
+	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
+
+	mask = 1 << (gpio_num % 8);
+	reg = (gpio_num / 8) + it87_gpio->io_base;
+
+	return !!(inb(reg) & mask);
+}
+
+static int it87_gpio_direction_in(struct gpio_chip *chip, unsigned gpio_num)
+{
+	u8 mask, group;
+	int rc = 0;
+	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
+
+	mask = 1 << (gpio_num % 8);
+	group = (gpio_num / 8);
+
+	spin_lock(&it87_gpio->lock);
+
+	rc = superio_enter();
+	if (rc)
+		goto exit;
+
+	/* clear the output enable bit */
+	superio_clear_mask(mask, group + it87_gpio->output_base);
+
+	superio_exit();
+
+exit:
+	spin_unlock(&it87_gpio->lock);
+	return rc;
+}
+
+static int it87_gpio_set(struct gpio_chip *chip, unsigned int gpio_num, int val)
+{
+	u8 mask, curr_vals;
+	u16 reg;
+	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
+
+	mask = 1 << (gpio_num % 8);
+	reg = (gpio_num / 8) + it87_gpio->io_base;
+
+	curr_vals = inb(reg);
+	if (val)
+		outb(curr_vals | mask, reg);
+	else
+		outb(curr_vals & ~mask, reg);
+
+	return 0;
+}
+
+static int it87_gpio_direction_out(struct gpio_chip *chip,
+				   unsigned gpio_num, int val)
+{
+	u8 mask, group;
+	int rc = 0;
+	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
+
+	mask = 1 << (gpio_num % 8);
+	group = (gpio_num / 8);
+
+	guard(spinlock)(&it87_gpio->lock);
+
+	rc = superio_enter();
+	if (rc)
+		return rc;
+
+	/* set the output enable bit */
+	superio_set_mask(mask, group + it87_gpio->output_base);
+
+	rc = it87_gpio_set(chip, gpio_num, val);
+	superio_exit();
+	return rc;
+}
+
+static const struct gpio_chip it87_template_chip = {
+	.label			= KBUILD_MODNAME,
+	.owner			= THIS_MODULE,
+	.request		= it87_gpio_request,
+	.get			= it87_gpio_get,
+	.direction_input	= it87_gpio_direction_in,
+	.set			= it87_gpio_set,
+	.direction_output	= it87_gpio_direction_out,
+	.base			= -1
+};
+
+static int __init it87_gpio_init(void)
+{
+	int rc = 0, i;
+	u16 chip_type;
+	u8 chip_rev, gpio_ba_reg;
+	char *labels, **labels_table;
+
+	struct it87_gpio *it87_gpio = &it87_gpio_chip;
+
+	rc = superio_enter();
+	if (rc)
+		return rc;
+
+	chip_type = superio_inw(CHIPID);
+	chip_rev  = superio_inb(CHIPREV) & 0x0f;
+	superio_exit();
+
+	it87_gpio->chip = it87_template_chip;
+
+	switch (chip_type) {
+	case IT8613_ID:
+		gpio_ba_reg = 0x62;
+		it87_gpio->io_size = 8;  /* it8613 only needs 6, use 8 for alignment */
+		it87_gpio->output_base = 0xc8;
+		it87_gpio->simple_base = 0xc0;
+		it87_gpio->simple_size = 6;
+		it87_gpio->chip.ngpio = 64;  /* has 48, use 64 for convenient calc */
+		break;
+	case IT8620_ID:
+	case IT8628_ID:
+		gpio_ba_reg = 0x62;
+		it87_gpio->io_size = 11;
+		it87_gpio->output_base = 0xc8;
+		it87_gpio->simple_size = 0;
+		it87_gpio->chip.ngpio = 64;
+		break;
+	case IT8718_ID:
+	case IT8728_ID:
+	case IT8732_ID:
+	case IT8772_ID:
+	case IT8786_ID:
+		gpio_ba_reg = 0x62;
+		it87_gpio->io_size = 8;
+		it87_gpio->output_base = 0xc8;
+		it87_gpio->simple_base = 0xc0;
+		it87_gpio->simple_size = 5;
+		it87_gpio->chip.ngpio = 64;
+		break;
+	case IT8761_ID:
+		gpio_ba_reg = 0x60;
+		it87_gpio->io_size = 4;
+		it87_gpio->output_base = 0xf0;
+		it87_gpio->simple_size = 0;
+		it87_gpio->chip.ngpio = 16;
+		break;
+	case NO_DEV_ID:
+		pr_err("no device\n");
+		return -ENODEV;
+	default:
+		pr_err("Unknown Chip found, Chip %04x Revision %x\n",
+		       chip_type, chip_rev);
+		return -ENODEV;
+	}
+
+	rc = superio_enter();
+	if (rc)
+		return rc;
+
+	superio_select(GPIO);
+
+	/* fetch GPIO base address */
+	it87_gpio->io_base = superio_inw(gpio_ba_reg);
+
+	superio_exit();
+
+	pr_info("Found Chip IT%04x rev %x. %u GPIO lines starting at %04xh\n",
+		chip_type, chip_rev, it87_gpio->chip.ngpio,
+		it87_gpio->io_base);
+
+	if (!request_region(it87_gpio->io_base, it87_gpio->io_size,
+							KBUILD_MODNAME))
+		return -EBUSY;
+
+	/* Set up aliases for the GPIO connection.
+	 *
+	 * ITE documentation for recent chips such as the IT8728F
+	 * refers to the GPIO lines as GPxy, with a coordinates system
+	 * where x is the GPIO group (starting from 1) and y is the
+	 * bit within the group.
+	 *
+	 * By creating these aliases, we make it easier to understand
+	 * to which GPIO pin we're referring to.
+	 */
+	labels = kcalloc(it87_gpio->chip.ngpio, sizeof("it87_gpXY"),
+								GFP_KERNEL);
+	labels_table = kcalloc(it87_gpio->chip.ngpio, sizeof(const char *),
+								GFP_KERNEL);
+
+	if (!labels || !labels_table) {
+		rc = -ENOMEM;
+		goto labels_free;
+	}
+
+	for (i = 0; i < it87_gpio->chip.ngpio; i++) {
+		char *label = &labels[i * sizeof("it87_gpXY")];
+
+		sprintf(label, "it87_gp%u%u", 1+(i/8), i%8);
+		labels_table[i] = label;
+	}
+
+	it87_gpio->chip.names = (const char *const*)labels_table;
+
+	rc = gpiochip_add_data(&it87_gpio->chip, it87_gpio);
+	if (rc)
+		goto labels_free;
+
+	return 0;
+
+labels_free:
+	kfree(labels_table);
+	kfree(labels);
+	release_region(it87_gpio->io_base, it87_gpio->io_size);
+	return rc;
+}
+
+static void __exit it87_gpio_exit(void)
+{
+	struct it87_gpio *it87_gpio = &it87_gpio_chip;
+
+	gpiochip_remove(&it87_gpio->chip);
+	release_region(it87_gpio->io_base, it87_gpio->io_size);
+	kfree(it87_gpio->chip.names[0]);
+	kfree(it87_gpio->chip.names);
+}
+
+module_init(it87_gpio_init);
+module_exit(it87_gpio_exit);
+
+MODULE_AUTHOR("Diego Elio Pettenò <flameeyes@flameeyes.eu>");
+MODULE_DESCRIPTION("GPIO interface for IT87xx Super I/O chips");
+MODULE_LICENSE("GPL");