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, 424 insertions, 0 deletions

diff --git a/drivers/char/ds1620.c b/drivers/char/ds1620.c
new file mode 100644
index 000000000..44a1cdbd4
--- /dev/null
+++ b/drivers/char/ds1620.c
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620
+ *   thermometer driver (as used in the Rebel.com NetWinder)
+ */
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/delay.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/capability.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+
+#include <mach/hardware.h>
+#include <asm/mach-types.h>
+#include <linux/uaccess.h>
+#include <asm/therm.h>
+
+#ifdef CONFIG_PROC_FS
+/* define for /proc interface */
+#define THERM_USE_PROC
+#endif
+
+/* Definitions for DS1620 chip */
+#define THERM_START_CONVERT	0xee
+#define THERM_RESET		0xaf
+#define THERM_READ_CONFIG	0xac
+#define THERM_READ_TEMP		0xaa
+#define THERM_READ_TL		0xa2
+#define THERM_READ_TH		0xa1
+#define THERM_WRITE_CONFIG	0x0c
+#define THERM_WRITE_TL		0x02
+#define THERM_WRITE_TH		0x01
+
+#define CFG_CPU			2
+#define CFG_1SHOT		1
+
+static DEFINE_MUTEX(ds1620_mutex);
+static const char *fan_state[] = { "off", "on", "on (hardwired)" };
+
+/*
+ * Start of NetWinder specifics
+ *  Note!  We have to hold the gpio lock with IRQs disabled over the
+ *  whole of our transaction to the Dallas chip, since there is a
+ *  chance that the WaveArtist driver could touch these bits to
+ *  enable or disable the speaker.
+ */
+extern unsigned int system_rev;
+
+static inline void netwinder_ds1620_set_clk(int clk)
+{
+	nw_gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);
+}
+
+static inline void netwinder_ds1620_set_data(int dat)
+{
+	nw_gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);
+}
+
+static inline int netwinder_ds1620_get_data(void)
+{
+	return nw_gpio_read() & GPIO_DATA;
+}
+
+static inline void netwinder_ds1620_set_data_dir(int dir)
+{
+	nw_gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
+}
+
+static inline void netwinder_ds1620_reset(void)
+{
+	nw_cpld_modify(CPLD_DS_ENABLE, 0);
+	nw_cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE);
+}
+
+static inline void netwinder_lock(unsigned long *flags)
+{
+	raw_spin_lock_irqsave(&nw_gpio_lock, *flags);
+}
+
+static inline void netwinder_unlock(unsigned long *flags)
+{
+	raw_spin_unlock_irqrestore(&nw_gpio_lock, *flags);
+}
+
+static inline void netwinder_set_fan(int i)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&nw_gpio_lock, flags);
+	nw_gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0);
+	raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
+}
+
+static inline int netwinder_get_fan(void)
+{
+	if ((system_rev & 0xf000) == 0x4000)
+		return FAN_ALWAYS_ON;
+
+	return (nw_gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF;
+}
+
+/*
+ * End of NetWinder specifics
+ */
+
+static void ds1620_send_bits(int nr, int value)
+{
+	int i;
+
+	for (i = 0; i < nr; i++) {
+		netwinder_ds1620_set_data(value & 1);
+		netwinder_ds1620_set_clk(0);
+		udelay(1);
+		netwinder_ds1620_set_clk(1);
+		udelay(1);
+
+		value >>= 1;
+	}
+}
+
+static unsigned int ds1620_recv_bits(int nr)
+{
+	unsigned int value = 0, mask = 1;
+	int i;
+
+	netwinder_ds1620_set_data(0);
+
+	for (i = 0; i < nr; i++) {
+		netwinder_ds1620_set_clk(0);
+		udelay(1);
+
+		if (netwinder_ds1620_get_data())
+			value |= mask;
+
+		mask <<= 1;
+
+		netwinder_ds1620_set_clk(1);
+		udelay(1);
+	}
+
+	return value;
+}
+
+static void ds1620_out(int cmd, int bits, int value)
+{
+	unsigned long flags;
+
+	netwinder_lock(&flags);
+	netwinder_ds1620_set_clk(1);
+	netwinder_ds1620_set_data_dir(0);
+	netwinder_ds1620_reset();
+
+	udelay(1);
+
+	ds1620_send_bits(8, cmd);
+	if (bits)
+		ds1620_send_bits(bits, value);
+
+	udelay(1);
+
+	netwinder_ds1620_reset();
+	netwinder_unlock(&flags);
+
+	msleep(20);
+}
+
+static unsigned int ds1620_in(int cmd, int bits)
+{
+	unsigned long flags;
+	unsigned int value;
+
+	netwinder_lock(&flags);
+	netwinder_ds1620_set_clk(1);
+	netwinder_ds1620_set_data_dir(0);
+	netwinder_ds1620_reset();
+
+	udelay(1);
+
+	ds1620_send_bits(8, cmd);
+
+	netwinder_ds1620_set_data_dir(1);
+	value = ds1620_recv_bits(bits);
+
+	netwinder_ds1620_reset();
+	netwinder_unlock(&flags);
+
+	return value;
+}
+
+static int cvt_9_to_int(unsigned int val)
+{
+	if (val & 0x100)
+		val |= 0xfffffe00;
+
+	return val;
+}
+
+static void ds1620_write_state(struct therm *therm)
+{
+	ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
+	ds1620_out(THERM_WRITE_TL, 9, therm->lo);
+	ds1620_out(THERM_WRITE_TH, 9, therm->hi);
+	ds1620_out(THERM_START_CONVERT, 0, 0);
+}
+
+static void ds1620_read_state(struct therm *therm)
+{
+	therm->lo = cvt_9_to_int(ds1620_in(THERM_READ_TL, 9));
+	therm->hi = cvt_9_to_int(ds1620_in(THERM_READ_TH, 9));
+}
+
+static int ds1620_open(struct inode *inode, struct file *file)
+{
+	return stream_open(inode, file);
+}
+
+static ssize_t
+ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
+{
+	signed int cur_temp;
+	signed char cur_temp_degF;
+
+	cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1;
+
+	/* convert to Fahrenheit, as per wdt.c */
+	cur_temp_degF = (cur_temp * 9) / 5 + 32;
+
+	if (copy_to_user(buf, &cur_temp_degF, 1))
+		return -EFAULT;
+
+	return 1;
+}
+
+static int
+ds1620_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct therm therm;
+	union {
+		struct therm __user *therm;
+		int __user *i;
+	} uarg;
+	int i;
+
+	uarg.i = (int __user *)arg;
+
+	switch(cmd) {
+	case CMD_SET_THERMOSTATE:
+	case CMD_SET_THERMOSTATE2:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (cmd == CMD_SET_THERMOSTATE) {
+			if (get_user(therm.hi, uarg.i))
+				return -EFAULT;
+			therm.lo = therm.hi - 3;
+		} else {
+			if (copy_from_user(&therm, uarg.therm, sizeof(therm)))
+				return -EFAULT;
+		}
+
+		therm.lo <<= 1;
+		therm.hi <<= 1;
+
+		ds1620_write_state(&therm);
+		break;
+
+	case CMD_GET_THERMOSTATE:
+	case CMD_GET_THERMOSTATE2:
+		ds1620_read_state(&therm);
+
+		therm.lo >>= 1;
+		therm.hi >>= 1;
+
+		if (cmd == CMD_GET_THERMOSTATE) {
+			if (put_user(therm.hi, uarg.i))
+				return -EFAULT;
+		} else {
+			if (copy_to_user(uarg.therm, &therm, sizeof(therm)))
+				return -EFAULT;
+		}
+		break;
+
+	case CMD_GET_TEMPERATURE:
+	case CMD_GET_TEMPERATURE2:
+		i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
+
+		if (cmd == CMD_GET_TEMPERATURE)
+			i >>= 1;
+
+		return put_user(i, uarg.i) ? -EFAULT : 0;
+
+	case CMD_GET_STATUS:
+		i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3;
+
+		return put_user(i, uarg.i) ? -EFAULT : 0;
+
+	case CMD_GET_FAN:
+		i = netwinder_get_fan();
+
+		return put_user(i, uarg.i) ? -EFAULT : 0;
+
+	case CMD_SET_FAN:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (get_user(i, uarg.i))
+			return -EFAULT;
+
+		netwinder_set_fan(i);
+		break;
+		
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static long
+ds1620_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	int ret;
+
+	mutex_lock(&ds1620_mutex);
+	ret = ds1620_ioctl(file, cmd, arg);
+	mutex_unlock(&ds1620_mutex);
+
+	return ret;
+}
+
+#ifdef THERM_USE_PROC
+static int ds1620_proc_therm_show(struct seq_file *m, void *v)
+{
+	struct therm th;
+	int temp;
+
+	ds1620_read_state(&th);
+	temp =  cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
+
+	seq_printf(m, "Thermostat: HI %i.%i, LOW %i.%i; temperature: %i.%i C, fan %s\n",
+		   th.hi >> 1, th.hi & 1 ? 5 : 0,
+		   th.lo >> 1, th.lo & 1 ? 5 : 0,
+		   temp  >> 1, temp  & 1 ? 5 : 0,
+		   fan_state[netwinder_get_fan()]);
+	return 0;
+}
+#endif
+
+static const struct file_operations ds1620_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ds1620_open,
+	.read		= ds1620_read,
+	.unlocked_ioctl	= ds1620_unlocked_ioctl,
+};
+
+static struct miscdevice ds1620_miscdev = {
+	TEMP_MINOR,
+	"temp",
+	&ds1620_fops
+};
+
+static int __init ds1620_init(void)
+{
+	int ret;
+	struct therm th, th_start;
+
+	if (!machine_is_netwinder())
+		return -ENODEV;
+
+	ds1620_out(THERM_RESET, 0, 0);
+	ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
+	ds1620_out(THERM_START_CONVERT, 0, 0);
+
+	/*
+	 * Trigger the fan to start by setting
+	 * temperature high point low.  This kicks
+	 * the fan into action.
+	 */
+	ds1620_read_state(&th);
+	th_start.lo = 0;
+	th_start.hi = 1;
+	ds1620_write_state(&th_start);
+
+	msleep(2000);
+
+	ds1620_write_state(&th);
+
+	ret = misc_register(&ds1620_miscdev);
+	if (ret < 0)
+		return ret;
+
+#ifdef THERM_USE_PROC
+	if (!proc_create_single("therm", 0, NULL, ds1620_proc_therm_show))
+		printk(KERN_ERR "therm: unable to register /proc/therm\n");
+#endif
+
+	ds1620_read_state(&th);
+	ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
+
+	printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, "
+	       "current %i.%i C, fan %s.\n",
+	       th.hi >> 1, th.hi & 1 ? 5 : 0,
+	       th.lo >> 1, th.lo & 1 ? 5 : 0,
+	       ret   >> 1, ret   & 1 ? 5 : 0,
+	       fan_state[netwinder_get_fan()]);
+
+	return 0;
+}
+
+static void __exit ds1620_exit(void)
+{
+#ifdef THERM_USE_PROC
+	remove_proc_entry("therm", NULL);
+#endif
+	misc_deregister(&ds1620_miscdev);
+}
+
+module_init(ds1620_init);
+module_exit(ds1620_exit);
+
+MODULE_DESCRIPTION("Dallas Semiconductor DS1620 thermometer driver");
+MODULE_LICENSE("GPL");