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, 217 insertions, 0 deletions

diff --git a/drivers/hwmon/lm70.c b/drivers/hwmon/lm70.c
new file mode 100644
index 000000000..8b525725f
--- /dev/null
+++ b/drivers/hwmon/lm70.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * lm70.c
+ *
+ * The LM70 is a temperature sensor chip from National Semiconductor (NS).
+ * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com>
+ *
+ * The LM70 communicates with a host processor via an SPI/Microwire Bus
+ * interface. The complete datasheet is available at TI's website
+ * here:
+ * https://www.ti.com/product/LM70
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/sysfs.h>
+#include <linux/hwmon.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+
+#define DRVNAME		"lm70"
+
+#define LM70_CHIP_LM70		0	/* original NS LM70 */
+#define LM70_CHIP_TMP121	1	/* TI TMP121/TMP123 */
+#define LM70_CHIP_LM71		2	/* NS LM71 */
+#define LM70_CHIP_LM74		3	/* NS LM74 */
+#define LM70_CHIP_TMP122	4	/* TI TMP122/TMP124 */
+#define LM70_CHIP_TMP125	5	/* TI TMP125 */
+
+struct lm70 {
+	struct spi_device *spi;
+	struct mutex lock;
+	unsigned int chip;
+};
+
+/* sysfs hook function */
+static ssize_t temp1_input_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct lm70 *p_lm70 = dev_get_drvdata(dev);
+	struct spi_device *spi = p_lm70->spi;
+	int status, val = 0;
+	u8 rxbuf[2];
+	s16 raw = 0;
+
+	if (mutex_lock_interruptible(&p_lm70->lock))
+		return -ERESTARTSYS;
+
+	/*
+	 * spi_read() requires a DMA-safe buffer; so we use
+	 * spi_write_then_read(), transmitting 0 bytes.
+	 */
+	status = spi_write_then_read(spi, NULL, 0, &rxbuf[0], 2);
+	if (status < 0) {
+		dev_warn(dev, "spi_write_then_read failed with status %d\n",
+			 status);
+		goto out;
+	}
+	raw = (rxbuf[0] << 8) + rxbuf[1];
+	dev_dbg(dev, "rxbuf[0] : 0x%02x rxbuf[1] : 0x%02x raw=0x%04x\n",
+		rxbuf[0], rxbuf[1], raw);
+
+	/*
+	 * LM70:
+	 * The "raw" temperature read into rxbuf[] is a 16-bit signed 2's
+	 * complement value. Only the MSB 11 bits (1 sign + 10 temperature
+	 * bits) are meaningful; the LSB 5 bits are to be discarded.
+	 * See the datasheet.
+	 *
+	 * Further, each bit represents 0.25 degrees Celsius; so, multiply
+	 * by 0.25. Also multiply by 1000 to represent in millidegrees
+	 * Celsius.
+	 * So it's equivalent to multiplying by 0.25 * 1000 = 250.
+	 *
+	 * LM74 and TMP121/TMP122/TMP123/TMP124:
+	 * 13 bits of 2's complement data, discard LSB 3 bits,
+	 * resolution 0.0625 degrees celsius.
+	 *
+	 * LM71:
+	 * 14 bits of 2's complement data, discard LSB 2 bits,
+	 * resolution 0.0312 degrees celsius.
+	 *
+	 * TMP125:
+	 * MSB/D15 is a leading zero. D14 is the sign-bit. This is
+	 * followed by 9 temperature bits (D13..D5) in 2's complement
+	 * data format with a resolution of 0.25 degrees celsius per unit.
+	 * LSB 5 bits (D4..D0) share the same value as D5 and get discarded.
+	 */
+	switch (p_lm70->chip) {
+	case LM70_CHIP_LM70:
+		val = ((int)raw / 32) * 250;
+		break;
+
+	case LM70_CHIP_TMP121:
+	case LM70_CHIP_TMP122:
+	case LM70_CHIP_LM74:
+		val = ((int)raw / 8) * 625 / 10;
+		break;
+
+	case LM70_CHIP_LM71:
+		val = ((int)raw / 4) * 3125 / 100;
+		break;
+
+	case LM70_CHIP_TMP125:
+		val = (sign_extend32(raw, 14) / 32) * 250;
+		break;
+	}
+
+	status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */
+out:
+	mutex_unlock(&p_lm70->lock);
+	return status;
+}
+
+static DEVICE_ATTR_RO(temp1_input);
+
+static struct attribute *lm70_attrs[] = {
+	&dev_attr_temp1_input.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(lm70);
+
+/*----------------------------------------------------------------------*/
+
+#ifdef CONFIG_OF
+static const struct of_device_id lm70_of_ids[] = {
+	{
+		.compatible = "ti,lm70",
+		.data = (void *) LM70_CHIP_LM70,
+	},
+	{
+		.compatible = "ti,tmp121",
+		.data = (void *) LM70_CHIP_TMP121,
+	},
+	{
+		.compatible = "ti,tmp122",
+		.data = (void *) LM70_CHIP_TMP122,
+	},
+	{
+		.compatible = "ti,tmp125",
+		.data = (void *) LM70_CHIP_TMP125,
+	},
+	{
+		.compatible = "ti,lm71",
+		.data = (void *) LM70_CHIP_LM71,
+	},
+	{
+		.compatible = "ti,lm74",
+		.data = (void *) LM70_CHIP_LM74,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, lm70_of_ids);
+#endif
+
+static int lm70_probe(struct spi_device *spi)
+{
+	struct device *hwmon_dev;
+	struct lm70 *p_lm70;
+	int chip;
+
+	chip = (kernel_ulong_t)spi_get_device_match_data(spi);
+
+	/* signaling is SPI_MODE_0 */
+	if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
+		return -EINVAL;
+
+	/* NOTE:  we assume 8-bit words, and convert to 16 bits manually */
+
+	p_lm70 = devm_kzalloc(&spi->dev, sizeof(*p_lm70), GFP_KERNEL);
+	if (!p_lm70)
+		return -ENOMEM;
+
+	mutex_init(&p_lm70->lock);
+	p_lm70->chip = chip;
+	p_lm70->spi = spi;
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(&spi->dev,
+							   spi->modalias,
+							   p_lm70, lm70_groups);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct spi_device_id lm70_ids[] = {
+	{ "lm70",   LM70_CHIP_LM70 },
+	{ "tmp121", LM70_CHIP_TMP121 },
+	{ "tmp122", LM70_CHIP_TMP122 },
+	{ "tmp125", LM70_CHIP_TMP125 },
+	{ "lm71",   LM70_CHIP_LM71 },
+	{ "lm74",   LM70_CHIP_LM74 },
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, lm70_ids);
+
+static struct spi_driver lm70_driver = {
+	.driver = {
+		.name	= "lm70",
+		.of_match_table	= of_match_ptr(lm70_of_ids),
+	},
+	.id_table = lm70_ids,
+	.probe	= lm70_probe,
+};
+
+module_spi_driver(lm70_driver);
+
+MODULE_AUTHOR("Kaiwan N Billimoria");
+MODULE_DESCRIPTION("NS LM70 and compatibles Linux driver");
+MODULE_LICENSE("GPL");