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, 404 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-meson.c b/drivers/rtc/rtc-meson.c
new file mode 100644
index 000000000..21eceb9e2
--- /dev/null
+++ b/drivers/rtc/rtc-meson.c
@@ -0,0 +1,404 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RTC driver for the interal RTC block in the Amlogic Meson6, Meson8,
+ * Meson8b and Meson8m2 SoCs.
+ *
+ * The RTC is split in to two parts, the AHB front end and a simple serial
+ * connection to the actual registers. This driver manages both parts.
+ *
+ * Copyright (c) 2018 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+ * Copyright (c) 2015 Ben Dooks <ben.dooks@codethink.co.uk> for Codethink Ltd
+ * Based on origin by Carlo Caione <carlo@endlessm.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/rtc.h>
+
+/* registers accessed from cpu bus */
+#define RTC_ADDR0				0x00
+	#define RTC_ADDR0_LINE_SCLK		BIT(0)
+	#define RTC_ADDR0_LINE_SEN		BIT(1)
+	#define RTC_ADDR0_LINE_SDI		BIT(2)
+	#define RTC_ADDR0_START_SER		BIT(17)
+	#define RTC_ADDR0_WAIT_SER		BIT(22)
+	#define RTC_ADDR0_DATA			GENMASK(31, 24)
+
+#define RTC_ADDR1				0x04
+	#define RTC_ADDR1_SDO			BIT(0)
+	#define RTC_ADDR1_S_READY		BIT(1)
+
+#define RTC_ADDR2				0x08
+#define RTC_ADDR3				0x0c
+
+#define RTC_REG4				0x10
+	#define RTC_REG4_STATIC_VALUE		GENMASK(7, 0)
+
+/* rtc registers accessed via rtc-serial interface */
+#define RTC_COUNTER		(0)
+#define RTC_SEC_ADJ		(2)
+#define RTC_REGMEM_0		(4)
+#define RTC_REGMEM_1		(5)
+#define RTC_REGMEM_2		(6)
+#define RTC_REGMEM_3		(7)
+
+#define RTC_ADDR_BITS		(3)	/* number of address bits to send */
+#define RTC_DATA_BITS		(32)	/* number of data bits to tx/rx */
+
+#define MESON_STATIC_BIAS_CUR	(0x5 << 1)
+#define MESON_STATIC_VOLTAGE	(0x3 << 11)
+#define MESON_STATIC_DEFAULT    (MESON_STATIC_BIAS_CUR | MESON_STATIC_VOLTAGE)
+
+struct meson_rtc {
+	struct device		*dev;		/* device we bound from */
+	struct reset_control	*reset;		/* reset source */
+	struct regulator	*vdd;		/* voltage input */
+	struct regmap		*peripheral;	/* peripheral registers */
+	struct regmap		*serial;	/* serial registers */
+};
+
+static const struct regmap_config meson_rtc_peripheral_regmap_config = {
+	.name		= "peripheral-registers",
+	.reg_bits	= 8,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+	.max_register	= RTC_REG4,
+};
+
+/* RTC front-end serialiser controls */
+
+static void meson_rtc_sclk_pulse(struct meson_rtc *rtc)
+{
+	udelay(5);
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SCLK, 0);
+	udelay(5);
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SCLK,
+			   RTC_ADDR0_LINE_SCLK);
+}
+
+static void meson_rtc_send_bit(struct meson_rtc *rtc, unsigned int bit)
+{
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SDI,
+			   bit ? RTC_ADDR0_LINE_SDI : 0);
+	meson_rtc_sclk_pulse(rtc);
+}
+
+static void meson_rtc_send_bits(struct meson_rtc *rtc, u32 data,
+				unsigned int nr)
+{
+	u32 bit = 1 << (nr - 1);
+
+	while (bit) {
+		meson_rtc_send_bit(rtc, data & bit);
+		bit >>= 1;
+	}
+}
+
+static void meson_rtc_set_dir(struct meson_rtc *rtc, u32 mode)
+{
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SEN, 0);
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SDI, 0);
+	meson_rtc_send_bit(rtc, mode);
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SDI, 0);
+}
+
+static u32 meson_rtc_get_data(struct meson_rtc *rtc)
+{
+	u32 tmp, val = 0;
+	int bit;
+
+	for (bit = 0; bit < RTC_DATA_BITS; bit++) {
+		meson_rtc_sclk_pulse(rtc);
+		val <<= 1;
+
+		regmap_read(rtc->peripheral, RTC_ADDR1, &tmp);
+		val |= tmp & RTC_ADDR1_SDO;
+	}
+
+	return val;
+}
+
+static int meson_rtc_get_bus(struct meson_rtc *rtc)
+{
+	int ret, retries;
+	u32 val;
+
+	/* prepare bus for transfers, set all lines low */
+	val = RTC_ADDR0_LINE_SDI | RTC_ADDR0_LINE_SEN | RTC_ADDR0_LINE_SCLK;
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, val, 0);
+
+	for (retries = 0; retries < 3; retries++) {
+		/* wait for the bus to be ready */
+		if (!regmap_read_poll_timeout(rtc->peripheral, RTC_ADDR1, val,
+					      val & RTC_ADDR1_S_READY, 10,
+					      10000))
+			return 0;
+
+		dev_warn(rtc->dev, "failed to get bus, resetting RTC\n");
+
+		ret = reset_control_reset(rtc->reset);
+		if (ret)
+			return ret;
+	}
+
+	dev_err(rtc->dev, "bus is not ready\n");
+	return -ETIMEDOUT;
+}
+
+static int meson_rtc_serial_bus_reg_read(void *context, unsigned int reg,
+					 unsigned int *data)
+{
+	struct meson_rtc *rtc = context;
+	int ret;
+
+	ret = meson_rtc_get_bus(rtc);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SEN,
+			   RTC_ADDR0_LINE_SEN);
+	meson_rtc_send_bits(rtc, reg, RTC_ADDR_BITS);
+	meson_rtc_set_dir(rtc, 0);
+	*data = meson_rtc_get_data(rtc);
+
+	return 0;
+}
+
+static int meson_rtc_serial_bus_reg_write(void *context, unsigned int reg,
+					  unsigned int data)
+{
+	struct meson_rtc *rtc = context;
+	int ret;
+
+	ret = meson_rtc_get_bus(rtc);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SEN,
+			   RTC_ADDR0_LINE_SEN);
+	meson_rtc_send_bits(rtc, data, RTC_DATA_BITS);
+	meson_rtc_send_bits(rtc, reg, RTC_ADDR_BITS);
+	meson_rtc_set_dir(rtc, 1);
+
+	return 0;
+}
+
+static const struct regmap_bus meson_rtc_serial_bus = {
+	.reg_read	= meson_rtc_serial_bus_reg_read,
+	.reg_write	= meson_rtc_serial_bus_reg_write,
+};
+
+static const struct regmap_config meson_rtc_serial_regmap_config = {
+	.name		= "serial-registers",
+	.reg_bits	= 4,
+	.reg_stride	= 1,
+	.val_bits	= 32,
+	.max_register	= RTC_REGMEM_3,
+	.fast_io	= false,
+};
+
+static int meson_rtc_write_static(struct meson_rtc *rtc, u32 data)
+{
+	u32 tmp;
+
+	regmap_write(rtc->peripheral, RTC_REG4,
+		     FIELD_PREP(RTC_REG4_STATIC_VALUE, (data >> 8)));
+
+	/* write the static value and start the auto serializer */
+	tmp = FIELD_PREP(RTC_ADDR0_DATA, (data & 0xff)) | RTC_ADDR0_START_SER;
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0,
+			   RTC_ADDR0_DATA | RTC_ADDR0_START_SER, tmp);
+
+	/* wait for the auto serializer to complete */
+	return regmap_read_poll_timeout(rtc->peripheral, RTC_REG4, tmp,
+					!(tmp & RTC_ADDR0_WAIT_SER), 10,
+					10000);
+}
+
+/* RTC interface layer functions */
+
+static int meson_rtc_gettime(struct device *dev, struct rtc_time *tm)
+{
+	struct meson_rtc *rtc = dev_get_drvdata(dev);
+	u32 time;
+	int ret;
+
+	ret = regmap_read(rtc->serial, RTC_COUNTER, &time);
+	if (!ret)
+		rtc_time64_to_tm(time, tm);
+
+	return ret;
+}
+
+static int meson_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+	struct meson_rtc *rtc = dev_get_drvdata(dev);
+
+	return regmap_write(rtc->serial, RTC_COUNTER, rtc_tm_to_time64(tm));
+}
+
+static const struct rtc_class_ops meson_rtc_ops = {
+	.read_time	= meson_rtc_gettime,
+	.set_time	= meson_rtc_settime,
+};
+
+/* NVMEM interface layer functions */
+
+static int meson_rtc_regmem_read(void *context, unsigned int offset,
+				 void *buf, size_t bytes)
+{
+	struct meson_rtc *rtc = context;
+	unsigned int read_offset, read_size;
+
+	read_offset = RTC_REGMEM_0 + (offset / 4);
+	read_size = bytes / 4;
+
+	return regmap_bulk_read(rtc->serial, read_offset, buf, read_size);
+}
+
+static int meson_rtc_regmem_write(void *context, unsigned int offset,
+				  void *buf, size_t bytes)
+{
+	struct meson_rtc *rtc = context;
+	unsigned int write_offset, write_size;
+
+	write_offset = RTC_REGMEM_0 + (offset / 4);
+	write_size = bytes / 4;
+
+	return regmap_bulk_write(rtc->serial, write_offset, buf, write_size);
+}
+
+static int meson_rtc_probe(struct platform_device *pdev)
+{
+	struct nvmem_config meson_rtc_nvmem_config = {
+		.name = "meson-rtc-regmem",
+		.type = NVMEM_TYPE_BATTERY_BACKED,
+		.word_size = 4,
+		.stride = 4,
+		.size = 4 * 4,
+		.reg_read = meson_rtc_regmem_read,
+		.reg_write = meson_rtc_regmem_write,
+	};
+	struct device *dev = &pdev->dev;
+	struct meson_rtc *rtc;
+	struct rtc_device *rtc_dev;
+	void __iomem *base;
+	int ret;
+	u32 tm;
+
+	rtc = devm_kzalloc(dev, sizeof(struct meson_rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	rtc_dev = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc_dev))
+		return PTR_ERR(rtc_dev);
+
+	platform_set_drvdata(pdev, rtc);
+
+	rtc->dev = dev;
+
+	rtc_dev->ops = &meson_rtc_ops;
+	rtc_dev->range_max = U32_MAX;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	rtc->peripheral = devm_regmap_init_mmio(dev, base,
+					&meson_rtc_peripheral_regmap_config);
+	if (IS_ERR(rtc->peripheral)) {
+		dev_err(dev, "failed to create peripheral regmap\n");
+		return PTR_ERR(rtc->peripheral);
+	}
+
+	rtc->reset = devm_reset_control_get(dev, NULL);
+	if (IS_ERR(rtc->reset)) {
+		dev_err(dev, "missing reset line\n");
+		return PTR_ERR(rtc->reset);
+	}
+
+	rtc->vdd = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(rtc->vdd)) {
+		dev_err(dev, "failed to get the vdd-supply\n");
+		return PTR_ERR(rtc->vdd);
+	}
+
+	ret = regulator_enable(rtc->vdd);
+	if (ret) {
+		dev_err(dev, "failed to enable vdd-supply\n");
+		return ret;
+	}
+
+	ret = meson_rtc_write_static(rtc, MESON_STATIC_DEFAULT);
+	if (ret) {
+		dev_err(dev, "failed to set static values\n");
+		goto out_disable_vdd;
+	}
+
+	rtc->serial = devm_regmap_init(dev, &meson_rtc_serial_bus, rtc,
+				       &meson_rtc_serial_regmap_config);
+	if (IS_ERR(rtc->serial)) {
+		dev_err(dev, "failed to create serial regmap\n");
+		ret = PTR_ERR(rtc->serial);
+		goto out_disable_vdd;
+	}
+
+	/*
+	 * check if we can read RTC counter, if not then the RTC is probably
+	 * not functional. If it isn't probably best to not bind.
+	 */
+	ret = regmap_read(rtc->serial, RTC_COUNTER, &tm);
+	if (ret) {
+		dev_err(dev, "cannot read RTC counter, RTC not functional\n");
+		goto out_disable_vdd;
+	}
+
+	meson_rtc_nvmem_config.priv = rtc;
+	ret = devm_rtc_nvmem_register(rtc_dev, &meson_rtc_nvmem_config);
+	if (ret)
+		goto out_disable_vdd;
+
+	ret = devm_rtc_register_device(rtc_dev);
+	if (ret)
+		goto out_disable_vdd;
+
+	return 0;
+
+out_disable_vdd:
+	regulator_disable(rtc->vdd);
+	return ret;
+}
+
+static const __maybe_unused struct of_device_id meson_rtc_dt_match[] = {
+	{ .compatible = "amlogic,meson6-rtc", },
+	{ .compatible = "amlogic,meson8-rtc", },
+	{ .compatible = "amlogic,meson8b-rtc", },
+	{ .compatible = "amlogic,meson8m2-rtc", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, meson_rtc_dt_match);
+
+static struct platform_driver meson_rtc_driver = {
+	.probe		= meson_rtc_probe,
+	.driver		= {
+		.name		= "meson-rtc",
+		.of_match_table	= of_match_ptr(meson_rtc_dt_match),
+	},
+};
+module_platform_driver(meson_rtc_driver);
+
+MODULE_DESCRIPTION("Amlogic Meson RTC Driver");
+MODULE_AUTHOR("Ben Dooks <ben.dooks@codethink.co.uk>");
+MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:meson-rtc");