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, 380 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-gamecube.c b/drivers/rtc/rtc-gamecube.c
new file mode 100644
index 000000000..889028cec
--- /dev/null
+++ b/drivers/rtc/rtc-gamecube.c
@@ -0,0 +1,380 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nintendo GameCube, Wii and Wii U RTC driver
+ *
+ * This driver is for the MX23L4005, more specifically its real-time clock and
+ * SRAM storage.  The value returned by the RTC counter must be added with the
+ * offset stored in a bias register in SRAM (on the GameCube and Wii) or in
+ * /config/rtc.xml (on the Wii U).  The latter being very impractical to access
+ * from Linux, this driver assumes the bootloader has read it and stored it in
+ * SRAM like for the other two consoles.
+ *
+ * This device sits on a bus named EXI (which is similar to SPI), channel 0,
+ * device 1.  This driver assumes no other user of the EXI bus, which is
+ * currently the case but would have to be reworked to add support for other
+ * GameCube hardware exposed on this bus.
+ *
+ * References:
+ * - https://wiiubrew.org/wiki/Hardware/RTC
+ * - https://wiibrew.org/wiki/MX23L4005
+ *
+ * Copyright (C) 2018 rw-r-r-0644
+ * Copyright (C) 2021 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
+ *
+ * Based on rtc-gcn.c
+ * Copyright (C) 2004-2009 The GameCube Linux Team
+ * Copyright (C) 2005,2008,2009 Albert Herranz
+ * Based on gamecube_time.c from Torben Nielsen.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/time.h>
+
+/* EXI registers */
+#define EXICSR	0
+#define EXICR	12
+#define EXIDATA	16
+
+/* EXI register values */
+#define EXICSR_DEV		0x380
+	#define EXICSR_DEV1	0x100
+#define EXICSR_CLK		0x070
+	#define EXICSR_CLK_1MHZ	0x000
+	#define EXICSR_CLK_2MHZ	0x010
+	#define EXICSR_CLK_4MHZ	0x020
+	#define EXICSR_CLK_8MHZ	0x030
+	#define EXICSR_CLK_16MHZ 0x040
+	#define EXICSR_CLK_32MHZ 0x050
+#define EXICSR_INT		0x008
+	#define EXICSR_INTSET	0x008
+
+#define EXICR_TSTART		0x001
+#define EXICR_TRSMODE		0x002
+	#define EXICR_TRSMODE_IMM 0x000
+#define EXICR_TRSTYPE		0x00C
+	#define EXICR_TRSTYPE_R	0x000
+	#define EXICR_TRSTYPE_W	0x004
+#define EXICR_TLEN		0x030
+	#define EXICR_TLEN32	0x030
+
+/* EXI registers values to access the RTC */
+#define RTC_EXICSR	(EXICSR_DEV1 | EXICSR_CLK_8MHZ | EXICSR_INTSET)
+#define RTC_EXICR_W	(EXICR_TSTART | EXICR_TRSMODE_IMM | EXICR_TRSTYPE_W | EXICR_TLEN32)
+#define RTC_EXICR_R	(EXICR_TSTART | EXICR_TRSMODE_IMM | EXICR_TRSTYPE_R | EXICR_TLEN32)
+#define RTC_EXIDATA_W	0x80000000
+
+/* RTC registers */
+#define RTC_COUNTER	0x200000
+#define RTC_SRAM	0x200001
+#define RTC_SRAM_BIAS	0x200004
+#define RTC_SNAPSHOT	0x204000
+#define RTC_ONTMR	0x210000
+#define RTC_OFFTMR	0x210001
+#define RTC_TEST0	0x210004
+#define RTC_TEST1	0x210005
+#define RTC_TEST2	0x210006
+#define RTC_TEST3	0x210007
+#define RTC_CONTROL0	0x21000c
+#define RTC_CONTROL1	0x21000d
+
+/* RTC flags */
+#define RTC_CONTROL0_UNSTABLE_POWER	0x00000800
+#define RTC_CONTROL0_LOW_BATTERY	0x00000200
+
+struct priv {
+	struct regmap *regmap;
+	void __iomem *iob;
+	u32 rtc_bias;
+};
+
+static int exi_read(void *context, u32 reg, u32 *data)
+{
+	struct priv *d = (struct priv *)context;
+	void __iomem *iob = d->iob;
+
+	/* The spin loops here loop about 15~16 times each, so there is no need
+	 * to use a more expensive sleep method.
+	 */
+
+	/* Write register offset */
+	iowrite32be(RTC_EXICSR, iob + EXICSR);
+	iowrite32be(reg << 8, iob + EXIDATA);
+	iowrite32be(RTC_EXICR_W, iob + EXICR);
+	while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
+		cpu_relax();
+
+	/* Read data */
+	iowrite32be(RTC_EXICSR, iob + EXICSR);
+	iowrite32be(RTC_EXICR_R, iob + EXICR);
+	while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
+		cpu_relax();
+	*data = ioread32be(iob + EXIDATA);
+
+	/* Clear channel parameters */
+	iowrite32be(0, iob + EXICSR);
+
+	return 0;
+}
+
+static int exi_write(void *context, u32 reg, u32 data)
+{
+	struct priv *d = (struct priv *)context;
+	void __iomem *iob = d->iob;
+
+	/* The spin loops here loop about 15~16 times each, so there is no need
+	 * to use a more expensive sleep method.
+	 */
+
+	/* Write register offset */
+	iowrite32be(RTC_EXICSR, iob + EXICSR);
+	iowrite32be(RTC_EXIDATA_W | (reg << 8), iob + EXIDATA);
+	iowrite32be(RTC_EXICR_W, iob + EXICR);
+	while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
+		cpu_relax();
+
+	/* Write data */
+	iowrite32be(RTC_EXICSR, iob + EXICSR);
+	iowrite32be(data, iob + EXIDATA);
+	iowrite32be(RTC_EXICR_W, iob + EXICR);
+	while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
+		cpu_relax();
+
+	/* Clear channel parameters */
+	iowrite32be(0, iob + EXICSR);
+
+	return 0;
+}
+
+static const struct regmap_bus exi_bus = {
+	/* TODO: is that true?  Not that it matters here, but still. */
+	.fast_io = true,
+	.reg_read = exi_read,
+	.reg_write = exi_write,
+};
+
+static int gamecube_rtc_read_time(struct device *dev, struct rtc_time *t)
+{
+	struct priv *d = dev_get_drvdata(dev);
+	int ret;
+	u32 counter;
+	time64_t timestamp;
+
+	ret = regmap_read(d->regmap, RTC_COUNTER, &counter);
+	if (ret)
+		return ret;
+
+	/* Add the counter and the bias to obtain the timestamp */
+	timestamp = (time64_t)d->rtc_bias + counter;
+	rtc_time64_to_tm(timestamp, t);
+
+	return 0;
+}
+
+static int gamecube_rtc_set_time(struct device *dev, struct rtc_time *t)
+{
+	struct priv *d = dev_get_drvdata(dev);
+	time64_t timestamp;
+
+	/* Subtract the timestamp and the bias to obtain the counter value */
+	timestamp = rtc_tm_to_time64(t);
+	return regmap_write(d->regmap, RTC_COUNTER, timestamp - d->rtc_bias);
+}
+
+static int gamecube_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	struct priv *d = dev_get_drvdata(dev);
+	int value;
+	int control0;
+	int ret;
+
+	switch (cmd) {
+	case RTC_VL_READ:
+		ret = regmap_read(d->regmap, RTC_CONTROL0, &control0);
+		if (ret)
+			return ret;
+
+		value = 0;
+		if (control0 & RTC_CONTROL0_UNSTABLE_POWER)
+			value |= RTC_VL_DATA_INVALID;
+		if (control0 & RTC_CONTROL0_LOW_BATTERY)
+			value |= RTC_VL_BACKUP_LOW;
+		return put_user(value, (unsigned int __user *)arg);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static const struct rtc_class_ops gamecube_rtc_ops = {
+	.read_time	= gamecube_rtc_read_time,
+	.set_time	= gamecube_rtc_set_time,
+	.ioctl		= gamecube_rtc_ioctl,
+};
+
+static int gamecube_rtc_read_offset_from_sram(struct priv *d)
+{
+	struct device_node *np;
+	int ret;
+	struct resource res;
+	void __iomem *hw_srnprot;
+	u32 old;
+
+	np = of_find_compatible_node(NULL, NULL, "nintendo,latte-srnprot");
+	if (!np)
+		np = of_find_compatible_node(NULL, NULL,
+					     "nintendo,hollywood-srnprot");
+	if (!np) {
+		pr_info("HW_SRNPROT not found, assuming a GameCube\n");
+		return regmap_read(d->regmap, RTC_SRAM_BIAS, &d->rtc_bias);
+	}
+
+	ret = of_address_to_resource(np, 0, &res);
+	of_node_put(np);
+	if (ret) {
+		pr_err("no io memory range found\n");
+		return -1;
+	}
+
+	hw_srnprot = ioremap(res.start, resource_size(&res));
+	if (!hw_srnprot) {
+		pr_err("failed to ioremap hw_srnprot\n");
+		return -ENOMEM;
+	}
+	old = ioread32be(hw_srnprot);
+
+	/* TODO: figure out why we use this magic constant.  I obtained it by
+	 * reading the leftover value after boot, after IOSU already ran.
+	 *
+	 * On my Wii U, setting this register to 1 prevents the console from
+	 * rebooting properly, so wiiubrew.org must be missing something.
+	 *
+	 * See https://wiiubrew.org/wiki/Hardware/Latte_registers
+	 */
+	if (old != 0x7bf)
+		iowrite32be(0x7bf, hw_srnprot);
+
+	/* Get the offset from RTC SRAM.
+	 *
+	 * Its default location on the GameCube and on the Wii is in the SRAM,
+	 * while on the Wii U the bootloader needs to fill it with the contents
+	 * of /config/rtc.xml on the SLC (the eMMC).  We don’t do that from
+	 * Linux since it requires implementing a proprietary filesystem and do
+	 * file decryption, instead we require the bootloader to fill the same
+	 * SRAM address as on previous consoles.
+	 */
+	ret = regmap_read(d->regmap, RTC_SRAM_BIAS, &d->rtc_bias);
+
+	/* Reset SRAM access to how it was before, our job here is done. */
+	if (old != 0x7bf)
+		iowrite32be(old, hw_srnprot);
+
+	iounmap(hw_srnprot);
+
+	if (ret)
+		pr_err("failed to get the RTC bias\n");
+
+	return ret;
+}
+
+static const struct regmap_range rtc_rd_ranges[] = {
+	regmap_reg_range(0x200000, 0x200010),
+	regmap_reg_range(0x204000, 0x204000),
+	regmap_reg_range(0x210000, 0x210001),
+	regmap_reg_range(0x210004, 0x210007),
+	regmap_reg_range(0x21000c, 0x21000d),
+};
+
+static const struct regmap_access_table rtc_rd_regs = {
+	.yes_ranges =	rtc_rd_ranges,
+	.n_yes_ranges =	ARRAY_SIZE(rtc_rd_ranges),
+};
+
+static const struct regmap_range rtc_wr_ranges[] = {
+	regmap_reg_range(0x200000, 0x200010),
+	regmap_reg_range(0x204000, 0x204000),
+	regmap_reg_range(0x210000, 0x210001),
+	regmap_reg_range(0x21000d, 0x21000d),
+};
+
+static const struct regmap_access_table rtc_wr_regs = {
+	.yes_ranges =	rtc_wr_ranges,
+	.n_yes_ranges =	ARRAY_SIZE(rtc_wr_ranges),
+};
+
+static const struct regmap_config gamecube_rtc_regmap_config = {
+	.reg_bits = 24,
+	.val_bits = 32,
+	.rd_table = &rtc_rd_regs,
+	.wr_table = &rtc_wr_regs,
+	.max_register = 0x21000d,
+	.name = "gamecube-rtc",
+};
+
+static int gamecube_rtc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rtc_device *rtc;
+	struct priv *d;
+	int ret;
+
+	d = devm_kzalloc(dev, sizeof(struct priv), GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
+
+	d->iob = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(d->iob))
+		return PTR_ERR(d->iob);
+
+	d->regmap = devm_regmap_init(dev, &exi_bus, d,
+				     &gamecube_rtc_regmap_config);
+	if (IS_ERR(d->regmap))
+		return PTR_ERR(d->regmap);
+
+	ret = gamecube_rtc_read_offset_from_sram(d);
+	if (ret)
+		return ret;
+	dev_dbg(dev, "SRAM bias: 0x%x", d->rtc_bias);
+
+	dev_set_drvdata(dev, d);
+
+	rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	/* We can represent further than that, but it depends on the stored
+	 * bias and we can’t modify it persistently on all supported consoles,
+	 * so here we pretend to be limited to 2106.
+	 */
+	rtc->range_min = 0;
+	rtc->range_max = U32_MAX;
+	rtc->ops = &gamecube_rtc_ops;
+
+	return devm_rtc_register_device(rtc);
+}
+
+static const struct of_device_id gamecube_rtc_of_match[] = {
+	{.compatible = "nintendo,latte-exi" },
+	{.compatible = "nintendo,hollywood-exi" },
+	{.compatible = "nintendo,flipper-exi" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, gamecube_rtc_of_match);
+
+static struct platform_driver gamecube_rtc_driver = {
+	.probe		= gamecube_rtc_probe,
+	.driver		= {
+		.name	= "rtc-gamecube",
+		.of_match_table	= gamecube_rtc_of_match,
+	},
+};
+module_platform_driver(gamecube_rtc_driver);
+
+MODULE_AUTHOR("Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>");
+MODULE_DESCRIPTION("Nintendo GameCube, Wii and Wii U RTC driver");
+MODULE_LICENSE("GPL");