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

3 files changed, 271 insertions, 0 deletions

diff --git a/drivers/soc/cirrus/Kconfig b/drivers/soc/cirrus/Kconfig
new file mode 100644
index 000000000..d8b3b1e68
--- /dev/null
+++ b/drivers/soc/cirrus/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+if ARCH_EP93XX
+
+config EP93XX_SOC
+	bool "Cirrus EP93xx chips SoC"
+	select SOC_BUS
+	select AUXILIARY_BUS
+	default y
+	help
+	  Enable support SoC for Cirrus EP93xx chips.
+
+	  Cirrus EP93xx chips have several swlocked registers,
+	  this driver provides locked access for reset, pinctrl
+	  and clk devices implemented as auxiliary devices.
+
+endif
diff --git a/drivers/soc/cirrus/Makefile b/drivers/soc/cirrus/Makefile
new file mode 100644
index 000000000..9e6608b67
--- /dev/null
+++ b/drivers/soc/cirrus/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y	+= soc-ep93xx.o
diff --git a/drivers/soc/cirrus/soc-ep93xx.c b/drivers/soc/cirrus/soc-ep93xx.c
new file mode 100644
index 000000000..d55cf28ed
--- /dev/null
+++ b/drivers/soc/cirrus/soc-ep93xx.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SoC driver for Cirrus EP93xx chips.
+ * Copyright (C) 2022 Nikita Shubin <nikita.shubin@maquefel.me>
+ *
+ * Based on a rewrite of arch/arm/mach-ep93xx/core.c
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ * Copyright (C) 2007 Herbert Valerio Riedel <hvr@gnu.org>
+ *
+ * Thanks go to Michael Burian and Ray Lehtiniemi for their key
+ * role in the ep93xx Linux community.
+ */
+
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/init.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/sys_soc.h>
+
+#include <linux/soc/cirrus/ep93xx.h>
+
+#define EP93XX_SYSCON_DEVCFG		0x80
+
+#define EP93XX_SWLOCK_MAGICK		0xaa
+#define EP93XX_SYSCON_SWLOCK		0xc0
+#define EP93XX_SYSCON_SYSCFG		0x9c
+#define EP93XX_SYSCON_SYSCFG_REV_MASK	GENMASK(31, 28)
+#define EP93XX_SYSCON_SYSCFG_REV_SHIFT	28
+
+struct ep93xx_map_info {
+	spinlock_t lock;
+	void __iomem *base;
+	struct regmap *map;
+};
+
+/*
+ * EP93xx System Controller software locked register write
+ *
+ * Logic safeguards are included to condition the control signals for
+ * power connection to the matrix to prevent part damage. In addition, a
+ * software lock register is included that must be written with 0xAA
+ * before each register write to change the values of the four switch
+ * matrix control registers.
+ */
+static void ep93xx_regmap_write(struct regmap *map, spinlock_t *lock,
+				 unsigned int reg, unsigned int val)
+{
+	guard(spinlock_irqsave)(lock);
+
+	regmap_write(map, EP93XX_SYSCON_SWLOCK, EP93XX_SWLOCK_MAGICK);
+	regmap_write(map, reg, val);
+}
+
+static void ep93xx_regmap_update_bits(struct regmap *map, spinlock_t *lock,
+				      unsigned int reg, unsigned int mask,
+				      unsigned int val)
+{
+	guard(spinlock_irqsave)(lock);
+
+	regmap_write(map, EP93XX_SYSCON_SWLOCK, EP93XX_SWLOCK_MAGICK);
+	/* force write is required to clear swlock if no changes are made */
+	regmap_update_bits_base(map, reg, mask, val, NULL, false, true);
+}
+
+static void ep93xx_unregister_adev(void *_adev)
+{
+	struct auxiliary_device *adev = _adev;
+
+	auxiliary_device_delete(adev);
+	auxiliary_device_uninit(adev);
+}
+
+static void ep93xx_adev_release(struct device *dev)
+{
+	struct auxiliary_device *adev = to_auxiliary_dev(dev);
+	struct ep93xx_regmap_adev *rdev = to_ep93xx_regmap_adev(adev);
+
+	kfree(rdev);
+}
+
+static struct auxiliary_device __init *ep93xx_adev_alloc(struct device *parent,
+							 const char *name,
+							 struct ep93xx_map_info *info)
+{
+	struct ep93xx_regmap_adev *rdev __free(kfree) = NULL;
+	struct auxiliary_device *adev;
+	int ret;
+
+	rdev = kzalloc_obj(*rdev);
+	if (!rdev)
+		return ERR_PTR(-ENOMEM);
+
+	rdev->map = info->map;
+	rdev->base = info->base;
+	rdev->lock = &info->lock;
+	rdev->write = ep93xx_regmap_write;
+	rdev->update_bits = ep93xx_regmap_update_bits;
+
+	adev = &rdev->adev;
+	adev->name = name;
+	adev->dev.parent = parent;
+	adev->dev.release = ep93xx_adev_release;
+
+	ret = auxiliary_device_init(adev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return &no_free_ptr(rdev)->adev;
+}
+
+static int __init ep93xx_controller_register(struct device *parent, const char *name,
+					     struct ep93xx_map_info *info)
+{
+	struct auxiliary_device *adev;
+	int ret;
+
+	adev = ep93xx_adev_alloc(parent, name, info);
+	if (IS_ERR(adev))
+		return PTR_ERR(adev);
+
+	ret = auxiliary_device_add(adev);
+	if (ret) {
+		auxiliary_device_uninit(adev);
+		return ret;
+	}
+
+	return devm_add_action_or_reset(parent, ep93xx_unregister_adev, adev);
+}
+
+static unsigned int __init ep93xx_soc_revision(struct regmap *map)
+{
+	unsigned int val;
+
+	regmap_read(map, EP93XX_SYSCON_SYSCFG, &val);
+	val &= EP93XX_SYSCON_SYSCFG_REV_MASK;
+	val >>= EP93XX_SYSCON_SYSCFG_REV_SHIFT;
+	return val;
+}
+
+static const char __init *ep93xx_get_soc_rev(unsigned int rev)
+{
+	switch (rev) {
+	case EP93XX_CHIP_REV_D0:
+		return "D0";
+	case EP93XX_CHIP_REV_D1:
+		return "D1";
+	case EP93XX_CHIP_REV_E0:
+		return "E0";
+	case EP93XX_CHIP_REV_E1:
+		return "E1";
+	case EP93XX_CHIP_REV_E2:
+		return "E2";
+	default:
+		return "unknown";
+	}
+}
+
+static const char *pinctrl_names[] __initconst = {
+	"pinctrl-ep9301",	/* EP93XX_9301_SOC */
+	"pinctrl-ep9307",	/* EP93XX_9307_SOC */
+	"pinctrl-ep9312",	/* EP93XX_9312_SOC */
+};
+
+static int __init ep93xx_syscon_probe(struct platform_device *pdev)
+{
+	enum ep93xx_soc_model model;
+	struct ep93xx_map_info *map_info;
+	struct soc_device_attribute *attrs;
+	struct soc_device *soc_dev;
+	struct device *dev = &pdev->dev;
+	struct regmap *map;
+	void __iomem *base;
+	unsigned int rev;
+	int ret;
+
+	model = (enum ep93xx_soc_model)(uintptr_t)device_get_match_data(dev);
+
+	map = device_node_to_regmap(dev->of_node);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	attrs = devm_kzalloc(dev, sizeof(*attrs), GFP_KERNEL);
+	if (!attrs)
+		return -ENOMEM;
+
+	rev = ep93xx_soc_revision(map);
+
+	attrs->machine = of_flat_dt_get_machine_name();
+	attrs->family = "Cirrus Logic EP93xx";
+	attrs->revision = ep93xx_get_soc_rev(rev);
+
+	soc_dev = soc_device_register(attrs);
+	if (IS_ERR(soc_dev))
+		return PTR_ERR(soc_dev);
+
+	map_info = devm_kzalloc(dev, sizeof(*map_info), GFP_KERNEL);
+	if (!map_info)
+		return -ENOMEM;
+
+	spin_lock_init(&map_info->lock);
+	map_info->map = map;
+	map_info->base = base;
+
+	ret = ep93xx_controller_register(dev, pinctrl_names[model], map_info);
+	if (ret)
+		dev_err(dev, "registering pinctrl controller failed\n");
+
+	/*
+	 * EP93xx SSP clock rate was doubled in version E2. For more information
+	 * see section 6 "2x SSP (Synchronous Serial Port) Clock – Revision E2 only":
+	 *     http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
+	 */
+	if (rev == EP93XX_CHIP_REV_E2)
+		ret = ep93xx_controller_register(dev, "clk-ep93xx.e2", map_info);
+	else
+		ret = ep93xx_controller_register(dev, "clk-ep93xx", map_info);
+	if (ret)
+		dev_err(dev, "registering clock controller failed\n");
+
+	ret = ep93xx_controller_register(dev, "reset-ep93xx", map_info);
+	if (ret)
+		dev_err(dev, "registering reset controller failed\n");
+
+	return 0;
+}
+
+static const struct of_device_id ep9301_syscon_of_device_ids[] = {
+	{ .compatible	= "cirrus,ep9301-syscon", .data = (void *)EP93XX_9301_SOC },
+	{ .compatible	= "cirrus,ep9302-syscon", .data = (void *)EP93XX_9301_SOC },
+	{ .compatible	= "cirrus,ep9307-syscon", .data = (void *)EP93XX_9307_SOC },
+	{ .compatible	= "cirrus,ep9312-syscon", .data = (void *)EP93XX_9312_SOC },
+	{ .compatible	= "cirrus,ep9315-syscon", .data = (void *)EP93XX_9312_SOC },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver ep9301_syscon_driver = {
+	.driver = {
+		.name = "ep9301-syscon",
+		.of_match_table = ep9301_syscon_of_device_ids,
+	},
+};
+builtin_platform_driver_probe(ep9301_syscon_driver, ep93xx_syscon_probe);