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, 342 insertions, 0 deletions

diff --git a/drivers/input/joystick/n64joy.c b/drivers/input/joystick/n64joy.c
new file mode 100644
index 000000000..43a02bb99
--- /dev/null
+++ b/drivers/input/joystick/n64joy.c
@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Support for the four N64 controllers.
+ *
+ * Copyright (c) 2021 Lauri Kasanen
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/limits.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+
+MODULE_AUTHOR("Lauri Kasanen <cand@gmx.com>");
+MODULE_DESCRIPTION("Driver for N64 controllers");
+MODULE_LICENSE("GPL");
+
+#define PIF_RAM 0x1fc007c0
+
+#define SI_DRAM_REG 0
+#define SI_READ_REG 1
+#define SI_WRITE_REG 4
+#define SI_STATUS_REG 6
+
+#define SI_STATUS_DMA_BUSY  BIT(0)
+#define SI_STATUS_IO_BUSY   BIT(1)
+
+#define N64_CONTROLLER_ID 0x0500
+
+#define MAX_CONTROLLERS 4
+
+static const char *n64joy_phys[MAX_CONTROLLERS] = {
+	"n64joy/port0",
+	"n64joy/port1",
+	"n64joy/port2",
+	"n64joy/port3",
+};
+
+struct n64joy_priv {
+	u64 si_buf[8] ____cacheline_aligned;
+	struct timer_list timer;
+	struct mutex n64joy_mutex;
+	struct input_dev *n64joy_dev[MAX_CONTROLLERS];
+	u32 __iomem *reg_base;
+	u8 n64joy_opened;
+};
+
+struct joydata {
+	unsigned int: 16; /* unused */
+	unsigned int err: 2;
+	unsigned int: 14; /* unused */
+
+	union {
+		u32 data;
+
+		struct {
+			unsigned int a: 1;
+			unsigned int b: 1;
+			unsigned int z: 1;
+			unsigned int start: 1;
+			unsigned int up: 1;
+			unsigned int down: 1;
+			unsigned int left: 1;
+			unsigned int right: 1;
+			unsigned int: 2; /* unused */
+			unsigned int l: 1;
+			unsigned int r: 1;
+			unsigned int c_up: 1;
+			unsigned int c_down: 1;
+			unsigned int c_left: 1;
+			unsigned int c_right: 1;
+			signed int x: 8;
+			signed int y: 8;
+		};
+	};
+};
+
+static void n64joy_write_reg(u32 __iomem *reg_base, const u8 reg, const u32 value)
+{
+	writel(value, reg_base + reg);
+}
+
+static u32 n64joy_read_reg(u32 __iomem *reg_base, const u8 reg)
+{
+	return readl(reg_base + reg);
+}
+
+static void n64joy_wait_si_dma(u32 __iomem *reg_base)
+{
+	while (n64joy_read_reg(reg_base, SI_STATUS_REG) &
+	       (SI_STATUS_DMA_BUSY | SI_STATUS_IO_BUSY))
+		cpu_relax();
+}
+
+static void n64joy_exec_pif(struct n64joy_priv *priv, const u64 in[8])
+{
+	unsigned long flags;
+
+	dma_cache_wback_inv((unsigned long) in, 8 * 8);
+	dma_cache_inv((unsigned long) priv->si_buf, 8 * 8);
+
+	local_irq_save(flags);
+
+	n64joy_wait_si_dma(priv->reg_base);
+
+	barrier();
+	n64joy_write_reg(priv->reg_base, SI_DRAM_REG, virt_to_phys(in));
+	barrier();
+	n64joy_write_reg(priv->reg_base, SI_WRITE_REG, PIF_RAM);
+	barrier();
+
+	n64joy_wait_si_dma(priv->reg_base);
+
+	barrier();
+	n64joy_write_reg(priv->reg_base, SI_DRAM_REG, virt_to_phys(priv->si_buf));
+	barrier();
+	n64joy_write_reg(priv->reg_base, SI_READ_REG, PIF_RAM);
+	barrier();
+
+	n64joy_wait_si_dma(priv->reg_base);
+
+	local_irq_restore(flags);
+}
+
+static const u64 polldata[] ____cacheline_aligned = {
+	0xff010401ffffffff,
+	0xff010401ffffffff,
+	0xff010401ffffffff,
+	0xff010401ffffffff,
+	0xfe00000000000000,
+	0,
+	0,
+	1
+};
+
+static void n64joy_poll(struct timer_list *t)
+{
+	const struct joydata *data;
+	struct n64joy_priv *priv = container_of(t, struct n64joy_priv, timer);
+	struct input_dev *dev;
+	u32 i;
+
+	n64joy_exec_pif(priv, polldata);
+
+	data = (struct joydata *) priv->si_buf;
+
+	for (i = 0; i < MAX_CONTROLLERS; i++) {
+		if (!priv->n64joy_dev[i])
+			continue;
+
+		dev = priv->n64joy_dev[i];
+
+		/* d-pad */
+		input_report_key(dev, BTN_DPAD_UP, data[i].up);
+		input_report_key(dev, BTN_DPAD_DOWN, data[i].down);
+		input_report_key(dev, BTN_DPAD_LEFT, data[i].left);
+		input_report_key(dev, BTN_DPAD_RIGHT, data[i].right);
+
+		/* c buttons */
+		input_report_key(dev, BTN_FORWARD, data[i].c_up);
+		input_report_key(dev, BTN_BACK, data[i].c_down);
+		input_report_key(dev, BTN_LEFT, data[i].c_left);
+		input_report_key(dev, BTN_RIGHT, data[i].c_right);
+
+		/* matching buttons */
+		input_report_key(dev, BTN_START, data[i].start);
+		input_report_key(dev, BTN_Z, data[i].z);
+
+		/* remaining ones: a, b, l, r */
+		input_report_key(dev, BTN_0, data[i].a);
+		input_report_key(dev, BTN_1, data[i].b);
+		input_report_key(dev, BTN_2, data[i].l);
+		input_report_key(dev, BTN_3, data[i].r);
+
+		input_report_abs(dev, ABS_X, data[i].x);
+		input_report_abs(dev, ABS_Y, data[i].y);
+
+		input_sync(dev);
+	}
+
+	mod_timer(&priv->timer, jiffies + msecs_to_jiffies(16));
+}
+
+static int n64joy_open(struct input_dev *dev)
+{
+	struct n64joy_priv *priv = input_get_drvdata(dev);
+
+	scoped_guard(mutex_intr, &priv->n64joy_mutex) {
+		if (!priv->n64joy_opened) {
+			/*
+			 * We could use the vblank irq, but it's not important
+			 * if the poll point slightly changes.
+			 */
+			timer_setup(&priv->timer, n64joy_poll, 0);
+			mod_timer(&priv->timer, jiffies + msecs_to_jiffies(16));
+		}
+
+		priv->n64joy_opened++;
+		return 0;
+	}
+
+	return -EINTR;
+}
+
+static void n64joy_close(struct input_dev *dev)
+{
+	struct n64joy_priv *priv = input_get_drvdata(dev);
+
+	guard(mutex)(&priv->n64joy_mutex);
+
+	if (!--priv->n64joy_opened)
+		timer_delete_sync(&priv->timer);
+}
+
+static const u64 __initconst scandata[] ____cacheline_aligned = {
+	0xff010300ffffffff,
+	0xff010300ffffffff,
+	0xff010300ffffffff,
+	0xff010300ffffffff,
+	0xfe00000000000000,
+	0,
+	0,
+	1
+};
+
+/*
+ * The target device is embedded and RAM-constrained. We save RAM
+ * by initializing in __init code that gets dropped late in boot.
+ * For the same reason there is no module or unloading support.
+ */
+static int __init n64joy_probe(struct platform_device *pdev)
+{
+	const struct joydata *data;
+	struct n64joy_priv *priv;
+	struct input_dev *dev;
+	int err = 0;
+	u32 i, j, found = 0;
+
+	priv = kzalloc_obj(*priv);
+	if (!priv)
+		return -ENOMEM;
+	mutex_init(&priv->n64joy_mutex);
+
+	priv->reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->reg_base)) {
+		err = PTR_ERR(priv->reg_base);
+		goto fail;
+	}
+
+	/* The controllers are not hotpluggable, so we can scan in init */
+	n64joy_exec_pif(priv, scandata);
+
+	data = (struct joydata *) priv->si_buf;
+
+	for (i = 0; i < MAX_CONTROLLERS; i++) {
+		if (!data[i].err && data[i].data >> 16 == N64_CONTROLLER_ID) {
+			found++;
+
+			dev = priv->n64joy_dev[i] = input_allocate_device();
+			if (!priv->n64joy_dev[i]) {
+				err = -ENOMEM;
+				goto fail;
+			}
+
+			input_set_drvdata(dev, priv);
+
+			dev->name = "N64 controller";
+			dev->phys = n64joy_phys[i];
+			dev->id.bustype = BUS_HOST;
+			dev->id.vendor = 0;
+			dev->id.product = data[i].data >> 16;
+			dev->id.version = 0;
+			dev->dev.parent = &pdev->dev;
+
+			dev->open = n64joy_open;
+			dev->close = n64joy_close;
+
+			/* d-pad */
+			input_set_capability(dev, EV_KEY, BTN_DPAD_UP);
+			input_set_capability(dev, EV_KEY, BTN_DPAD_DOWN);
+			input_set_capability(dev, EV_KEY, BTN_DPAD_LEFT);
+			input_set_capability(dev, EV_KEY, BTN_DPAD_RIGHT);
+			/* c buttons */
+			input_set_capability(dev, EV_KEY, BTN_LEFT);
+			input_set_capability(dev, EV_KEY, BTN_RIGHT);
+			input_set_capability(dev, EV_KEY, BTN_FORWARD);
+			input_set_capability(dev, EV_KEY, BTN_BACK);
+			/* matching buttons */
+			input_set_capability(dev, EV_KEY, BTN_START);
+			input_set_capability(dev, EV_KEY, BTN_Z);
+			/* remaining ones: a, b, l, r */
+			input_set_capability(dev, EV_KEY, BTN_0);
+			input_set_capability(dev, EV_KEY, BTN_1);
+			input_set_capability(dev, EV_KEY, BTN_2);
+			input_set_capability(dev, EV_KEY, BTN_3);
+
+			for (j = 0; j < 2; j++)
+				input_set_abs_params(dev, ABS_X + j,
+						     S8_MIN, S8_MAX, 0, 0);
+
+			err = input_register_device(dev);
+			if (err) {
+				input_free_device(dev);
+				goto fail;
+			}
+		}
+	}
+
+	pr_info("%u controller(s) connected\n", found);
+
+	if (!found)
+		return -ENODEV;
+
+	return 0;
+fail:
+	for (i = 0; i < MAX_CONTROLLERS; i++) {
+		if (!priv->n64joy_dev[i])
+			continue;
+		input_unregister_device(priv->n64joy_dev[i]);
+	}
+	return err;
+}
+
+static struct platform_driver n64joy_driver = {
+	.driver = {
+		.name = "n64joy",
+	},
+};
+
+static int __init n64joy_init(void)
+{
+	return platform_driver_probe(&n64joy_driver, n64joy_probe);
+}
+
+module_init(n64joy_init);