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, 267 insertions, 0 deletions

diff --git a/drivers/media/rc/ir-imon-decoder.c b/drivers/media/rc/ir-imon-decoder.c
new file mode 100644
index 000000000..dc68f64e7
--- /dev/null
+++ b/drivers/media/rc/ir-imon-decoder.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: GPL-2.0+
+// ir-imon-decoder.c - handle iMon protocol
+//
+// Copyright (C) 2018 by Sean Young <sean@mess.org>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include "rc-core-priv.h"
+
+#define IMON_UNIT		416 /* us */
+#define IMON_BITS		30
+#define IMON_CHKBITS		(BIT(30) | BIT(25) | BIT(24) | BIT(22) | \
+				 BIT(21) | BIT(20) | BIT(19) | BIT(18) | \
+				 BIT(17) | BIT(16) | BIT(14) | BIT(13) | \
+				 BIT(12) | BIT(11) | BIT(10) | BIT(9))
+
+/*
+ * This protocol has 30 bits. The format is one IMON_UNIT header pulse,
+ * followed by 30 bits. Each bit is one IMON_UNIT check field, and then
+ * one IMON_UNIT field with the actual bit (1=space, 0=pulse).
+ * The check field is always space for some bits, for others it is pulse if
+ * both the preceding and current bit are zero, else space. IMON_CHKBITS
+ * defines which bits are of type check.
+ *
+ * There is no way to distinguish an incomplete message from one where
+ * the lower bits are all set, iow. the last pulse is for the lowest
+ * bit which is 0.
+ */
+enum imon_state {
+	STATE_INACTIVE,
+	STATE_BIT_CHK,
+	STATE_BIT_START,
+	STATE_FINISHED,
+	STATE_ERROR,
+};
+
+static void ir_imon_decode_scancode(struct rc_dev *dev)
+{
+	struct imon_dec *imon = &dev->raw->imon;
+
+	/* Keyboard/Mouse toggle */
+	if (imon->bits == 0x299115b7)
+		imon->stick_keyboard = !imon->stick_keyboard;
+
+	if ((imon->bits & 0xfc0000ff) == 0x680000b7) {
+		int rel_x, rel_y;
+		u8 buf;
+
+		buf = imon->bits >> 16;
+		rel_x = (buf & 0x08) | (buf & 0x10) >> 2 |
+			(buf & 0x20) >> 4 | (buf & 0x40) >> 6;
+		if (imon->bits & 0x02000000)
+			rel_x |= ~0x0f;
+		buf = imon->bits >> 8;
+		rel_y = (buf & 0x08) | (buf & 0x10) >> 2 |
+			(buf & 0x20) >> 4 | (buf & 0x40) >> 6;
+		if (imon->bits & 0x01000000)
+			rel_y |= ~0x0f;
+
+		if (rel_x && rel_y && imon->stick_keyboard) {
+			if (abs(rel_y) > abs(rel_x))
+				imon->bits = rel_y > 0 ?
+					0x289515b7 : /* KEY_DOWN */
+					0x2aa515b7;  /* KEY_UP */
+			else
+				imon->bits = rel_x > 0 ?
+					0x2ba515b7 : /* KEY_RIGHT */
+					0x29a515b7;  /* KEY_LEFT */
+		}
+
+		if (!imon->stick_keyboard) {
+			input_report_rel(dev->input_dev, REL_X, rel_x);
+			input_report_rel(dev->input_dev, REL_Y, rel_y);
+
+			input_report_key(dev->input_dev, BTN_LEFT,
+					 (imon->bits & 0x00010000) != 0);
+			input_report_key(dev->input_dev, BTN_RIGHT,
+					 (imon->bits & 0x00040000) != 0);
+		}
+	}
+
+	rc_keydown(dev, RC_PROTO_IMON, imon->bits, 0);
+}
+
+/**
+ * ir_imon_decode() - Decode one iMON pulse or space
+ * @dev:	the struct rc_dev descriptor of the device
+ * @ev:		the struct ir_raw_event descriptor of the pulse/space
+ *
+ * This function returns -EINVAL if the pulse violates the state machine
+ */
+static int ir_imon_decode(struct rc_dev *dev, struct ir_raw_event ev)
+{
+	struct imon_dec *data = &dev->raw->imon;
+
+	if (!is_timing_event(ev)) {
+		if (ev.overflow)
+			data->state = STATE_INACTIVE;
+		return 0;
+	}
+
+	dev_dbg(&dev->dev,
+		"iMON decode started at state %d bitno %d (%uus %s)\n",
+		data->state, data->count, ev.duration, TO_STR(ev.pulse));
+
+	/*
+	 * Since iMON protocol is a series of bits, if at any point
+	 * we encounter an error, make sure that any remaining bits
+	 * aren't parsed as a scancode made up of less bits.
+	 *
+	 * Note that if the stick is held, then the remote repeats
+	 * the scancode with about 12ms between them. So, make sure
+	 * we have at least 10ms of space after an error. That way,
+	 * we're at a new scancode.
+	 */
+	if (data->state == STATE_ERROR) {
+		if (!ev.pulse && ev.duration > MS_TO_US(10))
+			data->state = STATE_INACTIVE;
+		return 0;
+	}
+
+	for (;;) {
+		if (!geq_margin(ev.duration, IMON_UNIT, IMON_UNIT / 2))
+			return 0;
+
+		decrease_duration(&ev, IMON_UNIT);
+
+		switch (data->state) {
+		case STATE_INACTIVE:
+			if (ev.pulse) {
+				data->state = STATE_BIT_CHK;
+				data->bits = 0;
+				data->count = IMON_BITS;
+			}
+			break;
+		case STATE_BIT_CHK:
+			if (IMON_CHKBITS & BIT(data->count))
+				data->last_chk = ev.pulse;
+			else if (ev.pulse)
+				goto err_out;
+			data->state = STATE_BIT_START;
+			break;
+		case STATE_BIT_START:
+			data->bits <<= 1;
+			if (!ev.pulse)
+				data->bits |= 1;
+
+			if (IMON_CHKBITS & BIT(data->count)) {
+				if (data->last_chk != !(data->bits & 3))
+					goto err_out;
+			}
+
+			if (!data->count--)
+				data->state = STATE_FINISHED;
+			else
+				data->state = STATE_BIT_CHK;
+			break;
+		case STATE_FINISHED:
+			if (ev.pulse)
+				goto err_out;
+			ir_imon_decode_scancode(dev);
+			data->state = STATE_INACTIVE;
+			break;
+		}
+	}
+
+err_out:
+	dev_dbg(&dev->dev,
+		"iMON decode failed at state %d bitno %d (%uus %s)\n",
+		data->state, data->count, ev.duration, TO_STR(ev.pulse));
+
+	data->state = STATE_ERROR;
+
+	return -EINVAL;
+}
+
+/**
+ * ir_imon_encode() - Encode a scancode as a stream of raw events
+ *
+ * @protocol:	protocol to encode
+ * @scancode:	scancode to encode
+ * @events:	array of raw ir events to write into
+ * @max:	maximum size of @events
+ *
+ * Returns:	The number of events written.
+ *		-ENOBUFS if there isn't enough space in the array to fit the
+ *		encoding. In this case all @max events will have been written.
+ */
+static int ir_imon_encode(enum rc_proto protocol, u32 scancode,
+			  struct ir_raw_event *events, unsigned int max)
+{
+	struct ir_raw_event *e = events;
+	int i, pulse;
+
+	if (!max--)
+		return -ENOBUFS;
+	init_ir_raw_event_duration(e, 1, IMON_UNIT);
+
+	for (i = IMON_BITS; i >= 0; i--) {
+		if (BIT(i) & IMON_CHKBITS)
+			pulse = !(scancode & (BIT(i) | BIT(i + 1)));
+		else
+			pulse = 0;
+
+		if (pulse == e->pulse) {
+			e->duration += IMON_UNIT;
+		} else {
+			if (!max--)
+				return -ENOBUFS;
+			init_ir_raw_event_duration(++e, pulse, IMON_UNIT);
+		}
+
+		pulse = !(scancode & BIT(i));
+
+		if (pulse == e->pulse) {
+			e->duration += IMON_UNIT;
+		} else {
+			if (!max--)
+				return -ENOBUFS;
+			init_ir_raw_event_duration(++e, pulse, IMON_UNIT);
+		}
+	}
+
+	if (e->pulse)
+		e++;
+
+	return e - events;
+}
+
+static int ir_imon_register(struct rc_dev *dev)
+{
+	struct imon_dec *imon = &dev->raw->imon;
+
+	imon->stick_keyboard = false;
+
+	return 0;
+}
+
+static struct ir_raw_handler imon_handler = {
+	.protocols	= RC_PROTO_BIT_IMON,
+	.decode		= ir_imon_decode,
+	.encode		= ir_imon_encode,
+	.carrier	= 38000,
+	.raw_register	= ir_imon_register,
+	.min_timeout	= IMON_UNIT * IMON_BITS * 2,
+};
+
+static int __init ir_imon_decode_init(void)
+{
+	ir_raw_handler_register(&imon_handler);
+
+	pr_info("IR iMON protocol handler initialized\n");
+	return 0;
+}
+
+static void __exit ir_imon_decode_exit(void)
+{
+	ir_raw_handler_unregister(&imon_handler);
+}
+
+module_init(ir_imon_decode_init);
+module_exit(ir_imon_decode_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sean Young <sean@mess.org>");
+MODULE_DESCRIPTION("iMON IR protocol decoder");