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, 407 insertions, 0 deletions

diff --git a/drivers/media/rc/ir-rc6-decoder.c b/drivers/media/rc/ir-rc6-decoder.c
new file mode 100644
index 000000000..3b2c8bab3
--- /dev/null
+++ b/drivers/media/rc/ir-rc6-decoder.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* ir-rc6-decoder.c - A decoder for the RC6 IR protocol
+ *
+ * Copyright (C) 2010 by David Härdeman <david@hardeman.nu>
+ */
+
+#include "rc-core-priv.h"
+#include <linux/module.h>
+
+/*
+ * This decoder currently supports:
+ * RC6-0-16	(standard toggle bit in header)
+ * RC6-6A-20	(no toggle bit)
+ * RC6-6A-24	(no toggle bit)
+ * RC6-6A-32	(MCE version with toggle bit in body)
+ */
+
+#define RC6_UNIT		444	/* microseconds */
+#define RC6_HEADER_NBITS	4	/* not including toggle bit */
+#define RC6_0_NBITS		16
+#define RC6_6A_32_NBITS		32
+#define RC6_6A_NBITS		128	/* Variable 8..128 */
+#define RC6_PREFIX_PULSE	(6 * RC6_UNIT)
+#define RC6_PREFIX_SPACE	(2 * RC6_UNIT)
+#define RC6_BIT_START		(1 * RC6_UNIT)
+#define RC6_BIT_END		(1 * RC6_UNIT)
+#define RC6_TOGGLE_START	(2 * RC6_UNIT)
+#define RC6_TOGGLE_END		(2 * RC6_UNIT)
+#define RC6_SUFFIX_SPACE	(6 * RC6_UNIT)
+#define RC6_MODE_MASK		0x07	/* for the header bits */
+#define RC6_STARTBIT_MASK	0x08	/* for the header bits */
+#define RC6_6A_MCE_TOGGLE_MASK	0x8000	/* for the body bits */
+#define RC6_6A_LCC_MASK		0xffff0000 /* RC6-6A-32 long customer code mask */
+#define RC6_6A_MCE_CC		0x800f0000 /* MCE customer code */
+#define RC6_6A_ZOTAC_CC		0x80340000 /* Zotac customer code */
+#define RC6_6A_KATHREIN_CC	0x80460000 /* Kathrein RCU-676 customer code */
+#ifndef CHAR_BIT
+#define CHAR_BIT 8	/* Normally in <limits.h> */
+#endif
+
+enum rc6_mode {
+	RC6_MODE_0,
+	RC6_MODE_6A,
+	RC6_MODE_UNKNOWN,
+};
+
+enum rc6_state {
+	STATE_INACTIVE,
+	STATE_PREFIX_SPACE,
+	STATE_HEADER_BIT_START,
+	STATE_HEADER_BIT_END,
+	STATE_TOGGLE_START,
+	STATE_TOGGLE_END,
+	STATE_BODY_BIT_START,
+	STATE_BODY_BIT_END,
+	STATE_FINISHED,
+};
+
+static enum rc6_mode rc6_mode(struct rc6_dec *data)
+{
+	switch (data->header & RC6_MODE_MASK) {
+	case 0:
+		return RC6_MODE_0;
+	case 6:
+		if (!data->toggle)
+			return RC6_MODE_6A;
+		fallthrough;
+	default:
+		return RC6_MODE_UNKNOWN;
+	}
+}
+
+/**
+ * ir_rc6_decode() - Decode one RC6 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_rc6_decode(struct rc_dev *dev, struct ir_raw_event ev)
+{
+	struct rc6_dec *data = &dev->raw->rc6;
+	u32 scancode;
+	u8 toggle;
+	enum rc_proto protocol;
+
+	if (!is_timing_event(ev)) {
+		if (ev.overflow)
+			data->state = STATE_INACTIVE;
+		return 0;
+	}
+
+	if (!geq_margin(ev.duration, RC6_UNIT, RC6_UNIT / 2))
+		goto out;
+
+again:
+	dev_dbg(&dev->dev, "RC6 decode started at state %i (%uus %s)\n",
+		data->state, ev.duration, TO_STR(ev.pulse));
+
+	if (!geq_margin(ev.duration, RC6_UNIT, RC6_UNIT / 2))
+		return 0;
+
+	switch (data->state) {
+
+	case STATE_INACTIVE:
+		if (!ev.pulse)
+			break;
+
+		/* Note: larger margin on first pulse since each RC6_UNIT
+		   is quite short and some hardware takes some time to
+		   adjust to the signal */
+		if (!eq_margin(ev.duration, RC6_PREFIX_PULSE, RC6_UNIT))
+			break;
+
+		data->state = STATE_PREFIX_SPACE;
+		data->count = 0;
+		return 0;
+
+	case STATE_PREFIX_SPACE:
+		if (ev.pulse)
+			break;
+
+		if (!eq_margin(ev.duration, RC6_PREFIX_SPACE, RC6_UNIT / 2))
+			break;
+
+		data->state = STATE_HEADER_BIT_START;
+		data->header = 0;
+		return 0;
+
+	case STATE_HEADER_BIT_START:
+		if (!eq_margin(ev.duration, RC6_BIT_START, RC6_UNIT / 2))
+			break;
+
+		data->header <<= 1;
+		if (ev.pulse)
+			data->header |= 1;
+		data->count++;
+		data->state = STATE_HEADER_BIT_END;
+		return 0;
+
+	case STATE_HEADER_BIT_END:
+		if (data->count == RC6_HEADER_NBITS)
+			data->state = STATE_TOGGLE_START;
+		else
+			data->state = STATE_HEADER_BIT_START;
+
+		decrease_duration(&ev, RC6_BIT_END);
+		goto again;
+
+	case STATE_TOGGLE_START:
+		if (!eq_margin(ev.duration, RC6_TOGGLE_START, RC6_UNIT / 2))
+			break;
+
+		data->toggle = ev.pulse;
+		data->state = STATE_TOGGLE_END;
+		return 0;
+
+	case STATE_TOGGLE_END:
+		if (!(data->header & RC6_STARTBIT_MASK)) {
+			dev_dbg(&dev->dev, "RC6 invalid start bit\n");
+			break;
+		}
+
+		data->state = STATE_BODY_BIT_START;
+		decrease_duration(&ev, RC6_TOGGLE_END);
+		data->count = 0;
+		data->body = 0;
+
+		switch (rc6_mode(data)) {
+		case RC6_MODE_0:
+			data->wanted_bits = RC6_0_NBITS;
+			break;
+		case RC6_MODE_6A:
+			data->wanted_bits = RC6_6A_NBITS;
+			break;
+		default:
+			dev_dbg(&dev->dev, "RC6 unknown mode\n");
+			goto out;
+		}
+		goto again;
+
+	case STATE_BODY_BIT_START:
+		if (eq_margin(ev.duration, RC6_BIT_START, RC6_UNIT / 2)) {
+			/* Discard LSB's that won't fit in data->body */
+			if (data->count++ < CHAR_BIT * sizeof data->body) {
+				data->body <<= 1;
+				if (ev.pulse)
+					data->body |= 1;
+			}
+			data->state = STATE_BODY_BIT_END;
+			return 0;
+		} else if (RC6_MODE_6A == rc6_mode(data) && !ev.pulse &&
+				geq_margin(ev.duration, RC6_SUFFIX_SPACE, RC6_UNIT / 2)) {
+			data->state = STATE_FINISHED;
+			goto again;
+		}
+		break;
+
+	case STATE_BODY_BIT_END:
+		if (data->count == data->wanted_bits)
+			data->state = STATE_FINISHED;
+		else
+			data->state = STATE_BODY_BIT_START;
+
+		decrease_duration(&ev, RC6_BIT_END);
+		goto again;
+
+	case STATE_FINISHED:
+		if (ev.pulse)
+			break;
+
+		switch (rc6_mode(data)) {
+		case RC6_MODE_0:
+			scancode = data->body;
+			toggle = data->toggle;
+			protocol = RC_PROTO_RC6_0;
+			dev_dbg(&dev->dev, "RC6(0) scancode 0x%04x (toggle: %u)\n",
+				scancode, toggle);
+			break;
+
+		case RC6_MODE_6A:
+			if (data->count > CHAR_BIT * sizeof data->body) {
+				dev_dbg(&dev->dev, "RC6 too many (%u) data bits\n",
+					data->count);
+				goto out;
+			}
+
+			scancode = data->body;
+			switch (data->count) {
+			case 20:
+				protocol = RC_PROTO_RC6_6A_20;
+				toggle = 0;
+				break;
+			case 24:
+				protocol = RC_PROTO_RC6_6A_24;
+				toggle = 0;
+				break;
+			case 32:
+				switch (scancode & RC6_6A_LCC_MASK) {
+				case RC6_6A_MCE_CC:
+				case RC6_6A_KATHREIN_CC:
+				case RC6_6A_ZOTAC_CC:
+					protocol = RC_PROTO_RC6_MCE;
+					toggle = !!(scancode & RC6_6A_MCE_TOGGLE_MASK);
+					scancode &= ~RC6_6A_MCE_TOGGLE_MASK;
+					break;
+				default:
+					protocol = RC_PROTO_RC6_6A_32;
+					toggle = 0;
+					break;
+				}
+				break;
+			default:
+				dev_dbg(&dev->dev, "RC6(6A) unsupported length\n");
+				goto out;
+			}
+
+			dev_dbg(&dev->dev, "RC6(6A) proto 0x%04x, scancode 0x%08x (toggle: %u)\n",
+				protocol, scancode, toggle);
+			break;
+		default:
+			dev_dbg(&dev->dev, "RC6 unknown mode\n");
+			goto out;
+		}
+
+		rc_keydown(dev, protocol, scancode, toggle);
+		data->state = STATE_INACTIVE;
+		return 0;
+	}
+
+out:
+	dev_dbg(&dev->dev, "RC6 decode failed at state %i (%uus %s)\n",
+		data->state, ev.duration, TO_STR(ev.pulse));
+	data->state = STATE_INACTIVE;
+	return -EINVAL;
+}
+
+static const struct ir_raw_timings_manchester ir_rc6_timings[4] = {
+	{
+		.leader_pulse		= RC6_PREFIX_PULSE,
+		.leader_space		= RC6_PREFIX_SPACE,
+		.clock			= RC6_UNIT,
+		.invert			= 1,
+	},
+	{
+		.clock			= RC6_UNIT * 2,
+		.invert			= 1,
+	},
+	{
+		.clock			= RC6_UNIT,
+		.invert			= 1,
+		.trailer_space		= RC6_SUFFIX_SPACE,
+	},
+};
+
+/**
+ * ir_rc6_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.
+ *		-EINVAL if the scancode is ambiguous or invalid.
+ */
+static int ir_rc6_encode(enum rc_proto protocol, u32 scancode,
+			 struct ir_raw_event *events, unsigned int max)
+{
+	int ret;
+	struct ir_raw_event *e = events;
+
+	if (protocol == RC_PROTO_RC6_0) {
+		/* Modulate the header (Start Bit & Mode-0) */
+		ret = ir_raw_gen_manchester(&e, max - (e - events),
+					    &ir_rc6_timings[0],
+					    RC6_HEADER_NBITS, (1 << 3));
+		if (ret < 0)
+			return ret;
+
+		/* Modulate Trailer Bit */
+		ret = ir_raw_gen_manchester(&e, max - (e - events),
+					    &ir_rc6_timings[1], 1, 0);
+		if (ret < 0)
+			return ret;
+
+		/* Modulate rest of the data */
+		ret = ir_raw_gen_manchester(&e, max - (e - events),
+					    &ir_rc6_timings[2], RC6_0_NBITS,
+					    scancode);
+		if (ret < 0)
+			return ret;
+
+	} else {
+		int bits;
+
+		switch (protocol) {
+		case RC_PROTO_RC6_MCE:
+		case RC_PROTO_RC6_6A_32:
+			bits = 32;
+			break;
+		case RC_PROTO_RC6_6A_24:
+			bits = 24;
+			break;
+		case RC_PROTO_RC6_6A_20:
+			bits = 20;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		/* Modulate the header (Start Bit & Header-version 6 */
+		ret = ir_raw_gen_manchester(&e, max - (e - events),
+					    &ir_rc6_timings[0],
+					    RC6_HEADER_NBITS, (1 << 3 | 6));
+		if (ret < 0)
+			return ret;
+
+		/* Modulate Trailer Bit */
+		ret = ir_raw_gen_manchester(&e, max - (e - events),
+					    &ir_rc6_timings[1], 1, 0);
+		if (ret < 0)
+			return ret;
+
+		/* Modulate rest of the data */
+		ret = ir_raw_gen_manchester(&e, max - (e - events),
+					    &ir_rc6_timings[2],
+					    bits,
+					    scancode);
+		if (ret < 0)
+			return ret;
+	}
+
+	return e - events;
+}
+
+static struct ir_raw_handler rc6_handler = {
+	.protocols	= RC_PROTO_BIT_RC6_0 | RC_PROTO_BIT_RC6_6A_20 |
+			  RC_PROTO_BIT_RC6_6A_24 | RC_PROTO_BIT_RC6_6A_32 |
+			  RC_PROTO_BIT_RC6_MCE,
+	.decode		= ir_rc6_decode,
+	.encode		= ir_rc6_encode,
+	.carrier	= 36000,
+	.min_timeout	= RC6_SUFFIX_SPACE,
+};
+
+static int __init ir_rc6_decode_init(void)
+{
+	ir_raw_handler_register(&rc6_handler);
+
+	printk(KERN_INFO "IR RC6 protocol handler initialized\n");
+	return 0;
+}
+
+static void __exit ir_rc6_decode_exit(void)
+{
+	ir_raw_handler_unregister(&rc6_handler);
+}
+
+module_init(ir_rc6_decode_init);
+module_exit(ir_rc6_decode_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
+MODULE_DESCRIPTION("RC6 IR protocol decoder");