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, 284 insertions, 0 deletions

diff --git a/drivers/hid/hid-uclogic-params.h b/drivers/hid/hid-uclogic-params.h
new file mode 100644
index 000000000..c84ff17fb
--- /dev/null
+++ b/drivers/hid/hid-uclogic-params.h
@@ -0,0 +1,284 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ *  HID driver for UC-Logic devices not fully compliant with HID standard
+ *  - tablet initialization and parameter retrieval
+ *
+ *  Copyright (c) 2018 Nikolai Kondrashov
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#ifndef _HID_UCLOGIC_PARAMS_H
+#define _HID_UCLOGIC_PARAMS_H
+
+#include <linux/usb.h>
+#include <linux/hid.h>
+#include <linux/list.h>
+
+#define UCLOGIC_MOUSE_FRAME_QUIRK	BIT(0)
+#define UCLOGIC_BATTERY_QUIRK		BIT(1)
+
+/* Types of pen in-range reporting */
+enum uclogic_params_pen_inrange {
+	/* Normal reports: zero - out of proximity, one - in proximity */
+	UCLOGIC_PARAMS_PEN_INRANGE_NORMAL = 0,
+	/* Inverted reports: zero - in proximity, one - out of proximity */
+	UCLOGIC_PARAMS_PEN_INRANGE_INVERTED,
+	/* No reports */
+	UCLOGIC_PARAMS_PEN_INRANGE_NONE,
+};
+
+/* Types of frames */
+enum uclogic_params_frame_type {
+	/* Frame with buttons */
+	UCLOGIC_PARAMS_FRAME_BUTTONS = 0,
+	/* Frame with buttons and a dial */
+	UCLOGIC_PARAMS_FRAME_DIAL,
+	/* Frame with buttons and a mouse (shaped as a dial + touchpad) */
+	UCLOGIC_PARAMS_FRAME_MOUSE,
+};
+
+/*
+ * Pen report's subreport data.
+ */
+struct uclogic_params_pen_subreport {
+	/*
+	 * The value of the second byte of the pen report indicating this
+	 * subreport. If zero, the subreport should be considered invalid and
+	 * not matched.
+	 */
+	__u8 value;
+
+	/*
+	 * The ID to be assigned to the report, if the second byte of the pen
+	 * report is equal to "value". Only valid if "value" is not zero.
+	 */
+	__u8 id;
+};
+
+/*
+ * Tablet interface's pen input parameters.
+ *
+ * Must use declarative (descriptive) language, not imperative, to simplify
+ * understanding and maintain consistency.
+ *
+ * Noop (preserving functionality) when filled with zeroes.
+ */
+struct uclogic_params_pen {
+	/*
+	 * True if pen usage is invalid for this interface and should be
+	 * ignored, false otherwise.
+	 */
+	bool usage_invalid;
+	/*
+	 * Pointer to report descriptor part describing the pen inputs.
+	 * Allocated with kmalloc. NULL if the part is not specified.
+	 */
+	const __u8 *desc_ptr;
+	/*
+	 * Size of the report descriptor.
+	 * Only valid, if "desc_ptr" is not NULL.
+	 */
+	unsigned int desc_size;
+	/* Report ID, if reports should be tweaked, zero if not */
+	unsigned int id;
+	/* The list of subreports, only valid if "id" is not zero */
+	struct uclogic_params_pen_subreport subreport_list[3];
+	/* Type of in-range reporting, only valid if "id" is not zero */
+	enum uclogic_params_pen_inrange inrange;
+	/*
+	 * True, if reports include fragmented high resolution coords, with
+	 * high-order X and then Y bytes following the pressure field.
+	 * Only valid if "id" is not zero.
+	 */
+	bool fragmented_hires;
+	/*
+	 * True if the pen reports tilt in bytes at offset 10 (X) and 11 (Y),
+	 * and the Y tilt direction is flipped.
+	 * Only valid if "id" is not zero.
+	 */
+	bool tilt_y_flipped;
+	/*
+	 * True, if reports include fragmented high resolution X coords.
+	 * This moves bytes 10-11 to the LSB of the X coordinate.
+	 */
+	bool fragmented_hires2;
+};
+
+/*
+ * Parameters of frame control inputs of a tablet interface.
+ *
+ * Must use declarative (descriptive) language, not imperative, to simplify
+ * understanding and maintain consistency.
+ *
+ * Noop (preserving functionality) when filled with zeroes.
+ */
+struct uclogic_params_frame {
+	/*
+	 * Pointer to report descriptor part describing the frame inputs.
+	 * Allocated with kmalloc. NULL if the part is not specified.
+	 */
+	const __u8 *desc_ptr;
+	/*
+	 * Size of the report descriptor.
+	 * Only valid, if "desc_ptr" is not NULL.
+	 */
+	unsigned int desc_size;
+	/*
+	 * Report ID, if reports should be tweaked, zero if not.
+	 */
+	unsigned int id;
+	/*
+	 * The suffix to add to the input device name, if not NULL.
+	 */
+	const char *suffix;
+	/*
+	 * Number of the least-significant bit of the 2-bit state of a rotary
+	 * encoder, in the report. Cannot point to a 2-bit field crossing a
+	 * byte boundary. Zero if not present. Only valid if "id" is not zero.
+	 */
+	unsigned int re_lsb;
+	/*
+	 * Offset of the Wacom-style device ID byte in the report, to be set
+	 * to pad device ID (0xf), for compatibility with Wacom drivers. Zero
+	 * if no changes to the report should be made. The ID byte will be set
+	 * to zero whenever the byte pointed by "touch_byte" is zero, if
+	 * the latter is valid. Only valid if "id" is not zero.
+	 */
+	unsigned int dev_id_byte;
+	/*
+	 * Offset of the touch ring/strip state byte, in the report.
+	 * Zero if not present. If dev_id_byte is also valid and non-zero,
+	 * then the device ID byte will be cleared when the byte pointed to by
+	 * this offset is zero. Only valid if "id" is not zero.
+	 */
+	unsigned int touch_byte;
+	/*
+	 * The value to anchor the reversed touch ring/strip reports at.
+	 * I.e. one, if the reports should be flipped without offset.
+	 * Zero if no reversal should be done.
+	 * Only valid if "touch_byte" is valid and not zero.
+	 */
+	__s8 touch_flip_at;
+	/*
+	 * Maximum value of the touch ring/strip report around which the value
+	 * should be wrapped when flipping according to "touch_flip_at".
+	 * The minimum valid value is considered to be one, with zero being
+	 * out-of-proximity (finger lift) value.
+	 * Only valid if "touch_flip_at" is valid and not zero.
+	 */
+	__s8 touch_max;
+	/*
+	 * Offset of the bitmap dial byte, in the report. Zero if not present.
+	 * Only valid if "id" is not zero. A bitmap dial sends reports with a
+	 * dedicated bit per direction: 1 means clockwise rotation, 2 means
+	 * counterclockwise, as opposed to the normal 1 and -1.
+	 */
+	unsigned int bitmap_dial_byte;
+	/*
+	 * Destination offset for the second bitmap dial byte, if the tablet
+	 * supports a second dial at all.
+	 */
+	unsigned int bitmap_second_dial_destination_byte;
+};
+
+/*
+ * List of works to be performed when a certain raw event is received.
+ */
+struct uclogic_raw_event_hook {
+	struct hid_device *hdev;
+	__u8 *event;
+	size_t size;
+	struct work_struct work;
+	struct list_head list;
+};
+
+/*
+ * Tablet interface report parameters.
+ *
+ * Must use declarative (descriptive) language, not imperative, to simplify
+ * understanding and maintain consistency.
+ *
+ * When filled with zeros represents a "noop" configuration - passes all
+ * reports unchanged and lets the generic HID driver handle everything.
+ *
+ * The resulting device report descriptor is assembled from all the report
+ * descriptor parts referenced by the structure. No order of assembly should
+ * be assumed. The structure represents original device report descriptor if
+ * all the parts are NULL.
+ */
+struct uclogic_params {
+	/*
+	 * True if the whole interface is invalid, false otherwise.
+	 */
+	bool invalid;
+	/*
+	 * Pointer to the common part of the replacement report descriptor,
+	 * allocated with kmalloc. NULL if no common part is needed.
+	 * Only valid, if "invalid" is false.
+	 */
+	const __u8 *desc_ptr;
+	/*
+	 * Size of the common part of the replacement report descriptor.
+	 * Only valid, if "desc_ptr" is valid and not NULL.
+	 */
+	unsigned int desc_size;
+	/*
+	 * Pen parameters and optional report descriptor part.
+	 * Only valid, if "invalid" is false.
+	 */
+	struct uclogic_params_pen pen;
+	/*
+	 * The list of frame control parameters and optional report descriptor
+	 * parts. Only valid, if "invalid" is false.
+	 */
+	struct uclogic_params_frame frame_list[3];
+	/*
+	 * List of event hooks.
+	 */
+	struct uclogic_raw_event_hook *event_hooks;
+};
+
+/* Driver data */
+struct uclogic_drvdata {
+	/* Interface parameters */
+	struct uclogic_params params;
+	/* Pointer to the replacement report descriptor. NULL if none. */
+	const __u8 *desc_ptr;
+	/*
+	 * Size of the replacement report descriptor.
+	 * Only valid if desc_ptr is not NULL
+	 */
+	unsigned int desc_size;
+	/* Pen input device */
+	struct input_dev *pen_input;
+	/* In-range timer */
+	struct timer_list inrange_timer;
+	/* Last rotary encoder state, or U8_MAX for none */
+	u8 re_state;
+	/* Device quirks */
+	unsigned long quirks;
+};
+
+/* Initialize a tablet interface and discover its parameters */
+extern int uclogic_params_init(struct uclogic_params *params,
+				struct hid_device *hdev);
+
+/* Get a replacement report descriptor for a tablet's interface. */
+extern int uclogic_params_get_desc(const struct uclogic_params *params,
+					const __u8 **pdesc,
+					unsigned int *psize);
+
+/* Free resources used by tablet interface's parameters */
+extern void uclogic_params_cleanup(struct uclogic_params *params);
+
+/* Dump tablet interface parameters with hid_dbg() */
+extern void uclogic_params_hid_dbg(const struct hid_device *hdev,
+					const struct uclogic_params *params);
+
+#endif /* _HID_UCLOGIC_PARAMS_H */