ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 299 insertions, 0 deletions

diff --git a/drivers/hid/hid-picolcd.h b/drivers/hid/hid-picolcd.h
new file mode 100644
index 000000000..57c9d0a67
--- /dev/null
+++ b/drivers/hid/hid-picolcd.h
@@ -0,0 +1,299 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/***************************************************************************
+ *   Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org>  *
+ *                                                                         *
+ *   Based on Logitech G13 driver (v0.4)                                   *
+ *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
+ *                                                                         *
+ ***************************************************************************/
+
+#define PICOLCD_NAME "PicoLCD (graphic)"
+
+/* Report numbers */
+#define REPORT_ERROR_CODE      0x10 /* LCD: IN[16]  */
+#define   ERR_SUCCESS            0x00
+#define   ERR_PARAMETER_MISSING  0x01
+#define   ERR_DATA_MISSING       0x02
+#define   ERR_BLOCK_READ_ONLY    0x03
+#define   ERR_BLOCK_NOT_ERASABLE 0x04
+#define   ERR_BLOCK_TOO_BIG      0x05
+#define   ERR_SECTION_OVERFLOW   0x06
+#define   ERR_INVALID_CMD_LEN    0x07
+#define   ERR_INVALID_DATA_LEN   0x08
+#define REPORT_KEY_STATE       0x11 /* LCD: IN[2]   */
+#define REPORT_IR_DATA         0x21 /* LCD: IN[63]  */
+#define REPORT_EE_DATA         0x32 /* LCD: IN[63]  */
+#define REPORT_MEMORY          0x41 /* LCD: IN[63]  */
+#define REPORT_LED_STATE       0x81 /* LCD: OUT[1]  */
+#define REPORT_BRIGHTNESS      0x91 /* LCD: OUT[1]  */
+#define REPORT_CONTRAST        0x92 /* LCD: OUT[1]  */
+#define REPORT_RESET           0x93 /* LCD: OUT[2]  */
+#define REPORT_LCD_CMD         0x94 /* LCD: OUT[63] */
+#define REPORT_LCD_DATA        0x95 /* LCD: OUT[63] */
+#define REPORT_LCD_CMD_DATA    0x96 /* LCD: OUT[63] */
+#define	REPORT_EE_READ         0xa3 /* LCD: OUT[63] */
+#define REPORT_EE_WRITE        0xa4 /* LCD: OUT[63] */
+#define REPORT_ERASE_MEMORY    0xb2 /* LCD: OUT[2]  */
+#define REPORT_READ_MEMORY     0xb3 /* LCD: OUT[3]  */
+#define REPORT_WRITE_MEMORY    0xb4 /* LCD: OUT[63] */
+#define REPORT_SPLASH_RESTART  0xc1 /* LCD: OUT[1]  */
+#define REPORT_EXIT_KEYBOARD   0xef /* LCD: OUT[2]  */
+#define REPORT_VERSION         0xf1 /* LCD: IN[2],OUT[1]    Bootloader: IN[2],OUT[1]   */
+#define REPORT_BL_ERASE_MEMORY 0xf2 /*                      Bootloader: IN[36],OUT[4]  */
+#define REPORT_BL_READ_MEMORY  0xf3 /*                      Bootloader: IN[36],OUT[4]  */
+#define REPORT_BL_WRITE_MEMORY 0xf4 /*                      Bootloader: IN[36],OUT[36] */
+#define REPORT_DEVID           0xf5 /* LCD: IN[5], OUT[1]   Bootloader: IN[5],OUT[1]   */
+#define REPORT_SPLASH_SIZE     0xf6 /* LCD: IN[4], OUT[1]   */
+#define REPORT_HOOK_VERSION    0xf7 /* LCD: IN[2], OUT[1]   */
+#define REPORT_EXIT_FLASHER    0xff /*                      Bootloader: OUT[2]         */
+
+/* Description of in-progress IO operation, used for operations
+ * that trigger response from device */
+struct picolcd_pending {
+	struct hid_report *out_report;
+	struct hid_report *in_report;
+	struct completion ready;
+	int raw_size;
+	u8 raw_data[64];
+};
+
+
+#define PICOLCD_KEYS 17
+
+/* Per device data structure */
+struct picolcd_data {
+	struct hid_device *hdev;
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debug_reset;
+	struct dentry *debug_eeprom;
+	struct dentry *debug_flash;
+	struct mutex mutex_flash;
+	int addr_sz;
+#endif
+	u8 version[2];
+	unsigned short opmode_delay;
+	/* input stuff */
+	u8 pressed_keys[2];
+	struct input_dev *input_keys;
+#ifdef CONFIG_HID_PICOLCD_CIR
+	struct rc_dev *rc_dev;
+#endif
+	unsigned short keycode[PICOLCD_KEYS];
+
+#ifdef CONFIG_HID_PICOLCD_FB
+	/* Framebuffer stuff */
+	struct fb_info *fb_info;
+#endif /* CONFIG_HID_PICOLCD_FB */
+#ifdef CONFIG_HID_PICOLCD_LCD
+	struct lcd_device *lcd;
+	u8 lcd_contrast;
+#endif /* CONFIG_HID_PICOLCD_LCD */
+#ifdef CONFIG_HID_PICOLCD_BACKLIGHT
+	struct backlight_device *backlight;
+	u8 lcd_brightness;
+	u8 lcd_power;
+#endif /* CONFIG_HID_PICOLCD_BACKLIGHT */
+#ifdef CONFIG_HID_PICOLCD_LEDS
+	/* LED stuff */
+	u8 led_state;
+	struct led_classdev *led[8];
+#endif /* CONFIG_HID_PICOLCD_LEDS */
+
+	/* Housekeeping stuff */
+	spinlock_t lock;
+	struct mutex mutex;
+	struct picolcd_pending *pending;
+	int status;
+#define PICOLCD_BOOTLOADER 1
+#define PICOLCD_FAILED 2
+#define PICOLCD_CIR_SHUN 4
+};
+
+#ifdef CONFIG_HID_PICOLCD_FB
+struct picolcd_fb_data {
+	/* Framebuffer stuff */
+	spinlock_t lock;
+	struct picolcd_data *picolcd;
+	u8 update_rate;
+	u8 bpp;
+	u8 force;
+	u8 ready;
+	u8 *vbitmap;		/* local copy of what was sent to PicoLCD */
+	u8 *bitmap;		/* framebuffer */
+};
+#endif /* CONFIG_HID_PICOLCD_FB */
+
+/* Find a given report */
+#define picolcd_in_report(id, dev) picolcd_report(id, dev, HID_INPUT_REPORT)
+#define picolcd_out_report(id, dev) picolcd_report(id, dev, HID_OUTPUT_REPORT)
+
+struct hid_report *picolcd_report(int id, struct hid_device *hdev, int dir);
+
+#ifdef CONFIG_DEBUG_FS
+void picolcd_debug_out_report(struct picolcd_data *data,
+		struct hid_device *hdev, struct hid_report *report);
+#define hid_hw_request(a, b, c) \
+	do { \
+		picolcd_debug_out_report(hid_get_drvdata(a), a, b); \
+		hid_hw_request(a, b, c); \
+	} while (0)
+
+void picolcd_debug_raw_event(struct picolcd_data *data,
+		struct hid_device *hdev, struct hid_report *report,
+		u8 *raw_data, int size);
+
+void picolcd_init_devfs(struct picolcd_data *data,
+		struct hid_report *eeprom_r, struct hid_report *eeprom_w,
+		struct hid_report *flash_r, struct hid_report *flash_w,
+		struct hid_report *reset);
+
+void picolcd_exit_devfs(struct picolcd_data *data);
+#else
+static inline void picolcd_debug_out_report(struct picolcd_data *data,
+		struct hid_device *hdev, struct hid_report *report)
+{
+}
+static inline void picolcd_debug_raw_event(struct picolcd_data *data,
+		struct hid_device *hdev, struct hid_report *report,
+		u8 *raw_data, int size)
+{
+}
+static inline void picolcd_init_devfs(struct picolcd_data *data,
+		struct hid_report *eeprom_r, struct hid_report *eeprom_w,
+		struct hid_report *flash_r, struct hid_report *flash_w,
+		struct hid_report *reset)
+{
+}
+static inline void picolcd_exit_devfs(struct picolcd_data *data)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
+
+#ifdef CONFIG_HID_PICOLCD_FB
+int picolcd_fb_reset(struct picolcd_data *data, int clear);
+
+int picolcd_init_framebuffer(struct picolcd_data *data);
+
+void picolcd_exit_framebuffer(struct picolcd_data *data);
+
+void picolcd_fb_refresh(struct picolcd_data *data);
+#define picolcd_fbinfo(d) ((d)->fb_info)
+#else
+static inline int picolcd_fb_reset(struct picolcd_data *data, int clear)
+{
+	return 0;
+}
+static inline int picolcd_init_framebuffer(struct picolcd_data *data)
+{
+	return 0;
+}
+static inline void picolcd_exit_framebuffer(struct picolcd_data *data)
+{
+}
+static inline void picolcd_fb_refresh(struct picolcd_data *data)
+{
+}
+#define picolcd_fbinfo(d) NULL
+#endif /* CONFIG_HID_PICOLCD_FB */
+
+
+#ifdef CONFIG_HID_PICOLCD_BACKLIGHT
+int picolcd_init_backlight(struct picolcd_data *data,
+		struct hid_report *report);
+
+void picolcd_exit_backlight(struct picolcd_data *data);
+
+int picolcd_resume_backlight(struct picolcd_data *data);
+
+void picolcd_suspend_backlight(struct picolcd_data *data);
+#else
+static inline int picolcd_init_backlight(struct picolcd_data *data,
+		struct hid_report *report)
+{
+	return 0;
+}
+static inline void picolcd_exit_backlight(struct picolcd_data *data)
+{
+}
+static inline int picolcd_resume_backlight(struct picolcd_data *data)
+{
+	return 0;
+}
+static inline void picolcd_suspend_backlight(struct picolcd_data *data)
+{
+}
+
+#endif /* CONFIG_HID_PICOLCD_BACKLIGHT */
+
+
+#ifdef CONFIG_HID_PICOLCD_LCD
+int picolcd_init_lcd(struct picolcd_data *data,
+		struct hid_report *report);
+
+void picolcd_exit_lcd(struct picolcd_data *data);
+
+int picolcd_resume_lcd(struct picolcd_data *data);
+#else
+static inline int picolcd_init_lcd(struct picolcd_data *data,
+		struct hid_report *report)
+{
+	return 0;
+}
+static inline void picolcd_exit_lcd(struct picolcd_data *data)
+{
+}
+static inline int picolcd_resume_lcd(struct picolcd_data *data)
+{
+	return 0;
+}
+#endif /* CONFIG_HID_PICOLCD_LCD */
+
+
+#ifdef CONFIG_HID_PICOLCD_LEDS
+int picolcd_init_leds(struct picolcd_data *data,
+		struct hid_report *report);
+
+void picolcd_exit_leds(struct picolcd_data *data);
+
+void picolcd_leds_set(struct picolcd_data *data);
+#else
+static inline int picolcd_init_leds(struct picolcd_data *data,
+		struct hid_report *report)
+{
+	return 0;
+}
+static inline void picolcd_exit_leds(struct picolcd_data *data)
+{
+}
+static inline void picolcd_leds_set(struct picolcd_data *data)
+{
+}
+#endif /* CONFIG_HID_PICOLCD_LEDS */
+
+
+#ifdef CONFIG_HID_PICOLCD_CIR
+int picolcd_raw_cir(struct picolcd_data *data,
+		struct hid_report *report, u8 *raw_data, int size);
+
+int picolcd_init_cir(struct picolcd_data *data, struct hid_report *report);
+
+void picolcd_exit_cir(struct picolcd_data *data);
+#else
+static inline int picolcd_raw_cir(struct picolcd_data *data,
+		struct hid_report *report, u8 *raw_data, int size)
+{
+	return 1;
+}
+static inline int picolcd_init_cir(struct picolcd_data *data, struct hid_report *report)
+{
+	return 0;
+}
+static inline void picolcd_exit_cir(struct picolcd_data *data)
+{
+}
+#endif /* CONFIG_HID_PICOLCD_CIR */
+
+int picolcd_reset(struct hid_device *hdev);
+struct picolcd_pending *picolcd_send_and_wait(struct hid_device *hdev,
+			int report_id, const u8 *raw_data, int size);