From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops 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 --- drivers/input/input-compat.c | 163 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 163 insertions(+) create mode 100644 drivers/input/input-compat.c (limited to 'drivers/input/input-compat.c') diff --git a/drivers/input/input-compat.c b/drivers/input/input-compat.c new file mode 100644 index 000000000..a5043193e --- /dev/null +++ b/drivers/input/input-compat.c @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 32bit compatibility wrappers for the input subsystem. + * + * Very heavily based on evdev.c - Copyright (c) 1999-2002 Vojtech Pavlik + */ + +#include +#include +#include +#include "input-compat.h" + +#ifdef CONFIG_COMPAT + +int input_event_from_user(const char __user *buffer, + struct input_event *event) +{ + if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) { + struct input_event_compat compat_event; + + if (copy_from_user(&compat_event, buffer, + sizeof(struct input_event_compat))) + return -EFAULT; + + event->input_event_sec = compat_event.sec; + event->input_event_usec = compat_event.usec; + event->type = compat_event.type; + event->code = compat_event.code; + event->value = compat_event.value; + + } else { + if (copy_from_user(event, buffer, sizeof(struct input_event))) + return -EFAULT; + } + + return 0; +} + +int input_event_to_user(char __user *buffer, + const struct input_event *event) +{ + if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) { + struct input_event_compat compat_event; + + compat_event.sec = event->input_event_sec; + compat_event.usec = event->input_event_usec; + compat_event.type = event->type; + compat_event.code = event->code; + compat_event.value = event->value; + + if (copy_to_user(buffer, &compat_event, + sizeof(struct input_event_compat))) + return -EFAULT; + + } else { + if (copy_to_user(buffer, event, sizeof(struct input_event))) + return -EFAULT; + } + + return 0; +} + +int input_ff_effect_from_user(const char __user *buffer, size_t size, + struct ff_effect *effect) +{ + if (in_compat_syscall()) { + struct ff_effect_compat *compat_effect; + + if (size != sizeof(struct ff_effect_compat)) + return -EINVAL; + + /* + * It so happens that the pointer which needs to be changed + * is the last field in the structure, so we can retrieve the + * whole thing and replace just the pointer. + */ + compat_effect = (struct ff_effect_compat *)effect; + + if (copy_from_user(compat_effect, buffer, + sizeof(struct ff_effect_compat))) + return -EFAULT; + + if (compat_effect->type == FF_PERIODIC && + compat_effect->u.periodic.waveform == FF_CUSTOM) + effect->u.periodic.custom_data = + compat_ptr(compat_effect->u.periodic.custom_data); + } else { + if (size != sizeof(struct ff_effect)) + return -EINVAL; + + if (copy_from_user(effect, buffer, sizeof(struct ff_effect))) + return -EFAULT; + } + + return 0; +} + +int input_bits_to_string(char *buf, int buf_size, unsigned long bits, + bool skip_empty) +{ + int len = 0; + + if (in_compat_syscall()) { + u32 dword = bits >> 32; + if (dword || !skip_empty) + len += snprintf(buf, buf_size, "%x ", dword); + + dword = bits & 0xffffffffUL; + if (dword || !skip_empty || len) + len += snprintf(buf + len, max(buf_size - len, 0), + "%x", dword); + } else { + if (bits || !skip_empty) + len += snprintf(buf, buf_size, "%lx", bits); + } + + return len; +} + +#else + +int input_event_from_user(const char __user *buffer, + struct input_event *event) +{ + if (copy_from_user(event, buffer, sizeof(struct input_event))) + return -EFAULT; + + return 0; +} + +int input_event_to_user(char __user *buffer, + const struct input_event *event) +{ + if (copy_to_user(buffer, event, sizeof(struct input_event))) + return -EFAULT; + + return 0; +} + +int input_ff_effect_from_user(const char __user *buffer, size_t size, + struct ff_effect *effect) +{ + if (size != sizeof(struct ff_effect)) + return -EINVAL; + + if (copy_from_user(effect, buffer, sizeof(struct ff_effect))) + return -EFAULT; + + return 0; +} + +int input_bits_to_string(char *buf, int buf_size, unsigned long bits, + bool skip_empty) +{ + return bits || !skip_empty ? + snprintf(buf, buf_size, "%lx", bits) : 0; +} + +#endif /* CONFIG_COMPAT */ + +EXPORT_SYMBOL_GPL(input_event_from_user); +EXPORT_SYMBOL_GPL(input_event_to_user); +EXPORT_SYMBOL_GPL(input_ff_effect_from_user); -- cgit v1.3.1