152194fe9c
The input events use struct timeval to store event time, unfortunately
this structure is not y2038 safe and is being replaced in kernel with
y2038 safe structures.
Because of ABI concerns we can not change the size or the layout of
structure input_event, so we opt to re-interpreting the 'seconds' part
of timestamp as an unsigned value, effectively doubling the range of
values, to year 2106.
Newer glibc that has support for 32 bit applications to use 64 bit
time_t supplies __USE_TIME_BITS64 define [1], that we can use to present
the userspace with updated input_event layout. The updated layout will
cause the compile time breakage, alerting applications and distributions
maintainers to the issue. Existing 32 binaries will continue working
without any changes until 2038.
Ultimately userspace applications should switch to using monotonic or
boot time clocks, as realtime clock is not very well suited for input
event timestamps as it can go backwards (see a80b83b7b8 "Input: evdev -
add CLOCK_BOOTTIME support" by by John Stultz). With monotonic clock the
practical range of reported times will always fit into the pair of 32
bit values, as we do not expect any system to stay up for a hundred
years without a single reboot.
[1] https://sourceware.org/glibc/wiki/Y2038ProofnessDesign
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Patchwork-Id: 10148083
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
137 lines
3.3 KiB
C
137 lines
3.3 KiB
C
/*
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* 32bit compatibility wrappers for the input subsystem.
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*
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* Very heavily based on evdev.c - Copyright (c) 1999-2002 Vojtech Pavlik
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/export.h>
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#include <linux/uaccess.h>
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#include "input-compat.h"
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#ifdef CONFIG_COMPAT
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int input_event_from_user(const char __user *buffer,
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struct input_event *event)
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{
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if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
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struct input_event_compat compat_event;
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if (copy_from_user(&compat_event, buffer,
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sizeof(struct input_event_compat)))
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return -EFAULT;
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event->input_event_sec = compat_event.sec;
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event->input_event_usec = compat_event.usec;
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event->type = compat_event.type;
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event->code = compat_event.code;
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event->value = compat_event.value;
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} else {
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if (copy_from_user(event, buffer, sizeof(struct input_event)))
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return -EFAULT;
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}
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return 0;
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}
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int input_event_to_user(char __user *buffer,
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const struct input_event *event)
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{
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if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
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struct input_event_compat compat_event;
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compat_event.sec = event->input_event_sec;
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compat_event.usec = event->input_event_usec;
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compat_event.type = event->type;
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compat_event.code = event->code;
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compat_event.value = event->value;
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if (copy_to_user(buffer, &compat_event,
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sizeof(struct input_event_compat)))
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return -EFAULT;
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} else {
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if (copy_to_user(buffer, event, sizeof(struct input_event)))
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return -EFAULT;
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}
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return 0;
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}
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int input_ff_effect_from_user(const char __user *buffer, size_t size,
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struct ff_effect *effect)
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{
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if (in_compat_syscall()) {
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struct ff_effect_compat *compat_effect;
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if (size != sizeof(struct ff_effect_compat))
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return -EINVAL;
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/*
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* It so happens that the pointer which needs to be changed
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* is the last field in the structure, so we can retrieve the
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* whole thing and replace just the pointer.
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*/
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compat_effect = (struct ff_effect_compat *)effect;
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if (copy_from_user(compat_effect, buffer,
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sizeof(struct ff_effect_compat)))
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return -EFAULT;
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if (compat_effect->type == FF_PERIODIC &&
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compat_effect->u.periodic.waveform == FF_CUSTOM)
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effect->u.periodic.custom_data =
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compat_ptr(compat_effect->u.periodic.custom_data);
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} else {
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if (size != sizeof(struct ff_effect))
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return -EINVAL;
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if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
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return -EFAULT;
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}
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return 0;
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}
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#else
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int input_event_from_user(const char __user *buffer,
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struct input_event *event)
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{
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if (copy_from_user(event, buffer, sizeof(struct input_event)))
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return -EFAULT;
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return 0;
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}
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int input_event_to_user(char __user *buffer,
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const struct input_event *event)
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{
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if (copy_to_user(buffer, event, sizeof(struct input_event)))
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return -EFAULT;
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return 0;
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}
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int input_ff_effect_from_user(const char __user *buffer, size_t size,
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struct ff_effect *effect)
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{
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if (size != sizeof(struct ff_effect))
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return -EINVAL;
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if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
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return -EFAULT;
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return 0;
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}
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#endif /* CONFIG_COMPAT */
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EXPORT_SYMBOL_GPL(input_event_from_user);
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EXPORT_SYMBOL_GPL(input_event_to_user);
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EXPORT_SYMBOL_GPL(input_ff_effect_from_user);
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