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authorDeepa Dinamani <deepa.kernel@gmail.com>2018-01-07 17:44:42 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2018-01-09 16:40:30 -0800
commit152194fe9c3f03232b9c0d0264793a7fa4af82f8 (patch)
tree2c21b0ba04050b8a86562e55aec816f9ea029c4b
parenteca3be9b95ac7cf9442654a54962859d74f8e38a (diff)
Input: extend usable life of event timestamps to 2106 on 32 bit systems
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>
-rw-r--r--drivers/input/evdev.c20
-rw-r--r--drivers/input/input-compat.c8
-rw-r--r--drivers/input/input-compat.h3
-rw-r--r--drivers/input/misc/uinput.c4
-rw-r--r--include/uapi/linux/input.h11
5 files changed, 32 insertions, 14 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 925571475005..116088fc3621 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -135,10 +135,7 @@ static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
continue;
} else if (head != i) {
/* move entry to fill the gap */
- client->buffer[head].time = ev->time;
- client->buffer[head].type = ev->type;
- client->buffer[head].code = ev->code;
- client->buffer[head].value = ev->value;
+ client->buffer[head] = *ev;
}
num++;
@@ -157,6 +154,7 @@ static void __evdev_queue_syn_dropped(struct evdev_client *client)
{
struct input_event ev;
ktime_t time;
+ struct timespec64 ts;
time = client->clk_type == EV_CLK_REAL ?
ktime_get_real() :
@@ -164,7 +162,9 @@ static void __evdev_queue_syn_dropped(struct evdev_client *client)
ktime_get() :
ktime_get_boottime();
- ev.time = ktime_to_timeval(time);
+ ts = ktime_to_timespec64(time);
+ ev.input_event_sec = ts.tv_sec;
+ ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
ev.type = EV_SYN;
ev.code = SYN_DROPPED;
ev.value = 0;
@@ -241,7 +241,10 @@ static void __pass_event(struct evdev_client *client,
*/
client->tail = (client->head - 2) & (client->bufsize - 1);
- client->buffer[client->tail].time = event->time;
+ client->buffer[client->tail].input_event_sec =
+ event->input_event_sec;
+ client->buffer[client->tail].input_event_usec =
+ event->input_event_usec;
client->buffer[client->tail].type = EV_SYN;
client->buffer[client->tail].code = SYN_DROPPED;
client->buffer[client->tail].value = 0;
@@ -262,12 +265,15 @@ static void evdev_pass_values(struct evdev_client *client,
struct evdev *evdev = client->evdev;
const struct input_value *v;
struct input_event event;
+ struct timespec64 ts;
bool wakeup = false;
if (client->revoked)
return;
- event.time = ktime_to_timeval(ev_time[client->clk_type]);
+ ts = ktime_to_timespec64(ev_time[client->clk_type]);
+ event.input_event_sec = ts.tv_sec;
+ event.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
/* Interrupts are disabled, just acquire the lock. */
spin_lock(&client->buffer_lock);
diff --git a/drivers/input/input-compat.c b/drivers/input/input-compat.c
index 2186f71c9fe5..fda8d6d2a268 100644
--- a/drivers/input/input-compat.c
+++ b/drivers/input/input-compat.c
@@ -24,8 +24,8 @@ int input_event_from_user(const char __user *buffer,
sizeof(struct input_event_compat)))
return -EFAULT;
- event->time.tv_sec = compat_event.time.tv_sec;
- event->time.tv_usec = compat_event.time.tv_usec;
+ 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;
@@ -44,8 +44,8 @@ int input_event_to_user(char __user *buffer,
if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
struct input_event_compat compat_event;
- compat_event.time.tv_sec = event->time.tv_sec;
- compat_event.time.tv_usec = event->time.tv_usec;
+ 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;
diff --git a/drivers/input/input-compat.h b/drivers/input/input-compat.h
index 1563160a7af3..08cd755e73fd 100644
--- a/drivers/input/input-compat.h
+++ b/drivers/input/input-compat.h
@@ -18,7 +18,8 @@
#ifdef CONFIG_COMPAT
struct input_event_compat {
- struct compat_timeval time;
+ compat_ulong_t sec;
+ compat_ulong_t usec;
__u16 type;
__u16 code;
__s32 value;
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index d521aecbc078..cb4bdbd3e9e2 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -90,8 +90,8 @@ static int uinput_dev_event(struct input_dev *dev,
udev->buff[udev->head].code = code;
udev->buff[udev->head].value = value;
ktime_get_ts64(&ts);
- udev->buff[udev->head].time.tv_sec = ts.tv_sec;
- udev->buff[udev->head].time.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
+ udev->buff[udev->head].input_event_sec = ts.tv_sec;
+ udev->buff[udev->head].input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
wake_up_interruptible(&udev->waitq);
diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h
index 8c5a0bf6ee35..7288a7c573cc 100644
--- a/include/uapi/linux/input.h
+++ b/include/uapi/linux/input.h
@@ -21,10 +21,21 @@
/*
* The event structure itself
+ * Note that __USE_TIME_BITS64 is defined by libc based on
+ * application's request to use 64 bit time_t.
*/
struct input_event {
+#if (__BITS_PER_LONG != 32 || !defined(__USE_TIME_BITS64)) && !defined(__KERNEL)
struct timeval time;
+#define input_event_sec time.tv_sec
+#define input_event_usec time.tv_usec
+#else
+ __kernel_ulong_t __sec;
+ __kernel_ulong_t __usec;
+#define input_event_sec __sec
+#define input_event_usec __usec
+#endif
__u16 type;
__u16 code;
__s32 value;