[8/8] Input: input_event: fix struct padding on sparc64
diff mbox series

Message ID 20191108203435.112759-9-arnd@arndb.de
State New
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Series
  • y2038: bug fixes from y2038 work
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Commit Message

Arnd Bergmann Nov. 8, 2019, 8:34 p.m. UTC
Going through all uses of timeval, I noticed that we screwed up
input_event in the previous attempts to fix it:

The time fields now match between kernel and user space, but
all following fields are in the wrong place.

Add the required padding that is implied by the glibc timeval
definition to fix the layout, and add explicit initialization
to avoid leaking kernel stack data.

Cc: sparclinux@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: stable@vger.kernel.org
Fixes: 141e5dcaa735 ("Input: input_event - fix the CONFIG_SPARC64 mixup")
Fixes: 2e746942ebac ("Input: input_event - provide override for sparc64")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/input/evdev.c       | 3 +++
 drivers/input/misc/uinput.c | 3 +++
 include/uapi/linux/input.h  | 1 +
 3 files changed, 7 insertions(+)

Comments

Dmitry Torokhov Nov. 11, 2019, 6:28 p.m. UTC | #1
Hi Arnd,

On Fri, Nov 08, 2019 at 09:34:31PM +0100, Arnd Bergmann wrote:
> Going through all uses of timeval, I noticed that we screwed up
> input_event in the previous attempts to fix it:
> 
> The time fields now match between kernel and user space, but
> all following fields are in the wrong place.
> 
> Add the required padding that is implied by the glibc timeval
> definition to fix the layout, and add explicit initialization
> to avoid leaking kernel stack data.
> 
> Cc: sparclinux@vger.kernel.org
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: stable@vger.kernel.org
> Fixes: 141e5dcaa735 ("Input: input_event - fix the CONFIG_SPARC64 mixup")
> Fixes: 2e746942ebac ("Input: input_event - provide override for sparc64")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/input/evdev.c       | 3 +++
>  drivers/input/misc/uinput.c | 3 +++
>  include/uapi/linux/input.h  | 1 +
>  3 files changed, 7 insertions(+)
> 
> diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
> index d7dd6fcf2db0..24a90793caf0 100644
> --- a/drivers/input/evdev.c
> +++ b/drivers/input/evdev.c
> @@ -228,6 +228,9 @@ static void __pass_event(struct evdev_client *client,
>  						event->input_event_sec;
>  		client->buffer[client->tail].input_event_usec =
>  						event->input_event_usec;
> +#ifdef CONFIG_SPARC64
> +		client->buffer[client->tail].__pad = 0;
> +#endif
>  		client->buffer[client->tail].type = EV_SYN;
>  		client->buffer[client->tail].code = SYN_DROPPED;
>  		client->buffer[client->tail].value = 0;

I do not like ifdefs here, do you think we could write:

		client->buffer[client->tail] = (struct input_event) {
			.input_event_sec = event->input_event_sec,
			.input_event_usec = event->input_event_usec,
			.type = EV_SYN,
			.code = SYN_DROPPED,
		};

to ensure all padded fields are initialized? This is not hot path as we
do not expect queue to overfill too often.

Thanks.
Arnd Bergmann Nov. 11, 2019, 7:18 p.m. UTC | #2
On Mon, Nov 11, 2019 at 7:28 PM Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:

> I do not like ifdefs here, do you think we could write:
>
>                 client->buffer[client->tail] = (struct input_event) {
>                         .input_event_sec = event->input_event_sec,
>                         .input_event_usec = event->input_event_usec,
>                         .type = EV_SYN,
>                         .code = SYN_DROPPED,
>                 };
>
> to ensure all padded fields are initialized? This is not hot path as we
> do not expect queue to overfill too often.

Good idea, changed both instances now. Thanks for taking a look!

      Arnd

Patch
diff mbox series

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index d7dd6fcf2db0..24a90793caf0 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -228,6 +228,9 @@  static void __pass_event(struct evdev_client *client,
 						event->input_event_sec;
 		client->buffer[client->tail].input_event_usec =
 						event->input_event_usec;
+#ifdef CONFIG_SPARC64
+		client->buffer[client->tail].__pad = 0;
+#endif
 		client->buffer[client->tail].type = EV_SYN;
 		client->buffer[client->tail].code = SYN_DROPPED;
 		client->buffer[client->tail].value = 0;
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index 84051f20b18a..1d8c09e9fd47 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -80,6 +80,9 @@  static int uinput_dev_event(struct input_dev *dev,
 	ktime_get_ts64(&ts);
 	udev->buff[udev->head].input_event_sec = ts.tv_sec;
 	udev->buff[udev->head].input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
+#ifdef CONFIG_SPARC64
+	udev->buff[udev->head].__pad = 0;
+#endif
 	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 f056b2a00d5c..9a61c28ed3ae 100644
--- a/include/uapi/linux/input.h
+++ b/include/uapi/linux/input.h
@@ -34,6 +34,7 @@  struct input_event {
 	__kernel_ulong_t __sec;
 #if defined(__sparc__) && defined(__arch64__)
 	unsigned int __usec;
+	unsigned int __pad;
 #else
 	__kernel_ulong_t __usec;
 #endif