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SubjectRe: [ 044/218] Staging: Android alarm: IOCTL command encoding fix
From
On Fri, Sep 28, 2012 at 1:14 PM, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
> 3.4-stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: "Dae S. Kim" <dae@velatum.com>
>
> commit 6bd4a5d96c08dc2380f8053b1bd4f879f55cd3c9 upstream.
>
> Fixed a bug. Data was being written to user space using an IOCTL
> command encoded with _IOC_WRITE access mode.
>
> Signed-off-by: Dae S. Kim <dae@velatum.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> ---
> drivers/staging/android/android_alarm.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> --- a/drivers/staging/android/android_alarm.h
> +++ b/drivers/staging/android/android_alarm.h
> @@ -110,10 +110,12 @@ enum android_alarm_return_flags {
> #define ANDROID_ALARM_WAIT _IO('a', 1)
>
> #define ALARM_IOW(c, type, size) _IOW('a', (c) | ((type) << 4), size)
> +#define ALARM_IOR(c, type, size) _IOR('a', (c) | ((type) << 4), size)
> +
> /* Set alarm */
> #define ANDROID_ALARM_SET(type) ALARM_IOW(2, type, struct timespec)
> #define ANDROID_ALARM_SET_AND_WAIT(type) ALARM_IOW(3, type, struct timespec)
> -#define ANDROID_ALARM_GET_TIME(type) ALARM_IOW(4, type, struct timespec)
> +#define ANDROID_ALARM_GET_TIME(type) ALARM_IOR(4, type, struct timespec)
> #define ANDROID_ALARM_SET_RTC _IOW('a', 5, struct timespec)
> #define ANDROID_ALARM_BASE_CMD(cmd) (cmd & ~(_IOC(0, 0, 0xf0, 0)))
> #define ANDROID_ALARM_IOCTL_TO_TYPE(cmd) (_IOC_NR(cmd) >> 4)
>
>
> --
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This patch breaks Android userspace by changing the ioctl ABI to
/dev/alarm. It's definitely not a bug fix, as the IOW vs. IOR flag is
only ever used by drivers, and is not used by alarm-dev.c.

I would have commented sooner, but the original patch was not sent to
any lists I am on, nor any lists that Google can find.


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