Re: [PATCH v2 5/7] staging: android: binder: fix BC_FREE_BUFFER ioctl declaration

From: Arve Hjønnevåg
Date: Tue Apr 09 2013 - 19:55:39 EST


On Tue, Apr 9, 2013 at 3:00 AM, Serban Constantinescu
<serban.constantinescu@xxxxxxx> wrote:
> BinderDriverCommands mirror the ioctl usage. Thus the size of the
> structure passed through the interface should be used to generate the
> ioctl No.
>
> The change reflects the type being passed from the user space-a pointer
> to a binder_buffer. This change should not affect the existing 32bit
> user space since BC_FREE_BUFFER is computed as:
>
> #define _IOW(type,nr,size) \
> ((type) << _IOC_TYPESHIFT) | \
> ((nr) << _IOC_NRSHIFT) | \
> ((size) << _IOC_SIZESHIFT))
>
> and for a 32bit compiler BC_FREE_BUFFER will have the same computed
> value. This change will also ease our work in differentiating
> BC_FREE_BUFFER from COMPAT_BC_FREE_BUFFER.
>
> The change does not affect existing 32bit ABI.
>
> Signed-off-by: Serban Constantinescu <serban.constantinescu@xxxxxxx>

Acked-by: Arve Hjønnevåg <arve@xxxxxxxxxxx>

--
Arve Hjønnevåg
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