[PATCH wayland] protocol: Bump seat to version 7 and require keymaps be private

[Derek Foreman]

On 11/1/18 12:18 PM, Philipp Kerling wrote:
> Actually...  (below)

Yes, you are of course strictly correct.

However, the recent previous commits that bumped wl_seat version 9a18a8
and c5356e have also kept all three children in sync, and it's become
de-facto convention to do so.

Thanks,
Derek

> 2018-11-01 (木) の 11:15 -0500 に Derek Foreman さんは書きました:
>> Weston commit 76829fc4eaea329d2a525c3978271e13bd76c078 (and similar
>> commits for other compositors) protects the compositor's keyboard
>> mapping from client damage by duplicating the keymap for every
>> client.
>>
>> On some systems there are other potential fixes for this - such as
>> using sealed memfds on linux - but we can't use them since
>> essentially all client code anywhere has mapped the keyboard map
>> with a MAP_SHARED mmap() call.
>>
>> While we can't break years worth of code, we can require any future
>> clients to use MAP_PRIVATE if they use a seat version above 6.
>>
>> If a compositor can't use sealing or a similar facility, it should
>> still protect itself with copied keymaps, but clients must always
>> assume shared mapping of a keymap will fail.
>>
>> Signed-off-by: Derek Foreman <derek.foreman.samsung at gmail.com>
>> ---
>>  protocol/wayland.xml | 11 +++++++----
>>  1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/protocol/wayland.xml b/protocol/wayland.xml
>> index 141038b..802d433 100644
>> --- a/protocol/wayland.xml
>> +++ b/protocol/wayland.xml
>> @@ -1660,7 +1660,7 @@
>>      </request>
>>     </interface>
>>  
>> -  <interface name="wl_seat" version="6">
>> +  <interface name="wl_seat" version="7">
>>      <description summary="group of input devices">
>>        A seat is a group of keyboards, pointer and touch devices.
>> This
>>        object is published as a global during start up, or when such
>> a
>> @@ -1769,7 +1769,7 @@
>>  
>>    </interface>
>>  
>> -  <interface name="wl_pointer" version="6">
>> +  <interface name="wl_pointer" version="7">
> What is the reason for this version bump? The wl_pointer behavior is
> unaffected by the wl_keyboard change, right? As far as I understood the
> protocol versioning rules, bumping all child interfaces when updating
> one child interface is not required. In fact that would make their
> version counters quite superfluous.
> 
> (Same for wl_touch)
> 
>>      <description summary="pointer input device">
>>        The wl_pointer interface represents one or more input devices,
>>        such as mice, which control the pointer location and
>> pointer_focus
>> @@ -2092,7 +2092,7 @@
>>      </event>
>>    </interface>
>>  
>> -  <interface name="wl_keyboard" version="6">
>> +  <interface name="wl_keyboard" version="7">
>>      <description summary="keyboard input device">
>>        The wl_keyboard interface represents one or more keyboards
>>        associated with a seat.
>> @@ -2113,6 +2113,9 @@
>>        <description summary="keyboard mapping">
>>  	This event provides a file descriptor to the client which can
>> be
>>  	memory-mapped to provide a keyboard mapping description.
>> +
>> +	From version 7 onwards, the fd must be mapped with MAP_PRIVATE
>> by
>> +	the recipient, as MAP_SHARED may fail.
>>        </description>
>>        <arg name="format" type="uint" enum="keymap_format"
>> summary="keymap format"/>
>>        <arg name="fd" type="fd" summary="keymap file descriptor"/>
>> @@ -2203,7 +2206,7 @@
>>      </event>
>>    </interface>
>>  
>> -  <interface name="wl_touch" version="6">
>> +  <interface name="wl_touch" version="7">
>>      <description summary="touchscreen input device">
>>        The wl_touch interface represents a touchscreen
>>        associated with a seat.
>