User-level objects

li94575 li94575 at
Mon Dec 8 15:10:40 CET 2014

At 2014-12-07 07:36:38, "Adam Lackorzynski" <adam at> wrote:
>On Sat Dec 06, 2014 at 22:24:20 +0800, li94575 wrote:
>> As I know, we can set  access permissions for the kernel objects, and
>> access to user-level objects is  through IPC_Gate.
>> So, can I  set access permissions for user-level objects through the
>> IPC_Gate?
>Yes. This is done by giving the appropriate rights flags on mapping. In
>Ned's scripting, there are those ':mode("...")' statements (typically
>abbreviated with just ':m("...")' or just 'svr()' that define those
>permissions. However, bits to be used by user-level implementations are
>just the write bit.

If I only map a capability with reading permission for server object, but  I actually  perform a writing operation on the object with the capability, can you tell me where  the kernel do the permission checking?and for the objects, how to define the reading and writing operation?
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