[PATCH] ppc64: Implement a vDSO and use it for signal trampoline

[Benjamin Herrenschmidt]

> Right hand side is evaluated only when left hand side is used.
> Also very usefull. Example just mocked up:
> cmd_vdso32_cc = $(CC) -T $^ -o $@
> 
> Doing late evaluation will cause correct replacement of $^ and $@ when
> used. When cmd_vdso_32 is defined make does not know the desired values
> for $^ and $@ - this is only known when cmd_vdso_32 is actually used.
> 
> Hope this clarifies it.

Definitely, thanks.

Ben.