[RFC/PATCH] ARM: VDSO support

[Joseph Myers]

On Tue, 7 Apr 2015, Joseph Myers wrote:

> On Tue, 7 Apr 2015, Adhemerval Zanella wrote:
> 
> > On 07-04-2015 13:46, Joseph Myers wrote:
> > > On Fri, 3 Apr 2015, Nathan Lynch wrote:
> > >
> > >> This patch adds support for the ARM VDSO to glibc.  I have run make
> > >> check on OMAP5 using kernels with and without the VDSO, with no new
> > >> failures.
> > > How does this compare to the implementations for other architectures?  
> > > What are the points on which the VDSO interfaces vary between 
> > > architectures?  It would seem desirable for the code to be factored so 
> > > that the ARM code only contains the minimal set of things that are 
> > > necessarily ARM-specific (for example, just declaring the ARM-specific 
> > > choices before including architecture-independent files shared by all 
> > > architectures that can get these functions from a VDSO).
> > >
> > I see the factoring work being another subsequent patch that should not
> > impede the inclusion of proposed modification. 
> 
> I see it as a preparatory cleanup that is (unlike the main change) not 
> blocked on the kernel changes getting into kernel.org sources.

And, in any case, if a non-refactored patch is to go in, the analysis of 
how the implementations and interfaces for different architectures relate 
should be part of the justification for the implementation approach 
chosen.  That is, the questions I posed should be answered as questions, 
regardless of what patch the answers end up supporting.

-- 
Joseph S. Myers
joseph@codesourcery.com