Re: [PATCH v4] Makefile.compiler: replace cc-ifversion with compiler-specific macros

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, May 22, 2023 at 12:09:34PM +0200, Ricardo Cañuelo wrote:
> On vie, may 19 2023 at 08:57:24, Nick Desaulniers <ndesaulniers@google.com> wrote:
> > It could be; if the link order was changed, it's possible that this
> > target may be hitting something along the lines of:
> > https://isocpp.org/wiki/faq/ctors#static-init-order i.e. the "static
> > initialization order fiasco"
> >
> > I'm struggling to think of how this appears in C codebases, but I
> > swear years ago I had a discussion with GKH (maybe?) about this. I
> > think I was playing with converting Kbuild to use Ninja rather than
> > Make; the resulting kernel image wouldn't boot because I had modified
> > the order the object files were linked in.  If you were to randomly
> > shuffle the object files in the kernel, I recall some hazard that may
> > prevent boot.
> 
> I thought that was specifically a C++ problem? But then again, the
> kernel docs explicitly say that the ordering of obj-y goals in kbuild is
> significant in some instances [1]:

Yes, it matters, you can not change it.  If you do, systems will break.
It is the only way we have of properly ordering our init calls within
the same "level".

thanks,

greg k-h