Re: [llvmlinux] [PATCH] Make alignment cflags configurable.
From: Jan-Simon Moeller
Date: Wed Aug 12 2015 - 19:21:43 EST
Am Mittwoch, 12. August 2015, 15:37:05 schrieb H. Peter Anvin:
> NAK. This is crazy.
Ok roger that. What about the cc-option at least?
This way we can figure why it does not work for clang and keep things as-is
> On August 12, 2015 3:30:19 PM PDT, Jan-Simon Moeller <dl9pf@xxxxxx> wrote:
> >Hi all!
> >> You could mention that this is to fix the clang build. But why is it
> >> needed? It isn't that clang just doesn't accept the option, is it?
> >> Otherwise we could just use $(call cc-option, -falign-jumps=1) etc.
> >Yes it is to fix the build with clang.
> >I tried cc-option, but it does not improve the situation (more below).
> >This is why I chose the config option approach in the patch.
> >> Did you get to the bottom of the clang failure here? Just turning
> >> off without a coherent explanation doesn't seem like the right thing
> >> do.
> >I know it is not the final solution which is why I turned it into a
> >option. We can still debate if default should be "y" or "n". This way
> >we all
> >can proceed.
> >@Ingo: would it be fine if we wrap it into a config option defaulting
> >to "y" ?
> >What I can say so far is that although clang warns about the unknown
> >and ignores it, the resulting kernel still fails to boot somewhere
> >early in
> >start_kernel(). I'm still investigating.
> >My current trace ends like this:
> >page_address_init ~ setup_arch ~ then arch/x86/kernel/setup.c:898
> >setup.c:898 is a printk actually ...
> >early_idt_handler_array[i] ~> early_idt_handler_common
> >The mail thread is here:
> ><wild guess>
> >We still build with -no-integrated-as which means we use gas. Maybe the
> >is passed-on there and things get confused.
> ></wile guess>
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/