Re: [PATCH v5 02/11] tools: mkeficapsule: add firmwware image signing

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

Hi, Simon,

On Thu, Nov 04, 2021 at 09:11:59AM -0600, Simon Glass wrote:
> Hi Mark,
> 
> On Thu, 4 Nov 2021 at 08:31, Mark Kettenis <mark.kettenis@xs4all.nl> wrote:
> >
> > > From: Simon Glass <sjg@chromium.org>
> > > Date: Wed, 3 Nov 2021 20:51:25 -0600
> > >
> > > Hi Mark,
> > >
> > > On Tue, 2 Nov 2021 at 09:13, Mark Kettenis <mark.kettenis@xs4all.nl> wrote:
> > > >
> > > > > From: Simon Glass <sjg@chromium.org>
> > > > > Date: Tue, 2 Nov 2021 08:56:50 -0600
> > > > >
> > > > > Hi Takahiro,
> > > > >
> > > > > > > - can we just build the tool always?
> > > > > >
> > > > > > This is one of my questions.
> > > > > > Why do you want to do so while there are bunch of tools that are
> > > > > > not always built.
> > > > >
> > > > > Because I think all tools should be built always. It is fine if that
> > > > > happens due to CONFIG options but we should try to avoid making it
> > > > > complicated.
> > > >
> > > > Well, unless this patchset fixes things, we can't, because
> > > > mkeficapsule doesn't build on OpenBSD.  I tried looking into it, but I
> > > > can't figure out how this is even supposed to compile as a host tool:
> > > >
> > > >
> > > > In file included from tools/mkeficapsule.c:8:
> > > > In file included from include/malloc.h:369:
> > > > include/linux/string.h:15:24: error: conflicting types for 'strspn'
> > > > extern __kernel_size_t strspn(const char *,const char *);
> > > >                        ^
> > > > /usr/include/string.h:88:9: note: previous declaration is here
> > > > size_t   strspn(const char *, const char *);
> > >
> > > My guess is that linux/string.h should not be included, or perhaps
> > > __kernel_size_t should be defined to size_t.
> > >
> > > I doubt it would take an age to figure out, with a bit of fiddling.
> >
> > Well, I think the problem is quite fundamental.  Indeed I agree that
> > linux/string.h shouldn't be included.  It gets pulled in because the
> > tools include <malloc.h>.  Modern software really shouldn't include
> > that header anymore, and we removed it in OpenBSD some time ago.  But
> > even with that fixed, things break since the same header gets pulled
> > in from <efi.h>.
> >
> > Redefining __kernel_size_t doesn't provide a way out:
> >
> > tools/mkeficapsule.c:23:16: error: typedef redefinition with different types ('size_t' (aka 'unsigned long') vs 'unsigned int')
> > typedef size_t __kernel_size_t;
> >                ^
> > ./arch/arm/include/asm/posix_types.h:37:23: note: previous definition is here
> > typedef unsigned int            __kernel_size_t;
> >                                                ^
> >
> > This is on an amd64 host, so "unsigned int" clearly is the wrong type
> > for size_t.
> >
> > The fundamental problem seems to be that <efi.h> isn't safe to include
> > in a "host" tool because it includes "target" headers that
> > accidentally resolve to "system" headers on Linux systems.
> >
> > Maybe Takahiro or Heinrich have an idea how to fix that?  But in the
> > meantime it would be good if building this tool would remain optional.
> 
> Yes let's ask them to fix that as I agree this sounds wrong. We have
> several efi headers so perhaps just need to have the right stuff in
> each.

As far as I know, you initially introduced efi.h and efi_api.h.
What is your intent to have the two?

I think that efi_api.h contains definitions and interfaces defined
in UEFI specification for building EFI application/modules, hence
I believe that it should be target-independent. Right?

But it *includes* efi.h which also contains some definitions
defined in UEFI specification, while efi.h is only for U-Boot as
UEFI application.

I suspect that is the root cause.
Or should we thoroughly use linux headers like "efi/efi.h"
in this tool?

-Takahiro Akashi


> It is OK to have it optional with a CONFIG, but it should be enabled
> by default, otherwise no one will know it is there.
> 
> Can we get the OpenBSD environment into CI or is that just too hard?
> 
> Regards,
> Simon