Re: [PATCH v2 0/4] Introduce and use absolute_pointer macro

From: Linus Torvalds <torvalds@linux-foundation.org>
To: Ulrich Teichert <krypton@ulrich-teichert.org>
Cc: Michael Cree <mcree@orcon.net.nz>,
	Guenter Roeck <linux@roeck-us.net>,
	Richard Henderson <rth@twiddle.net>,
	Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	Matt Turner <mattst88@gmail.com>,
	"James E . J . Bottomley" <James.Bottomley@hansenpartnership.com>,
	Helge Deller <deller@gmx.de>,
	"David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	alpha <linux-alpha@vger.kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-parisc <linux-parisc@vger.kernel.org>,
	Netdev <netdev@vger.kernel.org>,
	Sparse Mailing-list <linux-sparse@vger.kernel.org>
Subject: Re: [PATCH v2 0/4] Introduce and use absolute_pointer macro
Date: Tue, 21 Sep 2021 13:42:38 -0700	[thread overview]
Message-ID: <CAHk-=wgricy21sU_rBue-MVNdj-uvCRr=Fn+9K-bBD0x5tCvYg@mail.gmail.com> (raw)
In-Reply-To: <202109211913.18LJDnXp031134@valdese.nms.ulrich-teichert.org>

On Tue, Sep 21, 2021 at 12:14 PM Ulrich Teichert
<krypton@ulrich-teichert.org> wrote:
>
> Right, I had DEBUG_INFO set. Stupid me. Now it looks much better:
>
> valdese:~/soft/linux/kernel-git> ls -lh arch/alpha/boot/vmlinux*
> -rwxr-xr-x 1 ut ut 6.4M Sep 21 18:12 arch/alpha/boot/vmlinux*
> -rw-r--r-- 1 ut ut 3.0M Sep 21 18:12 arch/alpha/boot/vmlinux.gz
>
> But it still dies before the first message from the kernel shows up.

Ok. That's a nasty situation to debug, and it's where things like "git
bisect" are really useful just to narrow things down.

... which isn't an option here. Too bad.

I also assume thete is no virtual environment that looks like a Jensen
that would help debug this. Which all makes it a bit nasty to try to
even guess at what goes wrong.

> I don't think I have to do something special with the
> compressed image and according to https://tldp.org/HOWTO/SRM-HOWTO/aboot.html
> I don't have to.

Yeah, it's more than two decades since I used an alpha, so I'm afraid
I can't help outside of the "let's make it compile again" thing.

It could easily be that the Jensen required that SRM bootimage, but
it's so long ago that I really don't remember at all.

> I would try the SRM bootimage (make bootimage), but the build is broken:

Well, that looks like something that should be fixed, and that I might look at.

> arch/alpha/boot/tools/objstrip.c:191:52: warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 5 has type ‘long long unsigned int’ [-Wformat=]
>       fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
>                                                     ^
> arch/alpha/boot/tools/objstrip.c:200:12: error: ‘struct exec’ has no member named ‘fh’
>   if (!(aout->fh.f_flags & COFF_F_EXEC)) {

This looks like the "make bootimage" thing was never designed to work
in a cross-build environment. I think.

Because it looks like what happens is that when you cross-compile, it
gets the x86-64 'struct exec', and then everything goes sideways.

> Was that the target used to get bootable CDROMs? Could that be broken since
> the move from aout to ELF? Ugh, sorry for raising so much trouble,

No, this is lovely. It would be really nice to get that Jensen target
working, if only because of silly historical reasons.

I'll see if I can get around to this.

              Linus