Re: Building arm64 EFI stub with -fpie breaks build of 4.9.x (undefined reference to `__efistub__GLOBAL_OFFSET_TABLE_')

2019-08-02 Thread Rolf Eike Beer
Nathan Chancellor wrote:
> On Fri, Aug 02, 2019 at 09:57:45AM +0200, Greg KH wrote:
> > On Thu, Jun 06, 2019 at 09:11:00AM +0200, Rolf Eike Beer wrote:
> > > Nick Desaulniers wrote:
> > > > On Wed, Jun 5, 2019 at 10:27 AM Nick Desaulniers
> > > > 
> > > >  wrote:
> > > > > On Wed, Jun 5, 2019 at 9:26 AM Greg KH  
wrote:
> > > > > > On Wed, Jun 05, 2019 at 05:19:40PM +0200, Rolf Eike Beer wrote:
> > > > > > > I decided to dig out a toy project which uses a DragonBoard
> > > > > > > 410c. This
> > > > > > > has
> > > > > > > been "running" with kernel 4.9, which I would keep this way for
> > > > > > > unrelated
> > > > > > > reasons. The vanilla 4.9 kernel wasn't bootable back then, but
> > > > > > > it was
> > > > > > > buildable, which was good enough.
> > > > > > > 
> > > > > > > Upgrading the kernel to 4.9.180 caused the boot to suddenly
> > > > > > > fail:
> > > > > > > 
> > > > > > > aarch64-unknown-linux-gnueabi-ld:
> > > > > > > ./drivers/firmware/efi/libstub/lib.a(arm64- stub.stub.o): in
> > > > > > > function
> > > > > > > `handle_kernel_image':
> > > > > > > /tmp/e2/build/linux-4.9.139/drivers/firmware/efi/libstub/arm64-s
> > > > > > > tub.c:
> > > > > > > 63:
> > > > > > > undefined reference to `__efistub__GLOBAL_OFFSET_TABLE_'
> > > > > > > aarch64-unknown-linux-gnueabi-ld:
> > > > > > > ./drivers/firmware/efi/libstub/lib.a(arm64- stub.stub.o):
> > > > > > > relocation
> > > > > > > R_AARCH64_ADR_PREL_PG_HI21 against symbol
> > > > > > > `__efistub__GLOBAL_OFFSET_TABLE_' which may bind externally can
> > > > > > > not
> > > > > > > be used when making a shared object; recompile with -fPIC
> > > > > > > /tmp/e2/build/linux-4.9.139/drivers/firmware/efi/libstub/arm64-s
> > > > > > > tub.c:
> > > > > > > 63:
> > > > > > > (.init.text+0xc): dangerous relocation: unsupported relocation
> > > > > > > /tmp/e2/build/linux-4.9.139/Makefile:1001: recipe for target
> > > > > > > 'vmlinux'
> > > > > > > failed -make[1]: *** [vmlinux] Error 1
> > > > > > > 
> > > > > > > This is caused by commit
> > > > > > > 27b5ebf61818749b3568354c64a8ec2d9cd5ecca from
> > > > > > > linux-4.9.y (which is 91ee5b21ee026c49e4e7483de69b55b8b47042be),
> > > > > > > reverting
> > > > > > > this commit fixes the build.

> > Did this ever get resolved, or is it still an issue?
> 
> This appears to have been resolved by commit 8fca3c364683 ("efi/libstub:
> Unify command line param parsing") in 4.9.181. I can build defconfig +
> CONFIG_RANDOMIZE_BASE without any issues.

I can confirm that 4.9.186 builds without issues with my original config.

Thanks for paying attention.

Eike
-- 
Rolf Eike Beer, emlix GmbH, http://www.emlix.com
Fon +49 551 30664-0, Fax +49 551 30664-11
Gothaer Platz 3, 37083 Göttingen, Germany
Sitz der Gesellschaft: Göttingen, Amtsgericht Göttingen HR B 3160
Geschäftsführung: Heike Jordan, Dr. Uwe Kracke – Ust-IdNr.: DE 205 198 055

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Re: Building arm64 EFI stub with -fpie breaks build of 4.9.x (undefined reference to `__efistub__GLOBAL_OFFSET_TABLE_')

2019-06-06 Thread Rolf Eike Beer
Ard Biesheuvel wrote:
> On Thu, 6 Jun 2019 at 09:50, Rolf Eike Beer  wrote:
> > Am Donnerstag, 6. Juni 2019, 09:38:41 CEST schrieb Rolf Eike Beer:
> > > Greg KH wrote:
> > > > On Wed, Jun 05, 2019 at 05:19:40PM +0200, Rolf Eike Beer wrote:
> > > > > I decided to dig out a toy project which uses a DragonBoard 410c.
> > > > > This
> > > > > has
> > > > > been "running" with kernel 4.9, which I would keep this way for
> > > > > unrelated
> > > > > reasons. The vanilla 4.9 kernel wasn't bootable back then, but it
> > > > > was
> > > > > buildable, which was good enough.
> > > > > 
> > > > > Upgrading the kernel to 4.9.180 caused the boot to suddenly fail:
> > > > > 
> > > > > aarch64-unknown-linux-gnueabi-ld:
> > > > > ./drivers/firmware/efi/libstub/lib.a(arm64- stub.stub.o): in
> > > > > function
> > > > > `handle_kernel_image':
> > > > > /tmp/e2/build/linux-4.9.139/drivers/firmware/efi/libstub/arm64-stub.
> > > > > c:63
> > > > > 
> > > > > undefined reference to `__efistub__GLOBAL_OFFSET_TABLE_'
> > > > > aarch64-unknown-linux-gnueabi-ld:
> > > > > ./drivers/firmware/efi/libstub/lib.a(arm64- stub.stub.o): relocation
> > > > > R_AARCH64_ADR_PREL_PG_HI21 against symbol
> > > > > `__efistub__GLOBAL_OFFSET_TABLE_' which may bind externally can not
> > > > > be
> > > > > used when making a shared object; recompile with -fPIC
> > > > > /tmp/e2/build/linux-4.9.139/drivers/firmware/efi/libstub/arm64-stub.
> > > > > c:63
> > > > > 
> > > > > (.init.text+0xc): dangerous relocation: unsupported relocation
> > > > > /tmp/e2/build/linux-4.9.139/Makefile:1001: recipe for target
> > > > > 'vmlinux'
> > > > > failed -make[1]: *** [vmlinux] Error 1
> > > > > 
> > > > > This is caused by commit 27b5ebf61818749b3568354c64a8ec2d9cd5ecca
> > > > > from
> > > > > linux-4.9.y (which is 91ee5b21ee026c49e4e7483de69b55b8b47042be),
> > > > > reverting
> > > > > this commit fixes the build.
> > > > > 
> > > > > This happens with vanilla binutils 2.32 and gcc 8.3.0 as well as
> > > > > 9.1.0.
> > > > > See
> > > > > the attached .config for reference.
> > > > > 
> > > > > If you have questions or patches just ping me.
> > > > 
> > > > Does Linus's latest tree also fail for you (or 5.1)?
> > > 
> > > 5.1.7 with the same config as before and "make olddefconfig" builds for
> > > me.
> > 
> > Just for the fun of it: both 4.19 and 4.19.48 also work.

> Could you please check whether patch
> 60f38de7a8d4e816100ceafd1b382df52527bd50 applies cleanly, and whether
> it fixes the problem? Thanks.

The part in drivers/firmware/efi/libstub/arm-stub.c needs to be applied by 
hand, but afterwards things build fine.

Eike
-- 
Rolf Eike Beer, emlix GmbH, http://www.emlix.com
Fon +49 551 30664-0, Fax +49 551 30664-11
Gothaer Platz 3, 37083 Göttingen, Germany
Sitz der Gesellschaft: Göttingen, Amtsgericht Göttingen HR B 3160
Geschäftsführung: Heike Jordan, Dr. Uwe Kracke – Ust-IdNr.: DE 205 198 055

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Re: Building arm64 EFI stub with -fpie breaks build of 4.9.x (undefined reference to `__efistub__GLOBAL_OFFSET_TABLE_')

2019-06-06 Thread Ard Biesheuvel
On Thu, 6 Jun 2019 at 09:08, Greg KH  wrote:
>
> On Thu, Jun 06, 2019 at 08:55:29AM +0200, Ard Biesheuvel wrote:
> > On Wed, 5 Jun 2019 at 22:48, Nick Desaulniers  
> > wrote:
> > >
> > > On Wed, Jun 5, 2019 at 11:42 AM Ard Biesheuvel
> > >  wrote:
> > > > For the record, this is an example of why I think backporting those
> > > > clang enablement patches is a bad idea.
> > >
> > > There's always a risk involved with backports of any kind; more CI
> > > coverage can help us mitigate some of these risks in an automated
> > > fashion before we get user reports like this.  I meet with the
> > > KernelCI folks weekly, so I'll double check on the coverage of the
> > > stable tree's branches.  The 0day folks are also very responsive and
> > > I've spoken with them a few times, so I'll try to get to the bottom of
> > > why this wasn't reported by either of those.
> > >
> > > Also, these patches help keep Android, CrOS, and Google internal
> > > production kernels closer to their upstream sources.
> > >
> > > > We can't actually build those
> > > > kernels with clang, can we? So what is the point? 
> > >
> > > Here's last night's build:
> > > https://travis-ci.com/ClangBuiltLinux/continuous-integration/builds/114388434
> > >
> >
> > If you are saying that plain upstream 4.9-stable defconfig can be
> > built with Clang, then I am pleasantly surprised.
>
> I know some specific configs can, there's no rule that I know of that
> 'defconfig' support is required.  But then again, it might also work,
> try it and see :)
>

Well, it is the rule that the arm64 maintainers use.

> > > Also, Android and CrOS have shipped X million devices w/ 4.9 kernels
> > > built with Clang.  I think this number will grow at least one order of
> > > magnitude imminently.
> > >
> >
> > I know that (since you keep reminding me :-)), but obviously, Google
> > does not care about changes that regress GCC support.
>
> What are you talking about?  Bugs happen all the time, what specifically
> did "Google" do to break gcc support?  If you are referring to this
> patch, and it is a regression, of course I will revert it.  But note
> that gcc and 4.9 works just fine for all of the other users right now,
> remember we do do a lot of testing of these releases.
>

Don't get me wrong: I am not blaming Google for this. But having
strict Documented/ stable-rules, violating them by backporting patches
that are clearly not bug fixes, and *then* saying 'bugs happen all the
time' makes no sense to me at all.


Re: Building arm64 EFI stub with -fpie breaks build of 4.9.x (undefined reference to `__efistub__GLOBAL_OFFSET_TABLE_')

2019-06-06 Thread Rolf Eike Beer
Am Donnerstag, 6. Juni 2019, 09:38:41 CEST schrieb Rolf Eike Beer:
> Greg KH wrote:
> > On Wed, Jun 05, 2019 at 05:19:40PM +0200, Rolf Eike Beer wrote:
> > > I decided to dig out a toy project which uses a DragonBoard 410c. This
> > > has
> > > been "running" with kernel 4.9, which I would keep this way for
> > > unrelated
> > > reasons. The vanilla 4.9 kernel wasn't bootable back then, but it was
> > > buildable, which was good enough.
> > > 
> > > Upgrading the kernel to 4.9.180 caused the boot to suddenly fail:
> > > 
> > > aarch64-unknown-linux-gnueabi-ld:
> > > ./drivers/firmware/efi/libstub/lib.a(arm64- stub.stub.o): in function
> > > `handle_kernel_image':
> > > /tmp/e2/build/linux-4.9.139/drivers/firmware/efi/libstub/arm64-stub.c:63
> > > :
> > > undefined reference to `__efistub__GLOBAL_OFFSET_TABLE_'
> > > aarch64-unknown-linux-gnueabi-ld:
> > > ./drivers/firmware/efi/libstub/lib.a(arm64- stub.stub.o): relocation
> > > R_AARCH64_ADR_PREL_PG_HI21 against symbol
> > > `__efistub__GLOBAL_OFFSET_TABLE_' which may bind externally can not be
> > > used when making a shared object; recompile with -fPIC
> > > /tmp/e2/build/linux-4.9.139/drivers/firmware/efi/libstub/arm64-stub.c:63
> > > :
> > > (.init.text+0xc): dangerous relocation: unsupported relocation
> > > /tmp/e2/build/linux-4.9.139/Makefile:1001: recipe for target 'vmlinux'
> > > failed -make[1]: *** [vmlinux] Error 1
> > > 
> > > This is caused by commit 27b5ebf61818749b3568354c64a8ec2d9cd5ecca from
> > > linux-4.9.y (which is 91ee5b21ee026c49e4e7483de69b55b8b47042be),
> > > reverting
> > > this commit fixes the build.
> > > 
> > > This happens with vanilla binutils 2.32 and gcc 8.3.0 as well as 9.1.0.
> > > See
> > > the attached .config for reference.
> > > 
> > > If you have questions or patches just ping me.
> > 
> > Does Linus's latest tree also fail for you (or 5.1)?
> 
> 5.1.7 with the same config as before and "make olddefconfig" builds for me.

Just for the fun of it: both 4.19 and 4.19.48 also work.

Eike
-- 
Rolf Eike Beer, emlix GmbH, http://www.emlix.com
Fon +49 551 30664-0, Fax +49 551 30664-11
Gothaer Platz 3, 37083 Göttingen, Germany
Sitz der Gesellschaft: Göttingen, Amtsgericht Göttingen HR B 3160
Geschäftsführung: Heike Jordan, Dr. Uwe Kracke – Ust-IdNr.: DE 205 198 055

emlix - smart embedded open source

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