qt5base: fix build on Aarch64_be a53

PATCH New Fabrice Fontaine 2 participants 2 messages Oct 20, 2018 – Nov 3, 2018

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Fabrice Fontaine

author

2018-10-20 12:58 UTC #0 lore raw

PATCH 1/1 qt5base: fix build on Aarch64_be a53

Build on Aarch64_be a53 with binutils gold linker in version 2.28 fails:
/home/rclinux/rc-buildroot-test/scripts/instance-0/output/host/opt/ext-toolchain/bin/../lib/gcc/aarch64_be-linux-gnu/7.3.1/../../../../aarch64_be-linux-gnu/bin/ld.gold: internal error in update_erratum_insn, at /home/tcwg-buildslave/workspace/tcwg-make-release/builder_arch/amd64/label/tcwg-x86_64-build/target/aarch64_be-linux-gnu/snapshots/binutils-gdb.git~users~linaro~binutils-2_28-branch/gold/aarch64.cc:998

This error is related to 843419 erratum:
- https://lore.kernel.org/patchwork/patch/847483/
- http://sourceware-org.1504.n7.nabble.com/PATCH-gold-Fix-aarch64-fix-errata-and-relocate-erratum-stubs-internal-error-td465738.html

Issue is that old versions of GNU gold are known to produce broken code with --fix-cortex-a53-843419 as explained in:
- https://sourceware.org/ml/binutils-cvs/2015-06/msg00188.html
- https://sourceware.org/bugzilla/show_bug.cgi?id=21491

Issue has been fixed in:
- https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e70c0b5f07daf63474e805f8d0a45152fcd60468

We don't know if ARM64_ERRATUM_843419 is enabled or disabled when we're using GNU gold so we don't know if we have to pass --fix-cortex-a53-843419 or --no-fix-cortex-a53-843419 to the linker.

We don't know either what is the version of binutils used by an external toolchain.

So, disable gold linker through the -no-use-gold-linker option of the configure script to fix the issue

Fixes:
- http://autobuild.buildroot.org/results/eb55bf44622697039a4ced510ee2d45b950d0a08

Signed-off-by Fabrice Fontaine <[email protected]>

---
 package/qt5/qt5base/qt5base.mk | 6 ++++++
 1 file changed, 6 insertions(+)

package/qt5/qt5base/qt5base.mk +6 -0

index ab2b883fc4..d3c6c31d45 100644
@@ -27,6 +27,12 @@ QT5BASE_CONFIGURE_OPTS += \
 	-no-pch \
 	-shared
 
+# internal error in update_erratum_insn on Aarch64 a53 with gold before
+# binutils 2.29: https://sourceware.org/bugzilla/show_bug.cgi?id=21491
+ifeq ($(BR2_aarch64_be)$(BR2_cortex_a53)$(BR2_TOOLCHAIN_USES_GLIBC),yyy)
+QT5BASE_CONFIGURE_OPTS += -no-use-gold-linker
+endif
+
 ifeq ($(BR2_PACKAGE_QT5_VERSION_5_6),y)
 QT5BASE_DEPENDENCIES += pcre
 else

Signature · 1 line

2.17.1

Thomas Petazzoni

2018-11-03 13:56 UTC #1 lore raw

PATCH 1/1 qt5base: fix build on Aarch64_be a53

Hello Fabrice,

Quoted 38 lines · Fabrice Fontaine

Build on Aarch64_be a53 with binutils gold linker in version 2.28 fails:
/home/rclinux/rc-buildroot-test/scripts/instance-0/output/host/opt/ext-toolchain/bin/../lib/gcc/aarch64_be-linux-gnu/7.3.1/../../../../aarch64_be-linux-gnu/bin/ld.gold: internal error in update_erratum_insn, at /home/tcwg-buildslave/workspace/tcwg-make-release/builder_arch/amd64/label/tcwg-x86_64-build/target/aarch64_be-linux-gnu/snapshots/binutils-gdb.git~users~linaro~binutils-2_28-branch/gold/aarch64.cc:998
This error is related to 843419 erratum:
- https://lore.kernel.org/patchwork/patch/847483/
- http://sourceware-org.1504.n7.nabble.com/PATCH-gold-Fix-aarch64-fix-errata-and-relocate-erratum-stubs-internal-error-td465738.html
Issue is that old versions of GNU gold are known to produce broken code with --fix-cortex-a53-843419 as explained in:
- https://sourceware.org/ml/binutils-cvs/2015-06/msg00188.html
- https://sourceware.org/bugzilla/show_bug.cgi?id=21491
Issue has been fixed in:
- https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e70c0b5f07daf63474e805f8d0a45152fcd60468
We don't know if ARM64_ERRATUM_843419 is enabled or disabled when we're using GNU gold so we don't know if we have to pass --fix-cortex-a53-843419 or --no-fix-cortex-a53-843419 to the linker.
We don't know either what is the version of binutils used by an external toolchain.
So, disable gold linker through the -no-use-gold-linker option of the configure script to fix the issue
Fixes:
- http://autobuild.buildroot.org/results/eb55bf44622697039a4ced510ee2d45b950d0a08
Signed-off-by Fabrice Fontaine <[email protected]>
---
 package/qt5/qt5base/qt5base.mk | 6 ++++++
 1 file changed, 6 insertions(+)
package/qt5/qt5base/qt5base.mk +0 -0
index ab2b883fc4..d3c6c31d45 100644

package/qt5/qt5base/qt5base.mk QT5BASE_CONFIGURE_OPTS += \ · line 32

Quoted 6 lines

package/qt5/qt5base/qt5base.mk +3 -0

@@ -27,6 +27,12 @@ QT5BASE_CONFIGURE_OPTS += \
 	-no-pch \
 	-shared
 
+# internal error in update_erratum_insn on Aarch64 a53 with gold before
+# binutils 2.29: https://sourceware.org/bugzilla/show_bug.cgi?id=21491
+ifeq ($(BR2_aarch64_be)$(BR2_cortex_a53)$(BR2_TOOLCHAIN_USES_GLIBC),yyy)

I have a few questions:

- I'm not sure what makes this bug specific to AArch64 Big Endian. Reading the links you pointed in the commit log, it seems like a generic AArch64 bug, which could affect both LE and BE configurations. Did I miss something ?

- What makes this bug specific to glibc ?

Overall, I think we should instead:

- Introduce a BR2_TOOLCHAIN_HAS_BINUTILS_BUG_21491 hidden option in toolchain/Config.in, next to BR2_TOOLCHAIN_HAS_BINUTILS_BUG_19615 that we already have.

- Select this option from the known external toolchains that are affected by the issue, and in package/binutils/Config.in.host for all affected binutils versions.

And then use that in qt5base.mk to work around the problem.

Of course, this would leave users of custom external toolchains out in the blue, but it is already the case with BR2_TOOLCHAIN_HAS_BINUTILS_BUG_19615 anyway. Perhaps we will have to ask for the binutils version used in custom external toolchains, if this sort of issue annoys too many people.

Best regards,

Thomas

Signature · 3 lines

Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com