Am Mittwoch, 5. Juni 2019, 20:42:32 CEST schrieb Ard Biesheuvel:
On Wed, 5 Jun 2019 at 18:26, Greg KH gregkh@linuxfoundation.org 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.
It would be helpful to get a relocation dump (objdump -r) of arm64-stub.o to figure out which symbol needs a 'hidden' annotation to prevent GCC from emitting it as a PIC reference requiring a GOT. Alternatively, we can just revert this patch from 4.9
See attached file. This is with a few patches cherry-picked from upstream, none of them did help. Hope that doesn't make anything worse, at least the error message looks the same.
Eike