On Wed, 5 Jun 2019 at 18:26, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> 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)? > > Nick, do we need to add another fix that is in mainline for this to work > properly? > For the record, this is an example of why I think backporting those clang enablement patches is a bad idea. We can't actually build those kernels with clang, can we? So what is the point? </grumpy> 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
