On Wed, Jun 05, 2019 at 08:42:32PM +0200, Ard Biesheuvel wrote: > 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> Yes "we" can. I do. Why can't you? And lots of devices rely on clang support for their kernels, as much as I would like to ignore them, I can't :( thanks, greg k-h
