6.4.9-zen1: Clang LTO broken

[aidanharris]

This is a regression from 6.4.8

make defconfig
export CC=clang-16
export HOSTCC=$CC
env PATH=/usr/lib/llvm/16/bin:"$PATH" LIBCLANG_PATH=/usr/lib/llvm/16/lib64 make CC=$CC HOSTCC=$CC LLVM=1 LLVM_IAS=1 V=1 -j1
# enable thin-lto when prompted, don't enable CFI
+ ld.lld -m elf_x86_64 --thinlto-cache-dir=.thinlto-cache -mllvm -import-instr-limit=5 -z noexecstack --emit-relocs --discard-none -z max-page-size=0x200000 --build-id=sha1 --orphan-handling=error --script=./arch/x86/kernel/vmlinux.lds --strip-debug -o .tmp_vmlinux.kallsyms1 --whole-archive vmlinux.o .vmlinux.export.o init/version-timestamp.o --no-whole-archive --start-group --end-group
ld.lld: error: ./arch/x86/kernel/vmlinux.lds:35: unable to move location counter backward for: .text
ld.lld: error: ./arch/x86/kernel/vmlinux.lds:203: at least one side of the expression must be absolute
ld.lld: error: ./arch/x86/kernel/vmlinux.lds:204: at least one side of the expression must be absolute
ld.lld: error: SRSO function pair won't alias
ld.lld: error: ./arch/x86/kernel/vmlinux.lds:35: unable to move location counter backward for: .text
ld.lld: error: ./arch/x86/kernel/vmlinux.lds:203: at least one side of the expression must be absolute
ld.lld: error: ./arch/x86/kernel/vmlinux.lds:204: at least one side of the expression must be absolute
ld.lld: error: SRSO function pair won't alias
ld.lld: error: ./arch/x86/kernel/vmlinux.lds:35: unable to move location counter backward for: .text
ld.lld: error: ./arch/x86/kernel/vmlinux.lds:203: at least one side of the expression must be absolute
ld.lld: error: ./arch/x86/kernel/vmlinux.lds:204: at least one side of the expression must be absolute
ld.lld: error: SRSO function pair won't alias

[aidanharris]

Toolchain info:

$ clang-16 --version
clang version 16.0.6
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/16/bin
Configuration file: /etc/clang/clang.cfg
$ ld.lld --version
LLD 16.0.6 (compatible with GNU linkers)

[damentz]

The v6.4.9 release was an urgent security release: https://lwn.net/Articles/940798/

Not only is this simply upstream (has nothing to do with Zen Kernel), they acknowledge they may have broken things. Stay tuned to v6.4.10 and later releases, or let them know on the mailing list that Clang LTO is broken yourself.