x86/boot: Discard .eh_frame sections
When using GCC as compiler and LLVM's lld as linker, linking setup.elf
fails:
LD arch/x86/boot/setup.elf
ld.lld: error: init sections too big!
This happens because GCC generates .eh_frame sections for most of the
files in that directory, then ld.lld places the merged section before
__end_init, triggering an assert in the linker script.
Fix this by discarding the .eh_frame sections, as suggested by Boris.
The kernel proper linker script discards them too.
[ bp: Going back in history, 64-bit kernel proper has been discarding
.eh_frame since 2002:
commit
acca80acefe20420e69561cf55be64f16c34ea97
Author: Andi Kleen <ak@muc.de>
Date: Tue Oct 29 23:54:35 2002 -0800
[PATCH] x86-64 updates for 2.5.44
...
- Remove the .eh_frame on linking. This saves several hundred KB in the
bzImage
]
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Ilie Halip <ilie.halip@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com
Cc: Andy Lutomirski <luto@kernel.org>
Cc: clang-built-linux@googlegroups.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lore.kernel.org/lkml/20191118175223.GM6363@zn.tnic/
Link: https://github.com/ClangBuiltLinux/linux/issues/760
Link: https://lkml.kernel.org/r/20191126144545.19354-1-ilie.halip@gmail.com