[PATCH v3] x86/boot: discard .eh_frame sections

From: Ilie Halip
Date: Tue Nov 26 2019 - 09:46:48 EST


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.

Signed-off-by: Ilie Halip <ilie.halip@xxxxxxxxx>
Link: https://lore.kernel.org/lkml/20191118175223.GM6363@xxxxxxx/
Link: https://github.com/ClangBuiltLinux/linux/issues/760
Suggested-by: Borislav Petkov <bp@xxxxxxxxx>
---

Changes in V3:
* discard .eh_frame instead of placing it after .rodata

Changes in V2:
* removed wildcard for input sections (.eh_frame* -> .eh_frame)

arch/x86/boot/setup.ld | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/boot/setup.ld b/arch/x86/boot/setup.ld
index 0149e41d42c2..3da1c37c6dd5 100644
--- a/arch/x86/boot/setup.ld
+++ b/arch/x86/boot/setup.ld
@@ -51,7 +51,10 @@ SECTIONS
. = ALIGN(16);
_end = .;

- /DISCARD/ : { *(.note*) }
+ /DISCARD/ : {
+ *(.eh_frame)
+ *(.note*)
+ }

/*
* The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
--
2.17.1