This is a note to let you know that I've just added the patch titled
x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
to the 5.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-kconfig-do-not-allow-config_x86_x32_abi-y-with-l.patch
and it can be found in the queue-5.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e8663d977af04f63a87d7c68d4035078a3635784
Author: Nathan Chancellor <nathan@xxxxxxxxxx>
Date: Mon Mar 14 12:48:42 2022 -0700
x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
[ Upstream commit aaeed6ecc1253ce1463fa1aca0b70a4ccbc9fa75 ]
There are two outstanding issues with CONFIG_X86_X32_ABI and
llvm-objcopy, with similar root causes:
1. llvm-objcopy does not properly convert .note.gnu.property when going
from x86_64 to x86_x32, resulting in a corrupted section when
linking:
https://github.com/ClangBuiltLinux/linux/issues/1141
2. llvm-objcopy produces corrupted compressed debug sections when going
from x86_64 to x86_x32, also resulting in an error when linking:
https://github.com/ClangBuiltLinux/linux/issues/514
After commit 41c5ef31ad71 ("x86/ibt: Base IBT bits"), the
.note.gnu.property section is always generated when
CONFIG_X86_KERNEL_IBT is enabled, which causes the first issue to become
visible with an allmodconfig build:
ld.lld: error: arch/x86/entry/vdso/vclock_gettime-x32.o:(.note.gnu.property+0x1c): program property is too short
To avoid this error, do not allow CONFIG_X86_X32_ABI to be selected when
using llvm-objcopy. If the two issues ever get fixed in llvm-objcopy,
this can be turned into a feature check.
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220314194842.3452-3-nathan@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5c2ccb85f2ef..d377d8af5a9f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2827,6 +2827,11 @@ config IA32_AOUT
config X86_X32
bool "x32 ABI for 64-bit mode"
depends on X86_64
+ # llvm-objcopy does not convert x86_64 .note.gnu.property or
+ # compressed debug sections to x86_x32 properly:
+ # https://github.com/ClangBuiltLinux/linux/issues/514
+ # https://github.com/ClangBuiltLinux/linux/issues/1141
+ depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
help
Include code to run binaries for the x32 native 32-bit ABI
for 64-bit processors. An x32 process gets access to the
