diff options
| author | Nathan Chancellor <nathan@kernel.org> | 2025-03-20 22:33:49 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-10 14:39:40 +0200 |
| commit | 59fc42318305cb38efb4f5565408150419be8451 (patch) | |
| tree | 412c0ccd805a409c00eb294bc98c0a34a16998b1 | |
| parent | c6f2a8146da1c30d947bbdddd5cd84566ed8ae5d (diff) | |
| download | linux-59fc42318305cb38efb4f5565408150419be8451.tar.gz linux-59fc42318305cb38efb4f5565408150419be8451.tar.bz2 linux-59fc42318305cb38efb4f5565408150419be8451.zip | |
ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE
commit e7607f7d6d81af71dcc5171278aadccc94d277cd upstream.
ld.lld prior to 21.0.0 does not support using the KEEP keyword within an
overlay description, which may be needed to avoid discarding necessary
sections within an overlay with '--gc-sections', which can be enabled
for the kernel via CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
Disallow CONFIG_LD_DEAD_CODE_DATA_ELIMINATION without support for KEEP
within OVERLAY and introduce a macro, OVERLAY_KEEP, that can be used to
conditionally add KEEP when it is properly supported to avoid breaking
old versions of ld.lld.
Cc: stable@vger.kernel.org
Link: https://github.com/llvm/llvm-project/commit/381599f1fe973afad3094e55ec99b1620dba7d8c
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
[nathan: Fix conflict in init/Kconfig due to lack of RUSTC symbols]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm/Kconfig | 2 | ||||
| -rw-r--r-- | arch/arm/include/asm/vmlinux.lds.h | 6 | ||||
| -rw-r--r-- | init/Kconfig | 5 |
3 files changed, 12 insertions, 1 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 202397be76d8..d0040fb67c36 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -118,7 +118,7 @@ config ARM select HAVE_KERNEL_XZ select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M select HAVE_KRETPROBES if HAVE_KPROBES - select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_IS_LLD) + select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_CAN_USE_KEEP_IN_OVERLAY) select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI select HAVE_OPTPROBES if !THUMB2_KERNEL diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h index f6623fc6cc39..14811b4f48ec 100644 --- a/arch/arm/include/asm/vmlinux.lds.h +++ b/arch/arm/include/asm/vmlinux.lds.h @@ -34,6 +34,12 @@ #define NOCROSSREFS #endif +#ifdef CONFIG_LD_CAN_USE_KEEP_IN_OVERLAY +#define OVERLAY_KEEP(x) KEEP(x) +#else +#define OVERLAY_KEEP(x) x +#endif + /* Set start/end symbol names to the LMA for the section */ #define ARM_LMA(sym, section) \ sym##_start = LOADADDR(section); \ diff --git a/init/Kconfig b/init/Kconfig index 293c565c6216..243d0087f944 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -129,6 +129,11 @@ config CC_HAS_COUNTED_BY # https://github.com/llvm/llvm-project/pull/112636 depends on !(CC_IS_CLANG && CLANG_VERSION < 190103) +config LD_CAN_USE_KEEP_IN_OVERLAY + # ld.lld prior to 21.0.0 did not support KEEP within an overlay description + # https://github.com/llvm/llvm-project/pull/130661 + def_bool LD_IS_BFD || LLD_VERSION >= 210000 + config PAHOLE_VERSION int default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE)) |