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authorNathan Chancellor <nathan@kernel.org>2025-03-20 22:33:49 +0100
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2025-03-26 13:31:47 +0000
commite7607f7d6d81af71dcc5171278aadccc94d277cd (patch)
tree83d0a1893f5958624b1c7f31ee9a842dac46446b
parentARM: 9442/1: smp: Fix IPI alignment in /proc/interrupts (diff)
downloadwireguard-linux-e7607f7d6d81af71dcc5171278aadccc94d277cd.tar.xz
wireguard-linux-e7607f7d6d81af71dcc5171278aadccc94d277cd.zip
ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE
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>
Diffstat (limited to '')
-rw-r--r--arch/arm/Kconfig2
-rw-r--r--arch/arm/include/asm/vmlinux.lds.h6
-rw-r--r--init/Kconfig5
3 files changed, 12 insertions, 1 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 202dbd17ad2f..25ed6f1a7c7a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -121,7 +121,7 @@ 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 89697f204715..a54db342653a 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 d0d021b3fa3b..fc994f5cd5db 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 RUSTC_HAS_COERCE_POINTEE
def_bool RUSTC_VERSION >= 108400