Files
kernel-agent/patches/arch/arm64/xor-neon-ffixed-x18-scs-build-fix-danctnix/0001-arm64-xor-neon-ffixed-x18-build-fix.patch
T
claude-noether a840f76907 patches/arch/arm64/xor-neon-...: fix malformed @@ hunk counts
The hunk header @@ -9,6 +9,10 @@ understated both old (actual 7) and
new (actual 12) line counts by 1. patch(1) standalone tolerates this
via fuzz, but in the concatenated cumulative the wrong counts cause
patch to mis-judge the hunk boundary and read the trailing context
line ('lib-...uaccess_flushcache.o') as the start of a new patch
header — 'malformed patch at line 4526'.

Cumulative b2sum: bd42cd39106298879eeb... -> ad9e2cb533957f218058...
(size unchanged at 157 458; only the @@ counts in the SCS patch
differ)
2026-05-18 16:58:19 +02:00

40 lines
1.5 KiB
Diff

From: Markus Fritsche <fritsche.markus@gmail.com>
Date: Mon, 18 May 2026 11:42:00 +0200
Subject: [PATCH] arm64: xor-neon: restore -ffixed-x18 when SHADOW_CALL_STACK=y
(GCC 15+ build fix)
GCC 15.2.1 enforces that -fsanitize=shadow-call-stack requires
-ffixed-x18 inside arm_neon.h's #pragma GCC target() blocks. The
existing CFLAGS_REMOVE_xor-neon.o line strips the kernel-wide
-ffixed-x18 (it's part of CC_FLAGS_NO_FPU) and CC_FLAGS_FPU does not
restore it, so xor-neon.c fails to build on stricter GCC versions
when CONFIG_SHADOW_CALL_STACK=y.
Add an explicit -ffixed-x18 just for this object, gated on the
SCS config so non-SCS builds are unaffected.
Build environment workaround; not a kernel-runtime bug.
---
arch/arm64/lib/Makefile | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 1234567..2345678 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -9,7 +9,12 @@ ifeq ($(CONFIG_KERNEL_MODE_NEON), y)
obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o
CFLAGS_xor-neon.o += $(CC_FLAGS_FPU)
CFLAGS_REMOVE_xor-neon.o += $(CC_FLAGS_NO_FPU)
+# GCC 15+ enforces that -fsanitize=shadow-call-stack requires -ffixed-x18
+# even after a #pragma GCC pop_options inside arm_neon.h. CC_FLAGS_REMOVE
+# above strips the kernel-wide -ffixed-x18 (part of CC_FLAGS_NO_FPU); add
+# it back here so xor-neon.c still compiles when SHADOW_CALL_STACK=y.
+CFLAGS_xor-neon.o += $(if $(CONFIG_SHADOW_CALL_STACK),-ffixed-x18)
endif
lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
--
2.54.0