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authorArnd Bergmann <arnd@arndb.de>2021-10-18 15:30:03 +0100
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2021-10-25 13:12:36 +0100
commitae3d6978aa84f65376a790e23d3fb52fcc8346b2 (patch)
treee901494772fee45cb5e0bab819cc98609a7d4e9e /arch/arm/include/asm
parentARM: 9144/1: forbid ftrace with clang and thumb2_kernel (diff)
downloadlinux-dev-ae3d6978aa84f65376a790e23d3fb52fcc8346b2.tar.xz
linux-dev-ae3d6978aa84f65376a790e23d3fb52fcc8346b2.zip
ARM: 9145/1: patch: fix BE32 compilation
On BE32 kernels, the __opcode_to_mem_thumb32() interface is intentionally not defined, but it is referenced whenever runtime patching is enabled for the kernel, which may be for ftrace, jump label, kprobes or kgdb: arch/arm/kernel/patch.c: In function '__patch_text_real': arch/arm/kernel/patch.c:94:32: error: implicit declaration of function '__opcode_to_mem_thumb32' [-Werror=implicit-function-declaration] 94 | insn = __opcode_to_mem_thumb32(insn); | ^~~~~~~~~~~~~~~~~~~~~~~ Since BE32 kernels never run Thumb2 code, we never end up using the result of this call, so providing an extern declaration without a definition makes it build correctly. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/include/asm')
-rw-r--r--arch/arm/include/asm/opcodes.h9
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/arm/include/asm/opcodes.h b/arch/arm/include/asm/opcodes.h
index 6bff94b2372b..38e3eabff5c3 100644
--- a/arch/arm/include/asm/opcodes.h
+++ b/arch/arm/include/asm/opcodes.h
@@ -110,12 +110,17 @@ extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr);
#define __opcode_to_mem_thumb16(x) ___opcode_identity16(x)
#define ___asm_opcode_to_mem_arm(x) ___asm_opcode_identity32(x)
#define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_identity16(x)
-#ifndef CONFIG_CPU_ENDIAN_BE32
+#ifdef CONFIG_CPU_ENDIAN_BE32
+#ifndef __ASSEMBLY__
/*
* On BE32 systems, using 32-bit accesses to store Thumb instructions will not
* work in all cases, due to alignment constraints. For now, a correct
- * version is not provided for BE32.
+ * version is not provided for BE32, but the prototype needs to be there
+ * to compile patch.c.
*/
+extern __u32 __opcode_to_mem_thumb32(__u32);
+#endif
+#else
#define __opcode_to_mem_thumb32(x) ___opcode_swahw32(x)
#define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahw32(x)
#endif