From 6aa2d9cf81f98c4cb1de523502a2764eebbcd09f Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 18 Oct 2021 15:30:04 +0100
Subject: [PATCH] ARM: 9134/1: remove duplicate memcpy() definition
Git-commit: eaf6cc7165c9c5aa3c2f9faa03a98598123d0afb
Patch-mainline: v5.15-rc7
References: stable-5.14.16

commit eaf6cc7165c9c5aa3c2f9faa03a98598123d0afb upstream.

Both the decompressor code and the kasan logic try to override
the memcpy() and memmove()  definitions, which leading to a clash
in a KASAN-enabled kernel with XZ decompression:

arch/arm/boot/compressed/decompress.c:50:9: error: 'memmove' macro redefined [-Werror,-Wmacro-redefined]
 #define memmove memmove
        ^
arch/arm/include/asm/string.h:59:9: note: previous definition is here
 #define memmove(dst, src, len) __memmove(dst, src, len)
        ^
arch/arm/boot/compressed/decompress.c:51:9: error: 'memcpy' macro redefined [-Werror,-Wmacro-redefined]
 #define memcpy memcpy
        ^
arch/arm/include/asm/string.h:58:9: note: previous definition is here
 #define memcpy(dst, src, len) __memcpy(dst, src, len)
        ^

Here we want the set of functions from the decompressor, so undefine
the other macros before the override.

Link: https://lore.kernel.org/linux-arm-kernel/CACRpkdZYJogU_SN3H9oeVq=zJkRgRT1gDz3xp59gdqWXxw-B=w@mail.gmail.com/
Link: https://lore.kernel.org/lkml/202105091112.F5rmd4By-lkp@intel.com/

Fixes: d6d51a96c7d6 ("ARM: 9014/2: Replace string mem* functions for KASan")
Fixes: a7f464f3db93 ("ARM: 7001/2: Wire up support for the XZ decompressor")
Reported-by: kernel test robot <lkp@intel.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 arch/arm/boot/compressed/decompress.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/boot/compressed/decompress.c b/arch/arm/boot/compressed/decompress.c
index aa075d8372ea..74255e819831 100644
--- a/arch/arm/boot/compressed/decompress.c
+++ b/arch/arm/boot/compressed/decompress.c
@@ -47,7 +47,10 @@ extern char * strchrnul(const char *, int);
 #endif
 
 #ifdef CONFIG_KERNEL_XZ
+/* Prevent KASAN override of string helpers in decompressor */
+#undef memmove
 #define memmove memmove
+#undef memcpy
 #define memcpy memcpy
 #include "../../../../lib/decompress_unxz.c"
 #endif
-- 
2.26.2