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[03/14] ARM: remove duplicate memcpy() definition

Message ID 20210928154143.2106903-4-arnd@kernel.org (mailing list archive)
State New, archived
Headers show
Series ARM: randconfig build fixes | expand

Commit Message

Arnd Bergmann Sept. 28, 2021, 3:41 p.m. UTC 
From: Arnd Bergmann <arnd@arndb.de>

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.

Fixes: d6d51a96c7d6 ("ARM: 9014/2: Replace string mem* functions for KASan")
Fixes: a7f464f3db93 ("ARM: 7001/2: Wire up support for the XZ decompressor")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/boot/compressed/decompress.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Linus Walleij Sept. 28, 2021, 9:39 p.m. UTC | #1 
On Tue, Sep 28, 2021 at 5:42 PM Arnd Bergmann <arnd@kernel.org> wrote:

> From: Arnd Bergmann <arnd@arndb.de>
>
> 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.
>
> Fixes: d6d51a96c7d6 ("ARM: 9014/2: Replace string mem* functions for KASan")
> Fixes: a7f464f3db93 ("ARM: 7001/2: Wire up support for the XZ decompressor")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Solves this, right?
https://lore.kernel.org/lkml/202105091112.F5rmd4By-lkp@intel.com/

Can you put in a reported-by and Link: to this so we got it tracked?

>  #ifdef CONFIG_KERNEL_XZ
> +#undef memmove
>  #define memmove memmove
> +#undef memcpy
>  #define memcpy memcpy
>  #include "../../../../lib/decompress_unxz.c"
>  #endif

That's clever, maybe drop a small comment in the code why we do this
pretty unintuitive looking thing and how this works?

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/arch/arm/boot/compressed/decompress.c b/arch/arm/boot/compressed/decompress.c
index aa075d8372ea..5b387c60accd 100644
--- a/arch/arm/boot/compressed/decompress.c
+++ b/arch/arm/boot/compressed/decompress.c
@@ -47,7 +47,9 @@  extern char * strchrnul(const char *, int);
 #endif
 
 #ifdef CONFIG_KERNEL_XZ
+#undef memmove
 #define memmove memmove
+#undef memcpy
 #define memcpy memcpy
 #include "../../../../lib/decompress_unxz.c"
 #endif