[PATCH] m68k: string: Make char intermediate in strcmp() signed

From: Geert Uytterhoeven
Date: Thu Dec 15 2022 - 08:30:21 EST


Since char became unsigned, strcmp() always returns a positive number.

"res" is used to store a byte difference, so it should be signed.

Fixes: 3bc753c06dd02a35 ("kbuild: treat char as always unsigned")
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
See "Re: [PATCH v9] kallsyms: Add self-test facility"
https://lore.kernel.org/r/CAMuHMdWM6+pC3yUqy+hHRrAf1BCz2sz1KQv2zxS+Wz-639X-aA@xxxxxxxxxxxxxx

I'm wondering how many surprises like this are still hidden...
---
arch/m68k/include/asm/string.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/m68k/include/asm/string.h b/arch/m68k/include/asm/string.h
index f759d944c4499404..b8f4ae19e8f6ee2c 100644
--- a/arch/m68k/include/asm/string.h
+++ b/arch/m68k/include/asm/string.h
@@ -42,7 +42,7 @@ static inline char *strncpy(char *dest, const char *src, size_t n)
#define __HAVE_ARCH_STRCMP
static inline int strcmp(const char *cs, const char *ct)
{
- char res;
+ signed char res;

asm ("\n"
"1: move.b (%0)+,%2\n" /* get *cs */
--
2.25.1