Commit dfe05fcca83d for kernel
commit dfe05fcca83d794cd76da1b6deb2dcd082aa1174
Author: Kees Cook <kees@kernel.org>
Date: Mon Mar 23 01:17:59 2026 +0000
x86: Remove arch-specific strncpy() implementation
strncpy() has no remaining callers in the kernel[1]. Remove the
x86-32-specific inline assembly implementation and __HAVE_ARCH_STRNCPY
define, falling back to the generic version in lib/string.c.
Link: https://github.com/KSPP/linux/issues/90 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
diff --git a/arch/x86/include/asm/string_32.h b/arch/x86/include/asm/string_32.h
index e9cce169bb4c..43ab6806ab53 100644
--- a/arch/x86/include/asm/string_32.h
+++ b/arch/x86/include/asm/string_32.h
@@ -9,9 +9,6 @@
#define __HAVE_ARCH_STRCPY
extern char *strcpy(char *dest, const char *src);
-#define __HAVE_ARCH_STRNCPY
-extern char *strncpy(char *dest, const char *src, size_t count);
-
#define __HAVE_ARCH_STRCAT
extern char *strcat(char *dest, const char *src);
diff --git a/arch/x86/lib/string_32.c b/arch/x86/lib/string_32.c
index f87ec24fa579..a9480d73c4f0 100644
--- a/arch/x86/lib/string_32.c
+++ b/arch/x86/lib/string_32.c
@@ -30,25 +30,6 @@ char *strcpy(char *dest, const char *src)
EXPORT_SYMBOL(strcpy);
#endif
-#ifdef __HAVE_ARCH_STRNCPY
-char *strncpy(char *dest, const char *src, size_t count)
-{
- int d0, d1, d2, d3;
- asm volatile("1:\tdecl %2\n\t"
- "js 2f\n\t"
- "lodsb\n\t"
- "stosb\n\t"
- "testb %%al,%%al\n\t"
- "jne 1b\n\t"
- "rep stosb\n"
- "2:"
- : "=&S" (d0), "=&D" (d1), "=&c" (d2), "=&a" (d3)
- : "0" (src), "1" (dest), "2" (count) : "memory");
- return dest;
-}
-EXPORT_SYMBOL(strncpy);
-#endif
-
#ifdef __HAVE_ARCH_STRCAT
char *strcat(char *dest, const char *src)
{