alpha: Remove arch-specific strncpy() implementation

strncpy() has no remaining callers in the kernel[1]. Remove the
alpha-specific assembly implementation and __HAVE_ARCH_STRNCPY define,
falling back to the generic version in lib/string.c.

The __stxncpy helper (stxncpy.S/ev6-stxncpy.S) is retained as it is
still used by strncat.

Link: https://github.com/KSPP/linux/issues/90
Signed-off-by: Kees Cook <kees@kernel.org>

diff --git a/arch/alpha/include/asm/string.h b/arch/alpha/include/asm/string.h
index f043f91ff98830c8557217c7b4a6a66cc6a732a8..7c7545a2319a70bbc70c0a4c990dea410052982f 100644 (file)
--- a/arch/alpha/include/asm/string.h
+++ b/arch/alpha/include/asm/string.h
@@ -47,8 +47,6 @@ extern inline void *__memset(void *s, int c, size_t n)
 
 #define __HAVE_ARCH_STRCPY
 extern char * strcpy(char *,const char *);
-#define __HAVE_ARCH_STRNCPY
-extern char * strncpy(char *, const char *, size_t);
 #define __HAVE_ARCH_STRCAT
 extern char * strcat(char *, const char *);
 #define __HAVE_ARCH_STRNCAT

diff --git a/arch/alpha/lib/strncpy.S b/arch/alpha/lib/strncpy.S
deleted file mode 100644 (file)
index cb90cf0..0000000
--- a/arch/alpha/lib/strncpy.S
+++ /dev/null
@@ -1,83 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * arch/alpha/lib/strncpy.S
- * Contributed by Richard Henderson (rth@tamu.edu)
- *
- * Copy no more than COUNT bytes of the null-terminated string from
- * SRC to DST.  If SRC does not cover all of COUNT, the balance is
- * zeroed.
- *
- * Or, rather, if the kernel cared about that weird ANSI quirk.  This
- * version has cropped that bit o' nastiness as well as assuming that
- * __stxncpy is in range of a branch.
- */
-#include <linux/export.h>
-       .set noat
-       .set noreorder
-
-       .text
-
-       .align 4
-       .globl strncpy
-       .ent strncpy
-strncpy:
-       .frame $30, 0, $26
-       .prologue 0
-
-       mov     $16, $0         # set return value now
-       beq     $18, $zerolen
-       unop
-       bsr     $23, __stxncpy  # do the work of the copy
-
-       unop
-       bne     $18, $multiword # do we have full words left?
-       subq    $24, 1, $3      # nope
-       subq    $27, 1, $4
-
-       or      $3, $24, $3     # clear the bits between the last
-       or      $4, $27, $4     # written byte and the last byte in COUNT
-       andnot  $3, $4, $4
-       zap     $1, $4, $1
-
-       stq_u   $1, 0($16)
-       ret
-
-       .align  4
-$multiword:
-       subq    $27, 1, $2      # clear the final bits in the prev word
-       or      $2, $27, $2
-       zapnot  $1, $2, $1
-       subq    $18, 1, $18
-
-       stq_u   $1, 0($16)
-       addq    $16, 8, $16
-       unop
-       beq     $18, 1f
-
-       nop
-       unop
-       nop
-       blbc    $18, 0f
-
-       stq_u   $31, 0($16)     # zero one word
-       subq    $18, 1, $18
-       addq    $16, 8, $16
-       beq     $18, 1f
-
-0:     stq_u   $31, 0($16)     # zero two words
-       subq    $18, 2, $18
-       stq_u   $31, 8($16)
-       addq    $16, 16, $16
-       bne     $18, 0b
-
-1:     ldq_u   $1, 0($16)      # clear the leading bits in the final word
-       subq    $24, 1, $2
-       or      $2, $24, $2
-
-       zap     $1, $2, $1
-       stq_u   $1, 0($16)
-$zerolen:
-       ret
-
-       .end    strncpy
-       EXPORT_SYMBOL(strncpy)

diff --git a/arch/alpha/lib/styncpy.S b/arch/alpha/lib/styncpy.S
index 72fc2754eb57c738051de7f880c63d98d11ca3cc..f1078ff125307b00d1876b5c46a2d511bdba742b 100644 (file)
--- a/arch/alpha/lib/styncpy.S
+++ b/arch/alpha/lib/styncpy.S
@@ -1,4 +1,3 @@
-#include "strncpy.S"
 #ifdef CONFIG_ALPHA_EV67
 #include "ev67-strncat.S"
 #else