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* [PATCH 0/2] sh: use generic strncpy()
@ 2019-12-18  7:31 Kuninori Morimoto
  2019-12-18  7:32 ` [PATCH] " Kuninori Morimoto
  2019-12-18  7:33 ` [PATCH] sh: fixup strncpy() Kuninori Morimoto
  0 siblings, 2 replies; 12+ messages in thread
From: Kuninori Morimoto @ 2019-12-18  7:31 UTC (permalink / raw)
  To: Yoshinori Sato, Rich Felker, Karl Nasrallah; +Cc: Linux-SH, Linux-Renesas


Hi

These are strncpy() fixup patches, and both are crated by Karl.
He created 2 patterns.

Mine (= Kuninori Morimoto) and/or His patches can solve
issue, but we can follow maintainer's slection

Thank you for your help !!
Best regards
---
Kuninori Morimoto

^ permalink raw reply	[flat|nested] 12+ messages in thread
* [PATCH] sh: use generic strncpy()
@ 2019-12-18  5:22 Kuninori Morimoto
  2019-12-18  8:02 ` Geert Uytterhoeven
  0 siblings, 1 reply; 12+ messages in thread
From: Kuninori Morimoto @ 2019-12-18  5:22 UTC (permalink / raw)
  To: Yoshinori Sato, Rich Felker; +Cc: Linux-SH, Linux-Renesas


From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

Current SH will get below warning at strncpy()

In file included from ${LINUX}/arch/sh/include/asm/string.h:3,
                 from ${LINUX}/include/linux/string.h:20,
                 from ${LINUX}/include/linux/bitmap.h:9,
                 from ${LINUX}/include/linux/nodemask.h:95,
                 from ${LINUX}/include/linux/mmzone.h:17,
                 from ${LINUX}/include/linux/gfp.h:6,
                 from ${LINUX}/innclude/linux/slab.h:15,
                 from ${LINUX}/linux/drivers/mmc/host/vub300.c:38:
${LINUX}/drivers/mmc/host/vub300.c: In function 'new_system_port_status':
${LINUX}/arch/sh/include/asm/string_32.h:51:42: warning: array subscript\
  80 is above array bounds of 'char[26]' [-Warray-bounds]
   : "0" (__dest), "1" (__src), "r" (__src+__n)
                                     ~~~~~^~~~

In general, strncpy() should behave like below.

	char dest[10];
	char *src = "12345";

	strncpy(dest, src, 10);
	// dest = {'1', '2', '3', '4', '5',
	           '\0','\0','\0','\0','\0'}

But, current SH strnpy() has 2 issues.
1st is it will access to out-of-memory (= src + 10).
2nd is it needs big fixup for it, and maintenance __asm__
code is difficult.

To solve these issues, this patch simply uses generic strncpy()
instead of architecture specific one.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
---
 arch/sh/include/asm/string_32.h | 26 --------------------------
 1 file changed, 26 deletions(-)

diff --git a/arch/sh/include/asm/string_32.h b/arch/sh/include/asm/string_32.h
index 3558b1d..be3f9a0 100644
--- a/arch/sh/include/asm/string_32.h
+++ b/arch/sh/include/asm/string_32.h
@@ -28,32 +28,6 @@ static inline char *strcpy(char *__dest, const char *__src)
 	return __xdest;
 }
 
-#define __HAVE_ARCH_STRNCPY
-static inline char *strncpy(char *__dest, const char *__src, size_t __n)
-{
-	register char *__xdest = __dest;
-	unsigned long __dummy;
-
-	if (__n == 0)
-		return __xdest;
-
-	__asm__ __volatile__(
-		"1:\n"
-		"mov.b	@%1+, %2\n\t"
-		"mov.b	%2, @%0\n\t"
-		"cmp/eq	#0, %2\n\t"
-		"bt/s	2f\n\t"
-		" cmp/eq	%5,%1\n\t"
-		"bf/s	1b\n\t"
-		" add	#1, %0\n"
-		"2:"
-		: "=r" (__dest), "=r" (__src), "=&z" (__dummy)
-		: "0" (__dest), "1" (__src), "r" (__src+__n)
-		: "memory", "t");
-
-	return __xdest;
-}
-
 #define __HAVE_ARCH_STRCMP
 static inline int strcmp(const char *__cs, const char *__ct)
 {
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 12+ messages in thread
end of thread, other threads:[~2020-06-08  0:57 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
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2019-12-18  7:31 [PATCH 0/2] sh: use generic strncpy() Kuninori Morimoto
2019-12-18  7:32 ` [PATCH] " Kuninori Morimoto
2019-12-18  7:35   ` Kuninori Morimoto
2019-12-18  7:33 ` [PATCH] sh: fixup strncpy() Kuninori Morimoto
2020-05-31  9:43   ` John Paul Adrian Glaubitz
2020-05-31 23:43     ` Kuninori Morimoto
2020-06-01  8:15       ` John Paul Adrian Glaubitz
2020-06-07 12:34       ` John Paul Adrian Glaubitz
2020-06-08  0:57         ` Kuninori Morimoto
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2019-12-18  5:22 [PATCH] sh: use generic strncpy() Kuninori Morimoto
2019-12-18  8:02 ` Geert Uytterhoeven
2019-12-19  0:45   ` Kuninori Morimoto

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