xtensa: shut up gcc-8 warnings

Message ID 20180102110035.1806925-1-arnd@arndb.de
State Accepted
Commit 32bb954dbf6db98562cb4477608dc546421caaf6
Headers show
Series
  • xtensa: shut up gcc-8 warnings
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Commit Message

Arnd Bergmann Jan. 2, 2018, 11 a.m.
Many uses of strncpy() on xtensa causes  a warning like

arch/xtensa/include/asm/string.h:56:42: warning: array subscript is above array bounds [-Warray-bounds]
   : "0" (__dest), "1" (__src), "r" (__src+__n)

This avoids the warning by turning the pointer arithmetic into an
integer operation that does not get checked the same way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
 arch/xtensa/include/asm/string.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.9.0

Comments

Max Filippov Jan. 2, 2018, 11:29 a.m. | #1
On Tue, Jan 2, 2018 at 3:00 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> Many uses of strncpy() on xtensa causes  a warning like

>

> arch/xtensa/include/asm/string.h:56:42: warning: array subscript is above array bounds [-Warray-bounds]

>    : "0" (__dest), "1" (__src), "r" (__src+__n)

>

> This avoids the warning by turning the pointer arithmetic into an

> integer operation that does not get checked the same way.

>

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

>  arch/xtensa/include/asm/string.h | 4 ++--

>  1 file changed, 2 insertions(+), 2 deletions(-)


Thanks, applied to my xtensa tree.

-- Max

Patch

diff --git a/arch/xtensa/include/asm/string.h b/arch/xtensa/include/asm/string.h
index 586bad9fe187..89b51a0c752f 100644
--- a/arch/xtensa/include/asm/string.h
+++ b/arch/xtensa/include/asm/string.h
@@ -53,7 +53,7 @@  static inline char *strncpy(char *__dest, const char *__src, size_t __n)
 		"bne	%1, %5, 1b\n"
 		"2:"
 		: "=r" (__dest), "=r" (__src), "=&r" (__dummy)
-		: "0" (__dest), "1" (__src), "r" (__src+__n)
+		: "0" (__dest), "1" (__src), "r" ((uintptr_t)__src+__n)
 		: "memory");
 
 	return __xdest;
@@ -101,7 +101,7 @@  static inline int strncmp(const char *__cs, const char *__ct, size_t __n)
 		"2:\n\t"
 		"sub	%2, %2, %3"
 		: "=r" (__cs), "=r" (__ct), "=&r" (__res), "=&r" (__dummy)
-		: "0" (__cs), "1" (__ct), "r" (__cs+__n));
+		: "0" (__cs), "1" (__ct), "r" ((uintptr_t)__cs+__n));
 
 	return __res;
 }