From: Namhyung Kim <namhyung@gmail.com>
To: Ma Ling <ling.ma@intel.com>
Cc: hpa@zytor.com, tglx@linutronix.de, linux-kernel@vger.kernel.org,
mingo@elte.hu
Subject: Re: [PATCH V2] [X86] Fix potential issue on memmove
Date: Thu, 12 Aug 2010 15:48:35 +0900 [thread overview]
Message-ID: <1281595715.1631.5.camel@leonhard> (raw)
> --- a/arch/x86/lib/memcpy_32.c
> +++ b/arch/x86/lib/memcpy_32.c
> @@ -25,19 +25,35 @@ void *memmove(void *dest, const void *src, size_t n)
> int d0, d1, d2;
>
> if (dest < src) {
> - memcpy(dest, src, n);
> + if ((dest + n) < src)
> + return memcpy(dest, src, n);
> + else
> + __asm__ __volatile__(
> + "rep\n\t"
> + "movsb\n\t"
> + : "=&c" (d0), "=&S" (d1), "=&D" (d2)
> + :"0" (n),
> + "1" (src),
> + "2" (dest)
> + :"memory");
> +
> } else {
> - __asm__ __volatile__(
> - "std\n\t"
> - "rep\n\t"
> - "movsb\n\t"
> - "cld"
> - : "=&c" (d0), "=&S" (d1), "=&D" (d2)
> - :"0" (n),
> - "1" (n-1+src),
> - "2" (n-1+dest)
> - :"memory");
> + if((src + count) < dest)
> + return memcpy(dest, src, count);
'count' should be 'n'.
--
Regards,
Namhyung Kim
next reply other threads:[~2010-08-12 6:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-12 6:48 Namhyung Kim [this message]
2010-08-12 6:52 ` [PATCH V2] [X86] Fix potential issue on memmove Ma, Ling
2010-08-12 14:15 ` H. Peter Anvin
2010-08-12 14:22 ` H. Peter Anvin
-- strict thread matches above, loose matches on Subject: below --
2010-08-11 22:20 ling.ma
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