From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:51002 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2407718AbfIVSwO (ORCPT ); Sun, 22 Sep 2019 14:52:14 -0400 From: Sasha Levin Subject: [PATCH AUTOSEL 5.2 096/185] s390/kasan: provide uninstrumented __strlen Date: Sun, 22 Sep 2019 14:47:54 -0400 Message-Id: <20190922184924.32534-96-sashal@kernel.org> In-Reply-To: <20190922184924.32534-1-sashal@kernel.org> References: <20190922184924.32534-1-sashal@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vasily Gorbik , Ilya Leoshkevich , Sasha Levin , linux-s390@vger.kernel.org From: Vasily Gorbik [ Upstream commit f45f7b5bdaa4828ce871cf03f7c01599a0de57a5 ] s390 kasan code uses sclp_early_printk to report initialization failures. The code doing that should not be instrumented, because kasan shadow memory has not been set up yet. Even though sclp_early_core.c is compiled with instrumentation disabled it uses strlen function, which is instrumented and would produce shadow memory access if used. To avoid that, introduce uninstrumented __strlen function to be used instead. Before commit 7e0d92f00246 ("s390/kasan: improve string/memory functions checks") few string functions (including strlen) were escaping kasan instrumentation due to usage of platform specific versions which are implemented in inline assembly. Fixes: 7e0d92f00246 ("s390/kasan: improve string/memory functions checks") Acked-by: Ilya Leoshkevich Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin --- arch/s390/include/asm/string.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/s390/include/asm/string.h b/arch/s390/include/asm/string.h index 70d87db54e627..4c0690fc5167e 100644 --- a/arch/s390/include/asm/string.h +++ b/arch/s390/include/asm/string.h @@ -71,11 +71,16 @@ extern void *__memmove(void *dest, const void *src, size_t n); #define memcpy(dst, src, len) __memcpy(dst, src, len) #define memmove(dst, src, len) __memmove(dst, src, len) #define memset(s, c, n) __memset(s, c, n) +#define strlen(s) __strlen(s) + +#define __no_sanitize_prefix_strfunc(x) __##x #ifndef __NO_FORTIFY #define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */ #endif +#else +#define __no_sanitize_prefix_strfunc(x) x #endif /* defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__) */ void *__memset16(uint16_t *s, uint16_t v, size_t count); @@ -163,8 +168,8 @@ static inline char *strcpy(char *dst, const char *src) } #endif -#ifdef __HAVE_ARCH_STRLEN -static inline size_t strlen(const char *s) +#if defined(__HAVE_ARCH_STRLEN) || (defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)) +static inline size_t __no_sanitize_prefix_strfunc(strlen)(const char *s) { register unsigned long r0 asm("0") = 0; const char *tmp = s; -- 2.20.1