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[2a01:cb05:91d1:4800:52c2:e8ff:fee9:f96f]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-44a8ea7d0besm18897552f8f.4.2026.05.03.06.12.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 03 May 2026 06:12:47 -0700 (PDT) From: Guilhem Massol To: kees@kernel.org Cc: linux-kernel@vger.kernel.org, Guilhem Massol Subject: [PATCH] string: Use __restrict__ according to ISO/IEC 9899:TC3 Date: Sun, 3 May 2026 15:12:45 +0200 Message-ID: <20260503131245.13868-1-guilhem.massol85@gmail.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Source: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf Some functions in lib/string.c needs to use restrict according to sections: * 7.21.2.1: memcpy * 7.21.2.3: strcpy * 7.21.2.4: strncpy * 7.21.3.1: strcat * 7.21.3.2: strncat Signed-off-by: Guilhem Massol --- include/linux/string.h | 12 ++++++------ lib/string.c | 12 ++++++------ 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/include/linux/string.h b/include/linux/string.h index b850bd91b3d8..07679485104b 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -65,12 +65,12 @@ void *vmemdup_array_user(const void __user *src, size_t= n, size_t size) #include =20 #ifndef __HAVE_ARCH_STRCPY -extern char * strcpy(char *,const char *); +extern char * strcpy(char *__restrict__, const char *__restrict__); #endif #ifndef __HAVE_ARCH_STRNCPY -extern char * strncpy(char *,const char *, __kernel_size_t); +extern char * strncpy(char *__restrict__, const char *__restrict__, __kern= el_size_t); #endif -ssize_t sized_strscpy(char *, const char *, size_t); +ssize_t sized_strscpy(char *__restrict__, const char *__restrict__, size_t= ); =20 /* * The 2 argument style can only be used when dst is an array with a @@ -149,10 +149,10 @@ ssize_t sized_strscpy(char *, const char *, size_t); CONCATENATE(__strscpy_pad, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__) =20 #ifndef __HAVE_ARCH_STRCAT -extern char * strcat(char *, const char *); +extern char * strcat(char *__restrict__, const char *__restrict__); #endif #ifndef __HAVE_ARCH_STRNCAT -extern char * strncat(char *, const char *, __kernel_size_t); +extern char * strncat(char *__restrict__, const char *__restrict__, __kern= el_size_t); #endif #ifndef __HAVE_ARCH_STRLCAT extern size_t strlcat(char *, const char *, __kernel_size_t); @@ -257,7 +257,7 @@ extern void **__memcat_p(void **a, void **b); }) =20 #ifndef __HAVE_ARCH_MEMCPY -extern void * memcpy(void *,const void *,__kernel_size_t); +extern void * memcpy(void *__restrict__, const void *__restrict__, __kerne= l_size_t); #endif #ifndef __HAVE_ARCH_MEMMOVE extern void * memmove(void *,const void *,__kernel_size_t); diff --git a/lib/string.c b/lib/string.c index b632c71df1a5..9b492402ad04 100644 --- a/lib/string.c +++ b/lib/string.c @@ -77,7 +77,7 @@ EXPORT_SYMBOL(strcasecmp); #endif =20 #ifndef __HAVE_ARCH_STRCPY -char *strcpy(char *dest, const char *src) +char *strcpy(char *__restrict__ dest, const char *__restrict__ src) { char *tmp =3D dest; =20 @@ -89,7 +89,7 @@ EXPORT_SYMBOL(strcpy); #endif =20 #ifndef __HAVE_ARCH_STRNCPY -char *strncpy(char *dest, const char *src, size_t count) +char *strncpy(char *__restrict__ dest, const char *__restrict__ src, size_= t count) { char *tmp =3D dest; =20 @@ -110,7 +110,7 @@ EXPORT_SYMBOL(strncpy); # define ALLBUTLAST_BYTE_MASK (~0ul >> 8) #endif =20 -ssize_t sized_strscpy(char *dest, const char *src, size_t count) +ssize_t sized_strscpy(char *__restrict__ dest, const char *__restrict__ sr= c, size_t count) { const struct word_at_a_time constants =3D WORD_AT_A_TIME_CONSTANTS; size_t max =3D count; @@ -215,7 +215,7 @@ char *stpcpy(char *__restrict__ dest, const char *__res= trict__ src) EXPORT_SYMBOL(stpcpy); =20 #ifndef __HAVE_ARCH_STRCAT -char *strcat(char *dest, const char *src) +char *strcat(char *__restrict__ dest, const char *__restrict__ src) { char *tmp =3D dest; =20 @@ -229,7 +229,7 @@ EXPORT_SYMBOL(strcat); #endif =20 #ifndef __HAVE_ARCH_STRNCAT -char *strncat(char *dest, const char *src, size_t count) +char *strncat(char *__restrict__ dest, const char *__restrict__ src, size_= t count) { char *tmp =3D dest; =20 @@ -618,7 +618,7 @@ EXPORT_SYMBOL(memset64); * You should not use this function to access IO space, use memcpy_toio() * or memcpy_fromio() instead. */ -void *memcpy(void *dest, const void *src, size_t count) +void *memcpy(void *__restrict__ dest, const void *__restrict__ src, size_t= count) { char *tmp =3D dest; const char *s =3D src; --=20 2.54.0