Re: [RFC][PATCH v2 2/7] implement memmem()

[Steven Rostedt <rostedt@goodmis.org>]

On Fri,  6 Feb 2015 04:00:10 +0000
Al Viro <viro@ZenIV.linux.org.uk> wrote:

> From: Al Viro <viro@zeniv.linux.org.uk>
> 
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
>  include/linux/string.h |  1 +
>  lib/string.c           | 34 ++++++++++++++++++++++------------
>  2 files changed, 23 insertions(+), 12 deletions(-)
> 
> diff --git a/include/linux/string.h b/include/linux/string.h
> index 2e22a2e..87f9fba 100644
> --- a/include/linux/string.h
> +++ b/include/linux/string.h
> @@ -75,6 +75,7 @@ extern char * strstr(const char *, const char *);
>  #endif
>  #ifndef __HAVE_ARCH_STRNSTR
>  extern char * strnstr(const char *, const char *, size_t);
> +extern void * memmem(const void *, size_t, const void *, size_t);
>  #endif
>  #ifndef __HAVE_ARCH_STRLEN
>  extern __kernel_size_t strlen(const char *);
> diff --git a/lib/string.c b/lib/string.c
> index 1006330..2035dbe 100644
> --- a/lib/string.c
> +++ b/lib/string.c
> @@ -740,27 +740,37 @@ EXPORT_SYMBOL(strstr);
>  #endif
>  
>  #ifndef __HAVE_ARCH_STRNSTR

Although I do not see any archs that have this set, if one were to set
it, then memmem() would also have to be implemented.

Should this patch add a:

#ifndef __HAVE_ARCH_MEMMEM

?

-- Steve

> +
>  /**
> - * strnstr - Find the first substring in a length-limited string
> + * memmem - Find the first length-limited substring in a length-limited string
>   * @s1: The string to be searched
> + * @len1: the maximum number of characters to search
>   * @s2: The string to search for
> - * @len: the maximum number of characters to search
> + * @len2: the length of the string being searched
>   */
> -char *strnstr(const char *s1, const char *s2, size_t len)
> +void *memmem(const void *s1, size_t len1, const void *s2, size_t len2)
>  {