[PATCH v1 1/1] string: Group str_has_prefix() and strstarts()

[PATCH v1 1/1] string: Group str_has_prefix() and strstarts()

[Andy Shevchenko]

The two str_has_prefix() and strstarts() are about the same
with a slight difference on what they return. Group them in
the header.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 include/linux/string.h | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/include/linux/string.h b/include/linux/string.h
index 01621ad0f598..fdd3442c6bcb 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -345,16 +345,6 @@ extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
 
 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out);
 
-/**
- * strstarts - does @str start with @prefix?
- * @str: string to examine
- * @prefix: prefix to look for.
- */
-static inline bool strstarts(const char *str, const char *prefix)
-{
-	return strncmp(str, prefix, strlen(prefix)) == 0;
-}
-
 size_t memweight(const void *ptr, size_t bytes);
 
 /**
@@ -562,4 +552,14 @@ static __always_inline size_t str_has_prefix(const char *str, const char *prefix
 	return strncmp(str, prefix, len) == 0 ? len : 0;
 }
 
+/**
+ * strstarts - does @str start with @prefix?
+ * @str: string to examine
+ * @prefix: prefix to look for.
+ */
+static inline bool strstarts(const char *str, const char *prefix)
+{
+	return strncmp(str, prefix, strlen(prefix)) == 0;
+}
+
 #endif /* _LINUX_STRING_H_ */
-- 
2.47.2

Re: [PATCH v1 1/1] string: Group str_has_prefix() and strstarts()

[Kees Cook]

On Fri, Jul 11, 2025 at 11:55:14AM +0300, Andy Shevchenko wrote:
> The two str_has_prefix() and strstarts() are about the same
> with a slight difference on what they return. Group them in
> the header.

It seems more like strstarts should just be a macro around
str_has_prefix() != 0?

-Kees

> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  include/linux/string.h | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/include/linux/string.h b/include/linux/string.h
> index 01621ad0f598..fdd3442c6bcb 100644
> --- a/include/linux/string.h
> +++ b/include/linux/string.h
> @@ -345,16 +345,6 @@ extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
>  
>  int ptr_to_hashval(const void *ptr, unsigned long *hashval_out);
>  
> -/**
> - * strstarts - does @str start with @prefix?
> - * @str: string to examine
> - * @prefix: prefix to look for.
> - */
> -static inline bool strstarts(const char *str, const char *prefix)
> -{
> -	return strncmp(str, prefix, strlen(prefix)) == 0;
> -}
> -
>  size_t memweight(const void *ptr, size_t bytes);
>  
>  /**
> @@ -562,4 +552,14 @@ static __always_inline size_t str_has_prefix(const char *str, const char *prefix
>  	return strncmp(str, prefix, len) == 0 ? len : 0;
>  }
>  
> +/**
> + * strstarts - does @str start with @prefix?
> + * @str: string to examine
> + * @prefix: prefix to look for.
> + */
> +static inline bool strstarts(const char *str, const char *prefix)
> +{
> +	return strncmp(str, prefix, strlen(prefix)) == 0;
> +}
> +
>  #endif /* _LINUX_STRING_H_ */
> -- 
> 2.47.2
> 

-- 
Kees Cook

Re: [PATCH v1 1/1] string: Group str_has_prefix() and strstarts()

[Andy Shevchenko]

On Tue, Jul 15, 2025 at 8:24 AM Kees Cook <kees@kernel.org> wrote:
>
> On Fri, Jul 11, 2025 at 11:55:14AM +0300, Andy Shevchenko wrote:
> > The two str_has_prefix() and strstarts() are about the same
> > with a slight difference on what they return. Group them in
> > the header.
>
> It seems more like strstarts should just be a macro around
> str_has_prefix() != 0?

This change is only about grouping, but if you think it worth
modifying, I am not going to object. Just that I am about to have my
vacation and I leave this as is for now. Up to you how to proceed.


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] string: Group str_has_prefix() and strstarts()

[Andy Shevchenko]

On Tue, Jul 15, 2025 at 9:52 AM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Tue, Jul 15, 2025 at 8:24 AM Kees Cook <kees@kernel.org> wrote:
> >
> > On Fri, Jul 11, 2025 at 11:55:14AM +0300, Andy Shevchenko wrote:
> > > The two str_has_prefix() and strstarts() are about the same
> > > with a slight difference on what they return. Group them in
> > > the header.
> >
> > It seems more like strstarts should just be a macro around
> > str_has_prefix() != 0?

Actually this won't work for len == 0, would it?

> This change is only about grouping, but if you think it worth
> modifying, I am not going to object. Just that I am about to have my
> vacation and I leave this as is for now. Up to you how to proceed.


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] string: Group str_has_prefix() and strstarts()

[Kees Cook]

On Fri, 11 Jul 2025 11:55:14 +0300, Andy Shevchenko wrote:
> The two str_has_prefix() and strstarts() are about the same
> with a slight difference on what they return. Group them in
> the header.
> 
> 

Applied to for-next/hardening, thanks!

[1/1] string: Group str_has_prefix() and strstarts()
      https://git.kernel.org/kees/c/2d8ae9a4f1bc

Take care,

-- 
Kees Cook