[PATCH v2 02/10] gcov: Replace strncmp with str_has_prefix

[PATCH v2 02/10] gcov: Replace strncmp with str_has_prefix

[Chuhong Yuan]

strncmp(str, const, len) is error-prone because len
is easy to have typo.
The example is the hard-coded len has counting error
or sizeof(const) forgets - 1.
So we prefer using newly introduced str_has_prefix
to substitute such strncmp.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
---
Changes in v2:
  - Revise the description.

 kernel/gcov/fs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c
index e5eb5ea7ea59..67296c1768b4 100644
--- a/kernel/gcov/fs.c
+++ b/kernel/gcov/fs.c
@@ -354,7 +354,7 @@ static char *get_link_target(const char *filename, const struct gcov_link *ext)
  */
 static const char *deskew(const char *basename)
 {
-	if (strncmp(basename, SKEW_PREFIX, sizeof(SKEW_PREFIX) - 1) == 0)
+	if (str_has_prefix(basename, SKEW_PREFIX))
 		return basename + sizeof(SKEW_PREFIX) - 1;
 	return basename;
 }
-- 
2.20.1

Re: [PATCH v2 02/10] gcov: Replace strncmp with str_has_prefix

[Peter Oberparleiter]

On 02.08.2019 03:46, Chuhong Yuan wrote:
> strncmp(str, const, len) is error-prone because len
> is easy to have typo.
> The example is the hard-coded len has counting error
> or sizeof(const) forgets - 1.
> So we prefer using newly introduced str_has_prefix
> to substitute such strncmp.
> 
> Signed-off-by: Chuhong Yuan <hslester96@gmail.com>

Looks sane!

Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>

> ---
> Changes in v2:
>   - Revise the description.
> 
>  kernel/gcov/fs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c
> index e5eb5ea7ea59..67296c1768b4 100644
> --- a/kernel/gcov/fs.c
> +++ b/kernel/gcov/fs.c
> @@ -354,7 +354,7 @@ static char *get_link_target(const char *filename, const struct gcov_link *ext)
>   */
>  static const char *deskew(const char *basename)
>  {
> -	if (strncmp(basename, SKEW_PREFIX, sizeof(SKEW_PREFIX) - 1) == 0)
> +	if (str_has_prefix(basename, SKEW_PREFIX))
>  		return basename + sizeof(SKEW_PREFIX) - 1;
>  	return basename;
>  }
> 


-- 
Peter Oberparleiter
Linux on Z Development - IBM Germany