Re: [Intel-gfx] [PATCH i-g-t 2/3] Remove extra '\0' in strncpy in igt_save_module_param

2018-06-04 Thread Arkadiusz Hiler 
Title is slightly missleading. We don't remove extra NULL characer from
anywhere. We just account for it by subtracting 1 from the destination
buffer size.

So maybe "Account for NULL character when using strncpy"?

On Tue, May 29, 2018 at 09:46:55PM -0300, Rodrigo Siqueira wrote:
> This patch fix the following gcc warning:
> 
> warning: ‘strncpy’ specified bound 32 equals destination size
> [-Wstringop-truncation]
>   strncpy(data->name, name, PARAM_NAME_MAX_SZ);
> 
> This error happens due to the '\0' character appended by strncpy. Notice
> that reduces by one in the total of bytes to be copied, in this case, is
> harmless because the strings received in the parameter already have
> '\0'.
> 
> Signed-off-by: Rodrigo Siqueira 
> ---
>  lib/igt_aux.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/igt_aux.c b/lib/igt_aux.c
> index 5dd2761e..06f586d6 100644
> --- a/lib/igt_aux.c
> +++ b/lib/igt_aux.c
> @@ -1240,7 +1240,7 @@ static void igt_save_module_param(const char *name, 
> const char *file_path)
>   data = calloc(1, sizeof (*data));
>   igt_assert(data);
>  
> - strncpy(data->name, name, PARAM_NAME_MAX_SZ);
> + strncpy(data->name, name, PARAM_NAME_MAX_SZ - 1); // -1 because of '\0'

I am not necessary sure that the comment is needed, as "buflen - 1" is
quite typical.

-- 
Cheers,
Arek
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[Intel-gfx] [PATCH i-g-t 2/3] Remove extra '\0' in strncpy in igt_save_module_param

2018-05-29 Thread Rodrigo Siqueira 
This patch fix the following gcc warning:

warning: ‘strncpy’ specified bound 32 equals destination size
[-Wstringop-truncation]
  strncpy(data->name, name, PARAM_NAME_MAX_SZ);

This error happens due to the '\0' character appended by strncpy. Notice
that reduces by one in the total of bytes to be copied, in this case, is
harmless because the strings received in the parameter already have
'\0'.

Signed-off-by: Rodrigo Siqueira 
---
 lib/igt_aux.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/igt_aux.c b/lib/igt_aux.c
index 5dd2761e..06f586d6 100644
--- a/lib/igt_aux.c
+++ b/lib/igt_aux.c
@@ -1240,7 +1240,7 @@ static void igt_save_module_param(const char *name, const 
char *file_path)
data = calloc(1, sizeof (*data));
igt_assert(data);
 
-   strncpy(data->name, name, PARAM_NAME_MAX_SZ);
+   strncpy(data->name, name, PARAM_NAME_MAX_SZ - 1); // -1 because of '\0'
 
fd = open(file_path, O_RDONLY);
igt_assert(fd >= 0);
-- 
2.17.0

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