[PATCH] cpu: maxfreq: fix build errors on arm32 + gcc10

[Colin Ian King]

On 08/01/2021 14:38, Alex Hung wrote:
> The below errors were observed on armhf with Groovy and Hirsute
> cpu/maxfreq/maxfreq.c:28:23: error: ‘%s’ directive output may be
> truncated writing between 3 and 2147483645 bytes into a region of
> size 4072 [-Werror=format-truncation=]
>    28 | #define CPU_FREQ_PATH "/sys/devices/system/cpu"
>       |                       ^~~~~~~~~~~~~~~~~~~~~~~~~
> cpu/maxfreq/maxfreq.c:143:4: note: in expansion of macro ‘CPU_FREQ_PATH’
>   143 |    CPU_FREQ_PATH "/%s/cpufreq/scaling_available_frequencies",
>       |    ^~~~~~~~~~~~~
> cpu/maxfreq/maxfreq.c:143:20: note: format string is defined here
>   143 |    CPU_FREQ_PATH "/%s/cpufreq/scaling_available_frequencies",
>       |                    ^~
> 
> Signed-off-by: Alex Hung <alex.hung at canonical.com>
> ---
>  src/cpu/maxfreq/maxfreq.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/src/cpu/maxfreq/maxfreq.c b/src/cpu/maxfreq/maxfreq.c
> index 168a69e8..b0ce0fe9 100644
> --- a/src/cpu/maxfreq/maxfreq.c
> +++ b/src/cpu/maxfreq/maxfreq.c
> @@ -139,9 +139,9 @@ static int maxfreq_test1(fwts_framework *fw)
>  		    strlen(entry->d_name) < 3)
>  			continue;
>  
> -		snprintf(path, sizeof(path),
> -			CPU_FREQ_PATH "/%s/cpufreq/scaling_available_frequencies",
> -			entry->d_name);
> +		strncpy(path, CPU_FREQ_PATH, strlen(CPU_FREQ_PATH) + 1);

I'd prefer strlcpy as it's safer.

> +		snprintf(path + strlen(CPU_FREQ_PATH), sizeof(path) - strlen(CPU_FREQ_PATH),
> +			"/%s/cpufreq/scaling_available_frequencies", entry->d_name);
>  
>  		if ((data = fwts_get(path)) == NULL)
>  			continue;
> @@ -214,4 +214,3 @@ static fwts_framework_ops maxfreq_ops = {
>  };
>  
>  FWTS_REGISTER("maxfreq", &maxfreq_ops, FWTS_TEST_ANYTIME, FWTS_FLAG_BATCH)
> -
>