[PATCH v2 3/3] boot: android: rework bootargs concatenation

[Mattijs Korpershoek]

Hi Nicolas,

Thank you for the patch.

On mar., déc. 17, 2024 at 14:29, Nicolas Belin <nbelin at baylibre.com> wrote:

> Rework the bootargs concatenation allocating more accurately
> the length that is needed.
> Do not forget an extra byte for the null termination byte as,
> in some cases, the allocation was 1 byte short.
>
> Fixes: 86f4695b ("image: Fix Android boot image support")
> Signed-off-by: Nicolas Belin <nbelin at baylibre.com>

Reviewed-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>

> ---
>  boot/image-android.c | 29 ++++++++++++++++-------------
>  1 file changed, 16 insertions(+), 13 deletions(-)
>
> diff --git a/boot/image-android.c b/boot/image-android.c
> index 362a5c7435a3a8bcf7b674b96e31069a91a892b5..61ac312db7ad9ba6c55727469dd4ded61824c67c 100644
> --- a/boot/image-android.c
> +++ b/boot/image-android.c
> @@ -287,37 +287,40 @@ int android_image_get_kernel(const void *hdr,
>  	       kernel_addr, DIV_ROUND_UP(img_data.kernel_size, 1024));
>  
>  	int len = 0;
> +	char *bootargs = env_get("bootargs");
> +
> +	if (bootargs)
> +		len += strlen(bootargs);
> +
>  	if (*img_data.kcmdline) {
>  		printf("Kernel command line: %s\n", img_data.kcmdline);
> -		len += strlen(img_data.kcmdline);
> +		len += strlen(img_data.kcmdline) + (len ? 1 : 0); /* +1 for extra space */
>  	}
>  
>  	if (*img_data.kcmdline_extra) {
>  		printf("Kernel extra command line: %s\n", img_data.kcmdline_extra);
> -		len += strlen(img_data.kcmdline_extra);
> +		len += strlen(img_data.kcmdline_extra) + (len ? 1 : 0); /* +1 for extra space */
>  	}
>  
> -	char *bootargs = env_get("bootargs");
> -	if (bootargs)
> -		len += strlen(bootargs);
> -
> -	char *newbootargs = malloc(len + 2);
> +	char *newbootargs = malloc(len + 1); /* +1 for the '\0' */
>  	if (!newbootargs) {
>  		puts("Error: malloc in android_image_get_kernel failed!\n");
>  		return -ENOMEM;
>  	}
> -	*newbootargs = '\0';
> +	*newbootargs = '\0'; /* set to Null in case no components below are present */
>  
> -	if (bootargs) {
> +	if (bootargs)
>  		strcpy(newbootargs, bootargs);
> -		strcat(newbootargs, " ");
> -	}
>  
> -	if (*img_data.kcmdline)
> +	if (*img_data.kcmdline) {
> +		if (*newbootargs) /* If there is something in newbootargs, a space is needed */
> +			strcat(newbootargs, " ");
>  		strcat(newbootargs, img_data.kcmdline);
> +	}
>  
>  	if (*img_data.kcmdline_extra) {
> -		strcat(newbootargs, " ");
> +		if (*newbootargs) /* If there is something in newbootargs, a space is needed */
> +			strcat(newbootargs, " ");
>  		strcat(newbootargs, img_data.kcmdline_extra);
>  	}
>  
>
> -- 
> 2.34.1