Re: [PATCH v2 4/7] cmdline: Add capability to prepend the command line

[Will Deacon <will@kernel.org>]

On Tue, Mar 02, 2021 at 05:25:20PM +0000, Christophe Leroy wrote:
> This patchs adds an option of prepend a text to the command
> line instead of appending it.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  include/linux/cmdline.h | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/cmdline.h b/include/linux/cmdline.h
> index ae3610bb0ee2..144346051e01 100644
> --- a/include/linux/cmdline.h
> +++ b/include/linux/cmdline.h
> @@ -31,7 +31,7 @@ static __always_inline size_t cmdline_strlcat(char *dest, const char *src, size_
>  }
>  
>  /*
> - * This function will append a builtin command line to the command
> + * This function will append or prepend a builtin command line to the command
>   * line provided by the bootloader. Kconfig options can be used to alter
>   * the behavior of this builtin command line.
>   * @dest: The destination of the final appended/prepended string.
> @@ -50,6 +50,9 @@ static __always_inline void cmdline_build(char *dest, const char *src, size_t le
>  		cmdline_strlcat(dest, CONFIG_CMDLINE, length);
>  		return;
>  	}
> +
> +	if (IS_ENABLED(CONFIG_CMDLINE_PREPEND) && sizeof(CONFIG_CMDLINE) > 1)
> +		cmdline_strlcat(dest, CONFIG_CMDLINE " ", length);

Same comment as the other patch: I don't think we need to worry about the
sizeof() here.

Will