Re: [PATCH -next] printk: Export match_devname_and_update_preferred_console()

[Tony Lindgren]

On Mon, Sep 09, 2024 at 03:56:52PM +0800, Yu Liao wrote:
> When building serial_base as a module, modpost fails with the following
> error message:
> 
>   ERROR: modpost: "match_devname_and_update_preferred_console"
>   [drivers/tty/serial/serial_base.ko] undefined!
> 
> Export the symbol to allow using it from modules.

I think the issue is with CONFIG_PRINTK is no set, and serial drivers
select SERIAL_CORE_CONSOLE? And when serial_base is a module, there is
no kernel console.

I replied earlier today to the lkp error report along those lines, but
please let me know if there is more to the issue than that.

Regards,

Tony

> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202409071312.qlwtTOS1-lkp@xxxxxxxxx/
> Fixes: 12c91cec3155 ("serial: core: Add serial_base_match_and_update_preferred_console()")
> Signed-off-by: Yu Liao <liaoyu15@xxxxxxxxxx>
> ---
>  kernel/printk/printk.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index c22b07049c38..6ff8d47e145f 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -2620,6 +2620,7 @@ int match_devname_and_update_preferred_console(const char *devname,
>  
>  	return -ENOENT;
>  }
> +EXPORT_SYMBOL_GPL(match_devname_and_update_preferred_console);
>  
>  bool console_suspend_enabled = true;
>  EXPORT_SYMBOL(console_suspend_enabled);
> -- 
> 2.33.0
>