Re: [PATCH 1/2] dyndbg: dont panic over bad input

[Greg KH]

On Mon, Sep 21, 2020 at 01:04:32PM -0600, Jim Cromie wrote:
> This BUG_ON, from 2009, caught the impossible case of a word-char both
> starting and ending a string (loosely speaking).  A bad (reverted)
> patch finally hit this case, but even "impossibly bad input" is no
> reason to panic the kernel.  Instead pr_err and return -EINVAL.
> 
> Reported-by: Petr Mladek <pmladek@xxxxxxxx>
> Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
> ---
>  lib/dynamic_debug.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
> index 2d4dfd44b0fa5..90ddf07ce34fe 100644
> --- a/lib/dynamic_debug.c
> +++ b/lib/dynamic_debug.c
> @@ -259,7 +259,10 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
>  		} else {
>  			for (end = buf; *end && !isspace(*end); end++)
>  				;
> -			BUG_ON(end == buf);
> +			if (end == buf) {
> +				pr_err("expected non-empty bareword");

Need a "\n" here, right?

thanks,

greg k-h