[PATCH 1/6] lib/cmdline.c: Add backslash support to kernel commandline parsing.

[Michal Suchánek]

On Fri, 15 Sep 2017 18:14:09 +0100
Al Viro <viro at ZenIV.linux.org.uk> wrote:

> On Fri, Sep 15, 2017 at 07:02:46PM +0200, Michal Suchanek wrote:
> 
> >  	for (i = 0; args[i]; i++) {
> > -		if (isspace(args[i]) && !in_quote)
> > +		if (isspace(args[i]) && !in_quote && !backslash)
> >  			break;
> > -		if (equals == 0) {
> > -			if (args[i] == '=')
> > -				equals = i;
> > +
> > +		if ((equals == 0) && (args[i] == '='))
> > +			equals = i;
> > +
> > +		if (!backslash) {
> > +			if ((args[i] == '"') || (args[i] == '\\'))
> > {
> > +				if (args[i] == '"')
> > +					in_quote = !in_quote;
> > +				if (args[i] == '\\')
> > +					backslash = 1;
> > +
> > +				memmove(args + 1, args, i);
> > +				args++;
> > +				i--;
> > +			}
> > +		} else {
> > +			backslash = 0;
> >  		}
> > -		if (args[i] == '"')
> > -			in_quote = !in_quote;
> >  	}  
> 
> ... and that makes for Unidiomatic Work With Strings Award for this
> September. Using memmove() for string rewrite is almost always bad
> taste; in this case it's also (as usual) broken.

Care to share how it is broken?

Thanks

Michal