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

From: Michal SuchÃnek
Date: Fri Sep 15 2017 - 13:29:04 EST


On Fri, 15 Sep 2017 18:14:09 +0100
Al Viro <viro@xxxxxxxxxxxxxxxxxx> 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