Re: [PATCH v4 3/9] vsprintf: Do not check address of well-known strings

[Andy Shevchenko]

On Mon, 2018-04-09 at 14:19 +0200, Petr Mladek wrote:
> On Sat 2018-04-07 17:12:35, Andy Shevchenko wrote:
> > On Fri, 2018-04-06 at 11:15 +0200, Petr Mladek wrote:
> > > On Thu 2018-04-05 15:30:51, Rasmus Villemoes wrote:
> > > > On 2018-04-04 10:58, Petr Mladek wrote:

> > > > > 
> > > > Please leave string() alone, except for moving the < PAGE_SIZE
> > > > check
> > > > to
> > > > a new helper checked_string (feel free to find a better name),
> > > > and
> > > > use
> > > > checked_string for handling %s and possibly the few other cases
> > > > where
> > > > we're passing a user-supplied pointer. That avoids cluttering
> > > > the
> > > > entire
> > > > file with double-underscore calls, and e.g. in the %pO case,
> > > > it's
> > > > easier
> > > > to understand why one uses two different *string() helpers if
> > > > the
> > > > name
> > > > of one somehow conveys how it is different from the other.
> > > 
> > > I understand your reasoning. I thought about exactly this as well.
> > > My problem is that string() will then be unsafe. It might be
> > > dangerous
> > > when porting patches.
> > 
> > I agree with Rasmus, and your argument here from my point of view
> > kinda
> > weak. Are we really going to backport this patches? Why? We lived
> > w/o
> > them for a long time. What's changed now?
> 
> Someone might have out-of-tree patch that adds yet another format
> specifier. It might call string() that checks for (null) now but
> it it won't if we rename it as you suggest. People used to safe
> string() might miss this when the patch is send upstream for
> inclusion, ...

This is even weaker argument. Sorry, but I don't care about out-of-tree
core patches. If they have them, they are doing completely wrong, or the
patches are crappy.

-- 
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy