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From: Andy Shevchenko <andy.shevchenko@gmail.com>
Date: Tue, 30 Jan 2024 01:30:47 +0200
Message-ID: <CAHp75Ve=bnGQR=mf2B-uPKjhwcOhBr6O=7Q-wm5AWSShOg+urQ@mail.gmail.com>
Subject: Re: [RFC] string: Allow 2-argument strscpy()
To: Kees Cook <keescook@chromium.org>
Cc: Justin Stitt <justinstitt@google.com>, Andy Shevchenko <andy@kernel.org>, 
	Rasmus Villemoes <linux@rasmusvillemoes.dk>, linux-hardening@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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On Tue, Jan 30, 2024 at 1:27=E2=80=AFAM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Tue, Jan 30, 2024 at 12:03=E2=80=AFAM Kees Cook <keescook@chromium.org=
> wrote:
> > On Mon, Jan 29, 2024 at 09:55:25PM +0000, Justin Stitt wrote:
> > > On Mon, Jan 29, 2024 at 12:29:04PM -0800, Kees Cook wrote:

..

> > > BTW, this hack for function overloading is insane. Never really looke=
d into
> > > it before.
> >
> > It very much is. :P Hence the RFC nature of this patch. I don't think w=
e
> > any any other API in the kernel that does this (though there are plenty
> > of wild macro wrappers to do similar tricks, like the syscall wrappers)=
.
>
> PCI has a couple of such.
>
> > > I like this, though, should you include documentation changes/additio=
ns?
> >
> > Yeah, though I'm not sure how to do this -- kerndoc expects a fixed
> > number of arguments. :P Maybe I can just do something like add
> > "optional" to @size:
>
> Use ... See again PCI header (pci.h). One of the macros there has a
> valid kernel-doc.
>
> >  * strscpy - Copy a C-string into a sized buffer
> >  * @p: Where to copy the string to
> >  * @q: Where to copy the string from
> >  * @size: Size of destination buffer (optional)

FWIW,
https://elixir.bootlin.com/linux/latest/source/include/linux/pci.h#L1517


--=20
With Best Regards,
Andy Shevchenko