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Message-ID: <28404b52d58efa0a3e85ce05ce0b210049ed6050.camel@perches.com>
Subject: Re: [PATCH v5] Documentation/checkpatch: Prefer strscpy/strscpy_pad
 over strcpy/strlcpy/strncpy
From: Joe Perches <joe@perches.com>
To: Kees Cook <keescook@chromium.org>, NitinGote <nitin.r.gote@intel.com>
Cc: corbet@lwn.net, akpm@linux-foundation.org, apw@canonical.com, 
	linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com
Date: Mon, 22 Jul 2019 10:40:58 -0700
In-Reply-To: <201907221029.B0CBED4F@keescook>
References: <20190717043005.19627-1-nitin.r.gote@intel.com>
	 <201907221029.B0CBED4F@keescook>
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On Mon, 2019-07-22 at 10:30 -0700, Kees Cook wrote:
> On Wed, Jul 17, 2019 at 10:00:05AM +0530, NitinGote wrote:
> > From: Nitin Gote <nitin.r.gote@intel.com>
> > 
> > Added check in checkpatch.pl to
> > 1. Deprecate strcpy() in favor of strscpy().
> > 2. Deprecate strlcpy() in favor of strscpy().
> > 3. Deprecate strncpy() in favor of strscpy() or strscpy_pad().
> > 
> > Updated strncpy() section in Documentation/process/deprecated.rst
> > to cover strscpy_pad() case.
> > 
> > Signed-off-by: Nitin Gote <nitin.r.gote@intel.com>
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> 
> Joe, does this address your checkpatch concerns?

Well, kinda.

strscpy_pad isn't used anywhere in the kernel.

And

+        "strncpy"				=> "strscpy, strscpy_pad or for non-NUL-terminated strings, strncpy() can still be used, but destinations should be marked with __nonstring",

is a bit verbose.  This could be simply:

+        "strncpy" => "strscpy - for non-NUL-terminated uses, strncpy() dst should be __nonstring",

And I still prefer adding stracpy as it
reduces code verbosity and eliminates defects.