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Date:   Tue, 9 Jul 2019 07:40:50 -0600
From:   Jonathan Corbet <corbet@lwn.net>
To:     NitinGote <nitin.r.gote@intel.com>
Cc:     joe@perches.com, akpm@linux-foundation.org, apw@canonical.com,
        keescook@chromium.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] Added warnings in checkpatch.pl script to :
Message-ID: <20190709074050.289aab82@lwn.net>
In-Reply-To: <20190709122417.25778-1-nitin.r.gote@intel.com>
References: <20190709122417.25778-1-nitin.r.gote@intel.com>
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On Tue,  9 Jul 2019 17:54:17 +0530
NitinGote <nitin.r.gote@intel.com> wrote:

> From: Nitin Gote <nitin.r.gote@intel.com>

The patch needs a proper subject line.

> 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>
> ---
>  Change log:
>  v1->v2
>  - For string related apis, created different %deprecated_string_api
>    and these will get emitted at CHECK Level using command line option
>    -f/--file to avoid bad patched from novice script users.
> 
>  v2->v3
>  - Avoided use of $check in implementation.
>  - Incorporated trivial comments.
> 
>  Documentation/process/deprecated.rst |  6 +++---
>  scripts/checkpatch.pl                | 24 ++++++++++++++++++++++++
>  2 files changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/process/deprecated.rst b/Documentation/process/deprecated.rst
> index 49e0f64a3427..f564de3caf76 100644
> --- a/Documentation/process/deprecated.rst
> +++ b/Documentation/process/deprecated.rst
> @@ -93,9 +93,9 @@ will be NUL terminated. This can lead to various linear read overflows
>  and other misbehavior due to the missing termination. It also NUL-pads the
>  destination buffer if the source contents are shorter than the destination
>  buffer size, which may be a needless performance penalty for callers using
> -only NUL-terminated strings. The safe replacement is :c:func:`strscpy`.
> -(Users of :c:func:`strscpy` still needing NUL-padding will need an
> -explicit :c:func:`memset` added.)
> +only NUL-terminated strings. In this case, the safe replacement is
> +:c:func:`strscpy`. If, however, the destination buffer still needs
> +NUL-padding, the safe replacement is :c:func:`strscpy_pad`.

Please don't use :c:func: in anything new; just write that as strscpy()
(or whatever) and The Right Thing will happen.

(Maybe we need a checkpatch rule for that :)

Thanks,

jon