From: Matthew Wilcox <willy@infradead.org>
To: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>,
Nitin Gote <nitin.r.gote@intel.com>,
akpm@linux-foundation.org, corbet@lwn.net, apw@canonical.com,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-hardening@lists.openwall.com,
Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Subject: Re: [RFC PATCH] string.h: Add stracpy/stracpy_pad (was: Re: [PATCH] checkpatch: Added warnings in favor of strscpy().)
Date: Mon, 22 Jul 2019 11:27:04 -0700 [thread overview]
Message-ID: <20190722182703.GE363@bombadil.infradead.org> (raw)
In-Reply-To: <2c959c56c23d0052e5c35ecfa2f6051b17fb2798.camel@perches.com>
On Mon, Jul 22, 2019 at 10:58:15AM -0700, Joe Perches wrote:
> On Mon, 2019-07-22 at 10:43 -0700, Joe Perches wrote:
> > On Mon, 2019-07-22 at 10:33 -0700, Kees Cook wrote:
> > > On Thu, Jul 04, 2019 at 05:15:57PM -0700, Joe Perches wrote:
> > > > On Thu, 2019-07-04 at 13:46 -0700, Joe Perches wrote:
> > > > > On Thu, 2019-07-04 at 11:24 +0530, Nitin Gote wrote:
> > > > > > Added warnings in checkpatch.pl script 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.
> > > >
> > > > []
> > > >
> > > > I sent a patch series for some strscpy/strlcpy misuses.
> > > >
> > > > How about adding a macro helper to avoid the misuses like:
> > > > ---
> > > > include/linux/string.h | 16 ++++++++++++++++
> > > > 1 file changed, 16 insertions(+)
> > > >
> > > > diff --git a/include/linux/string.h b/include/linux/string.h
> > > > index 4deb11f7976b..ef01bd6f19df 100644
> > > > --- a/include/linux/string.h
> > > > +++ b/include/linux/string.h
> > > > @@ -35,6 +35,22 @@ ssize_t strscpy(char *, const char *, size_t);
> > > > /* Wraps calls to strscpy()/memset(), no arch specific code required */
> > > > ssize_t strscpy_pad(char *dest, const char *src, size_t count);
> > > >
> > > > +#define stracpy(to, from) \
> > > > +({ \
> > > > + size_t size = ARRAY_SIZE(to); \
> > > > + BUILD_BUG_ON(!__same_type(typeof(*to), char)); \
> > > > + \
> > > > + strscpy(to, from, size); \
> > > > +})
Where does the 'a' in 'stracpy' come from? Googling around finds other
people using a function called stracpy, but it takes different arguments.
http://stracpy.blogspot.com/ takes a size argument, as does
https://docs.polserver.com/doxygen/html/d5/dce/stracpy_8cpp_source.html
The one in the 'Links' webbrowser (can't find a link to its source) seems
like a strdup clone.
next prev parent reply other threads:[~2019-07-22 18:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-04 5:54 [PATCH] checkpatch: Added warnings in favor of strscpy() Nitin Gote
2019-07-04 20:46 ` Joe Perches
2019-07-05 0:15 ` [RFC PATCH] string.h: Add stracpy/stracpy_pad (was: Re: [PATCH] checkpatch: Added warnings in favor of strscpy().) Joe Perches
2019-07-22 17:33 ` Kees Cook
2019-07-22 17:43 ` Joe Perches
2019-07-22 17:58 ` Joe Perches
2019-07-22 18:21 ` Kees Cook
2019-07-22 18:27 ` Matthew Wilcox [this message]
2019-07-22 18:35 ` Joe Perches
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