On Tue, 28 Sep 2021, Kees Cook wrote: > On Tue, Sep 28, 2021 at 08:31:13PM +0000, Qing Zhao wrote: > > Hi, > > > > This is the patch for the gcc12 changes per your request. > > > > Kees provided most of the wording. > > > > Please take a look and let’s know whether it’s good for commit? > > > > thanks. > > > > Qing > > > > ================================================ > > > > > > From: qing zhao <qing.z...@oracle.com> > > Date: Tue, 28 Sep 2021 12:01:42 -0700 > > Subject: [PATCH] gcc-12/changes.html: Uninitialized stack variables > > initialization update > > > > * htdocs/gcc-12/changes.html (Eliminating uninitialized variables): > > Item about the support for automatic static variable initialization. > > --- > > htdocs/gcc-12/changes.html | 19 +++++++++++++++++++ > > 1 file changed, 19 insertions(+) > > > > diff --git a/htdocs/gcc-12/changes.html b/htdocs/gcc-12/changes.html > > index 1f156a9..8e2979c 100644 > > --- a/htdocs/gcc-12/changes.html > > +++ b/htdocs/gcc-12/changes.html > > @@ -245,6 +245,25 @@ a work-in-progress.</p> > > <!-- .................................................................. --> > > <h2>Other significant improvements</h2> > > > > +<h3 id="uninitialized">Eliminating uninitialized variables</h3> > > + > > +<ul> > > + <li>GCC can now initialize all stack variables implicitly, including > > + padding. This is intended to eliminate all classes of uninitialized > > + stack variable flaws. Lack of explicit initialization will still > > + warn when <code>-Wuninitialized</code> is active. For best > > + debugging, use of the new command-line option > > + <code>-ftrivial-auto-var-init=pattern</code> can be used to fill > > + variables with a repeated 0xFE pattern, which tends to illuminate > > + many bugs (e.g. pointers receive invalid addresses, sizes and indices > > + are very large). For best production results, the new command-line > > + option <code>-ftrivial-auto-var-init=zero</code> can be used to > > + fill variables with 0x00, which tends to provide a safer state for > > + bugs (e.g. pointers are NULL, strings are NULL filled, and sizes > > Minor nit: I've always been corrected that "NULL" refers to a pointer, and > "NUL" refers to the "null character", so the latter use of NULL should be > "NUL": ... pointers are NULL, strings are NUL filled, and size ... > > I mix this up all the time, so apologies if that got introduced by me! > :)
Also things like 0xFE and NULL should be wrapped in <code></code>, otherwise it looks good to me. Thanks, Richard. > -Kees > > > + and indices are 0). > > + </li> > > +</ul> > > + > > <h3 id="debug">Debugging formats</h3> > > > > <ul> > > -- > > 1.9.1 > > > > > > -- Richard Biener <rguent...@suse.de> SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
