linux-kernel - Re: [PATCH v6 6/44] kmsan: add ReST documentation

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Date:   Mon, 7 Nov 2022 15:24:50 +0100
From:   Alexander Potapenko <glider@...gle.com>
To:     Bagas Sanjaya <bagasdotme@...il.com>
Cc:     Alexander Viro <viro@...iv.linux.org.uk>,
        Alexei Starovoitov <ast@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Andrey Konovalov <andreyknvl@...gle.com>,
        Andy Lutomirski <luto@...nel.org>,
        Arnd Bergmann <arnd@...db.de>, Borislav Petkov <bp@...en8.de>,
        Christoph Hellwig <hch@....de>,
        Christoph Lameter <cl@...ux.com>,
        David Rientjes <rientjes@...gle.com>,
        Dmitry Vyukov <dvyukov@...gle.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Ilya Leoshkevich <iii@...ux.ibm.com>,
        Ingo Molnar <mingo@...hat.com>, Jens Axboe <axboe@...nel.dk>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Kees Cook <keescook@...omium.org>,
        Marco Elver <elver@...gle.com>,
        Mark Rutland <mark.rutland@....com>,
        Matthew Wilcox <willy@...radead.org>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Pekka Enberg <penberg@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Petr Mladek <pmladek@...e.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Vegard Nossum <vegard.nossum@...cle.com>,
        Vlastimil Babka <vbabka@...e.cz>, kasan-dev@...glegroups.com,
        linux-mm@...ck.org, linux-arch@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org
Subject: Re: [PATCH v6 6/44] kmsan: add ReST documentation

On Tue, Sep 6, 2022 at 5:10 AM Bagas Sanjaya <bagasdotme@...il.com> wrote:
>

Uh-oh, somehow missed this letter during the review process.

> > +  CPU: 0 PID: 6731 Comm: kunit_try_catch Tainted: G    B       E     5.16.0-rc3+ #104
> > +  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
> > +  =====================================================
>
> Are these table markers in the code block above part of kmsan output?

Correct.

>
> > +A use of uninitialized value ``v`` is reported by KMSAN in the following cases:
> > + - in a condition, e.g. ``if (v) { ... }``;
> > + - in an indexing or pointer dereferencing, e.g. ``array[v]`` or ``*v``;
> > + - when it is copied to userspace or hardware, e.g. ``copy_to_user(..., &v, ...)``;
> > + - when it is passed as an argument to a function, and
> > +   ``CONFIG_KMSAN_CHECK_PARAM_RETVAL`` is enabled (see below).
>
> The sentence before the list above is rendered as definition list term
> instead, so I add the blank line separator:
>
> ---- >8 ----
>
> diff --git a/Documentation/dev-tools/kmsan.rst b/Documentation/dev-tools/kmsan.rst
> index 2a53a801198cbf..55fa82212eb255 100644
> --- a/Documentation/dev-tools/kmsan.rst
> +++ b/Documentation/dev-tools/kmsan.rst
> @@ -67,6 +67,7 @@ uninitialized in the local variable, as well as the stack where the value was
>  copied to another memory location before use.
>
>  A use of uninitialized value ``v`` is reported by KMSAN in the following cases:
> +
>   - in a condition, e.g. ``if (v) { ... }``;
>   - in an indexing or pointer dereferencing, e.g. ``array[v]`` or ``*v``;
>   - when it is copied to userspace or hardware, e.g. ``copy_to_user(..., &v, ...)``;

Nice catch, thank you! Sent a patch to fix this.


-- 
Alexander Potapenko
Software Engineer

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