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From:   Alexander Potapenko <glider@google.com>
Date:   Mon, 7 Nov 2022 15:24:50 +0100
Message-ID: <CAG_fn=VXR0FGoJZ5BonxiFd7Wr3LX1hfF7PRRfm1=26B5v7vMA@mail.gmail.com>
Subject: Re: [PATCH v6 6/44] kmsan: add ReST documentation
To:     Bagas Sanjaya <bagasdotme@gmail.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Alexei Starovoitov <ast@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andrey Konovalov <andreyknvl@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@alien8.de>,
        Christoph Hellwig <hch@lst.de>,
        Christoph Lameter <cl@linux.com>,
        David Rientjes <rientjes@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Eric Dumazet <edumazet@google.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Ilya Leoshkevich <iii@linux.ibm.com>,
        Ingo Molnar <mingo@redhat.com>, Jens Axboe <axboe@kernel.dk>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Kees Cook <keescook@chromium.org>,
        Marco Elver <elver@google.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Matthew Wilcox <willy@infradead.org>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Pekka Enberg <penberg@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Petr Mladek <pmladek@suse.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Vegard Nossum <vegard.nossum@oracle.com>,
        Vlastimil Babka <vbabka@suse.cz>, kasan-dev@googlegroups.com,
        linux-mm@kvack.org, linux-arch@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org
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On Tue, Sep 6, 2022 at 5:10 AM Bagas Sanjaya <bagasdotme@gmail.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
> > +  =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
>
> 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 followi=
ng 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 sta=
ck 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.


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Alexander Potapenko
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