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From: Andrey Konovalov <andreyknvl@gmail.com>
Date: Fri, 16 Feb 2024 00:37:54 +0100
Message-ID: <CA+fCnZeo3dksyFgM5w=gz7Z_djG-ddesDQ4dfhqAwosNy5+1Hw@mail.gmail.com>
Subject: Re: [PATCH v2] kasan: Add documentation for CONFIG_KASAN_EXTRA_INFO
To: Juntong Deng <juntong.deng@outlook.com>
Cc: ryabinin.a.a@gmail.com, glider@google.com, dvyukov@google.com, 
	vincenzo.frascino@arm.com, corbet@lwn.net, kasan-dev@googlegroups.com, 
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
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On Thu, Feb 15, 2024 at 8:17=E2=80=AFPM Juntong Deng <juntong.deng@outlook.=
com> wrote:
>
> This patch adds CONFIG_KASAN_EXTRA_INFO introduction information to
> KASAN documentation.
>
> Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
> ---
> V1 -> V2: Fix run-on sentence.
>
>  Documentation/dev-tools/kasan.rst | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>
> diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/=
kasan.rst
> index a5a6dbe9029f..d7de44f5339d 100644
> --- a/Documentation/dev-tools/kasan.rst
> +++ b/Documentation/dev-tools/kasan.rst
> @@ -277,6 +277,27 @@ traces point to places in code that interacted with =
the object but that are not
>  directly present in the bad access stack trace. Currently, this includes
>  call_rcu() and workqueue queuing.
>
> +CONFIG_KASAN_EXTRA_INFO
> +~~~~~~~~~~~~~~~~~~~~~~~
> +
> +Enabling CONFIG_KASAN_EXTRA_INFO allows KASAN to record and report more
> +information. The extra information currently supported is the CPU number=
 and
> +timestamp at allocation and free. More information can help find the cau=
se of
> +the bug and correlate the error with other system events, at the cost of=
 using
> +extra memory to record more information (more cost details in the help t=
ext of
> +CONFIG_KASAN_EXTRA_INFO).
> +
> +Here is the report with CONFIG_KASAN_EXTRA_INFO enabled (only the
> +different parts are shown)::
> +
> +    =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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> +    ...
> +    Allocated by task 134 on cpu 5 at 229.133855s:
> +    ...
> +    Freed by task 136 on cpu 3 at 230.199335s:
> +    ...
> +    =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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> +
>  Implementation details
>  ----------------------
>
> --
> 2.39.2
>

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>