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Date: Sun, 24 Mar 2024 14:22:31 +0100
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Subject: Re: [v2] ice: Fix freeing uninitialized pointers
To: Dan Carpenter <dan.carpenter@linaro.org>,
 kernel-janitors@vger.kernel.org, netdev@vger.kernel.org,
 intel-wired-lan@lists.osuosl.org, smatch@vger.kernel.org
Cc: LKML <linux-kernel@vger.kernel.org>,
 Alexander Lobakin <aleksander.lobakin@intel.com>,
 Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
 David Laight <David.Laight@aculab.com>, "David S. Miller"
 <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>,
 Jakub Kicinski <kuba@kernel.org>,
 Jesse Brandeburg <jesse.brandeburg@intel.com>, Jiri Pirko
 <jiri@resnulli.us>, Jonathan Cameron <jic23@kernel.org>,
 Julia Lawall <julia.lawall@inria.fr>, Kees Cook <keescook@chromium.org>,
 Lukasz Czapnik <lukasz.czapnik@intel.com>, Paolo Abeni <pabeni@redhat.com>,
 Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com>,
 Dan Williams <dan.j.williams@intel.com>,
 Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
 Przemek Kitszel <przemyslaw.kitszel@intel.com>,
 Tony Nguyen <anthony.l.nguyen@intel.com>
References: <0efe132b-b343-4438-bb00-5a4b82722ed3@moroto.mountain>
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 <f292facc-8a22-42e1-9a41-5ec8bd665cb7@moroto.mountain>
Content-Language: en-GB
From: Markus Elfring <Markus.Elfring@web.de>
In-Reply-To: <f292facc-8a22-42e1-9a41-5ec8bd665cb7@moroto.mountain>
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>>> Automatically cleaned up pointers need to be initialized before exitin=
g
>>> their scope.  In this case, they need to be initialized to NULL before
>>> any return statement.
>>
>> * May we expect that compilers should report that affected variables
>>   were only declared here instead of appropriately defined
>>   (despite of attempts for scope-based resource management)?
>>
>
> We disabled GCC's check for uninitialized variables a long time ago
> because it had too many false positives.

Can further case distinctions (and compilation parameters) become more hel=
pful
according to the discussed handling of the attribute =E2=80=9C__cleanup=E2=
=80=9D (or =E2=80=9C__free=E2=80=9D)?


>> * Did you extend detection support in the source code analysis tool =E2=
=80=9CSmatch=E2=80=9D
>>   for a questionable implementation detail?
>
> Yes.  Smatch detects this as an uninitialized variable.

Does the corresponding warning indicate requirements for scope-based resou=
rce management?

Regards,
Markus