From: Nathan Chancellor <natechancellor@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
Alexander Potapenko <glider@google.com>,
Joe Perches <joe@perches.com>, Andy Whitcroft <apw@canonical.com>,
x86@kernel.org, drbd-dev@lists.linbit.com,
linux-block@vger.kernel.org, b43-dev@lists.infradead.org,
netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
linux-ide@vger.kernel.org, linux-clk@vger.kernel.org,
linux-spi@vger.kernel.org, linux-mm@kvack.org,
clang-built-linux@googlegroups.com
Subject: Re: [PATCH 00/10] Remove uninitialized_var() macro
Date: Wed, 3 Jun 2020 20:33:47 -0700 [thread overview]
Message-ID: <20200604033347.GA3962068@ubuntu-n2-xlarge-x86> (raw)
In-Reply-To: <20200603233203.1695403-1-keescook@chromium.org>
On Wed, Jun 03, 2020 at 04:31:53PM -0700, Kees Cook wrote:
> Using uninitialized_var() is dangerous as it papers over real bugs[1]
> (or can in the future), and suppresses unrelated compiler warnings
> (e.g. "unused variable"). If the compiler thinks it is uninitialized,
> either simply initialize the variable or make compiler changes.
>
> As recommended[2] by[3] Linus[4], remove the macro.
>
> Most of the 300 uses don't cause any warnings on gcc 9.3.0, so they're in
> a single treewide commit in this series. A few others needed to actually
> get cleaned up, and I broke those out into individual patches.
>
> -Kees
>
> [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
> [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
> [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
> [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/
>
> Kees Cook (10):
> x86/mm/numa: Remove uninitialized_var() usage
> drbd: Remove uninitialized_var() usage
> b43: Remove uninitialized_var() usage
> rtlwifi: rtl8192cu: Remove uninitialized_var() usage
> ide: Remove uninitialized_var() usage
> clk: st: Remove uninitialized_var() usage
> spi: davinci: Remove uninitialized_var() usage
> checkpatch: Remove awareness of uninitialized_var() macro
> treewide: Remove uninitialized_var() usage
> compiler: Remove uninitialized_var() macro
I applied all of these on top of cb8e59cc8720 and ran a variety of
builds with clang for arm32, arm64, mips, powerpc, s390, and x86_64 [1]
and only saw one warning pop up (which was about a variable being
unused, commented on patch 9 about it). No warnings about uninitialized
variables came up; clang's -Wuninitialized was not impacted by
78a5255ffb6a ("Stop the ad-hoc games with -Wno-maybe-initialized") so it
should have caught anything egregious.
[1]: https://github.com/nathanchance/llvm-kernel-testing
For the series, consider it:
Tested-by: Nathan Chancellor <natechancellor@gmail.com> [build]
next prev parent reply other threads:[~2020-06-04 3:33 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-03 23:31 [PATCH 00/10] Remove uninitialized_var() macro Kees Cook
2020-06-03 23:31 ` [PATCH 01/10] x86/mm/numa: Remove uninitialized_var() usage Kees Cook
2020-06-04 7:58 ` Thomas Gleixner
2020-06-04 11:41 ` Miguel Ojeda
2020-06-04 14:56 ` Kees Cook
2020-06-04 15:22 ` Miguel Ojeda
2020-06-04 14:34 ` Kees Cook
2020-06-04 21:39 ` Thomas Gleixner
2020-06-04 22:39 ` Kees Cook
2020-06-03 23:31 ` [PATCH 02/10] drbd: " Kees Cook
2020-06-04 19:56 ` Nick Desaulniers
2020-06-03 23:31 ` [PATCH 03/10] b43: " Kees Cook
2020-06-04 20:08 ` Nick Desaulniers
2020-06-04 20:18 ` Kees Cook
2020-06-04 20:25 ` Nick Desaulniers
2020-06-05 9:20 ` Kalle Valo
2020-06-03 23:31 ` [PATCH 04/10] rtlwifi: rtl8192cu: " Kees Cook
2020-06-04 20:16 ` Nick Desaulniers
2020-06-05 9:18 ` Kalle Valo
2020-06-03 23:31 ` [PATCH 05/10] ide: " Kees Cook
2020-06-04 19:29 ` Nick Desaulniers
2020-06-04 20:20 ` Kees Cook
2020-06-04 20:29 ` Nick Desaulniers
2020-06-15 19:32 ` Kees Cook
2020-06-04 20:58 ` Sedat Dilek
2020-06-03 23:31 ` [PATCH 06/10] clk: st: " Kees Cook
2020-06-04 4:38 ` Stephen Boyd
2020-06-03 23:32 ` [PATCH 07/10] spi: davinci: " Kees Cook
2020-06-04 19:40 ` Nick Desaulniers
2020-06-03 23:32 ` [PATCH 08/10] checkpatch: Remove awareness of uninitialized_var() macro Kees Cook
2020-06-04 0:02 ` Joe Perches
2020-06-04 1:40 ` Kees Cook
2020-06-04 1:47 ` Joe Perches
2020-06-04 2:44 ` Kees Cook
2020-06-04 2:53 ` Sedat Dilek
2020-06-04 3:46 ` Kees Cook
2020-06-03 23:32 ` [PATCH 09/10] treewide: Remove uninitialized_var() usage Kees Cook
2020-06-04 3:33 ` Nathan Chancellor
2020-06-04 4:02 ` Kees Cook
2020-06-04 10:45 ` Leon Romanovsky
2020-06-04 13:23 ` Jason Gunthorpe
2020-06-04 14:59 ` Kees Cook
2020-06-04 17:57 ` Jason Gunthorpe
2020-06-04 19:09 ` Geert Uytterhoeven
2020-06-05 9:25 ` Kalle Valo
2020-06-03 23:32 ` [PATCH 10/10] compiler: Remove uninitialized_var() macro Kees Cook
2020-06-04 0:00 ` Bart Van Assche
2020-06-04 0:50 ` Miguel Ojeda
2020-06-04 1:23 ` [PATCH 00/10] " Sedat Dilek
2020-06-04 1:44 ` Kees Cook
2020-06-04 1:46 ` Sedat Dilek
2020-06-04 3:33 ` Nathan Chancellor [this message]
2020-06-04 7:26 ` Sedat Dilek
2020-06-04 14:27 ` Kees Cook
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