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Date: Mon, 6 May 2024 10:09:49 -0700
From: Kees Cook <keescook@chromium.org>
To: John Hubbard <jhubbard@nvidia.com>
Cc: Shuah Khan <shuah@kernel.org>, Eric Biederman <ebiederm@xmission.com>,
	Muhammad Usama Anjum <usama.anjum@collabora.com>,
	Mark Brown <broonie@kernel.org>, linux-mm@kvack.org,
	Valentin Obst <kernel@valentinobst.de>,
	linux-kselftest@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>, llvm@lists.linux.dev
Subject: Re: [PATCH] selftests/exec: build with -fPIE instead of -pie, to
 make clang happy
Message-ID: <202405061007.F1A46E89@keescook>
References: <20240504022301.35250-1-jhubbard@nvidia.com>
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In-Reply-To: <20240504022301.35250-1-jhubbard@nvidia.com>

On Fri, May 03, 2024 at 07:23:01PM -0700, John Hubbard wrote:
> clang doesn't deal well with "-pie -static": it warns that -pie is an
> unused option here. Changing to "-fPIE -static" solves this problem for
> clang, while keeping the gcc results identical.
> 
> The problem is visible when building via:
> 
>     make LLVM=1 -C tools/testing/selftests
> 
> Again: gcc 13 produces identical binaries for all of these programs,
> both before and after this commit (using "-pie"), and after (using
> "-fPIE").
> 
> Also, the runtime results are the same for both clang and gcc builds.

Thanks for this! It got solved differently here:
https://lkml.kernel.org/r/20240416152831.3199999-1-usama.anjum@collabora.com

Does that work for you as well?

-Kees

-- 
Kees Cook