From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 559962500C5 for ; Thu, 3 Apr 2025 14:54:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743692061; cv=none; b=pk6XS1ouQBL6qmFyiOVXXLnLZIXv5L3CcnPf863RhPfJwKhB3mydWjdGTAJnPo4kJy0F+8yrfSWJ1dP14iSU3mAQnNBIIHrWAAT8//JTiK2zllJZyORnVN7DSooggKexLVjPBrUWAyp9mUerFefwpQjj7DO7kuPcE99V+gE0yOc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743692061; c=relaxed/simple; bh=bjHsE498GvFpBMUWpqL8nDc4Q6/iNiEANfOkEixkVxo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XAVgAnCfhEMu4ZMlcMt/P0KJcno1mEySF9BhG/vHIwbhQXrk8T73U5hdfgTHbEE8tmcsx0sOHwpHMAaUFpJoaPxtC9yRfSmIubhHsVaZLpr2YfvOwyxAfxhQgfxVHESfTdThSgn4ZCLfEodus5+8SprZq2ur63zgCo+2NB1mXDc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZCX1QEnU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ZCX1QEnU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 726ACC4CEE3; Thu, 3 Apr 2025 14:54:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1743692060; bh=bjHsE498GvFpBMUWpqL8nDc4Q6/iNiEANfOkEixkVxo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZCX1QEnU9mAvFEy3F+mJb6k+KBimzqehW4hswTg8+Zf4AUGz5osy/vggSw9fKlhpf rWspaH6NYbY7N9hSaxiy/zJoNKTciA8ejSDpI3y9JH5+la1K7MEb8/jFGqdenH9RA5 zftv2nY0cVOoeScrL+E38q5zq4XCVq84CXURjVqA= Date: Thu, 3 Apr 2025 15:52:53 +0100 From: Greg KH To: Kang Wenlin Cc: stable@vger.kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, ebiederm@xmission.com, keescook@chromium.org, akpm@linux-foundation.org Subject: Re: [PATCH 6.6.y 0/6] Backported patches to fix selftest tpdir2 Message-ID: <2025040344-coma-strict-4e8f@gregkh> References: <20250402082656.4177277-1-wenlin.kang@windriver.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250402082656.4177277-1-wenlin.kang@windriver.com> On Wed, Apr 02, 2025 at 04:26:50PM +0800, Kang Wenlin wrote: > From: Wenlin Kang > > The selftest tpdir2 terminated with a 'Segmentation fault' during loading. > > root@localhost:~# cd linux-kenel/tools/testing/selftests/arm64/abi && make > root@localhost:~/linux-kernel/tools/testing/selftests/arm64/abi# ./tpidr2 > Segmentation fault > > The cause of this is the __arch_clear_user() failure. > > load_elf_binary() [fs/binfmt_elf.c] > -> if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bes))) > -> padzero() > -> clear_user() [arch/arm64/include/asm/uaccess.h] > -> __arch_clear_user() [arch/arm64/lib/clear_user.S] > > For more details, please see: > https://lore.kernel.org/lkml/1d0342f3-0474-482b-b6db-81ca7820a462@t-8ch.de/T/ This is just a userspace issue (i.e. don't do that, and if you do want to do that, use a new kernel!) Why do these changes need to be backported, do you have real users that are crashing in this way to require these changes? thanks, greg k-h