From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 76E3F2BE7BE; Mon, 20 Jul 2026 09:30:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784539806; cv=none; b=iqeEu6vxUPfFrWu7WiPzVHqqT2InTI6NBD3wyumcVWQmSypadF0EVfrpuyuoEksTL1fCtD5EGB1qgww1FaU3iw8nopKTkJxLLu7fokr6jS6AKxt7LP0Pj1N1Wf8d7Ce+1d1QWkG/+E+CR0BdbU/HzBMU4794I5wXlORNv24I58g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784539806; c=relaxed/simple; bh=bkWbJ/QAnbfr8L7QR2SG5f1jORsy1B4vWJwYhrID5cg=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=reeCg6sBqhFIA1TfYiHLCAIRRi8EJwN2N+8WmNFkTSgmTUoJvk1zYOrKC6XPH7tezM8Qly8Bc7BqkLLx4xbq6zNHJsJo51Xfs3WZj8Ua3cJka9wP4HEJ+lU1nXgljfieEr94a6+2zseQNr8QpRZGYHkeVunH4aqFyhvyHoOl4QQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=J6mbuGxk; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="J6mbuGxk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3C541F00A3A; Mon, 20 Jul 2026 09:30:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784539805; bh=bkWbJ/QAnbfr8L7QR2SG5f1jORsy1B4vWJwYhrID5cg=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=J6mbuGxkLpqZydpajBTh4FlWXPgYyzShxLTY2D0QK/Q5+prANptJ6dl2sj2fX+5VS ocfXamTaRWja2odPfToMXenrn3l/8PWpcd0IWQGuekVB6ie4cyfHqmi6gPUrydOHwt L1WTAdHgn18D2YdsDKpw1784hy6xOktKpwzdg+QoXhgKohT7VW5Fj9dBnHwqflsYex tupldVGp4vNymI6m3YiGouRywPCFGdgflnv23hXWJe6F+u1vUd9b1uE1TXO80uX/Sq C0hAPo3xP+lseh3GQ+ELr0yx4im0dJAWfmAAnM+pdXaCPYCDfcE/sgNvK/MMJOD6Oj FoRe72tUUzGkQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v4 5/8] s390/mm: Remove folio handling for kernel faults in do_secure_storage_access() Reply-To: sashiko-reviews@lists.linux.dev To: "Heiko Carstens" Cc: "Vasily Gorbik" , "Alexander Gordeev" , linux-s390@vger.kernel.org, kvm@vger.kernel.org, "Heiko Carstens" In-Reply-To: <20260720085834.898025-6-hca@linux.ibm.com> References: <20260720085834.898025-1-hca@linux.ibm.com> <20260720085834.898025-6-hca@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 20 Jul 2026 09:30:04 +0000 Message-Id: <20260720093004.B3C541F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > Remove folio handling for secure storage access exceptions that happen > via the kernel mapping. Using folio_try_get() for exceptions via the > kernel mapping is racy: for example such an exception may happen on one > CPU, while a different CPU frees the corresponding page. Subsequently the > page can be part of a folio of different size, before the faulting CPU > executes folio_try_get(). This may lead to data corruption. >=20 > As of now this scenario does not seem to be possible, however with the > upcoming load_unaligned_zeropad() this is possible. >=20 > As a side effect PG_arch_1 is not cleared anymore for such faults via the > kernel mapping. However given that this bit is over-indicating it > shouldn't matter. >=20 > Tested-by: Christian Borntraeger > Signed-off-by: Heiko Carstens Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260720085834.8980= 25-1-hca@linux.ibm.com?part=3D5