From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22698C7EE39 for ; Sun, 29 Jun 2025 11:40:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9B3E16B0088; Sun, 29 Jun 2025 07:40:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 98BCA6B0089; Sun, 29 Jun 2025 07:40:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 87AE06B008A; Sun, 29 Jun 2025 07:40:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 6DCE76B0088 for ; Sun, 29 Jun 2025 07:40:48 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id EA86E8012E for ; Sun, 29 Jun 2025 11:40:47 +0000 (UTC) X-FDA: 83608246134.16.767B08C Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) by imf01.hostedemail.com (Postfix) with ESMTP id F214440004 for ; Sun, 29 Jun 2025 11:40:45 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=EuXds8Ov; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf01.hostedemail.com: domain of david.laight.linux@gmail.com designates 209.85.128.54 as permitted sender) smtp.mailfrom=david.laight.linux@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1751197246; a=rsa-sha256; cv=none; b=lRQKemD1qrkKzj7rYIDZw1OQPtjga+N7Hq13JATKWNKssj/lSoaQtageoJayF7NZ+VFqNj x1qhp1yvS5PyJyGk3BaZXg6WDehhpslS8J6CYSS4nf9T5/QkyRdzTmAHLbJG5KhEDxWn46 aH1CLp64h92Bljm2XAYebdy209GEpgA= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=EuXds8Ov; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf01.hostedemail.com: domain of david.laight.linux@gmail.com designates 209.85.128.54 as permitted sender) smtp.mailfrom=david.laight.linux@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1751197246; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/WM9wI+ftSuqEkYEs3zU3TH9PeO5T6PPzLJahZfyDzY=; b=g/HDE1/ii2OIxKqfJwEUepdadvV1WH7Tp9GObkzMeSuEvIJPi/y+8PN9Q0iugsEYkhNFJc zrMJ7Ln1j/heip9r/BV19K/0eEuWxV7+YPSoAgboxBWYd7+5DPlEq/Kuftf1swTHOL27kn YuSuWYfr2Yq6P3aKNwHj7HHumsu0G0s= Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-450cfb790f7so28629165e9.0 for ; Sun, 29 Jun 2025 04:40:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1751197244; x=1751802044; darn=kvack.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=/WM9wI+ftSuqEkYEs3zU3TH9PeO5T6PPzLJahZfyDzY=; b=EuXds8OvHDrCLtn2Nq4k0W/RxoHCygSfShGvEAQc6KNyjjAt+3XNlw0fm0aKn6Ikdc d+zKsAncLTlgHCec+EaFGGaj2R3dwsjtV84ARgQCPq3biKFauBPSJuL1LQP0akYjTZe2 e0B7q8Mfx6DVcx/Ot8ZrBcxvkzYm3I3DrpPoBkulmQ+vkTMwZj4bfxghjFfS/NQaOCjF f8+IXcT/eoZdBy8zFwRwHKcvwziA5LOUq/pDk2BGIYniM/pdQ5uhdfhF96MiDazZT/Ps u4tE511idO8wNQ91R4PfIZDej9bX+Ka/6mr2LIoGbKK/h/BCa6H1wLCzu4kBxddAfj9q pg0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1751197244; x=1751802044; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/WM9wI+ftSuqEkYEs3zU3TH9PeO5T6PPzLJahZfyDzY=; b=XijALAAw57LyB9czF1XoQ3l0aid5/52Vfn1TBjnvq4Gx/RuN6x21cN5zI12Ldc54tj WT0z/7ZBNThgXI2V1cvu/enZrafjLc6H9NCddSqMSIfGZzWz9U3IZnzAHrOIqqOFGtUH jveg+2mWxJ4C4QjXbJWFj07YP9+pkbeKSnbLBuEKSKuzEUt4ajC+JFYaG2DdxfZkLLAP +rhCMl96XEdcAgGqKzKMh5FzY7NjgX5d60zblhw/10fO7JplyGOTjBiI6vkkFSDN9P+w jKYff60psmsRFhOWX44ApcvTs+lEcScRQCNUEyvUugGme9L9EpvimkN0mG4UKQHmi2gi Ygqw== X-Forwarded-Encrypted: i=1; AJvYcCWvjSrS3mHFe7bwO7WEzqjzKAF1Fqv63rDS2QdVWw+ddDmpnVGZzD11Bv/WiDVLWGoNhSb6i1wqjg==@kvack.org X-Gm-Message-State: AOJu0YyQYEx8KiY6zKI68ZnLso9U2UiL+/14Fc8czuAoPAlVZiHh9fI2 sGwH7bB5EcunNAIBKkcdX9/hFEhPGsyCpHMzXX6kkn+TWI1r134tIWE6 X-Gm-Gg: ASbGncsqoaIgeomWVRYhlUkF+ye7HubAeKUPLfqtdcmV8o/J9IkMYPt2+qSEcv0oaU9 AnF6hPOtHEhjLRYYzUfaa8NClpneZ0jPmv2a2xP+sKqAuDbMF9aH8NFGS51k0oujGdvoIbKpGKi /R71K7mR+OTEMUQsTZC8DVDtiOHfPNMYv+D6JbQdW+xlBtKP+GCQNA40RXqzXEzavk9oFeYblWJ 7hp6ZXeiPxWW/rOI0yIHlVB3VZIbJTLOXmtg3WgqUUtwd+uEyKgYfTRzZgCR9K/jMcLi/OIDXKl y4Dt0jZ9FIx9amj+mrHw3pzDKii+9bkIIFSD6QWVJPeSZJRGhhJKMkldWF+5Zrs5mYMtVuGHK3U aKkq9IWuatrT6/kdr3Y1M8OFw8it7 X-Google-Smtp-Source: AGHT+IGG36v57mIHx9b8wattPhP5PhbXduaoeVXbueE5hKYc+gE5hVGbh4KVH7GNd0aydHy8k2cc9w== X-Received: by 2002:a05:600c:a48:b0:453:58e8:a445 with SMTP id 5b1f17b1804b1-45396a94e32mr40584365e9.11.1751197244036; Sun, 29 Jun 2025 04:40:44 -0700 (PDT) Received: from pumpkin (host-92-21-58-28.as13285.net. [92.21.58.28]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4538a390d05sm105209375e9.2.2025.06.29.04.40.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 29 Jun 2025 04:40:43 -0700 (PDT) Date: Sun, 29 Jun 2025 12:40:41 +0100 From: David Laight To: "Kirill A. Shutemov" Cc: Vegard Nossum , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Ard Biesheuvel , "Paul E. McKenney" , Josh Poimboeuf , Xiongwei Song , Xin Li , "Mike Rapoport (IBM)" , Brijesh Singh , Michael Roth , Tony Luck , Alexey Kardashevskiy , Alexander Shishkin , Jonathan Corbet , Sohil Mehta , Ingo Molnar , Pawan Gupta , Daniel Sneddon , Kai Huang , Sandipan Das , Breno Leitao , Rick Edgecombe , Alexei Starovoitov , Hou Tao , Juergen Gross , Kees Cook , Eric Biggers , Jason Gunthorpe , "Masami Hiramatsu (Google)" , Andrew Morton , Luis Chamberlain , Yuntao Wang , Rasmus Villemoes , Christophe Leroy , Tejun Heo , Changbin Du , Huang Shijie , Geert Uytterhoeven , Namhyung Kim , Arnaldo Carvalho de Melo , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv7 00/16] x86: Enable Linear Address Space Separation support Message-ID: <20250629124041.04a30869@pumpkin> In-Reply-To: References: <20250625125112.3943745-1-kirill.shutemov@linux.intel.com> <9b1c5e43-ff48-4af8-9ec8-1c1dc2b902ae@oracle.com> <1b96b0ca-5c14-4271-86c1-c305bf052b16@oracle.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Stat-Signature: r6sxeo8p89c8muxbxak3naajmyb7tcqk X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: F214440004 X-Rspam-User: X-HE-Tag: 1751197245-404911 X-HE-Meta: U2FsdGVkX19RGQVapzq9O/VeDLjjWDdEo1IHEPbxnO4jKexqiPsBKUPnXfn3koFondTenrSenWvmmZLv/14c21cI/PcjKgpw2Lft62Me+8s/YIofT5vFDgVybXvVGXJKwMdFi0tTwxHWgDMDJRL/okFPeoWqZtjqeGzIuXNyAYzgmzGO7zoRnOjwZVyF4ZJnWXRaV33PR63EuoZvF6AcEio7lFA7gFRvtCu+IFns7QeZxNhlg6YF3LTnQT6sX1/5xvdw174srNAEkSAy4CpF0NsAKwrkX1lRHUDL2vK5/cRF7cZ5aoagO0eccp9Ix2kZnIj1c+GmVFuq1NMVm7sNRir30jMu52A+lNd18ttTywnzalqkXwAXoAhtg7d+fyX6UQa94LM8l9eUYT9Ijkib52aLpW510u0R7uGBqObvUArZiRzV3/+96gylIEujEn2EB4xmzPk6UXQEz1g+CrVu92eBu1sbuP++h8fwx+Jn/eQEGdD0f2t6+ifpjLcCr0Xo8svff7LNUUDqIuAsqUF0DLgnl60fLckfyG7y6zexPYYcJ2uwOpDxM72nLFh5BiXgfbkElYskGbg0hbYqQQXfWS9G7jzwTDBhUj7EQ36T5uUsoJFb4pBM3beZFt2BAGFKz74bTJCX6be0qNqfR83ghD9fZVGVcxseZxiW3pIC1LGZlXrR0owyii/L8yJ/5tlijNZaf5WAccuSXU/8L+nY7qEqJQAunZMfDb/k3tec0WSbDpu4FT8yBJS8i6UCecJWGhsN5zqGsTmAZQxLwoSKItQGsk5/tVbg+oKpdtGq78KH28eZrCnVS9xQ3PmOsog7NBXF3ReNU98dIRkzCQY0AzT4urvLmQCETVn4AhboJ3nSc1dgf2RmfspjYq/WtZIc7lmuRJZ+U0qCstW/Zo7nBQqCfnM4Yr/z6yS3CtJgA4Qr2jOjCj57WmCbXilSq3gcFroLuFieJ583tEcCq69 uFZ5ubbJ 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 26 Jun 2025 15:47:36 +0300 "Kirill A. Shutemov" wrote: > On Thu, Jun 26, 2025 at 11:35:21AM +0200, Vegard Nossum wrote: > >=20 > > On 26/06/2025 11:22, Vegard Nossum wrote: =20 > > >=20 > > > On 25/06/2025 14:50, Kirill A. Shutemov wrote: =20 > > > > Linear Address Space Separation (LASS) is a security feature that > > > > intends to > > > > prevent malicious virtual address space accesses across user/kernel= mode. =20 > > >=20 > > > I applied these patches on top of tip/master and when I try to boot it > > > fails with errno 12 (ENOMEM - Cannot allocate memory): > > >=20 > > > [=C2=A0=C2=A0=C2=A0 1.517526] Kernel panic - not syncing: Requested i= nit /bin/bash > > > failed (error -12). =20 >=20 > For some reason, I failed to reproduce it. What is your toolchain? >=20 > > > Just using standard defconfig and booting in qemu/KVM with 2G RAM. > > >=20 > > > Bisect lands on "x86/asm: Introduce inline memcpy and memset". =20 > >=20 > > I think the newly added mulq to rep_stos_alternative clobbers %rdx, =20 >=20 > Yes, it makes sense. >=20 > > at > > least this patch fixed it for me: > >=20 > > diff --git a/arch/x86/include/asm/string.h b/arch/x86/include/asm/strin= g.h > > index 5cd0f18a431fe..bc096526432a1 100644 > > --- a/arch/x86/include/asm/string.h > > +++ b/arch/x86/include/asm/string.h > > @@ -28,7 +28,7 @@ static __always_inline void *__inline_memcpy(void *to, > > const void *from, size_t > > "2:\n\t" > > _ASM_EXTABLE_UA(1b, 2b) > > :"+c" (len), "+D" (to), "+S" (from), > > ASM_CALL_CONSTRAINT > > - : : "memory", _ASM_AX); > > + : : "memory", _ASM_AX, _ASM_DX); > >=20 > > return ret + len; > > } =20 >=20 > This part is not needed. rep_movs_alternative() doesn't touch RDX. >=20 > I will fold the patch below. >=20 > Or maybe some asm guru can suggest a better way to fix it without > clobbering RDX? Or separate out the code where the value is a compile-time zero. That is pretty much 99% of the calls. David