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 F0745C61DA4 for ; Thu, 9 Feb 2023 14:10:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6087C6B0071; Thu, 9 Feb 2023 09:10:48 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5B86C6B0072; Thu, 9 Feb 2023 09:10:48 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 481006B0074; Thu, 9 Feb 2023 09:10:48 -0500 (EST) 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 35E046B0071 for ; Thu, 9 Feb 2023 09:10:48 -0500 (EST) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id EACE340FA1 for ; Thu, 9 Feb 2023 14:10:47 +0000 (UTC) X-FDA: 80447939334.07.F119C48 Received: from mail-wm1-f50.google.com (mail-wm1-f50.google.com [209.85.128.50]) by imf22.hostedemail.com (Postfix) with ESMTP id EE0DFC000B for ; Thu, 9 Feb 2023 14:10:45 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="ha/BiTuH"; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf22.hostedemail.com: domain of glider@google.com designates 209.85.128.50 as permitted sender) smtp.mailfrom=glider@google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1675951846; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=2cJbXIc6sUIZ1i94zwcO4sqv/3DWkbU7YDfCfI7tRws=; b=I5zd5eXxJfIQC7ZwjZ7JaEg045bxrD5QJ4c1489a6IqIxyTYqZl4qEf+/gL19WTu1mCXdO 2nwXvfZ1Ap7pFMgLt3hmojTGrpj3FLIrjmrdLh+jFk/oCgpYv/km68Bzx9racbEEp89LSe sKwoXNBbPWI7XmEd/LLNYshrtALwO/E= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="ha/BiTuH"; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf22.hostedemail.com: domain of glider@google.com designates 209.85.128.50 as permitted sender) smtp.mailfrom=glider@google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1675951846; a=rsa-sha256; cv=none; b=6t1RPamhe+wAmTBqpW6tZdW8MO4EPzxGibJY9NOpNF/gbl7fHPXx/l0ZYdPcW8UF0MoULZ acOFL8xlmGAaAZ+BtNy5t01xH/7GNrclFBKkur6/eDB91W0DWWbM9RcLpI8khJg7ZVy/MU JTg9kAE9OjU4U27JSNqmexou/1DURNk= Received: by mail-wm1-f50.google.com with SMTP id n13so1500432wmr.4 for ; Thu, 09 Feb 2023 06:10:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=2cJbXIc6sUIZ1i94zwcO4sqv/3DWkbU7YDfCfI7tRws=; b=ha/BiTuHrB/wTAitAvR41ZEFDItgv+gg+2CCyDuNY2W03MoqjyfL+2kJk930XfZmlU iiT4DBYnp6FGvVyuZkYR+LrfvQsopxvgrXVYil8uO2Gfnc7F+bQH9zFTYOEJ/rMquSv2 yztSAU3SRJG0YAFJDIDyyObNtp7J/K/OjvOvt02Nzz/uUV2llphLcohPwjDtweFY0MqK UXWP5IHHT1eGbsV5aOz6A7VFJi2ud6YHJFAoY9Ax9GK6eH3s63uLavhYsTm0wdK/JCS1 I6jTSmEAgDcIeiMBQkjoEnljP8jxbj/8vqQX8J2UFEf3NwjcjOHxdvjCrF+ULsHh3wDL VAog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=2cJbXIc6sUIZ1i94zwcO4sqv/3DWkbU7YDfCfI7tRws=; b=7HXe/2+jPSuM+QNn/eTCm7MwDH/YJl6dWlU/5KKSIJ+tt4yrFg1dijeUz2CfnqG7kA B4cv3FQc8cGFnhixg7ABik9CjZvaWtFzBUVbwl+47H1rdHFmCKd/0UWUF9U61gsjz/Xr 9l3LWMOlcYH3EBoq7QgRcuXtcywv/jK87oeN6AEm17Hrm0ZQ7Xit+bUWFUxGCW5Ma9pk ewNdl+p1BxU1A3jWUqV5dzfGY4MtjxI3eeQ2SxIrNjm13ONdoiFmh3spoRmro65l4dN6 +aDPEKINTrm6lj1OWR80GXl9KENk2QC6JDy5wGYIIuYqjjM9Zh0g5TfrEH4Ci7grUHqN L1cw== X-Gm-Message-State: AO0yUKV6YVD8iYDeiPSM32H4BlGwI9udF+KqheuX91XA4il3YM1OlIci wmdyaBhZe/FULJtjMWQQAYpQt6krnh0l5DeY/n1xbw== X-Google-Smtp-Source: AK7set+veevx98XIJAiGJtc7Cal/+34P2vCmciNiu9Y/kYU7oHAwHt6eWolln0SD7AYnFjM7x7/xsqq8IbEZ9Kqf3Rg= X-Received: by 2002:a7b:c2e8:0:b0:3e0:196:208b with SMTP id e8-20020a7bc2e8000000b003e00196208bmr506757wmk.162.1675951844523; Thu, 09 Feb 2023 06:10:44 -0800 (PST) MIME-Version: 1.0 References: <20230123220500.21077-1-kirill.shutemov@linux.intel.com> <20230123220500.21077-7-kirill.shutemov@linux.intel.com> In-Reply-To: <20230123220500.21077-7-kirill.shutemov@linux.intel.com> From: Alexander Potapenko Date: Thu, 9 Feb 2023 15:10:07 +0100 Message-ID: Subject: Re: [PATCHv15 06/17] x86/uaccess: Provide untagged_addr() and remove tags before address check To: "Kirill A. Shutemov" Cc: Dave Hansen , Andy Lutomirski , Peter Zijlstra , x86@kernel.org, Kostya Serebryany , Andrey Ryabinin , Andrey Konovalov , Taras Madan , Dmitry Vyukov , "H . J . Lu" , Andi Kleen , Rick Edgecombe , Bharata B Rao , Jacob Pan , Ashok Raj , Linus Torvalds , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: EE0DFC000B X-Stat-Signature: zhbyebyh9x9hnczbm9p73mpuwe75rxpf X-HE-Tag: 1675951845-153934 X-HE-Meta: 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 VrWGgj7A ha35R5XYJUJGa+WsLYHxdGExM2cIFi56/V8NT9XbNkCx1BlswpY1GgSlgBCYpStnLWsQzNes8ZvADRl/+HlH5qBLPx2C7q3fNEWKtZnpgJ53GGF+ZaakzW8tyEyRvqgRTzxMCsW+cU7t4CowM7TNWUAsEiaXZFDLJbV18ZzfYqgRF54YyArAUsMBXLHfk08OjrOZrE+6tELEMm2/7FvbaMCFaoAFYINUhQJC56O8iaCM2ud7dSoFmIKpvsvNI+iAMa815KakA5rNjEYsFqb8U/3HJphGJA6KW1V8xDavcP8uu6JHHCE76GL4WYk2I2uhReEQkYNMBSSIkYfxN3W3K/c9kQOs3t3GvPD/ldTsHeDeclZTQVdTr8HWXljhTWmFvMlTpoHKgLZFkZYowpN9ggQMmO2SL9tSfqOavcBFwwqclXFEvfwkyYpjZ+9ZiQjUIBkSxnakxx7YKk3e3eGWhU2cK9A== 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: On Mon, Jan 23, 2023 at 11:05 PM Kirill A. Shutemov wrote: > > untagged_addr() is a helper used by the core-mm to strip tag bits and > get the address to the canonical shape based on rules of the current > thread. It only handles userspace addresses. > > The untagging mask is stored in per-CPU variable and set on context > switching to the task. > > The tags must not be included into check whether it's okay to access the > userspace address. Strip tags in access_ok(). > > Signed-off-by: Kirill A. Shutemov > Acked-by: Peter Zijlstra (Intel) Tested-by: Alexander Potapenko