From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 434C82D7DEB for ; Wed, 27 Aug 2025 17:58:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756317541; cv=none; b=cjDV0bFld96n19huly8qt9h9PgZn7HH8c6aBBPNJxcqXbUddwmbF/4c/BD7smmp0rxH916D9J9c8HhcfvBLHIhO6WbcWw6+XdCCRuFQQHTHt9C+vDK5x5F3X46GFo8xDZ6sg8V2f1Pf0YLCWNonJabL4jzaAZfq9IPUgHl/A5HE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756317541; c=relaxed/simple; bh=qM07M6YX83zAu1MJFTJWRYrFha6NM53dS1++QwRW8Xg=; h=From:Message-ID:Date:MIME-Version:Subject:To:Cc:References: In-Reply-To:Content-Type; b=VwrJd7QH8estFBSNYjRPZ4H3EZ3zoCjWeBEbs5c+7H0+YKc9eDnOD+25PgiQnan6mCnOTgygCQH9r8XUS/smpDaH+lLP72lRA4q3VDbPJsljxKB1cg/Y41gB3ofkENImbDSIzVaiCMUwVG5W9uE58RJXLZO7cfyekdhXSdRO5C4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=HVwOwXQY; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HVwOwXQY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1756317538; h=from:from: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; bh=68zTd9ybMYa+9LcXDQYMsbuSzuPSYGRrvVBPkMTfky4=; b=HVwOwXQYMpIHat+8S4uYaNfX54HQ+Ey6XHQ24v1ssLwmYMVRCTP2Awc59usiRTS/fxedsR 7pYMxvdOwbJFQMcHUclrPPvpJFaYDztzXvcWpEwap3AweUXml8lsRNSf/WeSVQVoNnu1UD sM9MMKcblGB9O/TWndFfvA8PM+PmbzE= Received: from mail-yw1-f197.google.com (mail-yw1-f197.google.com [209.85.128.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-208-SVFADXrOOau7w9dodkgj4A-1; Wed, 27 Aug 2025 13:58:57 -0400 X-MC-Unique: SVFADXrOOau7w9dodkgj4A-1 X-Mimecast-MFC-AGG-ID: SVFADXrOOau7w9dodkgj4A_1756317536 Received: by mail-yw1-f197.google.com with SMTP id 00721157ae682-71e7181cddeso638967b3.2 for ; Wed, 27 Aug 2025 10:58:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756317534; x=1756922334; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=68zTd9ybMYa+9LcXDQYMsbuSzuPSYGRrvVBPkMTfky4=; b=vIpnvrt8qd1DHwruwbdWG9by7njNnm4Tjus9L+N3jpEJvIXUVTsq8sCpHKuVyAwJjE sNbhDkBI7rmbmOjd0HmoZF8XGStNz6IUWgdGpdieXvouq+H4Wyi5eTWrP5DBeUhaOIPH eVXd8jDQ+EyGjdPqtAnjDOxpVuSfWC2Y/AG0biGEMRi5ZMlEaEsf1pOK/YdT/cR2KgXU mTppdsBjIl9jMtq5kdKNpYJidb6g7Sb2LEkA25zz5T0nitQrWDh0LyhLjxATgZe/5wCt K47ITChRRB4G0rIjwAbCQTf8ZAqkleo1iolHtX2KAmkYBfH8eueTfRt8Z6I9q6q/2S7x FzXg== X-Forwarded-Encrypted: i=1; AJvYcCUFNe+Fq0ZjK+A+YzCGNM9Iv2O3VyFs+EePA+176UzBfn1AjM4u81ZYge1nJ4U4pFyrQfgsEHJFwkj1yN0=@vger.kernel.org X-Gm-Message-State: AOJu0YzNexSEFCcWxkPGc4vIhJpTh3fj5aZtO2hqORBvP1f7qIkOgyTc jBqIYO8QUIfhPlFCxZ+R0Hw+jtiE5pJ1/PdnoCHSY9jnPJEVKPAmHQQBVl9srTqvua6aqm/oBVO /nlpMUX/0EIVrUdYskuHk2KROzy1/I01P5isKCEc99rE2vRMq2aZy5vESB+bXnvH3/w== X-Gm-Gg: ASbGnctxCnu3qN6Eo+filaf4Sny5TKzOUAm7PBJ1vGnHLv/d3TvcjgF5CuNJFAKXOuG HBAwQGy8x3AIDGmn9Jm1XHz+p6mqisFxwlp7wEVpZ7FWzC9LquGCoNxh2QuPW445PySN22qU3ju DvAnfZPDYlo0256EMIyf80qUuFbBcatoJ3C0YWGsN02r1Gfs00nr47zQKlunUdTFSwQMkyoL9Qm xngoBU0+U9L+vpqSltOzpHH0kxW+f1nhiFH+rt0hp8PliofAPzAeqNXUdW5HWIsC4zvLDmHGUex tEfnYQdE83eDU43kPFyZJNkeHznElyJcoFnH4e0xROWGLw9S4hLVajGw/bFWy4p8Uelqv9rVC47 I2zb5C/SZEw== X-Received: by 2002:a05:690c:d96:b0:721:1d52:1989 with SMTP id 00721157ae682-7211d523da1mr99240777b3.28.1756317533659; Wed, 27 Aug 2025 10:58:53 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHdT+RZwBJztTIfOFsLMwmdt6wt8HAm15gYADw5Qx7LUh/r5SyBZcKwlrd4mhwQThimE9Yenw== X-Received: by 2002:a05:690c:d96:b0:721:1d52:1989 with SMTP id 00721157ae682-7211d523da1mr99240227b3.28.1756317532998; Wed, 27 Aug 2025 10:58:52 -0700 (PDT) Received: from ?IPV6:2601:188:c180:4250:ecbe:130d:668d:951d? ([2601:188:c180:4250:ecbe:130d:668d:951d]) by smtp.gmail.com with ESMTPSA id 00721157ae682-721307edf15sm11492567b3.74.2025.08.27.10.58.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 27 Aug 2025 10:58:52 -0700 (PDT) From: Waiman Long X-Google-Original-From: Waiman Long Message-ID: <9d4c0d27-0ebd-4c6d-af38-d32ef420fde4@redhat.com> Date: Wed, 27 Aug 2025 13:58:50 -0400 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/futex: Fix futex_numa_mpol's memory out of range subtest To: =?UTF-8?Q?Andr=C3=A9_Almeida?= , Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org Cc: Darren Hart , Davidlohr Bueso , Ingo Molnar , Juri Lelli , Peter Zijlstra , Thomas Gleixner , Valentin Schneider , Borislav Petkov , kernel-dev@igalia.com References: <20250827154420.1292208-1-andrealmeid@igalia.com> Content-Language: en-US In-Reply-To: <20250827154420.1292208-1-andrealmeid@igalia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 8/27/25 11:44 AM, André Almeida wrote: > The "Memory out of range" subtest works by pointing the futex pointer > to the memory exactly after the allocated map (futex_ptr + mem_size). > This address is out of the allocated range for futex_ptr, but depending > on the memory layout, it might be pointing to a valid memory address of > the process. In order to make this test deterministic, create a "buffer > zone" with PROT_NONE just before allocating the valid futex_ptr memory, > to make sure that futex_ptr + mem_size falls into a memory address that > will return an invalid access error. > > Fixes: 3163369407ba ("selftests/futex: Add futex_numa_mpol") > Signed-off-by: André Almeida > --- > This patch comes from this series: > https://lore.kernel.org/lkml/20250704-tonyk-robust_test_cleanup-v1-13-c0ff4f24c4e1@igalia.com/ > --- > .../futex/functional/futex_numa_mpol.c | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/futex/functional/futex_numa_mpol.c b/tools/testing/selftests/futex/functional/futex_numa_mpol.c > index a9ecfb2d3932..1eb3e67d999b 100644 > --- a/tools/testing/selftests/futex/functional/futex_numa_mpol.c > +++ b/tools/testing/selftests/futex/functional/futex_numa_mpol.c > @@ -143,7 +143,7 @@ int main(int argc, char *argv[]) > { > struct futex32_numa *futex_numa; > int mem_size, i; > - void *futex_ptr; > + void *futex_ptr, *buffer_zone; > int c; > > while ((c = getopt(argc, argv, "chv:")) != -1) { > @@ -168,6 +168,17 @@ int main(int argc, char *argv[]) > ksft_set_plan(1); > > mem_size = sysconf(_SC_PAGE_SIZE); > + > + /* > + * The "Memory out of range" test depends on having a pointer to an > + * invalid address. To make this test deterministic, and to not depend > + * on the memory layout of the process, create a "buffer zone" with > + * PROT_NONE just before the valid memory (*futex_ptr). > + */ > + buffer_zone = mmap(NULL, mem_size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); > + if (buffer_zone == MAP_FAILED) > + ksft_exit_fail_msg("mmap() for %d bytes failed\n", mem_size); > + > futex_ptr = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); > if (futex_ptr == MAP_FAILED) > ksft_exit_fail_msg("mmap() for %d bytes failed\n", mem_size); This patch makes the assumption that consecutive mmap() calls will allocate pages consecutively downward from a certain address. I don't know if this assumption will be valid in all cases. I think it will be safer to just allocate the 2-page memory block and then change the 2nd page protection to PROT_NONE to make it a guard page. Cheers, Longman > @@ -229,6 +240,10 @@ int main(int argc, char *argv[]) > } > } > } > + > + munmap(buffer_zone, mem_size); > + munmap(futex_ptr, mem_size); > + > ksft_test_result_pass("NUMA MPOL tests passed\n"); > ksft_finished(); > return 0;