From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f50.google.com (mail-ed1-f50.google.com [209.85.208.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 67AB716D4E6 for ; Wed, 31 Jul 2024 07:43:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722411806; cv=none; b=n3tzlMswMbcNd80nh6C4QHTDusJNmBzn0J1ImIsk9M9zE0Uu3jTW1h52fW/MhvqBGNG8JL7PH0dprdX3njst5oQRGBYlzWDTfod2kfXnzrcN0fqp5ZW0jEE5LBWkaBt+Fb7rw1G4qYDiatP/mcdEiLhdOdzoSIJNd1thzjKUec8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722411806; c=relaxed/simple; bh=+RxIbRKdxBoqFwTrEcMqyr1qTFEZLj1r+9/p28lMvnE=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=tbFttqkz5VR2n3jkiYq+BwQvJ7BTjpQ6Nf9NuSzulbYucMAKI5+AYiCe8qMwBTq7+KFgCShpuFjTlBbNvc/zrmFnN1dQKkg3jvfZKHbsFFzU27yHxDw3Q29Q5Y4LL8rV0jQMKs1pzsaiA9ka/9upcG0mJ+4GYaztFZtChhs+iYo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.208.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-ed1-f50.google.com with SMTP id 4fb4d7f45d1cf-5a10835480bso7886327a12.2 for ; Wed, 31 Jul 2024 00:43:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722411803; x=1723016603; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :references:cc:to:from:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=vu1EISL8BN9yanPqcsi5XTIGcrHTZAMrGA+WEofj3pE=; b=T8B4wCiupZG3pnYKhzeLoTLvsotuvV5qsv1ERY8ZZqQxxJqXXYS6cN7PV+ZmtlwsdV +X/swJmaBfH2Z8QoJBim6f1Aus/SnO3lWPE9cNPeI6QlAYZl1/p/Ki0Dlvinep5R8kEt fSMbpbd3GwL2HLOq6IS0hyD0Fuq74ryQVazqA4qPLnB8FT07b20T0bfFzwjw8meNobsf Kzn62lqBprXgpojF44D30WXPvle1LH8jtW2rtYAlQbAuLYaNakU5BkWVSgEd8YRA2+QK mJMVv6+9rCWkFe54KI6/RfvuT6HD3Gn40JUlrEpHhMGVAbjxJO4ix31zLs86NCDnicAn 7cZA== X-Forwarded-Encrypted: i=1; AJvYcCUi/HAzMIC06luv7vhl/BEL5DoKInFXd4zVOB9ux03QNEZO5w5j/uzjuAWO9cReP5peZCEL8vOJEW3agaOwELiA9d5jUKFi X-Gm-Message-State: AOJu0YzaDUjpmCJPqhrrPg7/5X2fi1CU45o1A4Wq2nkDk3WJ6qSM+iI8 QkEQY6siUG/5+evBqV7hjn0RmadVQ6mLhRkgQN5GmnKGQYCD7+9D X-Google-Smtp-Source: AGHT+IE4/ttD3GJt957JgBhXxJvnGVVx7VCFsQ7PrQvOcUgOUqBmlVvKqefdIdCHtvpIPn7TgUub6Q== X-Received: by 2002:a17:907:eaa:b0:a7d:2c91:fb1b with SMTP id a640c23a62f3a-a7d40175b2cmr1070901466b.68.1722411802540; Wed, 31 Jul 2024 00:43:22 -0700 (PDT) Received: from ?IPV6:2a0b:e7c0:0:107::aaaa:69? ([2a0b:e7c0:0:107::aaaa:69]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a7acadb985csm732989666b.212.2024.07.31.00.43.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 31 Jul 2024 00:43:22 -0700 (PDT) Message-ID: <6f60115a-e69a-4ee8-b79b-cac016cac55d@kernel.org> Date: Wed, 31 Jul 2024 09:43:21 +0200 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: mmap 0-th page From: Jiri Slaby To: "michal.hrachovec@volny.cz" , stable@vger.kernel.org Cc: regressions@lists.linux.dev References: <3855f3cf-9c63-4498-853a-d3a0a2f47e7f@volny.cz> <54b32f3f-1e5a-4429-b81d-4ab91ceb6bcb@kernel.org> Content-Language: en-US Autocrypt: addr=jirislaby@kernel.org; keydata= xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSFKaXJpIFNsYWJ5 IDxqaXJpc2xhYnlAa2VybmVsLm9yZz7CwXcEEwEIACEFAlW3RUwCGwMFCwkIBwIGFQgJCgsC BBYCAwECHgECF4AACgkQvSWxBAa0cEnVTg//TQpdIAr8Tn0VAeUjdVIH9XCFw+cPSU+zMSCH eCZoA/N6gitEcnvHoFVVM7b3hK2HgoFUNbmYC0RdcSc80pOF5gCnACSP9XWHGWzeKCARRcQR 4s5YD8I4VV5hqXcKo2DFAtIOVbHDW+0okOzcecdasCakUTr7s2fXz97uuoc2gIBB7bmHUGAH XQXHvdnCLjDjR+eJN+zrtbqZKYSfj89s/ZHn5Slug6w8qOPT1sVNGG+eWPlc5s7XYhT9z66E l5C0rG35JE4PhC+tl7BaE5IwjJlBMHf/cMJxNHAYoQ1hWQCKOfMDQ6bsEr++kGUCbHkrEFwD UVA72iLnnnlZCMevwE4hc0zVhseWhPc/KMYObU1sDGqaCesRLkE3tiE7X2cikmj/qH0CoMWe gjnwnQ2qVJcaPSzJ4QITvchEQ+tbuVAyvn9H+9MkdT7b7b2OaqYsUP8rn/2k1Td5zknUz7iF oJ0Z9wPTl6tDfF8phaMIPISYrhceVOIoL+rWfaikhBulZTIT5ihieY9nQOw6vhOfWkYvv0Dl o4GRnb2ybPQpfEs7WtetOsUgiUbfljTgILFw3CsPW8JESOGQc0Pv8ieznIighqPPFz9g+zSu Ss/rpcsqag5n9rQp/H3WW5zKUpeYcKGaPDp/vSUovMcjp8USIhzBBrmI7UWAtuedG9prjqfO wU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02XFTI t4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P+nJW YIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYVnZAK DiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNeLuS8 f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+BavGQ 8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUFBqgk 3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpotgK4 /57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPDGHo7 39Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBKHQxz 1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkFAk6S 54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH/1ld wRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+Kzdr 90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj9YLx jhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbcezWI wZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+dyTKL wLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330mkR4g W6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/tJ98 f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCujlYQ DFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmffaK/ S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg= In-Reply-To: <54b32f3f-1e5a-4429-b81d-4ab91ceb6bcb@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 31. 07. 24, 9:39, Jiri Slaby wrote: > On 26. 07. 24, 12:36, michal.hrachovec@volny.cz wrote: >> I am trying to allocate the 0-th page with mmap function in my code. >> I am always getting this error with this error-code: mmap error ffffffff >> Then I was searching the internet for this topic and I have found the >> same topic at stackoverflow web pages. > > >         char *zero = mmap(NULL, 4096, PROT_READ | PROT_WRITE, > MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); >         *(char *)(NULL) = 'A'; >         printf("%c\n", *zero); > > still yields 'A' here with 6.10.2 w/ vm.mmap_min_addr=0. Yeah and mind LSMs... -- -- js suse labs