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 2F27AC54ED1 for ; Sat, 24 May 2025 21:45:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 44B456B007B; Sat, 24 May 2025 17:45:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3FBD56B0083; Sat, 24 May 2025 17:45:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2C3BE6B0085; Sat, 24 May 2025 17:45:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 0BA8A6B007B for ; Sat, 24 May 2025 17:45:55 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 5A322160EB5 for ; Sat, 24 May 2025 21:45:54 +0000 (UTC) X-FDA: 83479134228.08.BFB57EA Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf23.hostedemail.com (Postfix) with ESMTP id 2D75514000D for ; Sat, 24 May 2025 21:45:52 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=EPjwgJN+; spf=pass (imf23.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1748123152; 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=3f0POsuaZwbMCUgkWn24uYMKYFlgMDPWNaKoICRP4SY=; b=Ey6B6Kej7H0ryXkuVqgsLzrUoc+qCqzQypGbX7Sh6PJhLzIC/rVN584QmH7cdju0O3LHVH kE6I7PGY0wlreZjxw9JX7Dd6g4rH9l/q10C/aMOohquLekm89IxZDG3cOoD8FRyqMy5MH4 QbUZo9eknJh4845zbad+eKUbruaKcv8= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1748123152; a=rsa-sha256; cv=none; b=JTqw+NzBc2AO5jvwzODY5xDofK03nYoB6I8iKd1ycCxe6RTQ8LMlArAlhb19DfVBmZ22VA L3FO7YinZCf5HlVyXB2ZJNJ4xPFhReu4KiDqVMJhyVmu4iYZO9cnThgEOxEvjCnEERZHf0 Ikar9Ms2R4oQIUQBJdG0fxj/829BbiI= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=EPjwgJN+; spf=pass (imf23.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1748123151; 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:autocrypt:autocrypt; bh=3f0POsuaZwbMCUgkWn24uYMKYFlgMDPWNaKoICRP4SY=; b=EPjwgJN+8mctMXoXLL50lWKjPEbdTdiBFGUAT4/KbPnqD4IgQtOiB9Qv+ZWUS8ZwG5P0Oz 2Q9mA75Zsyr80Qyu8nF/YXeO7qT2VurcCW41Ejnu72tvB0PJlTsgIoTb1FVOhNFbnyXkIQ /sOhApf9Fh/sbp9ynLoG+mO+kDjdLuE= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-166-xvQSKnQPOpKxNj9aWtW3kQ-1; Sat, 24 May 2025 17:45:50 -0400 X-MC-Unique: xvQSKnQPOpKxNj9aWtW3kQ-1 X-Mimecast-MFC-AGG-ID: xvQSKnQPOpKxNj9aWtW3kQ_1748123149 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-442dc6f0138so4047935e9.0 for ; Sat, 24 May 2025 14:45:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1748123149; x=1748727949; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=3f0POsuaZwbMCUgkWn24uYMKYFlgMDPWNaKoICRP4SY=; b=aMhavXAkGL1su3NxAO2k7GIDCQEyfl0sANV3/+u9B7TxXMbjcRSda85OhVMw7ohhuY pFoWJFFoC82May5kEpnBS6BtqQvDKeZDzsbsyM2Q040P6n9F2ebKXo3rKdcabVmvsMGM P914JfreRD/5/o2yGTiG4CPBwdl5gFPUPRZLc5wCrDTZjr4FnTV9Yox4qM5rujig8hkt r0KcCRKvVIUARLxI40qRYBKOAV5cuZG4ttENMZu+iCAtAYHZR7Cx/UoAD2bCdtYhTteK 5h/shGSokRUxfhG0nC8huzcJddohp7oqqAPXt12vxVnaYmQN4kbKrbhBpamAzhQsskLs sGKA== X-Forwarded-Encrypted: i=1; AJvYcCWHjdjXFD7P65+Oodb6t/A0Gcislmz6F5ODcz8VD6nqdJhhudZ3DZa0aqMHkVJX3NUuiHS8OAxQ5g==@kvack.org X-Gm-Message-State: AOJu0YwZvri3M63+b/R/nzPNiUkb7h4gTDven+xvfs8hvveEKJH22QKD C06aSwSPTpU1Vii9rjmK7y4hBiP5HAHXDIxnFloamrwJswvf0jp9ifwDLQ/wM3ADo5Gcm10IhHz YZokVRQOdQULEVYGU9BtHXnTzJo5B18wSAZ8lHSc3f1vs+vi2aRyG X-Gm-Gg: ASbGnctIBPF2rc4XrAV0P0Ujf0MsvBaZsO1/1vgTaBQJvu5EjZzA4VodKyH5BYL24w5 TCsBDzowR9F6P+IgcWpsFgksziaKyrteuTAGXR66Cmb4U/mtN7M1IRYZSFKpSqgnfcJb57ESPwa yQDo3N/s2mgA//K7Q0+jNbLpMCYiiz1f1MNYZO5StGYCsUUa6Bw+6tUvZmf6MPZLyz0BJc7PzuQ CYiqzXL6x1X2Qxk0pw1uOT4A/KDVabTh5njVQtK4bxLq4U5RGCf0329Yt78a6K5Q1uBUZHC+Ve0 9PXcP1bC8AXE3AkDXdP6LxVovP8nVMFSLOnecBmyePJ9CRw+bXhlt5ApUpcgwthu+kcceXSM85z naqbsT1Zjx55zl4zdkcgLRdbHQut78QLd7EX/mHA= X-Received: by 2002:a05:6000:3103:b0:3a3:64b8:84de with SMTP id ffacd0b85a97d-3a4cb445221mr2819774f8f.1.1748123148797; Sat, 24 May 2025 14:45:48 -0700 (PDT) X-Google-Smtp-Source: AGHT+IG/kZfall6GGwVvQtttxy1WCaTjOisnJJX+Hz6av+6a281Q+zZAWkFkgOqElGaB9F++e4CMLQ== X-Received: by 2002:a05:6000:3103:b0:3a3:64b8:84de with SMTP id ffacd0b85a97d-3a4cb445221mr2819767f8f.1.1748123148383; Sat, 24 May 2025 14:45:48 -0700 (PDT) Received: from ?IPV6:2003:d8:2f38:b600:7d6d:5e38:70ec:12c6? (p200300d82f38b6007d6d5e3870ec12c6.dip0.t-ipconnect.de. [2003:d8:2f38:b600:7d6d:5e38:70ec:12c6]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-447f73d4b68sm191115745e9.23.2025.05.24.14.45.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 24 May 2025 14:45:47 -0700 (PDT) Message-ID: Date: Sat, 24 May 2025 23:45:46 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH] mm/mmap: Fix uprobe anon page be overwritten when expanding vma during mremap To: Oleg Nesterov , Pu Lehui , Lorenzo Stoakes Cc: mhiramat@kernel.org, peterz@infradead.org, akpm@linux-foundation.org, Liam.Howlett@oracle.com, vbabka@suse.cz, jannh@google.com, pfalcato@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, pulehui@huawei.com, Andrii Nakryiko , Jiri Olsa References: <20250521092503.3116340-1-pulehui@huaweicloud.com> <20250524164516.GA11642@redhat.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <20250524164516.GA11642@redhat.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: Wf6D2TK8jXOkbNJ-Vk4KtSsnJfCNEKI2qXK_YYR6A-c_1748123149 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 2D75514000D X-Stat-Signature: yrt85ogfxt6kyzomdeusutw1deamsist X-Rspam-User: X-HE-Tag: 1748123152-162265 X-HE-Meta: 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 99MRpw2R N/p+SxsfJoJpOaXQDFsvBLI9IMy0FnsavNzxroXR3qaDvZs1I0f73/xqMy1cmUR85INlhvsc7441ZdT0= 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 24.05.25 18:45, Oleg Nesterov wrote: > I am very glad that mm experts are already looking into this problem ;) > I can't help, today I don't understand mm/vma.c even remotely. But let > me ask a couple of stupid questions. > >> However, the >> upcomming move_page_tables step, which use set_pte_at to remap the vma2 >> uprobe anon page to the merged vma, will over map the old uprobe anon >> page in the merged vma, and lead the old uprobe anon page to be orphan. > > To be honest, I can't even understand this part due to my ignorance. > What does "the old uprobe anon page to be orphan" actually mean? > How can the unnecessary uprobe_mmap() lead to an "unbalanced" > inc_mm_counter(MM_ANONPAGES) ? Or what else can explain the > "BUG: Bad rss-counter state" from check_mm() ? Or there are more problems? Essentially, we end up mapping an anonymous page (when install the uprobe) after preparing the new VMA, but before moving over the pages from the old VMA. So when we then move over the pages from the old VMA, we overwrite the PTE mapping an anonymous page (due to uprobe). As we simply overwrite the PTE that is mapping an anonymous page, we run into inconsistency later: RSS counter mismatch, memory leak, etc. We should never be installing an anonymous page (due to uprobe) into a VMA during mremap() before moving over the pages from the old VMA. -- Cheers, David / dhildenb