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Fri, 30 May 2025 14:10:09 -0400 X-MC-Unique: 5txLKz2pPzi2D8PZTinHuA-1 X-Mimecast-MFC-AGG-ID: 5txLKz2pPzi2D8PZTinHuA_1748628608 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 231AF1956096; Fri, 30 May 2025 18:10:07 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.37]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 806B418001DA; Fri, 30 May 2025 18:10:02 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 30 May 2025 20:09:26 +0200 (CEST) Date: Fri, 30 May 2025 20:09:20 +0200 From: Oleg Nesterov To: David Hildenbrand Cc: Pu Lehui , lorenzo.stoakes@oracle.com, mhiramat@kernel.org, peterz@infradead.org, Liam.Howlett@oracle.com, akpm@linux-foundation.org, vbabka@suse.cz, jannh@google.com, pfalcato@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, pulehui@huawei.com Subject: Re: [RFC PATCH] mm/mmap: Fix uprobe anon page be overwritten when expanding vma during mremap Message-ID: <20250530180920.GC25160@redhat.com> References: <62b5ccf5-f1cd-43c2-b0bc-f542f40c5bdf@redhat.com> <13c5fe73-9e11-4465-b401-fc96a22dc5d1@redhat.com> <4cbc1e43-ea46-44de-9e2b-1c62dcd2b6d5@huaweicloud.com> <20250526154850.GA4156@redhat.com> <06bd94c0-fefe-4bdc-8483-2d9b6703c3d6@redhat.com> <57533126-eb30-4b56-bc4d-2f27514ae5ad@huaweicloud.com> <956124be-c73c-4023-9edd-25372f3f865a@huaweicloud.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Rspamd-Queue-Id: ADCA74000B X-Stat-Signature: pzskzwcz3jd931c78eshdmuqxdrfhmga X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1748628613-487417 X-HE-Meta: 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 6c1L7bNC C35/ajARf1tZ+EuOL1Ah5btfhqxSFfcOcW1v77uV3pqdAw0VvdgzYHdf7qlJIJqT1Fz2r8rLKvAYlHxti6v7wwcR0khtWnP+Bm079OPMmrImL8s4m4HkAAEk+jU7UkGO2UYXZA2QwIFJcmADumzmj7DoFq/TFI0j9SdVh5caFwAknGB7OsOmsjXI5oUa5OwBrLnQ2OQf13abO6WxSCi0jJ2P9t9FjvU9bYyxmCoWge9Btn4zE7qYXEbvY91gLxbAVcMq15Nribg3ksyC0xKI1qhH87reK6NeaqJk2eTJ1UHtw45WVlFESht5fgcrwE/fNUd71qXHnZ4KIS+7XwNsK5JM8XpnDwSVj7bNjOfLev2PTdzc= 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: Well, let me say this again ;) I can't really comment, I don't understand this code enough. That said... On 05/30, David Hildenbrand wrote: > > I wonder if there might be a clean way to move the uprobe_mmap() out of > vma_complete(). Me too. Not only the uprobe_mmap() calls in vma_complete() doesn't look right "in general" (at least to me). To remind, vma_complete/uprobe_mmap/install_breakpoint is not even called in, say, this case when VMA grows and moves. See https://lore.kernel.org/all/20250526173845.GC4156@redhat.com/ I guess we don't really care, but still... But just in case... I agree with Lehui and Lorenzo in that we need a short term fix, and the last patch from Lehui seems to fix the immediate problem. Oleg.