From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A02C45A0AD3; Thu, 17 Sep 2026 16:34:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789662854; cv=none; b=YEus6NRr4fUYo2VT5dvh23AMT9sMxG9TJBxPTH6OiqYybUo8zPjCybzSymlCFAlDeHZu8SysawROGdGmQlkxARZbMGSIRH5NXz9Ro5iW3LgadMf2ENJIupyWXt3QrmeDZ+xrsljTA4GV+LaCv+PnAISYvZEBxYO0wZW9aHUW8MQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789662854; c=relaxed/simple; bh=joQXUjvjM3OjL+Ta6QEJ1w5g7Vsv4M79ot1AULAZKpk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=GXEgOtLKoSUQkoBRiz4UIItSgHwuB4pDpi0vLhNGMJ33bmEJCvWvxnum9uj+/rumMvBuLmqZBG/1eWleOKFuPMR4CoBSlnAGvhqoTpFnepOI8s2DLWVMboq6N0VZvqdja1wDXcmWZPETZFxbqgqpWfyZd67JYRDU9wirsGj0Vc0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Pyt7zq3w; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Pyt7zq3w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5968D1F00893; Thu, 17 Sep 2026 16:33:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789662852; bh=GfRJzELhUA3zmjv637fDp+tblD+oWrGBxslIXX4F7cw=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=Pyt7zq3wVrUAhNpXFXSuMVbDH6B9z27BuC4N5wSlqvK2YZ+YYcE38ItXJSygGLBUo jAOODUNiB8Hl2Z9TIS2vNbKclQyw54/sJwA+VbvsXDn0TD6r5o228/oBdRI3ZVNXtE Vn6qrdsda/Xfpp6xcB32G5ie9VvVYF6zK2oGcw7N0Tr0KugM/8h8+9skPGKu81Fu1v dUTlbWz+k5DmldJr+jaFMBP1ti+JPFxPgg1webbI7hC3+m22mXIypG2Kegwu62ONHh IphxagghomlS1XLWIPjchqsW+MqR5DhD81KyMXcMv4/F4ESQ4UCrMz8qtzU5tzkm2V 9qfYZxVjVZdRw== From: "Lorenzo Stoakes (ARM)" Date: Thu, 17 Sep 2026 17:22:31 +0100 Subject: [PATCH v3 22/40] uprobes: remove VM_IO, set VM_MIXEDMAP for mapped kernel pages Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-22-4583d8a23bca@kernel.org> References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> In-Reply-To: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> To: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Greg Kroah-Hartman , Dennis Dalessandro , Jason Gunthorpe , Leon Romanovsky , Paul Moore , Stephen Smalley , Jaroslav Kysela , Takashi Iwai , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Doug Gilbert , "James E.J. Bottomley" , "Martin K. Petersen" , Jaya Kumar , Simona Vetter , Helge Deller , Sebastian Reichel , John Hubbard , Peter Xu , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Rik van Riel , Harry Yoo , Juri Lelli , Vincent Guittot , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Arnd Bergmann , Muchun Song , Oscar Salvador , "Matthew Wilcox (Oracle)" , Jan Kara , Marc Zyngier , Oliver Upton , Catalin Marinas , Madhavan Srinivasan , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , "David S. Miller" , Andreas Larsson , Alexander Viro , Christian Brauner , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Youngjun Park , Johannes Weiner , Qi Zheng , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Chengming Zhou , Michal Hocko , Miklos Szeredi , Xu Xin Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-usb@vger.kernel.org, linux-rdma@vger.kernel.org, selinux@vger.kernel.org, linux-sound@vger.kernel.org, bpf@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, fuse-devel@lists.linux.dev, "Lorenzo Stoakes (ARM)" X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=2070; i=ljs@kernel.org; h=from:subject:message-id; bh=joQXUjvjM3OjL+Ta6QEJ1w5g7Vsv4M79ot1AULAZKpk=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLLWCB/q4Fj8329FrtbDMiFFC29ptVwduSnTb/sdWLDt6 EPNQz15HaUsDGJcDLJiiizPv4jvDxIJm9d5wd8NZg4rE8gQBi5OAZhIjAYjQysXc4jOXOkLizqe C2g/vP3cILJezzj8ioBasHvjo9+dNYwMOz/GLnqz6VVSzVbf/sX67g2LDpjmmxbucpy7/tS7Rzs a2AE= X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 These are not MMIO pages so VMA_IO_BIT is an inappropriate flag to set. Instead, set them VMA_MIXEDMAP_BIT as they are kernel mappings and this is the appropriate flag to set for those. This provides the semantics required - no VMA merging is permitted, but does not prevent GUP. However this has no meaningful impact as these are refcounted and thus can be GUPed. A previous commit already prevented __mm_populate() from being invoked on XOL areas, which VMA_IO_BIT was previously relied upon to do, so that is no longer required. Both VMAs set a VMA name, so always_dump_vma() returns true before vma_dump_size() reaches its VMA_IO_BIT check, and thus there is no change in core dump behaviour. Change this for both the core xol_add_vma() function and the x86-specific get_uprobe_trampoline() function. Signed-off-by: Lorenzo Stoakes (ARM) --- arch/x86/kernel/uprobes.c | 2 +- kernel/events/uprobes.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 65a2de82ecd2..0f60c0d076b6 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -715,7 +715,7 @@ static struct vm_area_struct *get_uprobe_trampoline(struct mm_struct *mm, unsign *new_mapping = true; return _install_special_mapping(mm, vaddr, PAGE_SIZE, - VM_READ|VM_EXEC|VM_MAYEXEC|VM_MAYREAD|VM_IO, + VM_READ|VM_EXEC|VM_MAYEXEC|VM_MAYREAD|VM_MIXEDMAP, &tramp_mapping); } diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 7709ea882477..b89cc5cee002 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1726,8 +1726,8 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area) } vma = _install_special_mapping(mm, area->vaddr, PAGE_SIZE, - VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|VM_IO| - VM_SEALED_SYSMAP, + VM_EXEC|VM_MAYEXEC|VM_DONTCOPY| + VM_MIXEDMAP|VM_SEALED_SYSMAP, &xol_mapping); if (IS_ERR(vma)) { ret = PTR_ERR(vma); -- 2.55.0