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 3B00C4B4043; Mon, 12 Oct 2026 18:21:08 +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=1791829269; cv=none; b=B5sEwCeDg+Fq+zohu2uu1tdnQ9/AO0JG+QSXZF13smOxv58+NHyYeKAFgIrIlwPvrHth6LNtXk4jApLI+SS3uVATM5TLB1mVIj/4i6x2hi51hn8uP0rIXKyyBuFDjHHqhEayu5M6Qxg00gpq3RPovTQdeLvVbbXNrlZvdUmbHv0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791829269; c=relaxed/simple; bh=Lf5eDZfkEE1bp2DEa65JPLro3RhxvpNpskQCFEfCTgA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=r8uWQ0aSW2Ek4xuls/nZtg2YoSHo3tRZCYJ2s5JHgcKVJgrP0iuNpyZnlqY7dPY3cvdY8iqRGNB4535UVK+j5Z1KfpvQNUX289724H2j1nmB1gxYy2Qe5gSd27sbqn+/Jj5sgTwh6mK9kyeV910YaZor+i0ju+lIsCKZ7L6f9/4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VPUP1ptH; 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="VPUP1ptH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49A8A1F0089B; Mon, 12 Oct 2026 18:20:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791829267; bh=hHBESK2KlCwsi7XB84TfEpjCQoYTSyYlt8B230e+MvQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=VPUP1ptHnUHORU4MhilrkP5qlYiqZl6uWQDj+FeTap+RZDGyNIOHJBlPuJoyubu2U 27BPhvzI7hrw6tlV9qGYW3Bu9xbjOCwoT5tfsKgj5lDpP8wdrsja/bAdDi+YFjySu3 IwgvUFFeGgP9UR9jS6daeytrBIIe3ZFrXI1wyOg7/TFojKCyKzv+Adfn2hE4k+wDKl DI3jZ/atSDaAEZmzlmGBncR5yOZWy4taUp3tMoOLjqzqlsy8Z4Gxz7TnELqPvPiA84 Sc3daMmrLe9Fxn0SFCfRQ4uacS+2HvI80EDpBY4PxvpLH9W2BkEm1myXJR31ClMRGb 4yngVYRbe8aYg== Date: Mon, 12 Oct 2026 19:20:17 +0100 From: "Lorenzo Stoakes (ARM)" To: "David Hildenbrand (Arm)" Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , 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" , 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 , 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, Ihor Solodrai , Bert Karwatzki Subject: Re: [PATCH v5 21/38] uprobes: remove VM_IO, set VM_MIXEDMAP for mapped kernel pages Message-ID: References: <20261009-b4-mmap-prepare-vma-flag-sanify-v5-0-923b70125b1e@kernel.org> <20261009-b4-mmap-prepare-vma-flag-sanify-v5-21-923b70125b1e@kernel.org> <6f71b1b0-8988-4e19-9d4a-ce8a2de8fc63@kernel.org> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6f71b1b0-8988-4e19-9d4a-ce8a2de8fc63@kernel.org> On Mon, Oct 12, 2026 at 08:16:56PM +0200, David Hildenbrand (Arm) wrote: > On 10/9/26 20:04, Lorenzo Stoakes (ARM) wrote: > > 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. > > > > Reviewed-by: Suren Baghdasaryan > > 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); > > So these can now be GUP'ed. Let's hope that's fine ;) Yeah the commit message mentions that. Since they're refcounted I don't think there's any problem. > > Acked-by: David Hildenbrand (Arm) Thanks! > > -- > Cheers, > > David -- Cheers, Lorenzo