From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794673061; b=MWMB4vUUDD1eLbAMatpM99myUIadd18DlPD1XC7E1u1A4Lv20XoZz/HUQFc9PlH9/4jx 8bLWVxTm65bE1XOfaSbTV6PfRASmy3oAjgSFkgRYD2Alh8YgFCgd4PYYyevYafeITZnJY n1y7If7KwYAquBa4p9O123IPnApt/eUFFZfL9YDUrDD0XlawelOSLkD9KU2ZjfzeD/Yxb 7AzlaRR5aT1ZSOSuuqPXLyCBP0TXbG4hZ7BQjWxbZUevGoEvqatWiBwTi5t8vLDXSL8Lr ut4ZqVlsNhL5uXygX97UA2ISiYRF3uUoVrNuRwyLzg1dXf/ef0ECTDKcY10UQMyEkrQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794673061; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:Content-Language:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=LG93qKhG+N0YzkKVt1kZxr2I4R5vNgIJxzUIUOArJxg=; b=WOHT+qkjVw731WEQ4eoM81sblzQkNk2iIE1drtweHevNSPsAusMLU6JNcBYspwGUqsMQ 6CeaaHzKz4f6U5AQJza6+laObrcPTkCdy9pSGtsTQ82GsS2YbMKrkfXImHjE3CH2dE32E pzVlvA/dF9rjeHi7ZbqgD4eqNAjjIbla3TxBP56ugDzQulykbESlNHDXnymkSsPkoCmRq 5fCncAGANpd/ZwX2OI9kzj0rRQYJ1O5UTslt7M2JQVT/89/E4zWr14vt7w1l9behyYXEG hYIvTfD/JiYIZrjXpqmi3dA+zEfoc2OBEV/NHXy/l74pZR2IoKEGivZeHFV+vJ0IoHQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=H+o0zQKe; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DB538606A323; Sat, 14 Nov 2026 16:17:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=H+o0zQKe Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B4631F000C5; Sat, 14 Nov 2026 16:17:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794673061; bh=LG93qKhG+N0YzkKVt1kZxr2I4R5vNgIJxzUIUOArJxg=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=H+o0zQKevrxN2RqI7ZiEvtvyYAmczSPPRUty+Me1GnOITblIdxrCfOPY1BtO+Qb3x FwLY8mphgY8Y8Tey96xcy7xmmtpXOpSJOR4lt1PbvUsFAyVyaHoYa4Z6kmpTrPhzmf Yejfri/UxWoUkzbk/4Pt0DpyHJuCVKE3oantMWAJ84BpkYO5csTlSFqjDF6REMmZSF pnbnVPelq5lrwhWx/avtuYaYXGpa/zk3XdGOysdZ5Nta1VFwSNJn3XmafKfjboFLxC Jamcx1VKWKOIZskFqsMxw0wgW7UcWmBsHxQWNmLb5E6/qRT/S50HIogXBoVDTkksUu hGy8wtvaqIfwg== Message-ID: Date: Sat, 14 Nov 2026 17:17:27 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/5] mm,drm/i915,powerpc/spufs: vm_ops->access related fixes To: Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Andrew Morton , Willy Tarreau , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Simona Vetter , Chris Wilson , Matthew Auld , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , "Ritesh Harjani (IBM)" , Shrikanth Hegde , Rik van Riel , Benjamin Herrenschmidt Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linuxppc-dev@lists.ozlabs.org, Chris Mason , stable@vger.kernel.org, Felix Kuehling , =?UTF-8?Q?Christian_K=C3=B6nig?= References: <20261112-access_shite-v1-0-988a5c470db2@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20261112-access_shite-v1-0-988a5c470db2@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/12/26 23:08, David Hildenbrand (Arm) wrote: > While working on vm_ops->access related fixes in core code for FOLL_ANON > and VMA access permission + size handling, I stumbled over two driver > issues. Also, I have to update one selftest that specifies PROT_WRITE > but actually wants read-access. > > Fixing it all in this series, because it's all intertwined. > > In patch #5 we break a debugging use case for older ROCm versions, where > the amdgpu driver hacked around it by exploiting broken access checks in > core-mm. > > Tested as good as I can with selftests. I cannot really test the > i915 and powerpc/spufs stuff on real hardware. > > Signed-off-by: David Hildenbrand (Arm) > --- > Chris Mason (1): > mm: do not call vm_ops->access with FOLL_ANON > > David Hildenbrand (Arm) (4): > drm/i915: consider vm_pgoff in vm_access() > drm/i915/selftests: request read access for mmap access tests > powerpc/spufs: consider vm_pgoff in spufs_mem_mmap_access() > mm: check permissions and bounds for vm_ops->access > > arch/powerpc/platforms/cell/spufs/file.c | 3 ++- > drivers/gpu/drm/i915/gem/i915_gem_mman.c | 4 +++- > drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c | 3 ++- > mm/memory.c | 28 ++++++++++++++++++++-- > 4 files changed, 33 insertions(+), 5 deletions(-) > We get some test failures regarding error handling: e.g., https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_178442v1/shard-glk6/igt@gem_mmap_offset@oob-read.html It's all about error handling. Before the correct handling in patch #5, we would pass a size that exceeds the actual VMA to vm_access(), and that one would return -EIO. In the test above 8 bytes whereby the VMA only allowed for 4 more bytes. Now we properly handle that in core code and get a partial read completion on the 4 bytes. I think the test should be fixed to expect a partial read completion. We won't hack around this in core-mm. -- Cheers, David