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[2003:cb:c715:ee00:4e24:cf8e:3de0:8819]) by smtp.gmail.com with ESMTPSA id n14-20020adfe78e000000b0032196c508e3sm1612224wrm.53.2023.10.06.05.57.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 06 Oct 2023 05:57:37 -0700 (PDT) Message-ID: <4131ade7-c790-053c-99cb-3544f3c6523d@redhat.com> Date: Fri, 6 Oct 2023 14:57:35 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH v2 4/4] mm/gup: adapt get_user_page_vma_remote() to never return NULL To: Lorenzo Stoakes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Catalin Marinas , Will Deacon , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland Cc: Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Oleg Nesterov , Richard Cochran , Jason Gunthorpe , John Hubbard , Arnd Bergmann References: <00319ce292d27b3aae76a0eb220ce3f528187508.1696288092.git.lstoakes@gmail.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: <00319ce292d27b3aae76a0eb220ce3f528187508.1696288092.git.lstoakes@gmail.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4C2511C0011 X-Rspam-User: X-Stat-Signature: oyajunxyk173rna31n5agr8ga8sf3zi9 X-Rspamd-Server: rspam01 X-HE-Tag: 1696597061-91184 X-HE-Meta: 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 9660GLVy 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 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: On 03.10.23 01:14, Lorenzo Stoakes wrote: > get_user_pages_remote() will never return 0 except in the case of > FOLL_NOWAIT being specified, which we explicitly disallow. > > This simplifies error handling for the caller and avoids the awkwardness of > dealing with both errors and failing to pin. Failing to pin here is an > error. > > Suggested-by: Arnd Bergmann > Reviewed-by: Arnd Bergmann > Acked-by: Catalin Marinas > Signed-off-by: Lorenzo Stoakes > --- Reviewed-by: David Hildenbrand -- Cheers, David / dhildenb