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Sun, 06 Apr 2025 23:03:30 -0400 X-MC-Unique: o_2yWg37M9-P3nYTSprhoA-1 X-Mimecast-MFC-AGG-ID: o_2yWg37M9-P3nYTSprhoA_1743995008 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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3A4521956048; Mon, 7 Apr 2025 03:03:28 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (unknown [10.72.112.15]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7294E180094A; Mon, 7 Apr 2025 03:03:20 +0000 (UTC) From: Baoquan He To: linux-mm@kvack.org Cc: akpm@linux-foundation.org, osalvador@suse.de, david@redhat.com, mingo@kernel.org, yanjun.zhu@linux.dev, linux-kernel@vger.kernel.org, Baoquan He Subject: [PATCH v3 0/3] mm/gup: Minor fix, cleanup and improvements Date: Mon, 7 Apr 2025 11:03:03 +0800 Message-ID: <20250407030306.411977-1-bhe@redhat.com> MIME-Version: 1.0 Content-type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Rspamd-Queue-Id: D5C5818000B X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: 7hprpbf6bxuhg7u3ozhhbk49yymwjds3 X-HE-Tag: 1743995014-143344 X-HE-Meta: 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 WkTh1Fsu AEQicgUlP9x55LwZyScy83RQAzsPSuGo6QXk2BRasWMdmQVs6L01vf8XbehdiMvSTtG4+83wzuj3TjTgpMlr/9L2Yyrq/RFYfvVy7qqbLe7q2bQ866rMwqzYKKshFM/SPWJzBjJypW01p52cZqbMSMnRdNdEDmq3Z9NTPxU9/BuCZYGrinRN9e/FjOdmLuZve3oYVY/j7rgCMExIiINrd3VOIgIPfyNJAsWb2n2dGeAzhN5r0+8heAkwGDTzSIo+UWzEwKT4dgghFLUNqhpRtlP3lUPmGlXMfvVZbzICLbXUQNhll5wB9Tbbe6w== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: These are made when I explore codes in mm/gup.c. v2->v3: ========= - In patch 1, change to use local variable 'start' as a loop cursor in fault_in_readable() and fault_in_writeable() so that they have the consistent code style with fault_in_safe_writeable(). Doing this can avoid ugly long line caused by kinds of type cast (const char __user *). Thanks to David who suggested two ways including this one, I found this is better when changing code. - In patch2, changes to add VM_WARN_ON_ONCE() for both below chekcing because all external users of __get_user_pages() have done the checking in is_valid_gup_args() before calling __get_user_pages(). Just adding these VM_WARN_ON_ONCE() in case, e.g internal setting wrong flags in kernel code. Thanks to David for suggesting this. - (gup_flags & (FOLL_PIN | FOLL_GET)) == (FOLL_PIN | FOLL_GET)) - !!pages != !!(gup_flags & (FOLL_GET | FOLL_PIN)) - Drop - the old patch 3 of v2 because it's from misunderstanding; - the old patch 4, 5 of v2 because they have been merged into x86 tip tree by Ingo; - the old patch 7 of v2 because it has been coverred in another thread. Thanks to David for telling the thread link. - In patch 3, add reviewing tags from Oscar and David. v1->v2: ========== - In patch 1, I carelessly copied the fault_in_readable() as fault_in_writeable(). Thanks to Yanjun for pointing it out. - In patch 2, I copied the code in follow_page_pte() to __get_user_pages() directly w/o adjustment which is done but not merged to patch. That failed testing taken by lkp test robot, thanks for reporting. Baoquan He (3): mm/gup: fix wrongly calculated returned value in fault_in_safe_writeable() mm/gup: remove unneeded checking in follow_page_pte() mm/gup: remove gup_fast_pgd_leaf() and clean up the relevant codes mm/gup.c | 100 ++++++++++++++++--------------------------------------- 1 file changed, 28 insertions(+), 72 deletions(-) -- 2.41.0