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[172.10.233.147]) by smtp.gmail.com with ESMTPSA id z7-20020a81a247000000b00560c2e3ec63sm3404765ywg.77.2023.05.28.23.14.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 28 May 2023 23:15:00 -0700 (PDT) Date: Sun, 28 May 2023 23:14:48 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@ripple.attlocal.net To: Andrew Morton cc: Mike Kravetz , Mike Rapoport , "Kirill A. Shutemov" , Matthew Wilcox , David Hildenbrand , Suren Baghdasaryan , Qi Zheng , Yang Shi , Mel Gorman , Peter Xu , Peter Zijlstra , Will Deacon , Yu Zhao , Alistair Popple , Ralph Campbell , Ira Weiny , Steven Price , SeongJae Park , Naoya Horiguchi , Christophe Leroy , Zack Rusin , Jason Gunthorpe , Axel Rasmussen , Anshuman Khandual , Pasha Tatashin , Miaohe Lin , Minchan Kim , Christoph Hellwig , Song Liu , Thomas Hellstrom , Russell King , "David S. Miller" , Michael Ellerman , "Aneesh Kumar K.V" , Heiko Carstens , Christian Borntraeger , Claudio Imbrenda , Alexander Gordeev , Jann Horn , linux-arm-kernel@lists.infradead.org, sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 01/12] mm/pgtable: add rcu_read_lock() and rcu_read_unlock()s In-Reply-To: <35e983f5-7ed3-b310-d949-9ae8b130cdab@google.com> Message-ID: <88c445ae-552-5243-31a4-2674bac62d4d@google.com> References: <35e983f5-7ed3-b310-d949-9ae8b130cdab@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Rspamd-Queue-Id: 4918C40002 X-Rspam-User: X-Stat-Signature: s5uh9smxheyjzenqbh8g8wr9zu1emarx X-Rspamd-Server: rspam01 X-HE-Tag: 1685340901-786411 X-HE-Meta: U2FsdGVkX1+aVQ+3IqeJzHcYOrseJs8eLsiOkNPx8A0QQ2WoAKy5BM6oGJZBvQbnhjD3Il19BfmE9959Xi2XieR06G5SbWQJpt1dR5v3JriMvNGfYQb+TXE6O4UgIb1mCL/CiYefxiyktbzbG45pS4U60DFekh4NzN8UzJgV2lSWwba/g24riE9PVY8TdIRxOQRU1k0ETNcKQRdXyzNQzv6UdfwEwSjo/qUCvzyiPivzlFyd5SsDcgNR7XA0DCtWmBx8G+FMqtLLIt/RJv/bWHLvzr+3eVZdT4QEFb9kNlWtLF20nCss5X7X78M+V/5bv8ZI9AzS+COjdE5uhAJSfHnj1ac7od1LdKWNE1FCb3gr0h489Wc8sRw6RRO38fFgFb7C55qR7mw1YOkRHr8cey0pcOGyAaY7uZ7jdXCoOiefcm1ghmcGLjggFRgYM+8uC8LjY3KARTsd1E8NBOyHgFJAFpdhqp1jKYx0qjAgIPYwpOkN8g4HtBuVZabBtxIjW7U1dJN00ZFHdWRepDUPK5M/lOvTUs5QA4aJL+vX91fPU0fHl4HwJmkcFiATciCBh5GJXJ3mSkcdDRaDtXQzTPLh+AvoBN7PeOvasXLo8urspL/oSgTgVI8cTdAnhdo2LYRGmi0aE+87tqX+E2YOJNCVg2OEcZQxCct4NJsSz1Netqi4Xe/NXgetnuFJT77C+OQD3FxmmQRUhwoMLXyl24811GywV6PWEi+6o5mzzsJkCD2MrFsfsK27D7c3HVUQALJ6/4kVs0/2oXqUH8HJuslXNyPZCTrVztniQtQB26PcOxS9KslzpyHAvnTAdjU8oSyrNNuvV5JBgr7ppVkomHGzUc+L2CmUBqo3hln9W8Br2iW9l03ryxf900tejeIuvd45OZmwHJFzStq6nMI+Vi2wMYs0WELLzQK+ouExfE97THkvd6ChPdjwHDMsT5ZS8J74X4xTSoHzUEKcoKE Vl8aisi4 CLVJJCA2BN5ZESgph16htpKm2nwCruVtsYewxbPkURWN14XXQdNrae0cw3e5VWxAu8ZuKdo8BnBEQbQs60VJUAfD8PZFW6euIA8h9tnQURaIquThm/AX+/INCN5lRG058idFyQcHMNonbRj8zVUsdXaIWgczdYvXo1KGcEpA8ffftK7Icv+UKjrW5pnXtpUbQkOchGysTEEw0zlmy+Eh6csCtvTWnPfjNyLSOrSVwjmhgyZKSaAK1Svn1ZE+14PQlLPKMAVMMybgrLcC4HerOhgPqcVSfB7vytmcHysaJlR9oHoIWQuuqxzxMPKluyyOkMc9/DsiDdAssVTUjATs8/8uVZJo18hsL5lOJGtVVv4UnVzXf2cFHqQsH3GHBSM60tb3p/h/wu/VV2m4KXCitGtCfVLOLTQb/9NFE8D6FY4P2WPLXlV+yADwYyA== 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: Before putting them to use (several commits later), add rcu_read_lock() to pte_offset_map(), and rcu_read_unlock() to pte_unmap(). Make this a separate commit, since it risks exposing imbalances: prior commits have fixed all the known imbalances, but we may find some have been missed. Signed-off-by: Hugh Dickins --- include/linux/pgtable.h | 4 ++-- mm/pgtable-generic.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index a1326e61d7ee..8b0fc7fdc46f 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -99,7 +99,7 @@ static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address) ((pte_t *)kmap_local_page(pmd_page(*(pmd))) + pte_index((address))) #define pte_unmap(pte) do { \ kunmap_local((pte)); \ - /* rcu_read_unlock() to be added later */ \ + rcu_read_unlock(); \ } while (0) #else static inline pte_t *__pte_map(pmd_t *pmd, unsigned long address) @@ -108,7 +108,7 @@ static inline pte_t *__pte_map(pmd_t *pmd, unsigned long address) } static inline void pte_unmap(pte_t *pte) { - /* rcu_read_unlock() to be added later */ + rcu_read_unlock(); } #endif diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c index c7ab18a5fb77..674671835631 100644 --- a/mm/pgtable-generic.c +++ b/mm/pgtable-generic.c @@ -236,7 +236,7 @@ pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp) { pmd_t pmdval; - /* rcu_read_lock() to be added later */ + rcu_read_lock(); pmdval = pmdp_get_lockless(pmd); if (pmdvalp) *pmdvalp = pmdval; @@ -250,7 +250,7 @@ pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp) } return __pte_map(&pmdval, addr); nomap: - /* rcu_read_unlock() to be added later */ + rcu_read_unlock(); return NULL; } -- 2.35.3