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[172.10.233.147]) by smtp.gmail.com with ESMTPSA id b8-20020a252e48000000b00c61af359b15sm750774ybn.43.2023.07.11.21.30.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 Jul 2023 21:30:53 -0700 (PDT) Date: Tue, 11 Jul 2023 21:30:40 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@ripple.attlocal.net To: Andrew Morton Subject: [PATCH v3 01/13] mm/pgtable: add rcu_read_lock() and rcu_read_unlock()s In-Reply-To: <7cd843a9-aa80-14f-5eb2-33427363c20@google.com> Message-ID: References: <7cd843a9-aa80-14f-5eb2-33427363c20@google.com> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Miaohe Lin , David Hildenbrand , Peter Zijlstra , Yang Shi , Peter Xu , linux-kernel@vger.kernel.org, Song Liu , sparclinux@vger.kernel.org, Alexander Gordeev , Claudio Imbrenda , Will Deacon , linux-s390@vger.kernel.org, Yu Zhao , Ira Weiny , Alistair Popple , Russell King , Matthew Wilcox , Steven Price , Christoph Hellwig , Jason Gunthorpe , "Aneesh Kumar K.V" , Zi Yan , Huang Ying , Axel Rasmussen , Gerald Schaefer , Christian Borntraeger , Thomas Hellstrom , Ralph Campbell , Pasha Tatashin , Vasily Gorbik , Anshuman Khandual , Heiko Carstens , Qi Zheng , Suren Baghdasaryan , Vlastimil Babka , linux-arm-kernel@lists.infradead.org, SeongJae Park , Lorenzo Stoakes , Jann Horn , linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Naoya Horiguchi , Zack Rusin , Vishal Moola , Minchan Kim , "Kirill A. Shutemov" , Mel Gorman , "David S. Miller" , Mike Rapoport , Mike Kravetz Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 5063b482e34f..5134edcec668 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 4d454953046f..400e5a045848 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; }