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[172.10.233.147]) by smtp.gmail.com with ESMTPSA id i133-20020a816d8b000000b0056953ab06c5sm114950ywc.95.2023.06.08.12.37.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Jun 2023 12:37:52 -0700 (PDT) Date: Thu, 8 Jun 2023 12:37:48 -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 , Peter Zijlstra , Russell King , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Greg Ungerer , Michal Simek , Thomas Bogendoerfer , Helge Deller , John David Anglin , "Aneesh Kumar K.V" , Michael Ellerman , Alexandre Ghiti , Palmer Dabbelt , Heiko Carstens , Christian Borntraeger , Claudio Imbrenda , Alexander Gordeev , John Paul Adrian Glaubitz , "David S. Miller" , Chris Zankel , Max Filippov , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 23/23] xtensa: add pte_unmap() to balance pte_offset_map() In-Reply-To: Message-ID: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230608_123754_233337_6A285AD5 X-CRM114-Status: GOOD ( 14.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org To keep balance in future, remember to pte_unmap() after a successful pte_offset_map(). And act as if get_pte_for_vaddr() really needs a map there, to read the pteval before "unmapping", to be sure page table is not removed. Signed-off-by: Hugh Dickins --- arch/xtensa/mm/tlb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/xtensa/mm/tlb.c b/arch/xtensa/mm/tlb.c index 27a477dae232..0a11fc5f185b 100644 --- a/arch/xtensa/mm/tlb.c +++ b/arch/xtensa/mm/tlb.c @@ -179,6 +179,7 @@ static unsigned get_pte_for_vaddr(unsigned vaddr) pud_t *pud; pmd_t *pmd; pte_t *pte; + unsigned int pteval; if (!mm) mm = task->active_mm; @@ -197,7 +198,9 @@ static unsigned get_pte_for_vaddr(unsigned vaddr) pte = pte_offset_map(pmd, vaddr); if (!pte) return 0; - return pte_val(*pte); + pteval = pte_val(*pte); + pte_unmap(pte); + return pteval; } enum {