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[172.10.233.147]) by smtp.gmail.com with ESMTPSA id p185-20020a0dcdc2000000b0055a72f6a462sm2214413ywd.19.2023.05.09.21.43.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 May 2023 21:43:50 -0700 (PDT) Date: Tue, 9 May 2023 21:43:47 -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 , 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 , 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 02/23] arm64: allow pte_offset_map() to fail In-Reply-To: <77a5d8c-406b-7068-4f17-23b7ac53bc83@google.com> Message-ID: References: <77a5d8c-406b-7068-4f17-23b7ac53bc83@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org In rare transient cases, not yet made possible, pte_offset_map() and pte_offset_map_lock() may not find a page table: handle appropriately. Signed-off-by: Hugh Dickins Acked-by: Catalin Marinas --- arch/arm64/mm/fault.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 9e0db5c387e3..a58780d5fac4 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -177,6 +177,9 @@ static void show_pte(unsigned long addr) break; ptep = pte_offset_map(pmdp, addr); + if (!ptep) + break; + pte = READ_ONCE(*ptep); pr_cont(", pte=%016llx", pte_val(pte)); pte_unmap(ptep);