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b=AnRBLrwiGydV55YKVxP1C2hTU/+iQo4dd8w0faa4jtVHR4jHZ5anUbKb5yZ5ye3XS ys1kla9pYrDzdZbLunoTrtdPNqqAUbKtu1CJ//68MFbQyh5y7aZhC46YK55JtaUZA5 ra5G2sERmBqf/UFx2SPaMVXfoiGS2kPxfZFkZNOUlVD19QOqS/SUV5MZU/mFGOVgDv IXn6OG9dtirrJO/Dh3vnNlqnjzdI4qDmljqWq0kBU+c0CiDbOdoWE/pFltLXqLokVT r19LtiBw6rEEkbg+nNadg08rNjWgfdZZVOpJ69iuykQqloruiT2sEewRtB7kCuWmPz qDl5PWv830HDA== From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= To: Alexandre Ghiti , Albert Ou , David Hildenbrand , Palmer Dabbelt , Paul Walmsley , linux-riscv@lists.infradead.org Cc: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Andrew Bresticker , Chethan Seshadri , Lorenzo Stoakes , Oscar Salvador , Santosh Mamila , Sivakumar Munnangi , Sunil V L , linux-kernel@vger.kernel.org, linux-mm@kvack.org, virtualization@lists.linux-foundation.org Subject: [PATCH v2 5/8] riscv: mm: Take memory hotplug read-lock during kernel page table dump Date: Tue, 14 May 2024 16:04:43 +0200 Message-Id: <20240514140446.538622-6-bjorn@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240514140446.538622-1-bjorn@kernel.org> References: <20240514140446.538622-1-bjorn@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Stat-Signature: uitxj6bb6y7pn9rhcfs5er7oojsqtb1r X-Rspamd-Queue-Id: ADA9F40032 X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1715695527-836127 X-HE-Meta: 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 iLl42j9p yWF+DfIUQnxdkqCv8E5/1l9hexRfemsFwX2b7jc4gcaSHz/6mbRcdqdv+N6JJSudYxJZKZFm1Z7RyVOrW51/plq8oPQkAoxFiL61S9zeCldaDFkdPybgRMQj2qJqKONnb8TWWinliAPKln4GnU8zfjFvshp5RT/Aye051TCQsse3NRKmzaysxEWWc7Sgm1UyUvfwOxygW3vKR645SZa8KyPQj1LHU+hc8u+ziINw7YGTIej1v9V7RDVF1YLx/B19OKvYX7ivM0cGpAzzcL7EgaFlfJ5EZmCIN12gbrQ93ROGqGMe2iBK1HVSjcZqrCUBPYJYs5b8dMux9lOTL5pCXNhV4SUjdjWbj1hULhGoz5xyk8mn13YEOHtnLEDM3Q+kb0qBf 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: List-Subscribe: List-Unsubscribe: From: Björn Töpel During memory hot remove, the ptdump functionality can end up touching stale data. Avoid any potential crashes (or worse), by holding the memory hotplug read-lock while traversing the page table. This change is analogous to arm64's commit bf2b59f60ee1 ("arm64/mm: Hold memory hotplug lock while walking for kernel page table dump"). Signed-off-by: Björn Töpel --- arch/riscv/mm/ptdump.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c index 1289cc6d3700..9d5f657a251b 100644 --- a/arch/riscv/mm/ptdump.c +++ b/arch/riscv/mm/ptdump.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include @@ -370,7 +371,9 @@ bool ptdump_check_wx(void) static int ptdump_show(struct seq_file *m, void *v) { + get_online_mems(); ptdump_walk(m, m->private); + put_online_mems(); return 0; } -- 2.40.1