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Wed, 19 Aug 2020 15:18:43 -0700 (PDT) MIME-Version: 1.0 From: Jirka Hladky Date: Thu, 20 Aug 2020 00:18:33 +0200 Message-ID: Subject: init_on_alloc/init_on_free boot options To: Alexander Potapenko Cc: kernel-hardening@lists.openwall.com, linux-mm@kvack.org, linux-security-module@vger.kernel.org Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jhladky@redhat.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 9584C37610 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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: Hi Alex, Could you please help me to clarify the purpose of init_on_alloc=1 when init_on_free is enabled? If I get it right, init_on_free=1 alone guarantees that the memory returned by the page allocator and SL[AU]B is initialized with zeroes. What is the purpose of init_on_alloc=1 in that case? We are zeroing memory twice, or am I missing something? Thanks a lot! Jirka