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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id g25sm5314837pfo.150.2020.05.07.10.51.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2020 10:51:33 -0700 (PDT) Date: Thu, 7 May 2020 10:51:32 -0700 From: Kees Cook To: Anthony Yznaga Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, willy@infradead.org, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, rppt@linux.ibm.com, akpm@linux-foundation.org, hughd@google.com, ebiederm@xmission.com, masahiroy@kernel.org, ardb@kernel.org, ndesaulniers@google.com, dima@golovin.in, daniel.kiper@oracle.com, nivedita@alum.mit.edu, rafael.j.wysocki@intel.com, dan.j.williams@intel.com, zhenzhong.duan@oracle.com, jroedel@suse.de, bhe@redhat.com, guro@fb.com, Thomas.Lendacky@amd.com, andriy.shevchenko@linux.intel.com, hannes@cmpxchg.org, minchan@kernel.org, mhocko@kernel.org, ying.huang@intel.com, yang.shi@linux.alibaba.com, gustavo@embeddedor.com, ziqian.lzq@antfin.com, vdavydov.dev@gmail.com, jason.zeng@intel.com, kevin.tian@intel.com, zhiyuan.lv@intel.com, lei.l.li@intel.com, paul.c.lai@intel.com, ashok.raj@intel.com, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, kexec@lists.infradead.org Subject: Re: [RFC 21/43] x86/KASLR: PKRAM: support physical kaslr Message-ID: <202005071049.2D0939137D@keescook> References: <1588812129-8596-1-git-send-email-anthony.yznaga@oracle.com> <1588812129-8596-22-git-send-email-anthony.yznaga@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1588812129-8596-22-git-send-email-anthony.yznaga@oracle.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 06, 2020 at 05:41:47PM -0700, Anthony Yznaga wrote: > Avoid regions of memory that contain preserved pages when computing > slots used to select where to put the decompressed kernel. This is changing the slot-walking code instead of updating mem_avoid_overlap() -- that's where the check for a "reserved" memory area should live. For example, this is how both mem_avoid_memmap() and the setup_data memory areas are handled. Is there a reason mem_avoid_overlap() can't be used here? -- Kees Cook