From: Florian Weimer Subject: Re: [PATCH v9 00/51] powerpc, mm: Memory Protection Keys Date: Mon, 06 Nov 2017 22:28:41 +0100 Message-ID: <87efpbm706.fsf@mid.deneb.enyo.de> References: <1509958663-18737-1-git-send-email-linuxram@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1509958663-18737-1-git-send-email-linuxram@us.ibm.com> (Ram Pai's message of "Mon, 6 Nov 2017 00:56:52 -0800") Sender: linux-kernel-owner@vger.kernel.org To: Ram Pai Cc: mpe@ellerman.id.au, mingo@redhat.com, akpm@linux-foundation.org, corbet@lwn.net, arnd@arndb.de, linux-arch@vger.kernel.org, ebiederm@xmission.com, linux-doc@vger.kernel.org, x86@kernel.org, dave.hansen@intel.com, linux-kernel@vger.kernel.org, mhocko@kernel.org, linux-mm@kvack.org, paulus@samba.org, aneesh.kumar@linux.vnet.ibm.com, linux-kselftest@vger.kernel.org, bauerman@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, khandual@linux.vnet.ibm.com List-Id: linux-arch.vger.kernel.org * Ram Pai: > Testing: > ------- > This patch series has passed all the protection key > tests available in the selftest directory.The > tests are updated to work on both x86 and powerpc. > The selftests have passed on x86 and powerpc hardware. How do you deal with the key reuse problem? Is it the same as x86-64, where it's quite easy to accidentally grant existing threads access to a just-allocated key, either due to key reuse or a changed init_pkru parameter? What about siglongjmp from a signal handler? I wonder if it's possible to fix some of these things before the exact semantics of these interfaces are set in stone.