From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v2 23/31] arm64: Debugging support Date: Mon, 20 Aug 2012 20:10:59 +0000 Message-ID: <201208202010.59985.arnd@arndb.de> References: <1344966752-16102-1-git-send-email-catalin.marinas@arm.com> <20120820090754.GB25864@mudshark.cambridge.arm.com> <20120820092744.GD25864@mudshark.cambridge.arm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from moutng.kundenserver.de ([212.227.17.9]:51140 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752226Ab2HTULG (ORCPT ); Mon, 20 Aug 2012 16:11:06 -0400 In-Reply-To: <20120820092744.GD25864@mudshark.cambridge.arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Will Deacon Cc: Catalin Marinas , "linux-arch@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "ulrich.weigand@linaro.org" On Monday 20 August 2012, Will Deacon wrote: > On Mon, Aug 20, 2012 at 10:07:54AM +0100, Will Deacon wrote: > > On Fri, Aug 17, 2012 at 08:06:07AM +0100, Arnd Bergmann wrote: > > > Sorry for the dumb question, but why do you even need PTRACE_GET_THREAD_AREA > > > for 64 bit tasks? I thought the thread pointer is a GPR, or is this just > > > for compat tasks? > > > > The TLS is stored in a co-processor register which is read-only for > > userspace. > > I should elaborate: the register is RW for AArch64 tasks, RO for aarch32 > tasks (although that doesn't affect the need for the ptrace request). So can't you just /add/ that register to the GPR regset? Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Mon, 20 Aug 2012 20:10:59 +0000 Subject: [PATCH v2 23/31] arm64: Debugging support In-Reply-To: <20120820092744.GD25864@mudshark.cambridge.arm.com> References: <1344966752-16102-1-git-send-email-catalin.marinas@arm.com> <20120820090754.GB25864@mudshark.cambridge.arm.com> <20120820092744.GD25864@mudshark.cambridge.arm.com> Message-ID: <201208202010.59985.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Monday 20 August 2012, Will Deacon wrote: > On Mon, Aug 20, 2012 at 10:07:54AM +0100, Will Deacon wrote: > > On Fri, Aug 17, 2012 at 08:06:07AM +0100, Arnd Bergmann wrote: > > > Sorry for the dumb question, but why do you even need PTRACE_GET_THREAD_AREA > > > for 64 bit tasks? I thought the thread pointer is a GPR, or is this just > > > for compat tasks? > > > > The TLS is stored in a co-processor register which is read-only for > > userspace. > > I should elaborate: the register is RW for AArch64 tasks, RO for aarch32 > tasks (although that doesn't affect the need for the ptrace request). So can't you just /add/ that register to the GPR regset? Arnd