From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Naveen N. Rao" Subject: Re: [PATCH 3/5] powerpc64: Add .opd based function descriptor dereference Date: Sat, 16 Sep 2017 15:13:45 +0530 Message-ID: <20170916094345.d332z3odceqiyrll@naverao1-tp.localdomain> References: <20170916035347.19705-1-sergey.senozhatsky@gmail.com> <20170916035347.19705-4-sergey.senozhatsky@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Tony Luck , Fenghua Yu , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , "James E . J . Bottomley" , Helge Deller , Petr Mladek , linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, Alexei Starovoitov , Steven Rostedt , linux-kernel@vger.kernel.org, Jessica Yu , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Nicholas Piggin To: Sergey Senozhatsky Return-path: In-Reply-To: <20170916035347.19705-4-sergey.senozhatsky@gmail.com> List-ID: List-Id: linux-parisc.vger.kernel.org On 2017/09/16 12:53PM, Sergey Senozhatsky wrote: > We are moving towards separate kernel and module function descriptor > dereference callbacks. This patch enables it for powerpc64. > > For pointers that belong to the kernel > - Added __start_opd and __end_opd pointers, to track the kernel > .opd section address range; > > - Added dereference_kernel_function_descriptor(). Now we > will dereference only function pointers that are within > [__start_opd, __end_opd]; > > For pointers that belong to a module > - Added dereference_module_function_descriptor() to handle module > function descriptor dereference. Now we will dereference only > pointers that are within [module->opd.start, module->opd.end]. Would it be simpler to just use kernel_text_address() and dereference everything else? See commit 83e840c770f2c5 ("powerpc64/elfv1: Only dereference function descriptor for non-text symbols") for a related patch. - Naveen From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Naveen N. Rao" Date: Sat, 16 Sep 2017 09:55:45 +0000 Subject: Re: [PATCH 3/5] powerpc64: Add .opd based function descriptor dereference Message-Id: <20170916094345.d332z3odceqiyrll@naverao1-tp.localdomain> List-Id: References: <20170916035347.19705-1-sergey.senozhatsky@gmail.com> <20170916035347.19705-4-sergey.senozhatsky@gmail.com> In-Reply-To: <20170916035347.19705-4-sergey.senozhatsky@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Sergey Senozhatsky Cc: Tony Luck , Fenghua Yu , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , "James E . J . Bottomley" , Helge Deller , Petr Mladek , linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, Alexei Starovoitov , Steven Rostedt , linux-kernel@vger.kernel.org, Jessica Yu , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Nicholas Piggin On 2017/09/16 12:53PM, Sergey Senozhatsky wrote: > We are moving towards separate kernel and module function descriptor > dereference callbacks. This patch enables it for powerpc64. > > For pointers that belong to the kernel > - Added __start_opd and __end_opd pointers, to track the kernel > .opd section address range; > > - Added dereference_kernel_function_descriptor(). Now we > will dereference only function pointers that are within > [__start_opd, __end_opd]; > > For pointers that belong to a module > - Added dereference_module_function_descriptor() to handle module > function descriptor dereference. Now we will dereference only > pointers that are within [module->opd.start, module->opd.end]. Would it be simpler to just use kernel_text_address() and dereference everything else? See commit 83e840c770f2c5 ("powerpc64/elfv1: Only dereference function descriptor for non-text symbols") for a related patch. - Naveen