On 04/01/2017 at 11:57:00 +0100, Julia Lawall wrote : > > > On Tue, 3 Jan 2017, Russell King - ARM Linux wrote: > > > On Tue, Jan 03, 2017 at 09:31:18PM +0000, Russell King - ARM Linux wrote: > > > On Tue, Jan 03, 2017 at 01:18:29PM -0800, Kees Cook wrote: > > > > On Mon, Jan 2, 2017 at 6:06 AM, Russell King - ARM Linux > > > > <li...@armlinux.org.uk> wrote: > > > > > On Mon, Dec 26, 2016 at 05:01:02PM +0530, Bhumika Goyal wrote: > > > > >> The object armada38x_rtc_ops of type rtc_class_ops structure is not > > > > >> modified after getting initialized by armada38x_rtc_probe. Apart from > > > > >> getting referenced in init it is also passed as an argument to the > > > > >> function > > > > >> devm_rtc_device_register but this argument is of type const struct > > > > >> rtc_class_ops *. Therefore add __ro_after_init to its declaration. > > > > > > > > > > What I'd prefer here is for the structure to be duplicated, with one > > > > > copy having the alarm methods and one which does not. Both can then > > > > > be made "const" (so placed into the read-only section at link time) > > > > > and the probe function select between the two. > > > > > > > > > > I think that's a cleaner and better solution, even though it's > > > > > slightly larger. > > > > > > > > > > I'm not a fan of __ro_after_init being used where other solutions are > > > > > possible. > > > > > > > > Can the pointer that points to the struct rtc_class_ops be made > > > > ro_after_init? > > > > > > It's passed into the RTC core code, and probably stored in some > > > dynamically > > > allocated object, so probably no. It's the same class of problem as every > > > file_operations pointer in the kernel, or the thousand other operations > > > structure pointers that a running kernel has. > > I'm not sure to understand the question and the response. A quick check > with grep suggests that most rtc_class_ops pointers are already const. > There seem to be just some instances in specific drivers that are not. >
The question was whether the point to the rtc_class_ops could be made __ro_after_init. And Russell is right, it is pointed to by the ops pointer in a struct rtc_device and that struct is dynamically allocated in rtc_device_register(). -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- You received this message because you are subscribed to "rtc-linux". Membership options at http://groups.google.com/group/rtc-linux . Please read http://groups.google.com/group/rtc-linux/web/checklist before submitting a driver. --- You received this message because you are subscribed to the Google Groups "rtc-linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to rtc-linux+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
