Messages in this thread | | | Date | Tue, 3 Jan 2017 21:31:18 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH] rtc: armada38x: add __ro_after_init to armada38x_rtc_ops |
| |
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 > <linux@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.
-- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
| |