* Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > On Mon, Nov 30, 2015 at 01:52:10PM -0800, Kees Cook wrote: > > On Wed, Nov 25, 2015 at 11:51 PM, Ingo Molnar <mingo@xxxxxxxxxx> wrote: > > > * Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > >> +#ifdef CONFIG_DEBUG_RODATA > > > > > > Btw., could you please remove the Kconfig option altogether in an additional patch > > > and make read-only sections an always-on feature? It has been default-y for years > > > and all distros have it enabled. > > > > Yeah, this is something I've wanted to do for a while, but I would > > point out that only a few architectures have actually implemented it, > > and for arm and arm64 it was very recent: > > I don't think it can entirely be a kernel command line option. On ARM, > enabling DEBUG_RODATA has a substantial effect on the size of the kernel > image - we have to pad various sections to 1MB boundaries so we can > set the appropriate permissions. > > Forcing this layout on everyone won't work. Yeah, so I'd suggest to have it always-on on x86 (after adding the boot option), to simplify the x86 code and to make it more obvious that we rely on this. There's a moderate amount of #ifdeffery around this: triton:~/tip> git grep -w CONFIG_DEBUG_RODATA arch/x86/ | grep \# | wc -l 15 Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
