Hi Kees, On Fri, Jan 22, 2016 at 8:57 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > On Fri, Jan 22, 2016 at 11:16 AM, Laura Abbott <laura@xxxxxxxxxxxx> wrote: >> Kees had previously pushed a patch to do so but it exposed a couple of >> underlying issues, mostly with low power paths >> (c.f. http://article.gmane.org/gmane.linux.ports.arm.kernel/471199, >> http://article.gmane.org/gmane.linux.kernel.mm/143489) >> Those will need to be all fixed up before this could be made default. I'm working on fixing that... BTW, making the sections read-only is done quite late in the kernel startup process, which means it doesn't trigger for the writes to the text segment in secondary CPU bringup, but only for suspend/resume. > Yeah, I've got a patch waiting to reorganize CONFIG_ARM_KERNMEM_PERMS > to look more like arm64 (and x86) and get the feature correctly under > CONFIG_DEBUG_RODATA. I made it default=y on v7+. rmk asked me to wait > until -rc1 before resubmitting it. > > http://git.kernel.org/cgit/linux/kernel/git/kees/linux.git/commit/?h=kspp/arm-rodata&id=08bebfd2e7fb8a9f364ced74c356642d64e1f43e One other concern is indeed memory usage ("ALIGN(1<<SECTION_SHIFT)"?). Enabling CONFIG_ARM_KERNMEM_PERMS and CONFIG_DEBUG_RODATA in my test kernel configs make the kernel too big to boot (overwritten DTB?) for 3 out of 4 arm shmobile targets... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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
