On Mon, Nov 07, 2016 at 02:50:27PM -0500, Chris Metcalf wrote: > This is the minimal change to handle RO_AFTER_INIT_DATA. > The tile architecture already marks RO_DATA as read-only in > the kernel, so grouping RO_AFTER_INIT_DATA with RO_DATA, as is > done by default, means the kernel faults in init when it tries > to write to RO_AFTER_INIT_DATA. For now, just move it past the > end of the RODATA section so it is not specially treated. > --- > This is just to fix 4.9; I will post a more complete fix shortly > targeting 4.10. > > arch/tile/kernel/vmlinux.lds.S | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/tile/kernel/vmlinux.lds.S b/arch/tile/kernel/vmlinux.lds.S > index e1baf094fba4..dcd7445c31a2 100644 > --- a/arch/tile/kernel/vmlinux.lds.S > +++ b/arch/tile/kernel/vmlinux.lds.S > @@ -1,3 +1,6 @@ > +/* Handle ro_after_init data on our own. */ > +#define RO_AFTER_INIT_DATA > + > #include <asm-generic/vmlinux.lds.h> > #include <asm/page.h> > #include <asm/cache.h> > @@ -87,6 +90,7 @@ SECTIONS > > _sdata = .; /* Start of data section */ > RO_DATA_SECTION(PAGE_SIZE) > + RO_AFTER_INIT_DATA > RW_DATA_SECTION(L2_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE) > _edata = .;
imho, the minimal fix would be to just #define __ro_after_init __read_mostly within arch/tile/include/asm/cache.h. That's also what parisc currently has.
