On Tue, Oct 01, 2019 at 10:03:56AM +0100, Will Deacon wrote: > Hi Kees, > > On Thu, Sep 26, 2019 at 10:55:51AM -0700, Kees Cook wrote: > > The EXCEPTION_TABLE is read-only, so collapse it into RO_DATA. > > > > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > > --- > > arch/arm64/kernel/vmlinux.lds.S | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S > > index 81d94e371c95..c6ba2eee0ee8 100644 > > --- a/arch/arm64/kernel/vmlinux.lds.S > > +++ b/arch/arm64/kernel/vmlinux.lds.S > > @@ -5,6 +5,8 @@ > > * Written by Martin Mares <mj@xxxxxxxxxxxxxxxxxxxxxxxx> > > */ > > > > +#define RO_DATA_EXCEPTION_TABLE_ALIGN 8 > > + > > #include <asm-generic/vmlinux.lds.h> > > #include <asm/cache.h> > > #include <asm/kernel-pgtable.h> > > @@ -135,8 +137,8 @@ SECTIONS > > . = ALIGN(SEGMENT_ALIGN); > > _etext = .; /* End of text section */ > > > > - RO_DATA(PAGE_SIZE) /* everything from this point to */ > > - EXCEPTION_TABLE(8) /* __init_begin will be marked RO NX */ > > + /* everything from this point to __init_begin will be marked RO NX */ > > + RO_DATA(PAGE_SIZE) > > > > . = ALIGN(PAGE_SIZE); > > Do you reckon it would be worth merging this last ALIGN directive into the > RO_DATA definition too? Given that we want to map the thing read-only, it > really has to be aligned either side. Actually, taking a closer look, this appears to be redundant: RO_DATA() ends with: . = ALIGN(align) (where "align" is the "PAGE_SIZE" argument to RO_DATA()) > Anyway, that's only a nit, so: > > Acked-by: Will Deacon <will@xxxxxxxxxx> Thanks! > P.S. Please CC the arm64 maintainers on arm64 patches -- I nearly missed > this one! Okay, I can re-expand my list. I originally had done this but it was getting to be a rather large set of people. :) -- Kees Cook
