On Wed, Jun 26, 2019 at 09:45:08PM -0700, Andy Lutomirski wrote: > The vDSO is only configurable by command-line options, so make its > global variables __ro_after_init. This seems highly unlikely to > ever stop an exploit, but I think it's nice anyway. > > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxxxx> > Cc: Kernel Hardening <kernel-hardening@xxxxxxxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -Kees > --- > arch/x86/entry/vsyscall/vsyscall_64.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c > index 9c58ab807aeb..07003f3f1bfc 100644 > --- a/arch/x86/entry/vsyscall/vsyscall_64.c > +++ b/arch/x86/entry/vsyscall/vsyscall_64.c > @@ -42,7 +42,7 @@ > #define CREATE_TRACE_POINTS > #include "vsyscall_trace.h" > > -static enum { EMULATE, XONLY, NONE } vsyscall_mode = > +static enum { EMULATE, XONLY, NONE } vsyscall_mode __ro_after_init = > #ifdef CONFIG_LEGACY_VSYSCALL_NONE > NONE; > #elif defined(CONFIG_LEGACY_VSYSCALL_XONLY) > @@ -305,7 +305,7 @@ static const char *gate_vma_name(struct vm_area_struct *vma) > static const struct vm_operations_struct gate_vma_ops = { > .name = gate_vma_name, > }; > -static struct vm_area_struct gate_vma = { > +static struct vm_area_struct gate_vma __ro_after_init = { > .vm_start = VSYSCALL_ADDR, > .vm_end = VSYSCALL_ADDR + PAGE_SIZE, > .vm_page_prot = PAGE_READONLY_EXEC, > -- > 2.21.0 > -- Kees Cook