On Mon, Aug 22, 2016 at 11:35:36AM +0530, Aneesh Kumar K.V wrote: > Balbir Singh <bsinghar...@gmail.com> writes: > > > ISA 3 allows for prevention of instruction fetch and execution > > of user mode pages. If such an error occurs, SRR1 bit 35 > > reports the error. We catch and report the error in do_page_fault() > > > > But what does the error mean ? A buggy application ? IIUC, it indicate a > buggy kernel isn't it ?. So should we kill the application or panic() ? >
We oops.. basically we get a kernel fault. We handle it the same way we handle other kernel faults. > > > Signed-off-by: Balbir Singh <bsinghar...@gmail.com> > > --- > > arch/powerpc/mm/fault.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c > > index a4db22f..f162e77 100644 > > --- a/arch/powerpc/mm/fault.c > > +++ b/arch/powerpc/mm/fault.c > > @@ -404,6 +404,10 @@ good_area: > > (cpu_has_feature(CPU_FTR_NOEXECUTE) || > > !(vma->vm_flags & (VM_READ | VM_WRITE)))) > > goto bad_area; > > +#ifdef CONFIG_PPC_RADIX_MMU > > + if (radix_enabled() && regs->msr & PPC_BIT(35)) > > + goto bad_area; > > +#endif > > #ifdef CONFIG_PPC_STD_MMU > > /* > > * protfault should only happen due to us > > -aneesh >
