On Wed, Jun 07, 2017 at 02:34:40PM +0200, Martin Schwidefsky wrote:
> +#define arch_elf_pt_proc(ehdr, phdr, elf, interp, state) \
> +({ \
> + struct elf64_hdr *_ehdr = (void *) ehdr; \
> + struct elf64_phdr *_phdr = (void *) phdr; \
> + int _rc = 0; \
> + if (_ehdr->e_ident[EI_CLASS] == ELFCLASS64 && \
> + _phdr->p_type == PT_S390_REQUEST_PGSTE && \
> + !page_table_allocate_pgste && \
> + !test_thread_flag(TIF_REQUEST_PGSTE)) { \
> + set_thread_flag(TIF_REQUEST_PGSTE); \
> + set_pt_regs_flag(task_pt_regs(current), \
> + PIF_SYSCALL_RESTART); \
> + _rc = -EAGAIN; \
> + } \
> + _rc; \
> +})
I'm wondering if this should simply fail, if a PT_S390_REQUEST_PGSTE type
segment exists, but it is not ELFCLASS64?
It will fail later anyway on s390_enable_sie(), but...
> diff --git a/arch/s390/include/asm/mmu_context.h
> b/arch/s390/include/asm/mmu_context.h
> index c119d564d8f2..1201b18e817d 100644
> --- a/arch/s390/include/asm/mmu_context.h
> +++ b/arch/s390/include/asm/mmu_context.h
> @@ -25,7 +25,8 @@ static inline int init_new_context(struct task_struct *tsk,
> mm->context.gmap_asce = 0;
> mm->context.flush_mm = 0;
> #ifdef CONFIG_PGSTE
> - mm->context.alloc_pgste = page_table_allocate_pgste;
> + mm->context.alloc_pgste = page_table_allocate_pgste ||
> + test_thread_flag(TIF_REQUEST_PGSTE);
I think the alloc_pgste flag should be inherited on fork, no?
