On Thu, Jun 30, 2016 at 5:05 PM, Borislav Petkov <[email protected]> wrote: > On Thu, Jun 30, 2016 at 03:17:20PM +0200, Rafael J. Wysocki wrote: >> From: Rafael J. Wysocki <[email protected]> >> >> Logan Gunthorpe reports that hibernation stopped working reliably for >> him after commit ab76f7b4ab23 (x86/mm: Set NX on gap between __ex_table >> and rodata). > > ... > >> +static int relocate_restore_code(void) >> +{ >> + pgd_t *pgd; >> + pud_t *pud; >> + >> + relocated_restore_code = get_safe_page(GFP_ATOMIC); >> + if (!relocated_restore_code) >> + return -ENOMEM; >> + >> + memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE); >> + >> + /* Make the page containing the relocated code executable */ >> + pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code); >> + pud = pud_offset(pgd, relocated_restore_code); >> + if (pud_large(*pud)) { >> + set_pud(pud, __pud(pud_val(*pud) & ~_PAGE_NX)); >> + } else { >> + pmd_t *pmd = pmd_offset(pud, relocated_restore_code); >> + >> + if (pmd_large(*pmd)) { >> + set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX)); >> + } else { >> + pte_t *pte = pte_offset_kernel(pmd, >> relocated_restore_code); >> + >> + set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX)); >> + } >> + } >> + flush_tlb_all(); > > I know you want to flush TLBs but this causes the splat below on the > resume kernel. > > Most likely because: > > resume_target_kernel() does local_irq_disable() and then > > swsusp_arch_resume() -> relocate_restore_code() -> flush_tlb_all() > > and smp_call_function_many() doesn't like it when IRQs are disabled.
Right. Can I invoke __flush_tlb_all() from here to flush the TLB on the local CPU? That should be sufficient IMO. Thanks, Rafael
