Author: kib Date: Fri May 31 19:13:31 2019 New Revision: 348479 URL: https://svnweb.freebsd.org/changeset/base/348479
Log: MFC r348246: Fix a corner case in demotion of kernel mappings. Modified: stable/12/sys/amd64/amd64/pmap.c stable/12/sys/i386/i386/pmap.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/amd64/amd64/pmap.c ============================================================================== --- stable/12/sys/amd64/amd64/pmap.c Fri May 31 19:09:56 2019 (r348478) +++ stable/12/sys/amd64/amd64/pmap.c Fri May 31 19:13:31 2019 (r348479) @@ -4167,8 +4167,10 @@ pmap_demote_pde_locked(pmap_t pmap, pd_entry_t *pde, v " in pmap %p", va, pmap); return (FALSE); } - if (va < VM_MAXUSER_ADDRESS) + if (va < VM_MAXUSER_ADDRESS) { + mpte->wire_count = NPTEPG; pmap_resident_count_inc(pmap, 1); + } } mptepa = VM_PAGE_TO_PHYS(mpte); firstpte = (pt_entry_t *)PHYS_TO_DMAP(mptepa); @@ -4181,12 +4183,12 @@ pmap_demote_pde_locked(pmap_t pmap, pd_entry_t *pde, v newpte = pmap_swap_pat(pmap, newpte); /* - * If the page table page is new, initialize it. + * If the page table page is not leftover from an earlier promotion, + * initialize it. */ - if (mpte->wire_count == 1) { - mpte->wire_count = NPTEPG; + if ((oldpde & PG_PROMOTED) == 0) pmap_fill_ptp(firstpte, newpte); - } + KASSERT((*firstpte & PG_FRAME) == (newpte & PG_FRAME), ("pmap_demote_pde: firstpte and newpte map different physical" " addresses")); Modified: stable/12/sys/i386/i386/pmap.c ============================================================================== --- stable/12/sys/i386/i386/pmap.c Fri May 31 19:09:56 2019 (r348478) +++ stable/12/sys/i386/i386/pmap.c Fri May 31 19:13:31 2019 (r348479) @@ -2845,8 +2845,10 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t *pde, vm_offse " in pmap %p", va, pmap); return (FALSE); } - if (pmap != kernel_pmap) + if (pmap != kernel_pmap) { + mpte->wire_count = NPTEPG; pmap->pm_stats.resident_count++; + } } mptepa = VM_PAGE_TO_PHYS(mpte); @@ -2894,12 +2896,12 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t *pde, vm_offse newpte ^= PG_PDE_PAT | PG_PTE_PAT; /* - * If the page table page is new, initialize it. + * If the page table page is not leftover from an earlier promotion, + * initialize it. */ - if (mpte->wire_count == 1) { - mpte->wire_count = NPTEPG; + if ((oldpde & PG_PROMOTED) == 0) pmap_fill_ptp(firstpte, newpte); - } + KASSERT((*firstpte & PG_FRAME) == (newpte & PG_FRAME), ("pmap_demote_pde: firstpte and newpte map different physical" " addresses")); _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"