diff options
| -rw-r--r-- | sys/arch/i386/i386/pmap.c | 56 | ||||
| -rw-r--r-- | sys/arch/i386/i386/pmap.old.c | 56 |
2 files changed, 92 insertions, 20 deletions
diff --git a/sys/arch/i386/i386/pmap.c b/sys/arch/i386/i386/pmap.c index ceffc55e365..92d5d7609f2 100644 --- a/sys/arch/i386/i386/pmap.c +++ b/sys/arch/i386/i386/pmap.c @@ -1,4 +1,4 @@ -/* $OpenBSD: pmap.c,v 1.12 1996/06/16 10:24:19 deraadt Exp $ */ +/* $OpenBSD: pmap.c,v 1.13 1996/09/26 14:04:27 deraadt Exp $ */ /* $NetBSD: pmap.c,v 1.36 1996/05/03 19:42:22 christos Exp $ */ /* @@ -1077,17 +1077,53 @@ pmap_enter(pmap, va, pa, prot, wired) enter_stats.user++; #endif - /* - * Page Directory table entry not valid, we need a new PT page - */ pte = pmap_pte(pmap, va); if (!pte) { - printf("ptdi panic!\n"); - printf("pte %p pmap %p va %p\n", pte, pmap, va); - printf("pmap_pde(pmap, va) %p\n", pmap_pde(pmap, va)); - printf("pmap_pde_v(pmap_pde(pmap, va) %p\n", - pmap_pde_v(pmap_pde(pmap, va))); - panic("ptdi %x", pmap->pm_pdir[PTDPTDI]); + /* + * Page Directory table entry not valid, we need a new PT page + * + * we want to vm_fault in a new zero-filled PT page for our + * use. in order to do this, we want to call vm_fault() + * with the VA of where we want to put the PTE. but in + * order to call vm_fault() we need to know which vm_map + * we are faulting in. in the m68k pmap's this is easy + * since all PT pages live in one global vm_map ("pt_map") + * and we have a lot of virtual space we can use for the + * pt_map (since the kernel doesn't have to share its 4GB + * address space with processes). but in the i386 port + * the kernel must live in the top part of the virtual + * address space and PT pages live in their process' vm_map + * rather than a global one. the problem is that we have + * no way of knowing which vm_map is the correct one to + * fault on. + * + * XXX: see NetBSD PR#1834 and Mycroft's posting to + * tech-kern on 7 Jan 1996. + * + * rather than always calling panic, we try and make an + * educated guess as to which vm_map to use by using curproc. + * this is a workaround and may not fully solve the problem? + */ + + struct vm_map *vmap; + int rv; + vm_offset_t v; + + if (curproc == NULL || curproc->p_vmspace == NULL || + pmap != &curproc->p_vmspace->vm_pmap) + panic("ptdi %x", pmap->pm_pdir[PTDPTDI]); + + /* our guess about the vm_map was good! fault it in. */ + + vmap = &curproc->p_vmspace->vm_map; + v = trunc_page(vtopte(va)); + rv = vm_fault(vmap, v, VM_PROT_READ|VM_PROT_WRITE, FALSE); + if (rv != KERN_SUCCESS) + panic("ptdi2 %x", pmap->pm_pdir[PTDPTDI]); + vm_map_pageable(vmap, v, round_page(v+1), FALSE); + pte = pmap_pte(pmap, va); + if (!pte) + panic("ptdi3 %x", pmap->pm_pdir[PTDPTDI]); } #ifdef DEBUG if (pmapdebug & PDB_ENTER) diff --git a/sys/arch/i386/i386/pmap.old.c b/sys/arch/i386/i386/pmap.old.c index bec37667221..7eed88c927a 100644 --- a/sys/arch/i386/i386/pmap.old.c +++ b/sys/arch/i386/i386/pmap.old.c @@ -1,4 +1,4 @@ -/* $OpenBSD: pmap.old.c,v 1.12 1996/06/16 10:24:19 deraadt Exp $ */ +/* $OpenBSD: pmap.old.c,v 1.13 1996/09/26 14:04:27 deraadt Exp $ */ /* $NetBSD: pmap.c,v 1.36 1996/05/03 19:42:22 christos Exp $ */ /* @@ -1077,17 +1077,53 @@ pmap_enter(pmap, va, pa, prot, wired) enter_stats.user++; #endif - /* - * Page Directory table entry not valid, we need a new PT page - */ pte = pmap_pte(pmap, va); if (!pte) { - printf("ptdi panic!\n"); - printf("pte %p pmap %p va %p\n", pte, pmap, va); - printf("pmap_pde(pmap, va) %p\n", pmap_pde(pmap, va)); - printf("pmap_pde_v(pmap_pde(pmap, va) %p\n", - pmap_pde_v(pmap_pde(pmap, va))); - panic("ptdi %x", pmap->pm_pdir[PTDPTDI]); + /* + * Page Directory table entry not valid, we need a new PT page + * + * we want to vm_fault in a new zero-filled PT page for our + * use. in order to do this, we want to call vm_fault() + * with the VA of where we want to put the PTE. but in + * order to call vm_fault() we need to know which vm_map + * we are faulting in. in the m68k pmap's this is easy + * since all PT pages live in one global vm_map ("pt_map") + * and we have a lot of virtual space we can use for the + * pt_map (since the kernel doesn't have to share its 4GB + * address space with processes). but in the i386 port + * the kernel must live in the top part of the virtual + * address space and PT pages live in their process' vm_map + * rather than a global one. the problem is that we have + * no way of knowing which vm_map is the correct one to + * fault on. + * + * XXX: see NetBSD PR#1834 and Mycroft's posting to + * tech-kern on 7 Jan 1996. + * + * rather than always calling panic, we try and make an + * educated guess as to which vm_map to use by using curproc. + * this is a workaround and may not fully solve the problem? + */ + + struct vm_map *vmap; + int rv; + vm_offset_t v; + + if (curproc == NULL || curproc->p_vmspace == NULL || + pmap != &curproc->p_vmspace->vm_pmap) + panic("ptdi %x", pmap->pm_pdir[PTDPTDI]); + + /* our guess about the vm_map was good! fault it in. */ + + vmap = &curproc->p_vmspace->vm_map; + v = trunc_page(vtopte(va)); + rv = vm_fault(vmap, v, VM_PROT_READ|VM_PROT_WRITE, FALSE); + if (rv != KERN_SUCCESS) + panic("ptdi2 %x", pmap->pm_pdir[PTDPTDI]); + vm_map_pageable(vmap, v, round_page(v+1), FALSE); + pte = pmap_pte(pmap, va); + if (!pte) + panic("ptdi3 %x", pmap->pm_pdir[PTDPTDI]); } #ifdef DEBUG if (pmapdebug & PDB_ENTER) |