diff options
| author | Mark Kettenis <kettenis@cvs.openbsd.org> | 2021-09-11 18:08:33 +0000 |
|---|---|---|
| committer | Mark Kettenis <kettenis@cvs.openbsd.org> | 2021-09-11 18:08:33 +0000 |
| commit | 29a328f62bbcf1d086dd895edcfb74f4a4cf2dfb (patch) | |
| tree | 7527d1718532107d45348b7142ea65b4331a5024 /sys | |
| parent | 7ae2424bc3059ea6830539931f90712e57d11f9e (diff) | |
Change the scope of the locking in pmap_extract() to prevent a race between
walking the page tables and another thread calling pmap_remove() that ends
up removing a page table page.
tested by sthen@
ok deraadt@, mpi@
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/arch/i386/i386/pmap.c | 5 | ||||
| -rw-r--r-- | sys/arch/i386/i386/pmapae.c | 5 |
2 files changed, 6 insertions, 4 deletions
diff --git a/sys/arch/i386/i386/pmap.c b/sys/arch/i386/i386/pmap.c index a2f969fe23c..fe27c6703f2 100644 --- a/sys/arch/i386/i386/pmap.c +++ b/sys/arch/i386/i386/pmap.c @@ -1,4 +1,4 @@ -/* $OpenBSD: pmap.c,v 1.216 2021/09/06 12:59:59 mpi Exp $ */ +/* $OpenBSD: pmap.c,v 1.217 2021/09/11 18:08:32 kettenis Exp $ */ /* $NetBSD: pmap.c,v 1.91 2000/06/02 17:46:37 thorpej Exp $ */ /* @@ -1545,8 +1545,8 @@ pmap_extract_86(struct pmap *pmap, vaddr_t va, paddr_t *pap) { pt_entry_t *ptes, pte; + ptes = pmap_map_ptes_86(pmap); if (pmap_valid_entry(PDE(pmap, pdei(va)))) { - ptes = pmap_map_ptes_86(pmap); pte = ptes[atop(va)]; pmap_unmap_ptes_86(pmap); if (!pmap_valid_entry(pte)) @@ -1555,6 +1555,7 @@ pmap_extract_86(struct pmap *pmap, vaddr_t va, paddr_t *pap) *pap = (pte & PG_FRAME) | (va & ~PG_FRAME); return 1; } + pmap_unmap_ptes_86(pmap); return 0; } diff --git a/sys/arch/i386/i386/pmapae.c b/sys/arch/i386/i386/pmapae.c index ac171cb10d0..1a97cdbcc26 100644 --- a/sys/arch/i386/i386/pmapae.c +++ b/sys/arch/i386/i386/pmapae.c @@ -1,4 +1,4 @@ -/* $OpenBSD: pmapae.c,v 1.64 2021/09/06 12:59:59 mpi Exp $ */ +/* $OpenBSD: pmapae.c,v 1.65 2021/09/11 18:08:32 kettenis Exp $ */ /* * Copyright (c) 2006-2008 Michael Shalayeff @@ -1048,8 +1048,8 @@ pmap_extract_pae(struct pmap *pmap, vaddr_t va, paddr_t *pap) { pt_entry_t *ptes, pte; + ptes = pmap_map_ptes_pae(pmap); if (pmap_valid_entry(PDE(pmap, pdei(va)))) { - ptes = pmap_map_ptes_pae(pmap); pte = ptes[atop(va)]; pmap_unmap_ptes_pae(pmap); if (!pmap_valid_entry(pte)) @@ -1058,6 +1058,7 @@ pmap_extract_pae(struct pmap *pmap, vaddr_t va, paddr_t *pap) *pap = (pte & PG_FRAME) | (va & ~PG_FRAME); return 1; } + pmap_unmap_ptes_pae(pmap); return 0; } |