Author: alc Date: Sat Jan 4 19:50:25 2020 New Revision: 356354 URL: https://svnweb.freebsd.org/changeset/base/356354
Log: When a copy-on-write fault occurs, pmap_enter() is called on to replace the mapping to the old read-only page with a mapping to the new read-write page. To destroy the old mapping, pmap_enter() must destroy its page table and PV entries and invalidate its TLB entry. This change simply invalidates that TLB entry a little earlier, specifically, on amd64 and arm64, before the PV list lock is held. Reviewed by: kib, markj MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D23027 Modified: head/sys/amd64/amd64/pmap.c head/sys/arm64/arm64/pmap.c head/sys/i386/i386/pmap.c Modified: head/sys/amd64/amd64/pmap.c ============================================================================== --- head/sys/amd64/amd64/pmap.c Sat Jan 4 19:29:25 2020 (r356353) +++ head/sys/amd64/amd64/pmap.c Sat Jan 4 19:50:25 2020 (r356354) @@ -6131,8 +6131,10 @@ retry: */ if ((origpte & (PG_M | PG_RW)) == (PG_M | PG_RW)) vm_page_dirty(om); - if ((origpte & PG_A) != 0) + if ((origpte & PG_A) != 0) { + pmap_invalidate_page(pmap, va); vm_page_aflag_set(om, PGA_REFERENCED); + } CHANGE_PV_LIST_LOCK_TO_PHYS(&lock, opa); pv = pmap_pvh_remove(&om->md, pmap, va); KASSERT(pv != NULL, @@ -6144,9 +6146,13 @@ retry: ((om->flags & PG_FICTITIOUS) != 0 || TAILQ_EMPTY(&pa_to_pvh(opa)->pv_list))) vm_page_aflag_clear(om, PGA_WRITEABLE); - } - if ((origpte & PG_A) != 0) + } else { + /* + * Since this mapping is unmanaged, assume that PG_A + * is set. + */ pmap_invalidate_page(pmap, va); + } origpte = 0; } else { /* Modified: head/sys/arm64/arm64/pmap.c ============================================================================== --- head/sys/arm64/arm64/pmap.c Sat Jan 4 19:29:25 2020 (r356353) +++ head/sys/arm64/arm64/pmap.c Sat Jan 4 19:50:25 2020 (r356354) @@ -3449,8 +3449,10 @@ havel3: */ if (pmap_pte_dirty(orig_l3)) vm_page_dirty(om); - if ((orig_l3 & ATTR_AF) != 0) + if ((orig_l3 & ATTR_AF) != 0) { + pmap_invalidate_page(pmap, va); vm_page_aflag_set(om, PGA_REFERENCED); + } CHANGE_PV_LIST_LOCK_TO_PHYS(&lock, opa); pv = pmap_pvh_remove(&om->md, pmap, va); if ((m->oflags & VPO_UNMANAGED) != 0) @@ -3460,8 +3462,11 @@ havel3: ((om->flags & PG_FICTITIOUS) != 0 || TAILQ_EMPTY(&pa_to_pvh(opa)->pv_list))) vm_page_aflag_clear(om, PGA_WRITEABLE); + } else { + KASSERT((orig_l3 & ATTR_AF) != 0, + ("pmap_enter: unmanaged mapping lacks ATTR_AF")); + pmap_invalidate_page(pmap, va); } - pmap_invalidate_page(pmap, va); orig_l3 = 0; } else { /* Modified: head/sys/i386/i386/pmap.c ============================================================================== --- head/sys/i386/i386/pmap.c Sat Jan 4 19:29:25 2020 (r356353) +++ head/sys/i386/i386/pmap.c Sat Jan 4 19:50:25 2020 (r356354) @@ -3798,8 +3798,10 @@ __CONCAT(PMTYPE, enter)(pmap_t pmap, vm_offset_t va, v */ if ((origpte & (PG_M | PG_RW)) == (PG_M | PG_RW)) vm_page_dirty(om); - if ((origpte & PG_A) != 0) + if ((origpte & PG_A) != 0) { + pmap_invalidate_page_int(pmap, va); vm_page_aflag_set(om, PGA_REFERENCED); + } pv = pmap_pvh_remove(&om->md, pmap, va); KASSERT(pv != NULL, ("pmap_enter: no PV entry for %#x", va)); @@ -3810,9 +3812,13 @@ __CONCAT(PMTYPE, enter)(pmap_t pmap, vm_offset_t va, v ((om->flags & PG_FICTITIOUS) != 0 || TAILQ_EMPTY(&pa_to_pvh(opa)->pv_list))) vm_page_aflag_clear(om, PGA_WRITEABLE); - } - if ((origpte & PG_A) != 0) + } else { + /* + * Since this mapping is unmanaged, assume that PG_A + * is set. + */ pmap_invalidate_page_int(pmap, va); + } origpte = 0; } else { /* _______________________________________________ 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"
