d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

When a copy-on-write fault occurs, pmap_enter() is called on to replace the

Browse Source 
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
This commit is contained in:
Alan Cox 2020-01-04 19:50:25 +00:00
parent 31c251a046
commit 1c3a241032
3 changed files with 25 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
sys/amd64/amd64/pmap.c
View File

@ -6131,8 +6131,10 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
*/
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 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
((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 {
/*

9
sys/arm64/arm64/pmap.c
View File

@ -3449,8 +3449,10 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
*/
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 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
((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 {
/*

12
sys/i386/i386/pmap.c
View File

@ -3798,8 +3798,10 @@ __CONCAT(PMTYPE, enter)(pmap_t pmap, vm_offset_t va, vm_page_t m,
*/
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, vm_page_t m,
((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 {
/*