The branch main has been updated by alc:
URL:
https://cgit.FreeBSD.org/src/commit/?id=5a846c48f209d04dad36aa35a9968f557c4516f7
commit 5a846c48f209d04dad36aa35a9968f557c4516f7
Author: Alan Cox <a...@freebsd.org>
AuthorDate: 2025-07-16 08:08:49 +0000
Commit: Alan Cox <a...@freebsd.org>
CommitDate: 2025-07-17 22:10:29 +0000
pmap_enter_{l2,pde}: correct the handling of an error case
When pmap_enter_object()'s call to pmap_enter_{l2,pde}() fails to create
a managed mapping within the kernel address space due to the inability
to allocate a PV entry, it needs to remove the kernel page table page
from the pmap's trie of idle page table pages. Previously, it did not.
Reviewed by: andrew, kib, markj
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D51353
---
sys/amd64/amd64/pmap.c | 11 +++++++++++
sys/arm64/arm64/pmap.c | 12 ++++++++++++
2 files changed, 23 insertions(+)
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index 2c7777e608b9..14f57ca94ba7 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -7561,6 +7561,9 @@ pmap_enter_pde(pmap_t pmap, vm_offset_t va, pd_entry_t
newpde, u_int flags,
PG_RW = pmap_rw_bit(pmap);
KASSERT((newpde & (pmap_modified_bit(pmap) | PG_RW)) != PG_RW,
("pmap_enter_pde: newpde is missing PG_M"));
+ KASSERT((flags & (PMAP_ENTER_NOREPLACE | PMAP_ENTER_NORECLAIM)) !=
+ PMAP_ENTER_NORECLAIM,
+ ("pmap_enter_pde: flags is missing PMAP_ENTER_NOREPLACE"));
PG_V = pmap_valid_bit(pmap);
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
@@ -7689,6 +7692,14 @@ pmap_enter_pde(pmap_t pmap, vm_offset_t va, pd_entry_t
newpde, u_int flags,
if (!pmap_pv_insert_pde(pmap, va, newpde, flags, lockp)) {
if (pdpg != NULL)
pmap_abort_ptp(pmap, va, pdpg);
+ else {
+ KASSERT(va >= VM_MAXUSER_ADDRESS &&
+ (*pde & (PG_PS | PG_V)) == PG_V,
+ ("pmap_enter_pde: invalid kernel PDE"));
+ mt = pmap_remove_pt_page(pmap, va);
+ KASSERT(mt != NULL,
+ ("pmap_enter_pde: missing kernel PTP"));
+ }
if (uwptpg != NULL) {
mt = pmap_remove_pt_page(pmap, va);
KASSERT(mt == uwptpg,
diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index a09da794e77d..459cc8ebe505 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -5709,6 +5709,9 @@ pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t
new_l2, u_int flags,
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
KASSERT(ADDR_IS_CANONICAL(va),
("%s: Address not in canonical form: %lx", __func__, va));
+ KASSERT((flags & (PMAP_ENTER_NOREPLACE | PMAP_ENTER_NORECLAIM)) !=
+ PMAP_ENTER_NORECLAIM,
+ ("pmap_enter_l2: flags is missing PMAP_ENTER_NOREPLACE"));
if ((l2 = pmap_alloc_l2(pmap, va, &l2pg, (flags &
PMAP_ENTER_NOSLEEP) != 0 ? NULL : lockp)) == NULL) {
@@ -5828,6 +5831,15 @@ pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t
new_l2, u_int flags,
if (!pmap_pv_insert_l2(pmap, va, new_l2, flags, lockp)) {
if (l2pg != NULL)
pmap_abort_ptp(pmap, va, l2pg);
+ else {
+ KASSERT(ADDR_IS_KERNEL(va) &&
+ (pmap_load(l2) & ATTR_DESCR_MASK) ==
+ L2_TABLE,
+ ("pmap_enter_l2: invalid kernel L2E"));
+ mt = pmap_remove_pt_page(pmap, va);
+ KASSERT(mt != NULL,
+ ("pmap_enter_l2: missing kernel PTP"));
+ }
if (uwptpg != NULL) {
mt = pmap_remove_pt_page(pmap, va);
KASSERT(mt == uwptpg,
