Author: markj
Date: Mon Nov 18 15:28:10 2019
New Revision: 354814
URL: https://svnweb.freebsd.org/changeset/base/354814
Log:
MFC r353672:
Introduce pmap_change_prot() for amd64.
Modified:
stable/12/sys/amd64/amd64/pmap.c
stable/12/sys/amd64/include/pmap.h
Directory Properties:
stable/12/ (props changed)
Modified: stable/12/sys/amd64/amd64/pmap.c
==============================================================================
--- stable/12/sys/amd64/amd64/pmap.c Mon Nov 18 15:27:52 2019
(r354813)
+++ stable/12/sys/amd64/amd64/pmap.c Mon Nov 18 15:28:10 2019
(r354814)
@@ -1105,10 +1105,11 @@ static caddr_t crashdumpmap;
/*
* Internal flags for pmap_mapdev_internal() and
- * pmap_change_attr_locked().
+ * pmap_change_props_locked().
*/
-#define MAPDEV_FLUSHCACHE 0x0000001 /* Flush cache after
mapping. */
-#define MAPDEV_SETATTR 0x0000002 /* Modify existing
attrs. */
+#define MAPDEV_FLUSHCACHE 0x00000001 /* Flush cache after
mapping. */
+#define MAPDEV_SETATTR 0x00000002 /* Modify existing
attrs. */
+#define MAPDEV_ASSERTVALID 0x00000004 /* Assert mapping
validity. */
static void free_pv_chunk(struct pv_chunk *pc);
static void free_pv_entry(pmap_t pmap, pv_entry_t pv);
@@ -1129,8 +1130,8 @@ static void pmap_pvh_free(struct md_page *pvh,
pmap_t
static pv_entry_t pmap_pvh_remove(struct md_page *pvh, pmap_t pmap,
vm_offset_t va);
-static int pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode,
- int flags);
+static int pmap_change_props_locked(vm_offset_t va, vm_size_t size,
+ vm_prot_t prot, int mode, int flags);
static boolean_t pmap_demote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va);
static boolean_t pmap_demote_pde_locked(pmap_t pmap, pd_entry_t *pde,
vm_offset_t va, struct rwlock **lockp);
@@ -1153,14 +1154,13 @@ static void pmap_invalidate_pde_page(pmap_t pmap, vm_o
static void pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int mode);
static vm_page_t pmap_large_map_getptp_unlocked(void);
static vm_paddr_t pmap_large_map_kextract(vm_offset_t va);
-static void pmap_pde_attr(pd_entry_t *pde, int cache_bits, int mask);
#if VM_NRESERVLEVEL > 0
static void pmap_promote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va,
struct rwlock **lockp);
#endif
static boolean_t pmap_protect_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t
sva,
vm_prot_t prot);
-static void pmap_pte_attr(pt_entry_t *pte, int cache_bits, int mask);
+static void pmap_pte_props(pt_entry_t *pte, u_long bits, u_long mask);
static void pmap_pti_add_kva_locked(vm_offset_t sva, vm_offset_t eva,
bool exec);
static pdp_entry_t *pmap_pti_pdpe(vm_offset_t va);
@@ -7797,40 +7797,20 @@ restart:
* Miscellaneous support routines follow
*/
-/* Adjust the cache mode for a 4KB page mapped via a PTE. */
+/* Adjust the properties for a leaf page table entry. */
static __inline void
-pmap_pte_attr(pt_entry_t *pte, int cache_bits, int mask)
+pmap_pte_props(pt_entry_t *pte, u_long bits, u_long mask)
{
- u_int opte, npte;
+ u_long opte, npte;
- /*
- * The cache mode bits are all in the low 32-bits of the
- * PTE, so we can just spin on updating the low 32-bits.
- */
+ opte = *(u_long *)pte;
do {
- opte = *(u_int *)pte;
npte = opte & ~mask;
- npte |= cache_bits;
- } while (npte != opte && !atomic_cmpset_int((u_int *)pte, opte, npte));
+ npte |= bits;
+ } while (npte != opte && !atomic_fcmpset_long((u_long *)pte, &opte,
+ npte));
}
-/* Adjust the cache mode for a 2MB page mapped via a PDE. */
-static __inline void
-pmap_pde_attr(pd_entry_t *pde, int cache_bits, int mask)
-{
- u_int opde, npde;
-
- /*
- * The cache mode bits are all in the low 32-bits of the
- * PDE, so we can just spin on updating the low 32-bits.
- */
- do {
- opde = *(u_int *)pde;
- npde = opde & ~mask;
- npde |= cache_bits;
- } while (npde != opde && !atomic_cmpset_int((u_int *)pde, opde, npde));
-}
-
/*
* Map a set of physical memory pages into the kernel virtual
* address space. Return a pointer to where it is mapped. This
@@ -7884,7 +7864,8 @@ pmap_mapdev_internal(vm_paddr_t pa, vm_size_t size, in
va = PHYS_TO_DMAP(pa);
if ((flags & MAPDEV_SETATTR) != 0) {
PMAP_LOCK(kernel_pmap);
- i = pmap_change_attr_locked(va, size, mode,
flags);
+ i = pmap_change_props_locked(va, size,
+ PROT_NONE, mode, flags);
PMAP_UNLOCK(kernel_pmap);
} else
i = 0;
@@ -8070,21 +8051,46 @@ pmap_change_attr(vm_offset_t va, vm_size_t size, int m
int error;
PMAP_LOCK(kernel_pmap);
- error = pmap_change_attr_locked(va, size, mode, MAPDEV_FLUSHCACHE);
+ error = pmap_change_props_locked(va, size, PROT_NONE, mode,
+ MAPDEV_FLUSHCACHE);
PMAP_UNLOCK(kernel_pmap);
return (error);
}
+/*
+ * Changes the specified virtual address range's protections to those
+ * specified by "prot". Like pmap_change_attr(), protections for aliases
+ * in the direct map are updated as well. Protections on aliasing mappings may
+ * be a subset of the requested protections; for example, mappings in the
direct
+ * map are never executable.
+ */
+int
+pmap_change_prot(vm_offset_t va, vm_size_t size, vm_prot_t prot)
+{
+ int error;
+
+ /* Only supported within the kernel map. */
+ if (va < VM_MIN_KERNEL_ADDRESS)
+ return (EINVAL);
+
+ PMAP_LOCK(kernel_pmap);
+ error = pmap_change_props_locked(va, size, prot, -1,
+ MAPDEV_ASSERTVALID);
+ PMAP_UNLOCK(kernel_pmap);
+ return (error);
+}
+
static int
-pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode, int flags)
+pmap_change_props_locked(vm_offset_t va, vm_size_t size, vm_prot_t prot,
+ int mode, int flags)
{
vm_offset_t base, offset, tmpva;
vm_paddr_t pa_start, pa_end, pa_end1;
pdp_entry_t *pdpe;
- pd_entry_t *pde;
- pt_entry_t *pte;
- int cache_bits_pte, cache_bits_pde, error;
- boolean_t changed;
+ pd_entry_t *pde, pde_bits, pde_mask;
+ pt_entry_t *pte, pte_bits, pte_mask;
+ int error;
+ bool changed;
PMAP_LOCK_ASSERT(kernel_pmap, MA_OWNED);
base = trunc_page(va);
@@ -8098,9 +8104,33 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
if (base < DMAP_MIN_ADDRESS)
return (EINVAL);
- cache_bits_pde = pmap_cache_bits(kernel_pmap, mode, 1);
- cache_bits_pte = pmap_cache_bits(kernel_pmap, mode, 0);
- changed = FALSE;
+ /*
+ * Construct our flag sets and masks. "bits" is the subset of
+ * "mask" that will be set in each modified PTE.
+ *
+ * Mappings in the direct map are never allowed to be executable.
+ */
+ pde_bits = pte_bits = 0;
+ pde_mask = pte_mask = 0;
+ if (mode != -1) {
+ pde_bits |= pmap_cache_bits(kernel_pmap, mode, true);
+ pde_mask |= X86_PG_PDE_CACHE;
+ pte_bits |= pmap_cache_bits(kernel_pmap, mode, false);
+ pte_mask |= X86_PG_PTE_CACHE;
+ }
+ if (prot != VM_PROT_NONE) {
+ if ((prot & VM_PROT_WRITE) != 0) {
+ pde_bits |= X86_PG_RW;
+ pte_bits |= X86_PG_RW;
+ }
+ if ((prot & VM_PROT_EXECUTE) == 0 ||
+ va < VM_MIN_KERNEL_ADDRESS) {
+ pde_bits |= pg_nx;
+ pte_bits |= pg_nx;
+ }
+ pde_mask |= X86_PG_RW | pg_nx;
+ pte_mask |= X86_PG_RW | pg_nx;
+ }
/*
* Pages that aren't mapped aren't supported. Also break down 2MB pages
@@ -8108,15 +8138,18 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
*/
for (tmpva = base; tmpva < base + size; ) {
pdpe = pmap_pdpe(kernel_pmap, tmpva);
- if (pdpe == NULL || *pdpe == 0)
+ if (pdpe == NULL || *pdpe == 0) {
+ KASSERT((flags & MAPDEV_ASSERTVALID) == 0,
+ ("%s: addr %#lx is not mapped", __func__, tmpva));
return (EINVAL);
+ }
if (*pdpe & PG_PS) {
/*
* If the current 1GB page already has the required
- * memory type, then we need not demote this page. Just
+ * properties, then we need not demote this page. Just
* increment tmpva to the next 1GB page frame.
*/
- if ((*pdpe & X86_PG_PDE_CACHE) == cache_bits_pde) {
+ if ((*pdpe & pde_mask) == pde_bits) {
tmpva = trunc_1gpage(tmpva) + NBPDP;
continue;
}
@@ -8135,15 +8168,18 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
return (ENOMEM);
}
pde = pmap_pdpe_to_pde(pdpe, tmpva);
- if (*pde == 0)
+ if (*pde == 0) {
+ KASSERT((flags & MAPDEV_ASSERTVALID) == 0,
+ ("%s: addr %#lx is not mapped", __func__, tmpva));
return (EINVAL);
+ }
if (*pde & PG_PS) {
/*
* If the current 2MB page already has the required
- * memory type, then we need not demote this page. Just
+ * properties, then we need not demote this page. Just
* increment tmpva to the next 2MB page frame.
*/
- if ((*pde & X86_PG_PDE_CACHE) == cache_bits_pde) {
+ if ((*pde & pde_mask) == pde_bits) {
tmpva = trunc_2mpage(tmpva) + NBPDR;
continue;
}
@@ -8162,24 +8198,27 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
return (ENOMEM);
}
pte = pmap_pde_to_pte(pde, tmpva);
- if (*pte == 0)
+ if (*pte == 0) {
+ KASSERT((flags & MAPDEV_ASSERTVALID) == 0,
+ ("%s: addr %#lx is not mapped", __func__, tmpva));
return (EINVAL);
+ }
tmpva += PAGE_SIZE;
}
error = 0;
/*
* Ok, all the pages exist, so run through them updating their
- * cache mode if required.
+ * properties if required.
*/
+ changed = false;
pa_start = pa_end = 0;
for (tmpva = base; tmpva < base + size; ) {
pdpe = pmap_pdpe(kernel_pmap, tmpva);
if (*pdpe & PG_PS) {
- if ((*pdpe & X86_PG_PDE_CACHE) != cache_bits_pde) {
- pmap_pde_attr(pdpe, cache_bits_pde,
- X86_PG_PDE_CACHE);
- changed = TRUE;
+ if ((*pdpe & pde_mask) != pde_bits) {
+ pmap_pte_props(pdpe, pde_bits, pde_mask);
+ changed = true;
}
if (tmpva >= VM_MIN_KERNEL_ADDRESS &&
(*pdpe & PG_PS_FRAME) < dmaplimit) {
@@ -8191,9 +8230,10 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
pa_end += NBPDP;
else {
/* Run ended, update direct map. */
- error = pmap_change_attr_locked(
+ error = pmap_change_props_locked(
PHYS_TO_DMAP(pa_start),
- pa_end - pa_start, mode, flags);
+ pa_end - pa_start, prot, mode,
+ flags);
if (error != 0)
break;
/* Start physical address run. */
@@ -8206,10 +8246,9 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
}
pde = pmap_pdpe_to_pde(pdpe, tmpva);
if (*pde & PG_PS) {
- if ((*pde & X86_PG_PDE_CACHE) != cache_bits_pde) {
- pmap_pde_attr(pde, cache_bits_pde,
- X86_PG_PDE_CACHE);
- changed = TRUE;
+ if ((*pde & pde_mask) != pde_bits) {
+ pmap_pte_props(pde, pde_bits, pde_mask);
+ changed = true;
}
if (tmpva >= VM_MIN_KERNEL_ADDRESS &&
(*pde & PG_PS_FRAME) < dmaplimit) {
@@ -8221,9 +8260,10 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
pa_end += NBPDR;
else {
/* Run ended, update direct map. */
- error = pmap_change_attr_locked(
+ error = pmap_change_props_locked(
PHYS_TO_DMAP(pa_start),
- pa_end - pa_start, mode, flags);
+ pa_end - pa_start, prot, mode,
+ flags);
if (error != 0)
break;
/* Start physical address run. */
@@ -8234,10 +8274,9 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
tmpva = trunc_2mpage(tmpva) + NBPDR;
} else {
pte = pmap_pde_to_pte(pde, tmpva);
- if ((*pte & X86_PG_PTE_CACHE) != cache_bits_pte) {
- pmap_pte_attr(pte, cache_bits_pte,
- X86_PG_PTE_CACHE);
- changed = TRUE;
+ if ((*pte & pte_mask) != pte_bits) {
+ pmap_pte_props(pte, pte_bits, pte_mask);
+ changed = true;
}
if (tmpva >= VM_MIN_KERNEL_ADDRESS &&
(*pte & PG_FRAME) < dmaplimit) {
@@ -8249,9 +8288,10 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
pa_end += PAGE_SIZE;
else {
/* Run ended, update direct map. */
- error = pmap_change_attr_locked(
+ error = pmap_change_props_locked(
PHYS_TO_DMAP(pa_start),
- pa_end - pa_start, mode, flags);
+ pa_end - pa_start, prot, mode,
+ flags);
if (error != 0)
break;
/* Start physical address run. */
@@ -8265,8 +8305,8 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size
if (error == 0 && pa_start != pa_end && pa_start < dmaplimit) {
pa_end1 = MIN(pa_end, dmaplimit);
if (pa_start != pa_end1)
- error = pmap_change_attr_locked(PHYS_TO_DMAP(pa_start),
- pa_end1 - pa_start, mode, flags);
+ error = pmap_change_props_locked(PHYS_TO_DMAP(pa_start),
+ pa_end1 - pa_start, prot, mode, flags);
}
/*
Modified: stable/12/sys/amd64/include/pmap.h
==============================================================================
--- stable/12/sys/amd64/include/pmap.h Mon Nov 18 15:27:52 2019
(r354813)
+++ stable/12/sys/amd64/include/pmap.h Mon Nov 18 15:28:10 2019
(r354814)
@@ -428,6 +428,7 @@ void pmap_allow_2m_x_ept_recalculate(void);
void pmap_bootstrap(vm_paddr_t *);
int pmap_cache_bits(pmap_t pmap, int mode, boolean_t is_pde);
int pmap_change_attr(vm_offset_t, vm_size_t, int);
+int pmap_change_prot(vm_offset_t, vm_size_t, vm_prot_t);
void pmap_demote_DMAP(vm_paddr_t base, vm_size_t len, boolean_t invalidate);
void pmap_flush_cache_range(vm_offset_t, vm_offset_t);
void pmap_flush_cache_phys_range(vm_paddr_t, vm_paddr_t, vm_memattr_t);
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