Date: Mon, 18 Nov 2019 15:28:11 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r354814 - in stable/12/sys/amd64: amd64 include Message-ID: <201911181528.xAIFSBES033730@repo.freebsd.org>
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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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