xsm: Revert "Fix xsm_mmu_* and xsm_update_va_mapping hooks"

This reverts 23220:56a3b9c7367f, which removes all validation of the
target pages in the mapping. This crash was solved by properly marking
pages without known SIDs in 22207:20f139010445.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Committed-by: Keir Fraser <keir@xen.org>

xen/arch/x86/mm.c

@@ -3517,6 +3517,9 @@ int do_mmu_update(
         {
             p2m_type_t p2mt;
 
+            rc = xsm_mmu_normal_update(d, pg_owner, req.val);
+            if ( rc )
+                break;
             rc = -EINVAL;
 
             req.ptr -= cmd;
@@ -3545,14 +3548,6 @@ int do_mmu_update(
                           (unsigned long)(req.ptr & ~PAGE_MASK));
             page = mfn_to_page(mfn);
 
-            rc = xsm_mmu_normal_update(d, req.val, page);
-            if ( rc ) {
-                unmap_domain_page_with_cache(va, &mapcache);
-                put_page(page);
-                put_gfn(pt_owner, gmfn);
-                break;
-            }
-
             if ( page_lock(page) )
             {
                 switch ( page->u.inuse.type_info & PGT_type_mask )
@@ -3740,6 +3735,10 @@ int do_mmu_update(
             mfn = req.ptr >> PAGE_SHIFT;
             gpfn = req.val;
 
+            rc = xsm_mmu_machphys_update(d, mfn);
+            if ( rc )
+                break;
+
             if ( unlikely(!get_page_from_pagenr(mfn, pg_owner)) )
             {
                 MEM_LOG("Could not get page for mach->phys update");
@@ -3754,10 +3753,6 @@ int do_mmu_update(
                 break;
             }
 
-            rc = xsm_mmu_machphys_update(d, mfn_to_page(mfn));
-            if ( rc )
-                break;
-
             set_gpfn_from_mfn(mfn, gpfn);
 
             paging_mark_dirty(pg_owner, mfn);
@@ -4384,6 +4379,10 @@ static int __do_update_va_mapping(
 
     perfc_incr(calls_to_update_va);
 
+    rc = xsm_update_va_mapping(d, pg_owner, val);
+    if ( rc )
+        return rc;
+
     rc = -EINVAL;
     pl1e = guest_map_l1e(v, va, &gl1mfn);
     if ( unlikely(!pl1e || !get_page_from_pagenr(gl1mfn, d)) )
@@ -4403,13 +4402,6 @@ static int __do_update_va_mapping(
         goto out;
     }
 
-    rc = xsm_update_va_mapping(d, val, gl1pg);
-    if ( rc ) {
-        page_unlock(gl1pg);
-        put_page(gl1pg);
-        goto out;
-    }
-
     rc = mod_l1_entry(pl1e, val, gl1mfn, 0, v, pg_owner);
 
     page_unlock(gl1pg);

xen/include/xsm/xsm.h

@@ -141,12 +141,11 @@ struct xsm_operations {
     int (*getidletime) (void);
     int (*machine_memory_map) (void);
     int (*domain_memory_map) (struct domain *d);
-    int (*mmu_normal_update) (struct domain *d,
-			      intpte_t fpte, struct page_info *page);
-    int (*mmu_machphys_update) (struct domain *d, struct page_info *page);
-    int (*update_va_mapping) (struct domain *d,
-			      l1_pgentry_t pte,
-			      struct page_info *page);
+    int (*mmu_normal_update) (struct domain *d, struct domain *f, 
+                                                                intpte_t fpte);
+    int (*mmu_machphys_update) (struct domain *d, unsigned long mfn);
+    int (*update_va_mapping) (struct domain *d, struct domain *f, 
+                                                            l1_pgentry_t pte);
     int (*add_to_physmap) (struct domain *d1, struct domain *d2);
     int (*sendtrigger) (struct domain *d);
     int (*bind_pt_irq) (struct domain *d, struct xen_domctl_bind_pt_irq *bind);
@@ -595,22 +594,21 @@ static inline int xsm_domain_memory_map(struct domain *d)
     return xsm_call(domain_memory_map(d));
 }
 
-static inline int xsm_mmu_normal_update (struct domain *d,
-					 intpte_t fpte, struct page_info *page)
+static inline int xsm_mmu_normal_update (struct domain *d, struct domain *f, 
+                                                                intpte_t fpte)
 {
-    return xsm_call(mmu_normal_update(d, fpte, page));
+    return xsm_call(mmu_normal_update(d, f, fpte));
 }
 
-static inline int xsm_mmu_machphys_update (struct domain *d, struct page_info *page)
+static inline int xsm_mmu_machphys_update (struct domain *d, unsigned long mfn)
 {
-    return xsm_call(mmu_machphys_update(d, page));
+    return xsm_call(mmu_machphys_update(d, mfn));
 }
 
-static inline int xsm_update_va_mapping(struct domain *d,
-					l1_pgentry_t pte,
-					struct page_info *page)
+static inline int xsm_update_va_mapping(struct domain *d, struct domain *f, 
+                                                            l1_pgentry_t pte)
 {
-    return xsm_call(update_va_mapping(d, pte, page));
+    return xsm_call(update_va_mapping(d, f, pte));
 }
 
 static inline int xsm_add_to_physmap(struct domain *d1, struct domain *d2)

xen/xsm/dummy.c

@@ -400,20 +400,19 @@ static int dummy_domain_memory_map (struct domain *d)
     return 0;
 }
 
-static int dummy_mmu_normal_update (struct domain *d,
-				    intpte_t fpte, struct page_info *page)
+static int dummy_mmu_normal_update (struct domain *d, struct domain *f, 
+                                                                intpte_t fpte)
 {
     return 0;
 }
 
-static int dummy_mmu_machphys_update (struct domain *d, struct page_info *page)
+static int dummy_mmu_machphys_update (struct domain *d, unsigned long mfn)
 {
     return 0;
 }
 
-static int dummy_update_va_mapping (struct domain *d,
-				    l1_pgentry_t pte,
-				    struct page_info *page)
+static int dummy_update_va_mapping (struct domain *d, struct domain *f, 
+                                                            l1_pgentry_t pte)
 {
     return 0;
 }

xen/xsm/flask/hooks.c

@@ -348,6 +348,26 @@ static int get_page_sid(struct page_info *page, u32 *sid)
     return rc;
 }
 
+static int get_mfn_sid(unsigned long mfn, u32 *sid)
+{
+    int rc = 0;
+    struct page_info *page;
+
+    if ( mfn_valid(mfn) )
+    {
+        /*mfn is valid if this is a page that Xen is tracking!*/
+        page = mfn_to_page(mfn);
+        rc = get_page_sid(page, sid);
+    }
+    else
+    {
+        /*Possibly an untracked IO page?*/
+        rc = security_iomem_sid(mfn, sid);
+    }
+
+    return rc;    
+}
+
 static int flask_memory_adjust_reservation(struct domain *d1, struct domain *d2)
 {
     return domain_has_perm(d1, d2, SECCLASS_MMU, MMU__ADJUST);
@@ -987,11 +1007,12 @@ static int flask_domain_memory_map(struct domain *d)
     return domain_has_perm(current->domain, d, SECCLASS_MMU, MMU__MEMORYMAP);
 }
 
-static int flask_mmu_normal_update(struct domain *d, 
-                                   intpte_t fpte, struct page_info *page)
+static int flask_mmu_normal_update(struct domain *d, struct domain *f, 
+                                   intpte_t fpte)
 {
     int rc = 0;
     u32 map_perms = MMU__MAP_READ;
+    unsigned long fmfn;
     struct domain_security_struct *dsec;
     u32 fsid;
 
@@ -1000,38 +1021,42 @@ static int flask_mmu_normal_update(struct domain *d,
     if ( l1e_get_flags(l1e_from_intpte(fpte)) & _PAGE_RW )
         map_perms |= MMU__MAP_WRITE;
 
-    rc = get_page_sid(page, &fsid);
+    fmfn = get_gfn_untyped(f, l1e_get_pfn(l1e_from_intpte(fpte)));
+
+    rc = get_mfn_sid(fmfn, &fsid);
     if ( rc )
         return rc;
 
     return avc_has_perm(dsec->sid, fsid, SECCLASS_MMU, map_perms, NULL);
 }
 
-static int flask_mmu_machphys_update(struct domain *d, struct page_info *page)
+static int flask_mmu_machphys_update(struct domain *d, unsigned long mfn)
 {
     int rc = 0;
     u32 psid;
     struct domain_security_struct *dsec;
     dsec = d->ssid;
 
-    rc = get_page_sid(page, &psid);
+    rc = get_mfn_sid(mfn, &psid);
     if ( rc )
         return rc;
 
     return avc_has_perm(dsec->sid, psid, SECCLASS_MMU, MMU__UPDATEMP, NULL);
 }
 
-static int flask_update_va_mapping(struct domain *d,
-                                   l1_pgentry_t pte, struct page_info *page)
+static int flask_update_va_mapping(struct domain *d, struct domain *f,
+                                   l1_pgentry_t pte)
 {
     int rc = 0;
     u32 psid;
     u32 map_perms = MMU__MAP_READ;
+    unsigned long mfn;
     struct domain_security_struct *dsec;
 
     dsec = d->ssid;
 
-    rc = get_page_sid(page, &psid);
+    mfn = get_gfn_untyped(f, l1e_get_pfn(pte));
+    rc = get_mfn_sid(mfn, &psid);
     if ( rc )
         return rc;