1 files changed, 31 insertions, 13 deletions

diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index b8f4aee..0ff3763 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -159,7 +159,7 @@ vm_map_modify(struct vas vas, vaddr_t va, paddr_t pa, vm_prot_t prot, bool unmap
  *      crashes.
  */
 void *
-mmap_at(void *addr, size_t len, int prot, int flags, int fildes, off_t off)
+mmap(void *addr, size_t len, int prot, int flags, int fildes, off_t off)
 {
     struct vm_object *map_obj = NULL;
     struct cdevsw *cdevp;
@@ -179,11 +179,6 @@ mmap_at(void *addr, size_t len, int prot, int flags, int fildes, off_t off)
     npgs = len / DEFAULT_PAGESIZE;
     vas = pmap_read_vas();
 
-    if (addr == NULL) {
-        pr_error("mmap: NULL addr not supported\n");
-        return NULL;
-    }
-
     /* Validate flags */
     if (ISSET(flags, MAP_FIXED)) {
         pr_error("mmap: fixed mappings not yet supported\n");
@@ -216,11 +211,29 @@ mmap_at(void *addr, size_t len, int prot, int flags, int fildes, off_t off)
         }
 
         cdevp = map_obj->data;
-        if ((pa = cdevp->mmap(vp->dev, off, 0)) == 0) {
+        if ((pa = cdevp->mmap(vp->dev, len, off, 0)) == 0) {
             kprintf("mmap: dev mmap() gave 0\n");
             return NULL;
         }
 
+        /*
+         * If the address passed is NULL, just identity
+         * map everything.
+         *
+         * XXX: This is why the bounds check done in the
+         *      cdev mmap() *must* be correct.
+         *
+         * TODO: Use copy-on-write for this instead. Since mapping
+         *       certain devices may required a lot of memory to
+         *       be referenced anyways, we could use a buffered
+         *       copy-on-write technique where only a window of
+         *       pages can be mapped on-demand and other pages
+         *       freed when that window is exceeded.
+         */
+        if (addr == NULL) {
+            addr = (void *)pa;
+        }
+
         va = ALIGN_DOWN((vaddr_t)addr, DEFAULT_PAGESIZE);
         error = vm_map(vas, va, pa, prot, len);
         if (error != 0) {
@@ -231,6 +244,11 @@ mmap_at(void *addr, size_t len, int prot, int flags, int fildes, off_t off)
         goto done;
     }
 
+    if (addr == NULL) {
+        pr_error("mmap: NULL addr not supported\n");
+        return NULL;
+    }
+
     /* Only allocate new obj if needed */
     if (map_obj == NULL) {
         map_obj = dynalloc(sizeof(*map_obj));
@@ -292,7 +310,7 @@ done:
  *      multiple of the machine page size.
  */
 int
-munmap_at(void *addr, size_t len)
+munmap(void *addr, size_t len)
 {
     int pgno;
     vaddr_t va;
@@ -348,7 +366,7 @@ munmap_at(void *addr, size_t len)
  * arg5 -> off
  */
 scret_t
-mmap(struct syscall_args *scargs)
+sys_mmap(struct syscall_args *scargs)
 {
     void *addr;
     size_t len;
@@ -357,11 +375,11 @@ mmap(struct syscall_args *scargs)
 
     addr = (void *)scargs->arg0;
     len = scargs->arg1;
-    prot = scargs->arg2;
+    prot = scargs->arg2 | PROT_USER;
     flags = scargs->arg3;
     fildes = scargs->arg4;
     off = scargs->arg5;
-    return (scret_t)mmap_at(addr, len, prot, flags, fildes, off);
+    return (scret_t)mmap(addr, len, prot, flags, fildes, off);
 }
 
 /*
@@ -371,14 +389,14 @@ mmap(struct syscall_args *scargs)
  * arg1 -> len
  */
 scret_t
-munmap(struct syscall_args *scargs)
+sys_munmap(struct syscall_args *scargs)
 {
     void *addr;
     size_t len;
 
     addr = (void *)scargs->arg0;
     len = scargs->arg1;
-    return (scret_t)munmap_at(addr, len);
+    return (scret_t)munmap(addr, len);
 }
 
 /*