]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - drivers/xen/privcmd.c
mm: kill vma flag VM_RESERVED and mm->reserved_vm counter
[karo-tx-linux.git] / drivers / xen / privcmd.c
index ccee0f16bcf8c10e994855a6efadff99b5b6bda1..8adb9cc267f96e201ade041441ef8a317ce336d8 100644 (file)
@@ -76,7 +76,7 @@ static void free_page_list(struct list_head *pages)
  */
 static int gather_array(struct list_head *pagelist,
                        unsigned nelem, size_t size,
-                       void __user *data)
+                       const void __user *data)
 {
        unsigned pageidx;
        void *pagedata;
@@ -246,61 +246,117 @@ struct mmap_batch_state {
        domid_t domain;
        unsigned long va;
        struct vm_area_struct *vma;
-       int err;
-
-       xen_pfn_t __user *user;
+       /* A tristate:
+        *      0 for no errors
+        *      1 if at least one error has happened (and no
+        *          -ENOENT errors have happened)
+        *      -ENOENT if at least 1 -ENOENT has happened.
+        */
+       int global_error;
+       /* An array for individual errors */
+       int *err;
+
+       /* User-space mfn array to store errors in the second pass for V1. */
+       xen_pfn_t __user *user_mfn;
 };
 
 static int mmap_batch_fn(void *data, void *state)
 {
        xen_pfn_t *mfnp = data;
        struct mmap_batch_state *st = state;
+       int ret;
+
+       ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
+                                        st->vma->vm_page_prot, st->domain);
 
-       if (xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
-                                      st->vma->vm_page_prot, st->domain) < 0) {
-               *mfnp |= 0xf0000000U;
-               st->err++;
+       /* Store error code for second pass. */
+       *(st->err++) = ret;
+
+       /* And see if it affects the global_error. */
+       if (ret < 0) {
+               if (ret == -ENOENT)
+                       st->global_error = -ENOENT;
+               else {
+                       /* Record that at least one error has happened. */
+                       if (st->global_error == 0)
+                               st->global_error = 1;
+               }
        }
        st->va += PAGE_SIZE;
 
        return 0;
 }
 
-static int mmap_return_errors(void *data, void *state)
+static int mmap_return_errors_v1(void *data, void *state)
 {
        xen_pfn_t *mfnp = data;
        struct mmap_batch_state *st = state;
-
-       return put_user(*mfnp, st->user++);
+       int err = *(st->err++);
+
+       /*
+        * V1 encodes the error codes in the 32bit top nibble of the
+        * mfn (with its known limitations vis-a-vis 64 bit callers).
+        */
+       *mfnp |= (err == -ENOENT) ?
+                               PRIVCMD_MMAPBATCH_PAGED_ERROR :
+                               PRIVCMD_MMAPBATCH_MFN_ERROR;
+       return __put_user(*mfnp, st->user_mfn++);
 }
 
 static struct vm_operations_struct privcmd_vm_ops;
 
-static long privcmd_ioctl_mmap_batch(void __user *udata)
+static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
 {
        int ret;
-       struct privcmd_mmapbatch m;
+       struct privcmd_mmapbatch_v2 m;
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma;
        unsigned long nr_pages;
        LIST_HEAD(pagelist);
+       int *err_array = NULL;
        struct mmap_batch_state state;
 
        if (!xen_initial_domain())
                return -EPERM;
 
-       if (copy_from_user(&m, udata, sizeof(m)))
-               return -EFAULT;
+       switch (version) {
+       case 1:
+               if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch)))
+                       return -EFAULT;
+               /* Returns per-frame error in m.arr. */
+               m.err = NULL;
+               if (!access_ok(VERIFY_WRITE, m.arr, m.num * sizeof(*m.arr)))
+                       return -EFAULT;
+               break;
+       case 2:
+               if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2)))
+                       return -EFAULT;
+               /* Returns per-frame error code in m.err. */
+               if (!access_ok(VERIFY_WRITE, m.err, m.num * (sizeof(*m.err))))
+                       return -EFAULT;
+               break;
+       default:
+               return -EINVAL;
+       }
 
        nr_pages = m.num;
        if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT)))
                return -EINVAL;
 
-       ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t),
-                          m.arr);
+       ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), m.arr);
 
-       if (ret || list_empty(&pagelist))
+       if (ret)
                goto out;
+       if (list_empty(&pagelist)) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       err_array = kcalloc(m.num, sizeof(int), GFP_KERNEL);
+       if (err_array == NULL) {
+               ret = -ENOMEM;
+               goto out;
+       }
 
        down_write(&mm->mmap_sem);
 
@@ -315,24 +371,37 @@ static long privcmd_ioctl_mmap_batch(void __user *udata)
                goto out;
        }
 
-       state.domain = m.dom;
-       state.vma = vma;
-       state.va = m.addr;
-       state.err = 0;
+       state.domain        = m.dom;
+       state.vma           = vma;
+       state.va            = m.addr;
+       state.global_error  = 0;
+       state.err           = err_array;
 
-       ret = traverse_pages(m.num, sizeof(xen_pfn_t),
-                            &pagelist, mmap_batch_fn, &state);
+       /* mmap_batch_fn guarantees ret == 0 */
+       BUG_ON(traverse_pages(m.num, sizeof(xen_pfn_t),
+                            &pagelist, mmap_batch_fn, &state));
 
        up_write(&mm->mmap_sem);
 
-       if (state.err > 0) {
-               state.user = m.arr;
+       if (state.global_error && (version == 1)) {
+               /* Write back errors in second pass. */
+               state.user_mfn = (xen_pfn_t *)m.arr;
+               state.err      = err_array;
                ret = traverse_pages(m.num, sizeof(xen_pfn_t),
-                              &pagelist,
-                              mmap_return_errors, &state);
+                                    &pagelist, mmap_return_errors_v1, &state);
+       } else if (version == 2) {
+               ret = __copy_to_user(m.err, err_array, m.num * sizeof(int));
+               if (ret)
+                       ret = -EFAULT;
        }
 
+       /* If we have not had any EFAULT-like global errors then set the global
+        * error to -ENOENT if necessary. */
+       if ((ret == 0) && (state.global_error == -ENOENT))
+               ret = -ENOENT;
+
 out:
+       kfree(err_array);
        free_page_list(&pagelist);
 
        return ret;
@@ -354,7 +423,11 @@ static long privcmd_ioctl(struct file *file,
                break;
 
        case IOCTL_PRIVCMD_MMAPBATCH:
-               ret = privcmd_ioctl_mmap_batch(udata);
+               ret = privcmd_ioctl_mmap_batch(udata, 1);
+               break;
+
+       case IOCTL_PRIVCMD_MMAPBATCH_V2:
+               ret = privcmd_ioctl_mmap_batch(udata, 2);
                break;
 
        default:
@@ -380,13 +453,10 @@ static struct vm_operations_struct privcmd_vm_ops = {
 
 static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
 {
-       /* Unsupported for auto-translate guests. */
-       if (xen_feature(XENFEAT_auto_translated_physmap))
-               return -ENOSYS;
-
        /* DONTCOPY is essential for Xen because copy_page_range doesn't know
         * how to recreate these mappings */
-       vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
+       vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTCOPY |
+                        VM_DONTEXPAND | VM_DONTDUMP;
        vma->vm_ops = &privcmd_vm_ops;
        vma->vm_private_data = NULL;