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Diffstat (limited to 'drivers/xen/privcmd.c')
-rw-r--r--drivers/xen/privcmd.c89
1 files changed, 47 insertions, 42 deletions
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 0bbbccbb1f1..ca2b00e9d55 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -199,9 +199,6 @@ static long privcmd_ioctl_mmap(void __user *udata)
LIST_HEAD(pagelist);
struct mmap_mfn_state state;
- if (!xen_initial_domain())
- return -EPERM;
-
/* We only support privcmd_ioctl_mmap_batch for auto translated. */
if (xen_feature(XENFEAT_auto_translated_physmap))
return -ENOSYS;
@@ -261,11 +258,12 @@ struct mmap_batch_state {
* -ENOENT if at least 1 -ENOENT has happened.
*/
int global_error;
- /* An array for individual errors */
- int *err;
+ int version;
/* User-space mfn array to store errors in the second pass for V1. */
xen_pfn_t __user *user_mfn;
+ /* User-space int array to store errors in the second pass for V2. */
+ int __user *user_err;
};
/* auto translated dom0 note: if domU being created is PV, then mfn is
@@ -288,7 +286,19 @@ static int mmap_batch_fn(void *data, void *state)
&cur_page);
/* Store error code for second pass. */
- *(st->err++) = ret;
+ if (st->version == 1) {
+ if (ret < 0) {
+ /*
+ * V1 encodes the error codes in the 32bit top nibble of the
+ * mfn (with its known limitations vis-a-vis 64 bit callers).
+ */
+ *mfnp |= (ret == -ENOENT) ?
+ PRIVCMD_MMAPBATCH_PAGED_ERROR :
+ PRIVCMD_MMAPBATCH_MFN_ERROR;
+ }
+ } else { /* st->version == 2 */
+ *((int *) mfnp) = ret;
+ }
/* And see if it affects the global_error. */
if (ret < 0) {
@@ -305,20 +315,25 @@ static int mmap_batch_fn(void *data, void *state)
return 0;
}
-static int mmap_return_errors_v1(void *data, void *state)
+static int mmap_return_errors(void *data, void *state)
{
- xen_pfn_t *mfnp = data;
struct mmap_batch_state *st = state;
- 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++);
+ if (st->version == 1) {
+ xen_pfn_t mfnp = *((xen_pfn_t *) data);
+ if (mfnp & PRIVCMD_MMAPBATCH_MFN_ERROR)
+ return __put_user(mfnp, st->user_mfn++);
+ else
+ st->user_mfn++;
+ } else { /* st->version == 2 */
+ int err = *((int *) data);
+ if (err)
+ return __put_user(err, st->user_err++);
+ else
+ st->user_err++;
+ }
+
+ return 0;
}
/* Allocate pfns that are then mapped with gmfns from foreign domid. Update
@@ -357,12 +372,8 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
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;
-
switch (version) {
case 1:
if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch)))
@@ -396,10 +407,12 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
goto out;
}
- err_array = kcalloc(m.num, sizeof(int), GFP_KERNEL);
- if (err_array == NULL) {
- ret = -ENOMEM;
- goto out;
+ if (version == 2) {
+ /* Zero error array now to only copy back actual errors. */
+ if (clear_user(m.err, sizeof(int) * m.num)) {
+ ret = -EFAULT;
+ goto out;
+ }
}
down_write(&mm->mmap_sem);
@@ -427,7 +440,7 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
state.va = m.addr;
state.index = 0;
state.global_error = 0;
- state.err = err_array;
+ state.version = version;
/* mmap_batch_fn guarantees ret == 0 */
BUG_ON(traverse_pages(m.num, sizeof(xen_pfn_t),
@@ -435,21 +448,14 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
up_write(&mm->mmap_sem);
- if (version == 1) {
- if (state.global_error) {
- /* 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_v1, &state);
- } else
- ret = 0;
-
- } else if (version == 2) {
- ret = __copy_to_user(m.err, err_array, m.num * sizeof(int));
- if (ret)
- ret = -EFAULT;
- }
+ if (state.global_error) {
+ /* Write back errors in second pass. */
+ state.user_mfn = (xen_pfn_t *)m.arr;
+ state.user_err = m.err;
+ ret = traverse_pages(m.num, sizeof(xen_pfn_t),
+ &pagelist, mmap_return_errors, &state);
+ } else
+ ret = 0;
/* If we have not had any EFAULT-like global errors then set the global
* error to -ENOENT if necessary. */
@@ -457,7 +463,6 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
ret = -ENOENT;
out:
- kfree(err_array);
free_page_list(&pagelist);
return ret;