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path: root/drivers/xen/privcmd.c
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Diffstat (limited to 'drivers/xen/privcmd.c')
-rw-r--r--drivers/xen/privcmd.c226
1 files changed, 217 insertions, 9 deletions
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 6e3306f4a525..2077a3ac7c0c 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -22,6 +22,7 @@
#include <linux/pagemap.h>
#include <linux/seq_file.h>
#include <linux/miscdevice.h>
+#include <linux/moduleparam.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
@@ -32,6 +33,7 @@
#include <xen/xen.h>
#include <xen/privcmd.h>
#include <xen/interface/xen.h>
+#include <xen/interface/hvm/dm_op.h>
#include <xen/features.h>
#include <xen/page.h>
#include <xen/xen-ops.h>
@@ -43,16 +45,36 @@ MODULE_LICENSE("GPL");
#define PRIV_VMA_LOCKED ((void *)1)
+static unsigned int privcmd_dm_op_max_num = 16;
+module_param_named(dm_op_max_nr_bufs, privcmd_dm_op_max_num, uint, 0644);
+MODULE_PARM_DESC(dm_op_max_nr_bufs,
+ "Maximum number of buffers per dm_op hypercall");
+
+static unsigned int privcmd_dm_op_buf_max_size = 4096;
+module_param_named(dm_op_buf_max_size, privcmd_dm_op_buf_max_size, uint,
+ 0644);
+MODULE_PARM_DESC(dm_op_buf_max_size,
+ "Maximum size of a dm_op hypercall buffer");
+
+struct privcmd_data {
+ domid_t domid;
+};
+
static int privcmd_vma_range_is_mapped(
struct vm_area_struct *vma,
unsigned long addr,
unsigned long nr_pages);
-static long privcmd_ioctl_hypercall(void __user *udata)
+static long privcmd_ioctl_hypercall(struct file *file, void __user *udata)
{
+ struct privcmd_data *data = file->private_data;
struct privcmd_hypercall hypercall;
long ret;
+ /* Disallow arbitrary hypercalls if restricted */
+ if (data->domid != DOMID_INVALID)
+ return -EPERM;
+
if (copy_from_user(&hypercall, udata, sizeof(hypercall)))
return -EFAULT;
@@ -229,8 +251,9 @@ static int mmap_gfn_range(void *data, void *state)
return 0;
}
-static long privcmd_ioctl_mmap(void __user *udata)
+static long privcmd_ioctl_mmap(struct file *file, void __user *udata)
{
+ struct privcmd_data *data = file->private_data;
struct privcmd_mmap mmapcmd;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
@@ -245,6 +268,10 @@ static long privcmd_ioctl_mmap(void __user *udata)
if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
return -EFAULT;
+ /* If restriction is in place, check the domid matches */
+ if (data->domid != DOMID_INVALID && data->domid != mmapcmd.dom)
+ return -EPERM;
+
rc = gather_array(&pagelist,
mmapcmd.num, sizeof(struct privcmd_mmap_entry),
mmapcmd.entry);
@@ -416,8 +443,10 @@ static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs)
static const struct vm_operations_struct privcmd_vm_ops;
-static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
+static long privcmd_ioctl_mmap_batch(
+ struct file *file, void __user *udata, int version)
{
+ struct privcmd_data *data = file->private_data;
int ret;
struct privcmd_mmapbatch_v2 m;
struct mm_struct *mm = current->mm;
@@ -446,6 +475,10 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
return -EINVAL;
}
+ /* If restriction is in place, check the domid matches */
+ if (data->domid != DOMID_INVALID && data->domid != m.dom)
+ return -EPERM;
+
nr_pages = DIV_ROUND_UP(m.num, XEN_PFN_PER_PAGE);
if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT)))
return -EINVAL;
@@ -548,37 +581,210 @@ out_unlock:
goto out;
}
+static int lock_pages(
+ struct privcmd_dm_op_buf kbufs[], unsigned int num,
+ struct page *pages[], unsigned int nr_pages)
+{
+ unsigned int i;
+
+ for (i = 0; i < num; i++) {
+ unsigned int requested;
+ int pinned;
+
+ requested = DIV_ROUND_UP(
+ offset_in_page(kbufs[i].uptr) + kbufs[i].size,
+ PAGE_SIZE);
+ if (requested > nr_pages)
+ return -ENOSPC;
+
+ pinned = get_user_pages_fast(
+ (unsigned long) kbufs[i].uptr,
+ requested, FOLL_WRITE, pages);
+ if (pinned < 0)
+ return pinned;
+
+ nr_pages -= pinned;
+ pages += pinned;
+ }
+
+ return 0;
+}
+
+static void unlock_pages(struct page *pages[], unsigned int nr_pages)
+{
+ unsigned int i;
+
+ if (!pages)
+ return;
+
+ for (i = 0; i < nr_pages; i++) {
+ if (pages[i])
+ put_page(pages[i]);
+ }
+}
+
+static long privcmd_ioctl_dm_op(struct file *file, void __user *udata)
+{
+ struct privcmd_data *data = file->private_data;
+ struct privcmd_dm_op kdata;
+ struct privcmd_dm_op_buf *kbufs;
+ unsigned int nr_pages = 0;
+ struct page **pages = NULL;
+ struct xen_dm_op_buf *xbufs = NULL;
+ unsigned int i;
+ long rc;
+
+ if (copy_from_user(&kdata, udata, sizeof(kdata)))
+ return -EFAULT;
+
+ /* If restriction is in place, check the domid matches */
+ if (data->domid != DOMID_INVALID && data->domid != kdata.dom)
+ return -EPERM;
+
+ if (kdata.num == 0)
+ return 0;
+
+ if (kdata.num > privcmd_dm_op_max_num)
+ return -E2BIG;
+
+ kbufs = kcalloc(kdata.num, sizeof(*kbufs), GFP_KERNEL);
+ if (!kbufs)
+ return -ENOMEM;
+
+ if (copy_from_user(kbufs, kdata.ubufs,
+ sizeof(*kbufs) * kdata.num)) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ for (i = 0; i < kdata.num; i++) {
+ if (kbufs[i].size > privcmd_dm_op_buf_max_size) {
+ rc = -E2BIG;
+ goto out;
+ }
+
+ if (!access_ok(VERIFY_WRITE, kbufs[i].uptr,
+ kbufs[i].size)) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ nr_pages += DIV_ROUND_UP(
+ offset_in_page(kbufs[i].uptr) + kbufs[i].size,
+ PAGE_SIZE);
+ }
+
+ pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
+ if (!pages) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ xbufs = kcalloc(kdata.num, sizeof(*xbufs), GFP_KERNEL);
+ if (!xbufs) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ rc = lock_pages(kbufs, kdata.num, pages, nr_pages);
+ if (rc)
+ goto out;
+
+ for (i = 0; i < kdata.num; i++) {
+ set_xen_guest_handle(xbufs[i].h, kbufs[i].uptr);
+ xbufs[i].size = kbufs[i].size;
+ }
+
+ xen_preemptible_hcall_begin();
+ rc = HYPERVISOR_dm_op(kdata.dom, kdata.num, xbufs);
+ xen_preemptible_hcall_end();
+
+out:
+ unlock_pages(pages, nr_pages);
+ kfree(xbufs);
+ kfree(pages);
+ kfree(kbufs);
+
+ return rc;
+}
+
+static long privcmd_ioctl_restrict(struct file *file, void __user *udata)
+{
+ struct privcmd_data *data = file->private_data;
+ domid_t dom;
+
+ if (copy_from_user(&dom, udata, sizeof(dom)))
+ return -EFAULT;
+
+ /* Set restriction to the specified domain, or check it matches */
+ if (data->domid == DOMID_INVALID)
+ data->domid = dom;
+ else if (data->domid != dom)
+ return -EINVAL;
+
+ return 0;
+}
+
static long privcmd_ioctl(struct file *file,
unsigned int cmd, unsigned long data)
{
- int ret = -ENOSYS;
+ int ret = -ENOTTY;
void __user *udata = (void __user *) data;
switch (cmd) {
case IOCTL_PRIVCMD_HYPERCALL:
- ret = privcmd_ioctl_hypercall(udata);
+ ret = privcmd_ioctl_hypercall(file, udata);
break;
case IOCTL_PRIVCMD_MMAP:
- ret = privcmd_ioctl_mmap(udata);
+ ret = privcmd_ioctl_mmap(file, udata);
break;
case IOCTL_PRIVCMD_MMAPBATCH:
- ret = privcmd_ioctl_mmap_batch(udata, 1);
+ ret = privcmd_ioctl_mmap_batch(file, udata, 1);
break;
case IOCTL_PRIVCMD_MMAPBATCH_V2:
- ret = privcmd_ioctl_mmap_batch(udata, 2);
+ ret = privcmd_ioctl_mmap_batch(file, udata, 2);
+ break;
+
+ case IOCTL_PRIVCMD_DM_OP:
+ ret = privcmd_ioctl_dm_op(file, udata);
+ break;
+
+ case IOCTL_PRIVCMD_RESTRICT:
+ ret = privcmd_ioctl_restrict(file, udata);
break;
default:
- ret = -EINVAL;
break;
}
return ret;
}
+static int privcmd_open(struct inode *ino, struct file *file)
+{
+ struct privcmd_data *data = kzalloc(sizeof(*data), GFP_KERNEL);
+
+ if (!data)
+ return -ENOMEM;
+
+ /* DOMID_INVALID implies no restriction */
+ data->domid = DOMID_INVALID;
+
+ file->private_data = data;
+ return 0;
+}
+
+static int privcmd_release(struct inode *ino, struct file *file)
+{
+ struct privcmd_data *data = file->private_data;
+
+ kfree(data);
+ return 0;
+}
+
static void privcmd_close(struct vm_area_struct *vma)
{
struct page **pages = vma->vm_private_data;
@@ -647,6 +853,8 @@ static int privcmd_vma_range_is_mapped(
const struct file_operations xen_privcmd_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = privcmd_ioctl,
+ .open = privcmd_open,
+ .release = privcmd_release,
.mmap = privcmd_mmap,
};
EXPORT_SYMBOL_GPL(xen_privcmd_fops);
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-29 01:50:38 +0300