1 files changed, 56 insertions, 0 deletions

diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 79a1bb635662..a2e7a8563b38 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -110,6 +110,7 @@ enum sel_inos {
         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
         SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
         SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
+        SEL_STATUS,     /* export current status using mmap() */
         SEL_INO_NEXT,   /* The next inode number to use */
 };
 
@@ -171,6 +172,7 @@ static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
                 if (selinux_enforcing)
                         avc_ss_reset(0);
                 selnl_notify_setenforce(selinux_enforcing);
+                selinux_status_update_setenforce(selinux_enforcing);
         }
         length = count;
 out:
@@ -205,6 +207,59 @@ static const struct file_operations sel_handle_unknown_ops = {
         .llseek         = generic_file_llseek,
 };
 
+static int sel_open_handle_status(struct inode *inode, struct file *filp)
+{
+        struct page    *status = selinux_kernel_status_page();
+
+        if (!status)
+                return -ENOMEM;
+
+        filp->private_data = status;
+
+        return 0;
+}
+
+static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
+                                      size_t count, loff_t *ppos)
+{
+        struct page    *status = filp->private_data;
+
+        BUG_ON(!status);
+
+        return simple_read_from_buffer(buf, count, ppos,
+                                       page_address(status),
+                                       sizeof(struct selinux_kernel_status));
+}
+
+static int sel_mmap_handle_status(struct file *filp,
+                                  struct vm_area_struct *vma)
+{
+        struct page    *status = filp->private_data;
+        unsigned long   size = vma->vm_end - vma->vm_start;
+
+        BUG_ON(!status);
+
+        /* only allows one page from the head */
+        if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
+                return -EIO;
+        /* disallow writable mapping */
+        if (vma->vm_flags & VM_WRITE)
+                return -EPERM;
+        /* disallow mprotect() turns it into writable */
+        vma->vm_flags &= ~VM_MAYWRITE;
+
+        return remap_pfn_range(vma, vma->vm_start,
+                               page_to_pfn(status),
+                               size, vma->vm_page_prot);
+}
+
+static const struct file_operations sel_handle_status_ops = {
+        .open           = sel_open_handle_status,
+        .read           = sel_read_handle_status,
+        .mmap           = sel_mmap_handle_status,
+        .llseek         = generic_file_llseek,
+};
+
 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
                                  size_t count, loff_t *ppos)
@@ -1612,6 +1667,7 @@ static int sel_fill_super(struct super_block *sb, void *data, int silent)
                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
+                [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
                 /* last one */ {""}
         };
         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);