nfs: new subdir Documentation/filesystems/nfs

[safe/jmp/linux-2.6] / security / commoncap.c

diff --git a/security/commoncap.c b/security/commoncap.c
index aa97704..fe30751 100644 (file)
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -984,3 +984,33 @@ int cap_vm_enough_memory(struct mm_struct *mm, long pages)
                cap_sys_admin = 1;
        return __vm_enough_memory(mm, pages, cap_sys_admin);
 }
+
+/*
+ * cap_file_mmap - check if able to map given addr
+ * @file: unused
+ * @reqprot: unused
+ * @prot: unused
+ * @flags: unused
+ * @addr: address attempting to be mapped
+ * @addr_only: unused
+ *
+ * If the process is attempting to map memory below mmap_min_addr they need
+ * CAP_SYS_RAWIO.  The other parameters to this function are unused by the
+ * capability security module.  Returns 0 if this mapping should be allowed
+ * -EPERM if not.
+ */
+int cap_file_mmap(struct file *file, unsigned long reqprot,
+                 unsigned long prot, unsigned long flags,
+                 unsigned long addr, unsigned long addr_only)
+{
+       int ret = 0;
+
+       if (addr < dac_mmap_min_addr) {
+               ret = cap_capable(current, current_cred(), CAP_SYS_RAWIO,
+                                 SECURITY_CAP_AUDIT);
+               /* set PF_SUPERPRIV if it turns out we allow the low mmap */
+               if (ret == 0)
+                       current->flags |= PF_SUPERPRIV;
+       }
+       return ret;
+}