X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=security%2Fcommoncap.c;h=e3097c0a1311205cc231cee85cb012b271db1ed8;hb=adda766193ea1cf3137484a9521972d080d0b7af;hp=48b7e0228fa38455ee6c2bf0cb37876e96c99afb;hpb=661adc423d70203a56723701aaf255e16950dfdb;p=deliverable%2Flinux.git

diff --git a/security/commoncap.c b/security/commoncap.c
index 48b7e0228fa3..e3097c0a1311 100644
--- 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;
+}