ima: Align ima_file_mprotect() definition with LSM infrastructure

Change ima_file_mprotect() definition, so that it can be registered
as implementation of the file_mprotect hook.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Author: robertosassu

include/linux/ima.h

@@ -23,7 +23,8 @@ extern void ima_post_create_tmpfile(struct mnt_idmap *idmap,
 extern void ima_file_free(struct file *file);
 extern int ima_file_mmap(struct file *file, unsigned long reqprot,
 			 unsigned long prot, unsigned long flags);
-extern int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot);
+extern int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
+			     unsigned long prot);
 extern int ima_load_data(enum kernel_load_data_id id, bool contents);
 extern int ima_post_load_data(char *buf, loff_t size,
 			      enum kernel_load_data_id id, char *description);
@@ -84,7 +85,7 @@ static inline int ima_file_mmap(struct file *file, unsigned long reqprot,
 }
 
 static inline int ima_file_mprotect(struct vm_area_struct *vma,
-				    unsigned long prot)
+				    unsigned long reqprot, unsigned long prot)
 {
 	return 0;
 }

security/integrity/ima/ima_main.c

@@ -455,7 +455,8 @@ int ima_file_mmap(struct file *file, unsigned long reqprot,
 /**
  * ima_file_mprotect - based on policy, limit mprotect change
  * @vma: vm_area_struct protection is set to
- * @prot: contains the protection that will be applied by the kernel.
+ * @reqprot: protection requested by the application
+ * @prot: protection that will be applied by the kernel
  *
  * Files can be mmap'ed read/write and later changed to execute to circumvent
  * IMA's mmap appraisal policy rules.  Due to locking issues (mmap semaphore
@@ -465,7 +466,8 @@ int ima_file_mmap(struct file *file, unsigned long reqprot,
  *
  * On mprotect change success, return 0.  On failure, return -EACESS.
  */
-int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
+int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
+		      unsigned long prot)
 {
 	struct ima_template_desc *template = NULL;
 	struct file *file;

security/security.c

@@ -2831,7 +2831,7 @@ int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
 	ret = call_int_hook(file_mprotect, 0, vma, reqprot, prot);
 	if (ret)
 		return ret;
-	return ima_file_mprotect(vma, prot);
+	return ima_file_mprotect(vma, reqprot, prot);
 }
 
 /**