scripts/coccinelle/api/memdup_user.cocci

Source file repositories/reference/linux-study-clean/scripts/coccinelle/api/memdup_user.cocci

File Facts

System
Linux kernel
Corpus path
scripts/coccinelle/api/memdup_user.cocci
Extension
.cocci
Size
2666 bytes
Lines
120
Domain
Support Tooling And Documentation
Bucket
scripts
Inferred role
Support Tooling And Documentation: scripts
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/// Use memdup_user rather than duplicating its implementation
/// This is a little bit restricted to reduce false positives
///
// Confidence: High
// Copyright: (C) 2010-2012 Nicolas Palix.
// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.
// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.
// URL: https://coccinelle.gitlabpages.inria.fr/website
// Comments:
// Options: --no-includes --include-headers

virtual patch
virtual context
virtual org
virtual report

@initialize:python@
@@
filter = frozenset(['memdup_user', 'vmemdup_user'])

def relevant(p):
    return not (filter & {el.current_element for el in p})

@depends on patch@
expression from,to,size;
identifier l1,l2;
position p : script:python() { relevant(p) };
@@

-  to = \(kmalloc@p\|kzalloc@p\)
-		(size,\(GFP_KERNEL\|GFP_USER\|
-		      \(GFP_KERNEL\|GFP_USER\)|__GFP_NOWARN\));
+  to = memdup_user(from,size);
   if (
-      to==NULL
+      IS_ERR(to)
                 || ...) {
   <+... when != goto l1;
-  -ENOMEM
+  PTR_ERR(to)
   ...+>
   }
-  if (copy_from_user(to, from, size) != 0) {
-    <+... when != goto l2;
-    -EFAULT
-    ...+>
-  }

@depends on patch@
expression from,to,size;
identifier l1,l2;
position p : script:python() { relevant(p) };
@@

-  to = \(kvmalloc@p\|kvzalloc@p\)(size,\(GFP_KERNEL\|GFP_USER\));
+  to = vmemdup_user(from,size);
   if (
-      to==NULL
+      IS_ERR(to)
                 || ...) {
   <+... when != goto l1;
-  -ENOMEM
+  PTR_ERR(to)
   ...+>
   }
-  if (copy_from_user(to, from, size) != 0) {
-    <+... when != goto l2;
-    -EFAULT
-    ...+>

Annotation

Implementation Notes