scripts/coccinelle/free/ifnullfree.cocci

   1 /// NULL check before some freeing functions is not needed.
   2 ///
   3 /// Based on checkpatch warning
   4 /// "kfree(NULL) is safe this check is probably not required"
   5 /// and kfreeaddr.cocci by Julia Lawall.
   6 ///
   7 // Copyright: (C) 2014 Fabian Frederick.  GPLv2.
   8 // Comments: -
   9 // Options: --no-includes --include-headers
  10
  11 virtual patch
  12 virtual org
  13 virtual report
  14 virtual context
  15
  16 @r2 depends on patch@
  17 expression E;
  18 @@
  19 - if (E != NULL)
  20 (
  21   kfree(E);
  22 |
  23   kzfree(E);
  24 |
  25   debugfs_remove(E);
  26 |
  27   debugfs_remove_recursive(E);
  28 |
  29   usb_free_urb(E);
  30 |
  31   kmem_cache_destroy(E);
  32 |
  33   mempool_destroy(E);
  34 |
  35   dma_pool_destroy(E);
  36 )
  37
  38 @r depends on context || report || org @
  39 expression E;
  40 position p;
  41 @@
  42
  43 * if (E != NULL)
  44 *       \(kfree@p\|kzfree@p\|debugfs_remove@p\|debugfs_remove_recursive@p\|
  45 *         usb_free_urb@p\|kmem_cache_destroy@p\|mempool_destroy@p\|
  46 *         dma_pool_destroy@p\)(E);
  47
  48 @script:python depends on org@
  49 p << r.p;
  50 @@
  51
  52 cocci.print_main("NULL check before that freeing function is not needed", p)
  53
  54 @script:python depends on report@
  55 p << r.p;
  56 @@
  57
  58 msg = "WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values."
  59 coccilib.report.print_report(p[0], msg)