Coccinelle: Add api/kstrdup.cocci

/// Use kstrdup rather than duplicating its implementation

///

// Confidence: High

// Copyright: (C) 2010 Nicolas Palix, DIKU.  GPLv2.

// Copyright: (C) 2010 Julia Lawall, DIKU.  GPLv2.

// Copyright: (C) 2010 Gilles Muller, INRIA/LiP6.  GPLv2.

// URL: http://coccinelle.lip6.fr/

// Comments:

// Options: -no_includes -include_headers

virtual patch

@@

expression from,to;

expression flag,E1,E2;

statement S;

@@

-  to = kmalloc(strlen(from) + 1,flag);

+  to = kstrdup(from, flag);

   ... when != \(from = E1 \| to = E1 \)

   if (to==NULL || ...) S

   ... when != \(from = E2 \| to = E2 \)

-  strcpy(to, from);

@@

expression x,from,to;

expression flag,E1,E2,E3;

statement S;

@@

-   x = strlen(from) + 1;

    ... when != \( x = E1 \| from = E1 \)

-   to = \(kmalloc\|kzalloc\)(x,flag);

+   to = kstrdup(from, flag);

    ... when != \(x = E2 \| from = E2 \| to = E2 \)

    if (to==NULL || ...) S

    ... when != \(x = E3 \| from = E3 \| to = E3 \)

-   memcpy(to, from, x);