Coccinelle: Add null/kmerr.cocci

/// This semantic patch looks for kmalloc etc that are not followed by a

/// NULL check.  It only gives a report in the case where there is some

/// error handling code later in the function, which may be helpful

/// in determining what the error handling code for the call to kmalloc etc

/// should be.

///

// 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 context

virtual org

virtual report

@withtest@

expression x;

position p;

identifier f,fld;

@@

x@p = f(...);

... when != x->fld

\(x == NULL \| x != NULL\)

@fixed depends on context && !org && !report@

expression x,x1;

position p1 != withtest.p;

statement S;

position any withtest.p;

identifier f;

@@

*x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);

...

*x1@p = f(...);

if (!x1) S

// ------------------------------------------------------------------------

@rfixed depends on (org || report) && !context exists@

expression x,x1;

position p1 != withtest.p;

position p2;

statement S;

position any withtest.p;

identifier f;

@@

x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);

...

x1@p = f@p2(...);

if (!x1) S

@script:python depends on org@

p1 << rfixed.p1;

p2 << rfixed.p2;

@@

cocci.print_main("alloc call",p1)

cocci.print_secs("possible model",p2)

@script:python depends on report@

p1 << rfixed.p1;

p2 << rfixed.p2;

@@

msg = "alloc with no test, possible model on line %s" % (p2[0].line)

coccilib.report.print_report(p1[0],msg)