Commit 99fcec30 authored by Himangi Saraogi's avatar Himangi Saraogi Committed by Michal Marek
Browse files

Coccinelle: Script to detect cast after memory allocation 



This script detects cases of use of cast for the value returned by
kmalloc, kzalloc, kcalloc, kmem_cache_alloc, kmem_cache_zalloc,
kmem_cache_alloc_node, kmalloc_node and kzalloc_node and removes
the cast as it is not useful. This Coccinelle script replaces
drop_kmalloc_cast.cocci as it removes the casting in more limited
cases of kmalloc, kzalloc and kcalloc.

Signed-off-by: default avatarHimangi Saraogi <himangi774@gmail.com>
Acked-by: default avatarJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: default avatarMichal Marek <mmarek@suse.cz>
parent b5889ab7

scripts/coccinelle/api/alloc/drop_kmalloc_cast.cocci→scripts/coccinelle/api/alloc/alloc_cast.cocci

+72 −0
Original line number Diff line number Diff line 
/// Remove casting the values returned by memory allocation functions

/// like kmalloc, kzalloc, kmem_cache_alloc, kmem_cache_zalloc etc.

///

/// Casting (void *) value returned by kmalloc is useless

/// as mentioned in Documentation/CodingStyle, Chap 14.

///

//# This makes an effort to find cases of casting of values returned by

//# kmalloc, kzalloc, kcalloc, kmem_cache_alloc, kmem_cache_zalloc,

//# kmem_cache_alloc_node, kmalloc_node and kzalloc_node and removes

//# the casting as it is not required. The result in the patch case may

//#need some reformatting.

//

// Confidence: High

// Copyright: 2009,2010 Nicolas Palix, DIKU.  GPLv2.

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

// Copyright: 2014, Himangi Saraogi  GPLv2.

// Comments:

// Options: --no-includes --include-headers

//

// Keywords: kmalloc, kzalloc, kcalloc

// Version min: < 2.6.12 kmalloc

// Version min: < 2.6.12 kcalloc

// Version min:   2.6.14 kzalloc

//



virtual context

virtual patch
@@ -27,7 +27,8 @@ type T; 
@@



* (T *)

  \(kmalloc\|kzalloc\|kcalloc\)(...)

  \(kmalloc\|kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|

   kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\)(...)



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

//  For patch mode
@@ -38,7 +39,8 @@ type T; 
@@



- (T *)

  \(kmalloc\|kzalloc\|kcalloc\)(...)

  (\(kmalloc\|kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|

   kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\)(...))



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

//  For org and report mode
@@ -49,7 +51,8 @@ type T; 
position p;

@@



 (T@p *)\(kmalloc\|kzalloc\|kcalloc\)(...)

 (T@p *)\(kmalloc\|kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|

   kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\)(...)



@script:python depends on org@

p << r.p;
@@ -63,5 +66,7 @@ p << r.p; 
t << r.T;

@@



msg="WARNING: casting value returned by k[cmz]alloc to (%s *) is useless." % (t)

msg="WARNING: casting value returned by memory allocation function to (%s *) is useless." % (t)

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

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