Commit 82c2d813 authored by Sumera Priyadarsini's avatar Sumera Priyadarsini Committed by Julia Lawall
Browse files

coccinelle: iterators: Add for_each_child.cocci script 



While iterating over child nodes with the for_each functions, if
control is transferred from the middle of the loop, as in the case
of a break or return or goto, there is no decrement in the
reference counter thus ultimately resulting in a memory leak.

Add this script to detect potential memory leaks caused by
the absence of of_node_put() before break, goto, or, return
statements which transfer control outside the loop.

Signed-off-by: default avatarSumera Priyadarsini <sylphrenadin@gmail.com>
Signed-off-by: default avatarJulia Lawall <julia.lawall@inria.fr>
parent c5864560

scripts/coccinelle/iterators/for_each_child.cocci

0 → 100644
+358 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

// Adds missing of_node_put() before return/break/goto statement within a for_each iterator for child nodes.

//# False positives can be due to function calls within the for_each

//# loop that may encapsulate an of_node_put.

///

// Confidence: High

// Copyright: (C) 2020 Sumera Priyadarsini

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

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



virtual patch

virtual context

virtual org

virtual report



@r@

local idexpression n;

expression e1,e2;

iterator name for_each_node_by_name, for_each_node_by_type,

for_each_compatible_node, for_each_matching_node,

for_each_matching_node_and_match, for_each_child_of_node,

for_each_available_child_of_node, for_each_node_with_property;

iterator i;

statement S;

expression list [n1] es;

@@



(

(

for_each_node_by_name(n,e1) S

|

for_each_node_by_type(n,e1) S

|

for_each_compatible_node(n,e1,e2) S

|

for_each_matching_node(n,e1) S

|

for_each_matching_node_and_match(n,e1,e2) S

|

for_each_child_of_node(e1,n) S

|

for_each_available_child_of_node(e1,n) S

|

for_each_node_with_property(n,e1) S

)

&

i(es,n,...) S

)



@ruleone depends on patch && !context && !org && !report@



local idexpression r.n;

iterator r.i,i1;

expression e;

expression list [r.n1] es;

statement S;

@@



 i(es,n,...) {

   ...

(

   of_node_put(n);

|

   e = n

|

   return n;

|

   i1(...,n,...) S

|

- return of_node_get(n);

+ return n;

|

+  of_node_put(n);

?  return ...;

)

   ... when any

 }



@ruletwo depends on patch && !context && !org && !report@



local idexpression r.n;

iterator r.i,i1,i2;

expression e,e1;

expression list [r.n1] es;

statement S,S2;

@@



 i(es,n,...) {

   ...

(

   of_node_put(n);

|

   e = n

|

   i1(...,n,...) S

|

+  of_node_put(n);

?  break;

)

   ... when any

 }

... when != n

    when strict

    when forall

(

 n = e1;

|

?i2(...,n,...) S2

)



@rulethree depends on patch && !context && !org && !report exists@



local idexpression r.n;

iterator r.i,i1,i2;

expression e,e1;

identifier l;

expression list [r.n1] es;

statement S,S2;

@@



 i(es,n,...) {

   ...

(

   of_node_put(n);

|

   e = n

|

   i1(...,n,...) S

|

+  of_node_put(n);

?  goto l;

)

   ... when any

 }

... when exists

l: ... when != n

       when strict

       when forall

(

 n = e1;

|

?i2(...,n,...) S2

)



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



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

statement S;

expression e;

expression list[r.n1] es;

iterator r.i, i1;

local idexpression r.n;

position j0, j1;

@@



 i@j0(es,n,...) {

   ...

(

   of_node_put(n);

|

   e = n

|

   return n;

|

   i1(...,n,...) S

|

  return @j1 ...;

)

   ... when any

 }



@ruleone_disj depends on !patch && (context || org || report)@

expression list[r.n1] es;

iterator r.i;

local idexpression r.n;

position ruleone_context.j0, ruleone_context.j1;

@@



*  i@j0(es,n,...) {

   ...

*return  @j1...;

   ... when any

 }



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

statement S, S2;

expression e, e1;

expression list[r.n1] es;

iterator r.i, i1, i2;

local idexpression r.n;

position j0, j2;

@@



 i@j0(es,n,...) {

   ...

(

   of_node_put(n);

|

   e = n

|

   i1(...,n,...) S

|

  break@j2;

)

   ... when any

 }

... when != n

    when strict

    when forall

(

 n = e1;

|

?i2(...,n,...) S2

)



@ruletwo_disj depends on !patch && (context || org || report)@

statement S2;

expression e1;

expression list[r.n1] es;

iterator r.i, i2;

local idexpression r.n;

position ruletwo_context.j0, ruletwo_context.j2;

@@



*  i@j0(es,n,...) {

   ...

*break @j2;

   ... when any

 }

... when != n

    when strict

    when forall

(

  n = e1;

|

?i2(...,n,...) S2

)



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

identifier l;

statement S,S2;

expression e, e1;

expression list[r.n1] es;

iterator r.i, i1, i2;

local idexpression r.n;

position j0, j3;

@@



 i@j0(es,n,...) {

   ...

(

   of_node_put(n);

|

   e = n

|

   i1(...,n,...) S

|

  goto l@j3;

)

  ... when any

 }

... when exists

l:

... when != n

    when strict

    when forall

(

 n = e1;

|

?i2(...,n,...) S2

)



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

identifier l;

statement S2;

expression e1;

expression list[r.n1] es;

iterator r.i, i2;

local idexpression r.n;

position rulethree_context.j0, rulethree_context.j3;

@@



*  i@j0(es,n,...) {

   ...

*goto l@j3;

   ... when any

 }

... when exists

 l:

 ... when != n

     when strict

     when forall

(

 n = e1;

|

?i2(...,n,...) S2

)



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



@script:python ruleone_org depends on org@

i << r.i;

j0 << ruleone_context.j0;

j1 << ruleone_context. j1;

@@



msg = "WARNING: Function \"%s\" should have of_node_put() before return " % (i)

coccilib.org.print_safe_todo(j0[0], msg)

coccilib.org.print_link(j1[0], "")



@script:python ruletwo_org depends on org@

i << r.i;

j0 << ruletwo_context.j0;

j2 << ruletwo_context.j2;

@@



msg = "WARNING: Function \"%s\" should have of_node_put() before break " % (i)

coccilib.org.print_safe_todo(j0[0], msg)

coccilib.org.print_link(j2[0], "")



@script:python rulethree_org depends on org@

i << r.i;

j0 << rulethree_context.j0;

j3 << rulethree_context.j3;

@@



msg = "WARNING: Function \"%s\" should have of_node_put() before goto " % (i)

coccilib.org.print_safe_todo(j0[0], msg)

coccilib.org.print_link(j3[0], "")



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



@script:python ruleone_report depends on report@

i << r.i;

j0 << ruleone_context.j0;

j1 << ruleone_context.j1;

@@



msg = "WARNING: Function \"%s\" should have of_node_put() before return around line %s." % (i, j1[0].line)

coccilib.report.print_report(j0[0], msg)



@script:python ruletwo_report depends on report@

i << r.i;

j0 << ruletwo_context.j0;

j2 << ruletwo_context.j2;

@@



msg = "WARNING: Function \"%s\" should have of_node_put() before break around line %s." % (i,j2[0].line)

coccilib.report.print_report(j0[0], msg)



@script:python rulethree_report depends on report@

i << r.i;

j0 << rulethree_context.j0;

j3 << rulethree_context.j3;

@@



msg = "WARNING: Function \"%s\" should have of_node_put() before goto around lines %s." % (i,j3[0].line)

coccilib.report.print_report(j0[0], msg)

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