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: Sumera Priyadarsini <sylphrena...@gmail.com> ---- Changes in V2: - Add options --include-headers and --no-includes - Add 'when forall` to rules for break and goto --- .../coccinelle/iterators/for_each_child.cocci | 355 ++++++++++++++++++ 1 file changed, 355 insertions(+) create mode 100644 scripts/coccinelle/iterators/for_each_child.cocci diff --git a/scripts/coccinelle/iterators/for_each_child.cocci b/scripts/coccinelle/iterators/for_each_child.cocci new file mode 100644 index 000000000000..57caf9b8d7a5 --- /dev/null +++ b/scripts/coccinelle/iterators/for_each_child.cocci @@ -0,0 +1,355 @@ +// 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 +| ++ 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) -- 2.25.1 _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci