The call to of_parse_phandle()/of_find_node_by_name() ... returns a node pointer with refcount incremented thus it must be explicitly decremented after the last usage.
This SmPL is also looking for places where there is an of_node_put on some path but not on others. Suggested-by: Julia Lawall <[email protected]> Signed-off-by: Wen Yang <[email protected]> Cc: Julia Lawall <[email protected]> Cc: Gilles Muller <[email protected]> Cc: Nicolas Palix <[email protected]> Cc: Michal Marek <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: [email protected] --- scripts/coccinelle/free/of_node_put.cocci | 133 ++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) create mode 100644 scripts/coccinelle/free/of_node_put.cocci diff --git a/scripts/coccinelle/free/of_node_put.cocci b/scripts/coccinelle/free/of_node_put.cocci new file mode 100644 index 0000000..304293c --- /dev/null +++ b/scripts/coccinelle/free/of_node_put.cocci @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0 +/// Find missing of_node_put +/// +// Confidence: Moderate +// Copyright: (C) 2018-2019 Wen Yang, ZTE. +// Comments: +// Options: --no-includes --include-headers + +virtual report +virtual org + +@initialize:python@ +@@ + +msg_prefix = "ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line " +msg_suffix = ", but without a corresponding object release within this function." + +seen = set() + +def add_if_not_present (p1, p2): + if (p1, p2) not in seen: + seen.add((p1, p2)) + return True + return False + +@r1 exists@ +local idexpression struct device_node *x; +expression e, e1; +position p1, p2; +identifier f; +statement S; +type T; +@@ + +( +x = f@p1(...); +... when != e = (T)x + when any + when != true x == NULL + when != of_node_put(x) + when != of_get_next_parent(x) + when != of_find_matching_node(x, ...) + when != if (x) { ... of_node_put(x) ... } + when != if (x) { ... return x; } + when != v4l2_async_notifier_add_fwnode_subdev(<...x...>) + when != e1 = of_fwnode_handle(x) +( +if (x) { ... when forall + of_node_put(x) ... } +| +return x; +| +return of_fwnode_handle(x); +| +return@p2 ...; +) +& +x = f(...) +... +if (<+...x...+>) S +... +of_node_put(x); +) + +@script:python depends on report && r1@ +p1 << r1.p1; +p2 << r1.p2; +@@ + +if(add_if_not_present(p1[0].line, p2[0].line)): + coccilib.report.print_report(p2[0], msg_prefix + p1[0].line + msg_suffix) + +@script:python depends on org && r1@ +p1 << r1.p1; +p2 << r1.p2; +@@ + +cocci.print_main("acquired a node pointer with refcount incremented", p1) +cocci.print_secs("needed of_node_put", p2) + +@r2 exists@ +local idexpression struct device_node *x; +expression e, e1; +position p1, p2; +statement S; +type T; +@@ + +x = @p1\(of_find_compatible_node\|of_find_node_by_name\|of_parse_phandle\| + of_find_node_by_type\|of_find_node_by_name\|of_find_all_nodes\| + of_get_cpu_node\|of_get_parent\|of_get_next_parent\| + of_get_next_child\|of_get_next_available_child\|of_get_next_cpu_node\| + of_get_compatible_child\|of_get_child_by_name\|of_find_node_opts_by_path\| + of_find_node_with_property\|of_find_matching_node_and_match\|of_find_node_by_phandle\| + of_parse_phandle\)(...); +... +if (x == NULL || ...) S +... when != e = (T)x + when any + when != true x == NULL + when != of_node_put(x) + when != of_get_next_parent(x) + when != of_find_matching_node(x, ...) + when != if (x) { ... of_node_put(x) ... } + when != if (x) { ... return x; } + when != v4l2_async_notifier_add_fwnode_subdev(<...x...>) + when != e1 = of_fwnode_handle(x) +( +if (x) { ... when forall + of_node_put(x) ... } +| +return x; +| +return of_fwnode_handle(x); +| +return@p2 ...; +) + +@script:python depends on report && r2@ +p1 << r2.p1; +p2 << r2.p2; +@@ + +if(add_if_not_present(p1[0].line, p2[0].line)): + coccilib.report.print_report(p2[0], msg_prefix + p1[0].line + msg_suffix) + +@script:python depends on org && r2@ +p1 << r2.p1; +p2 << r2.p2; +@@ + +cocci.print_main("acquired a node pointer with refcount incremented", p1) +cocci.print_secs("needed of_node_put", p2) -- 2.9.5 _______________________________________________ Cocci mailing list [email protected] https://systeme.lip6.fr/mailman/listinfo/cocci
