[PATCH v1] ARM: OMAP2+: Fix OF node reference leaks in omap_hwmod

[Yuho Choi <dbgh9129@gmail.com>]

The OF helpers that return device nodes acquire references that must be
released by the caller.

_init() leaks the "ocp" bus node returned by of_find_node_by_name() on
all paths after lookup, and also leaks the child returned by
of_get_next_child() when parsing module flags. Route the post-lookup
returns through a common cleanup path and release the child after use.

omap_hwmod_setup_earlycon_flags() leaks the /chosen node and the UART
node resolved from stdout-path. Track them separately and drop both
references after use.

Fixes: 1aa8f0cb19e5 ("ARM: OMAP2+: Remove unused legacy code for interconnects")
Fixes: 4f2122473363 ("ARM: OMAP2+: Check also the first dts child for hwmod flags")
Fixes: 8dd6666f4937 ("ARM: OMAP2+: omap_hwmod: Add support for earlycon")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
---
 arch/arm/mach-omap2/omap_hwmod.c | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 974107ff18b4..03cd523dff87 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -2331,13 +2331,15 @@ static int __init _init(struct omap_hwmod *oh, void *data)
 	if (r < 0) {
 		WARN(1, "omap_hwmod: %s: doesn't have mpu register target base\n",
 		     oh->name);
-		return 0;
+		r = 0;
+		goto out_put_node;
 	}
 
 	r = _init_clocks(oh, np);
 	if (r < 0) {
 		WARN(1, "omap_hwmod: %s: couldn't init clocks\n", oh->name);
-		return -EINVAL;
+		r = -EINVAL;
+		goto out_put_node;
 	}
 
 	if (np) {
@@ -2345,13 +2347,19 @@ static int __init _init(struct omap_hwmod *oh, void *data)
 
 		parse_module_flags(oh, np);
 		child = of_get_next_child(np, NULL);
-		if (child)
+		if (child) {
 			parse_module_flags(oh, child);
+			of_node_put(child);
+		}
 	}
 
 	oh->_state = _HWMOD_STATE_INITIALIZED;
 
-	return 0;
+	r = 0;
+
+out_put_node:
+	of_node_put(bus);
+	return r;
 }
 
 /**
@@ -3608,13 +3616,13 @@ int omap_hwmod_init_module(struct device *dev,
 #ifdef CONFIG_SERIAL_EARLYCON
 static void __init omap_hwmod_setup_earlycon_flags(void)
 {
-	struct device_node *np;
+	struct device_node *np, *chosen;
 	struct omap_hwmod *oh;
 	const char *uart;
 
-	np = of_find_node_by_path("/chosen");
-	if (np) {
-		uart = of_get_property(np, "stdout-path", NULL);
+	chosen = of_find_node_by_path("/chosen");
+	if (chosen) {
+		uart = of_get_property(chosen, "stdout-path", NULL);
 		if (uart) {
 			np = of_find_node_by_path(uart);
 			if (np) {
@@ -3629,8 +3637,10 @@ static void __init omap_hwmod_setup_earlycon_flags(void)
 				if (oh)
 					oh->flags |= DEBUG_OMAPUART_FLAGS;
 			}
+			of_node_put(np);
 		}
 	}
+	of_node_put(chosen);
 }
 #endif
 
-- 
2.43.0