Relying on an unchecked of_iomap() which can return NULL is problematic here, an explicit check seems mandatory. Also the call to of_find_compatible_node() returns a device node with refcount incremented therefor an explicit of_node_put() is needed here.
Signed-off-by: Nicholas Mc Guire <hof...@osadl.org> Fixes: commit 22bae4290457 ("ARM: hi3xxx: add hotplug support") --- Problem found by an experimental coccinelle script The way id is used is a bit redundant with the function return - not really clear if this "double indication" is intentional or just happened ? Also note that hi3xxx_hotplug_init probably should be bool as that is how it is being used - the error return is not actually interpreted beyond detection of failure in its only call site hi3xxx_set_cpu(). Patch was compile tested with: hisi_defconfig (implies CONFIG_SMP=y) Patch is against 4.18-rc3 (localversion-next is next-20180712) arch/arm/mach-hisi/hotplug.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-hisi/hotplug.c b/arch/arm/mach-hisi/hotplug.c index 40857bf..4036ffe 100644 --- a/arch/arm/mach-hisi/hotplug.c +++ b/arch/arm/mach-hisi/hotplug.c @@ -148,13 +148,20 @@ static int hi3xxx_hotplug_init(void) struct device_node *node; node = of_find_compatible_node(NULL, NULL, "hisilicon,sysctrl"); - if (node) { - ctrl_base = of_iomap(node, 0); - id = HI3620_CTRL; - return 0; + if (!node) { + id = ERROR_CTRL; + return -ENOENT; } - id = ERROR_CTRL; - return -ENOENT; + + ctrl_base = of_iomap(node, 0); + of_node_put(node); + if (!ctrl_base) { + id = ERROR_CTRL; + return -ENOMEM; + } + + id = HI3620_CTRL; + return 0; } void hi3xxx_set_cpu(int cpu, bool enable) -- 2.1.4