m68k: let clk_enable() return immediately if clk is NULL

Similar to commit<742859adc721>("m68k: let clk_disable() return immediately if clk is NULL").
there should be a check for clk to prevent NULL pointer dereference.

Signed-off-by: Defang Bo <bodefang@126.com>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/m68k/coldfire/clk.c b/arch/m68k/coldfire/clk.c
index 7bc666e482eb..076a9caa9557 100644
--- a/arch/m68k/coldfire/clk.c
+++ b/arch/m68k/coldfire/clk.c
@@ -90,6 +90,10 @@ EXPORT_SYMBOL(clk_get);
 int clk_enable(struct clk *clk)
 {
 	unsigned long flags;
+
+	if (!clk)
+		return -EINVAL;
+
 	spin_lock_irqsave(&clk_lock, flags);
 	if ((clk->enabled++ == 0) && clk->clk_ops)
 		clk->clk_ops->enable(clk);