[PATCH v2 1/3] clk: Don't dereference parent clock if is NULL

From: Javier Martinez Canillas
Date: Thu Feb 12 2015 - 08:59:34 EST

The clock passed as an argument to clk_mux_determine_rate_flags()
has the CLK_SET_RATE_PARENT flag set but it has no parent, then a
NULL pointer will tried to be dereferenced.

This shouldn't happen since setting that flag for a clock with no
parent is a bug but the core should be robust to handle that case.

Fixes: 035a61c314eb3 ("clk: Make clk API return per-user struct clk instances")
Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>

Changes since v2:
- Pass NULL struct clk_hw argument to __clk_determine_rate() if parent is NULL.
suggested by Stephen Boyd.
drivers/clk/clk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 7f53166af5e6..5941af7b4665 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -800,8 +800,8 @@ clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
if (core->flags & CLK_SET_RATE_NO_REPARENT) {
parent = core->parent;
if (core->flags & CLK_SET_RATE_PARENT)
- best = __clk_determine_rate(parent->hw, rate,
- min_rate, max_rate);
+ best = __clk_determine_rate(parent ? parent->hw : NULL,
+ rate, min_rate, max_rate);
else if (parent)
best = clk_core_get_rate_nolock(parent);

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