2017-11-20 03:46:54

by Chunyan Zhang

[permalink] [raw]
Subject: [PATCH] clk: fix a panic error caused by accessing NULL pointer

From: Cai Li <[email protected]>

In some cases the clock parent would be set NULL when doing re-parent,
it will cause a NULL pointer accessing if clk_set trace event is enabled,
since the trace event function would not check the input parameter.

Signed-off-by: Cai Li <[email protected]>
Signed-off-by: Chunyan Zhang <[email protected]>
---
drivers/clk/clk.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index c8d83ac..64efaf0 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1242,13 +1242,12 @@ static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,

old_parent = __clk_set_parent_before(core, parent);

- trace_clk_set_parent(core, parent);
-
/* change clock input source */
- if (parent && core->ops->set_parent)
+ if (parent && core->ops->set_parent) {
+ trace_clk_set_parent(core, parent);
ret = core->ops->set_parent(core->hw, p_index);
-
- trace_clk_set_parent_complete(core, parent);
+ trace_clk_set_parent_complete(core, parent);
+ }

if (ret) {
flags = clk_enable_lock();
--
2.7.4


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