[PATCH] clk: Don't try to use a struct clk* after it could have been freed

From: Tomeu Vizoso
Date: Wed Oct 01 2014 - 12:04:07 EST


As __clk_release could call kfree on clk and then we wouldn't have a safe way
of getting the module that owns the clock.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
---
drivers/clk/clk.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index bacc06f..4eeb8de 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2205,14 +2205,16 @@ int __clk_get(struct clk *clk)

void __clk_put(struct clk *clk)
{
+ struct module *owner;
+
if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
return;

clk_prepare_lock();
+ owner = clk->owner;
kref_put(&clk->ref, __clk_release);
+ module_put(owner);
clk_prepare_unlock();
-
- module_put(clk->owner);
}

/*** clk rate change notifiers ***/
--
1.9.3

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