[PATCH AUTOSEL 4.14 080/108] clk: bcm2835: Fix return type of bcm2835_register_gate

[Sasha Levin]

From: Nathan Chancellor <natechancellor@xxxxxxxxx>

[ Upstream commit f376c43bec4f8ee8d1ba5c5c4cfbd6e84fb279cb ]

bcm2835_register_gate is used as a callback for the clk_register member
of bcm2835_clk_desc, which expects a struct clk_hw * return type but
bcm2835_register_gate returns a struct clk *.

This discrepancy is hidden by the fact that bcm2835_register_gate is
cast to the typedef bcm2835_clk_register by the _REGISTER macro. This
turns out to be a control flow integrity violation, which is how this
was noticed.

Change the return type of bcm2835_register_gate to be struct clk_hw *
and use clk_hw_register_gate to do so. This should be a non-functional
change as clk_register_gate calls clk_hw_register_gate anyways but this
is needed to avoid issues with further changes.

Fixes: b19f009d4510 ("clk: bcm2835: Migrate to clk_hw based registration and OF APIs")
Link: https://github.com/ClangBuiltLinux/linux/issues/1028
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Link: https://lkml.kernel.org/r/20200516080806.1459784-1-natechancellor@xxxxxxxxx
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/clk/bcm/clk-bcm2835.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 5f8082d89131..6db4204e5d5d 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1483,13 +1483,13 @@ static struct clk_hw *bcm2835_register_clock(struct bcm2835_cprman *cprman,
 	return &clock->hw;
 }
 
-static struct clk *bcm2835_register_gate(struct bcm2835_cprman *cprman,
+static struct clk_hw *bcm2835_register_gate(struct bcm2835_cprman *cprman,
 					 const struct bcm2835_gate_data *data)
 {
-	return clk_register_gate(cprman->dev, data->name, data->parent,
-				 CLK_IGNORE_UNUSED | CLK_SET_RATE_GATE,
-				 cprman->regs + data->ctl_reg,
-				 CM_GATE_BIT, 0, &cprman->regs_lock);
+	return clk_hw_register_gate(cprman->dev, data->name, data->parent,
+				    CLK_IGNORE_UNUSED | CLK_SET_RATE_GATE,
+				    cprman->regs + data->ctl_reg,
+				    CM_GATE_BIT, 0, &cprman->regs_lock);
 }
 
 typedef struct clk_hw *(*bcm2835_clk_register)(struct bcm2835_cprman *cprman,
-- 
2.25.1