[PATCH AUTOSEL 4.19 122/172] clk: bcm2835: Fix return type of bcm2835_register_gate

Sasha Levin
2020-06-18T01:58:30Z

From: Nathan Chancellor <natechancellor@gmail.com>

[ 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@gmail.com>
Link: https://lkml.kernel.org/r/20200516080806.1459784-1-natechancellor@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 7bef0666ae7e..1c093fb35ebe 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1447,13 +1447,13 @@ 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