diff options
| author | Douglas Anderson <dianders@chromium.org> | 2020-02-03 10:31:34 -0800 |
|---|---|---|
| committer | Stephen Boyd <sboyd@kernel.org> | 2020-02-03 23:04:02 -0800 |
| commit | 908b050114d8fefdddc57ec9fbc213c3690e7f5f (patch) | |
| tree | 08d32f4c7d1d2b31f48db60b71e739b416d45934 /drivers/clk | |
| parent | 73cb3106e883ac03cc4f15b20d525e6bde650526 (diff) | |
| download | linux-908b050114d8fefdddc57ec9fbc213c3690e7f5f.tar.gz linux-908b050114d8fefdddc57ec9fbc213c3690e7f5f.tar.bz2 linux-908b050114d8fefdddc57ec9fbc213c3690e7f5f.zip | |
clk: qcom: rcg2: Don't crash if our parent can't be found; return an error
When I got my clock parenting slightly wrong I ended up with a crash
that looked like this:
Unable to handle kernel NULL pointer dereference at virtual
address 0000000000000000
...
pc : clk_hw_get_rate+0x14/0x44
...
Call trace:
clk_hw_get_rate+0x14/0x44
_freq_tbl_determine_rate+0x94/0xfc
clk_rcg2_determine_rate+0x2c/0x38
clk_core_determine_round_nolock+0x4c/0x88
clk_core_round_rate_nolock+0x6c/0xa8
clk_core_round_rate_nolock+0x9c/0xa8
clk_core_set_rate_nolock+0x70/0x180
clk_set_rate+0x3c/0x6c
of_clk_set_defaults+0x254/0x360
platform_drv_probe+0x28/0xb0
really_probe+0x120/0x2dc
driver_probe_device+0x64/0xfc
device_driver_attach+0x4c/0x6c
__driver_attach+0xac/0xc0
bus_for_each_dev+0x84/0xcc
driver_attach+0x2c/0x38
bus_add_driver+0xfc/0x1d0
driver_register+0x64/0xf8
__platform_driver_register+0x4c/0x58
msm_drm_register+0x5c/0x60
...
It turned out that clk_hw_get_parent_by_index() was returning NULL and
we weren't checking. Let's check it so that we don't crash.
Fixes: ac269395cdd8 ("clk: qcom: Convert to clk_hw based provider APIs")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lkml.kernel.org/r/20200203103049.v4.1.I7487325fe8e701a68a07d3be8a6a4b571eca9cfa@changeid
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/qcom/clk-rcg2.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c index 973ecf4f6bc5..357159fe85b5 100644 --- a/drivers/clk/qcom/clk-rcg2.c +++ b/drivers/clk/qcom/clk-rcg2.c @@ -218,6 +218,9 @@ static int _freq_tbl_determine_rate(struct clk_hw *hw, const struct freq_tbl *f, clk_flags = clk_hw_get_flags(hw); p = clk_hw_get_parent_by_index(hw, index); + if (!p) + return -EINVAL; + if (clk_flags & CLK_SET_RATE_PARENT) { rate = f->freq; if (f->pre_div) { |