| Message ID | 20180428212521.29328-1-martin.blumenstingl@googlemail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Sat, Apr 28, 2018 at 11:25:21PM +0200, Martin Blumenstingl wrote: > Using the pwm-meson driver on the 32-bit SoCs causes memory corruption. > The result are some hard-to-explain errors, for example > devm_clk_register crashes with a NULL dereference somewhere deep in the > common clock framework code. > In some cases the kernel even refused to boot when any of the PWM > controllers were enables on Meson8b. > > The root cause seems to be an incorrect memory size in the devm_kcalloc > call in meson_pwm_probe. The code allocates an array of meson_pwm_channel > structs, but the size given is the size of the meson_pwm struct (which > seems like a small copy-and-paste error, as meson_pwm is allocated a few > lines above). > Even with this typo the code seemed to work fine on the 64-bit GX SoCs > (maybe due to the structs having the same size in the compiled result, > but I haven't checked this further). > > Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller") > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> > --- > drivers/pwm/pwm-meson.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Applied, thanks. Thierry
diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c index 0767deba8e62..822860b4801a 100644 --- a/drivers/pwm/pwm-meson.c +++ b/drivers/pwm/pwm-meson.c @@ -541,8 +541,8 @@ static int meson_pwm_probe(struct platform_device *pdev) meson->data = of_device_get_match_data(&pdev->dev); meson->inverter_mask = BIT(meson->chip.npwm) - 1; - channels = devm_kcalloc(&pdev->dev, meson->chip.npwm, sizeof(*meson), - GFP_KERNEL); + channels = devm_kcalloc(&pdev->dev, meson->chip.npwm, + sizeof(*channels), GFP_KERNEL); if (!channels) return -ENOMEM;
Using the pwm-meson driver on the 32-bit SoCs causes memory corruption. The result are some hard-to-explain errors, for example devm_clk_register crashes with a NULL dereference somewhere deep in the common clock framework code. In some cases the kernel even refused to boot when any of the PWM controllers were enables on Meson8b. The root cause seems to be an incorrect memory size in the devm_kcalloc call in meson_pwm_probe. The code allocates an array of meson_pwm_channel structs, but the size given is the size of the meson_pwm struct (which seems like a small copy-and-paste error, as meson_pwm is allocated a few lines above). Even with this typo the code seemed to work fine on the 64-bit GX SoCs (maybe due to the structs having the same size in the compiled result, but I haven't checked this further). Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> --- drivers/pwm/pwm-meson.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)