Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH] pwm: fix undefined behavior in stm32_pwm_apply | Date | Wed, 25 Jan 2017 23:31:34 +0100 |
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The stm32_pwm_apply randomly sets the polarity or doesn't, as pointed out by this gcc warning:
drivers/pwm/pwm-stm32.c: In function 'stm32_pwm_apply': drivers/pwm/pwm-stm32.c:204:33: error: 'curstate.polarity' may be used uninitialized in this function [-Werror=maybe-uninitialized]
I assume it was meant to compare the new state to the current state rather than an uninitialized stack variable, so let's do that instead.
Fixes: bafffb6e7bd1 ("pwm: Add driver for STM32 plaftorm") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/pwm/pwm-stm32.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c index ce6232ebefe1..6139512aab7b 100644 --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -189,7 +189,6 @@ static void stm32_pwm_disable(struct stm32_pwm *priv, int ch) static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { - struct pwm_state curstate; bool enabled; struct stm32_pwm *priv = to_stm32_pwm_dev(chip); int ret; @@ -201,7 +200,7 @@ static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, return 0; } - if (state->polarity != curstate.polarity) + if (state->polarity != pwm->state.polarity) stm32_pwm_set_polarity(priv, pwm->hwpwm, state->polarity); ret = stm32_pwm_config(priv, pwm->hwpwm, -- 2.9.0
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