[U-Boot] [PATCH 1/2] pwm: imx: Prevent NULL pointer dereference

Axel Lin
2015-05-23T07:16:48Z

pwm_id_to_reg() can return NULL, so add NULL testing to prevent NULL pointer
dereference.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
---
drivers/pwm/pwm-imx.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 40bf027..47799fc 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -18,6 +18,9 @@ int pwm_init(int pwm_id, int div, int invert)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);

+ if (!pwm)
+ return -1;
+
writel(0, &pwm->ir);
return 0;
}
@@ -28,6 +31,9 @@ int pwm_config(int pwm_id, int duty_ns, int period_ns)
unsigned long period_cycles, duty_cycles, prescale;
u32 cr;

+ if (!pwm)
+ return -1;
+
pwm_imx_get_parms(period_ns, duty_ns, &period_cycles, &duty_cycles,
&prescale);

@@ -47,6 +53,9 @@ int pwm_enable(int pwm_id)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);

+ if (!pwm)
+ return -1;
+
setbits_le32(&pwm->cr, PWMCR_EN);
return 0;
}
@@ -55,5 +64,8 @@ void pwm_disable(int pwm_id)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);

+ if (!pwm)
+ return;
+
clrbits_le32(&pwm->cr, PWMCR_EN);
}
--
2.1.0