[PATCH net v4 3/3] net: ti: icss-iep: Fix possible NULL pointer dereference for perout request
Meghana Malladi
m-malladi at ti.com
Tue Apr 15 02:05:43 PDT 2025
The ICSS IEP driver tracks perout and pps enable state with flags.
Currently when disabling pps and perout signals during icss_iep_exit(),
results in NULL pointer dereference for perout.
To fix the null pointer dereference issue, the icss_iep_perout_enable_hw
function can be modified to directly clear the IEP CMP registers when
disabling PPS or PEROUT, without referencing the ptp_perout_request
structure, as its contents are irrelevant in this case.
Fixes: 9b115361248d ("net: ti: icssg-prueth: Fix clearing of IEP_CMP_CFG registers during iep_init")
Reported-by: Dan Carpenter <dan.carpenter at linaro.org>
Closes: https://lore.kernel.org/all/7b1c7c36-363a-4085-b26c-4f210bee1df6@stanley.mountain/
Signed-off-by: Meghana Malladi <m-malladi at ti.com>
---
Changes from v3 (v4-v3):
- Fix the logic in icss_iep_perout_enable_hw() to clear IEP registers
when disabling periodic signal
drivers/net/ethernet/ti/icssg/icss_iep.c | 121 +++++++++++------------
1 file changed, 58 insertions(+), 63 deletions(-)
diff --git a/drivers/net/ethernet/ti/icssg/icss_iep.c b/drivers/net/ethernet/ti/icssg/icss_iep.c
index b4a34c57b7b4..2a1c43316f46 100644
--- a/drivers/net/ethernet/ti/icssg/icss_iep.c
+++ b/drivers/net/ethernet/ti/icssg/icss_iep.c
@@ -412,6 +412,22 @@ static int icss_iep_perout_enable_hw(struct icss_iep *iep,
int ret;
u64 cmp;
+ if (!on) {
+ /* Disable CMP 1 */
+ regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+ IEP_CMP_CFG_CMP_EN(1), 0);
+
+ /* clear CMP regs */
+ regmap_write(iep->map, ICSS_IEP_CMP1_REG0, 0);
+ if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
+ regmap_write(iep->map, ICSS_IEP_CMP1_REG1, 0);
+
+ /* Disable sync */
+ regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG, 0);
+
+ return 0;
+ }
+
/* Calculate width of the signal for PPS/PEROUT handling */
ts.tv_sec = req->on.sec;
ts.tv_nsec = req->on.nsec;
@@ -430,64 +446,39 @@ static int icss_iep_perout_enable_hw(struct icss_iep *iep,
if (ret)
return ret;
- if (on) {
- /* Configure CMP */
- regmap_write(iep->map, ICSS_IEP_CMP1_REG0, lower_32_bits(cmp));
- if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
- regmap_write(iep->map, ICSS_IEP_CMP1_REG1, upper_32_bits(cmp));
- /* Configure SYNC, based on req on width */
- regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG,
- div_u64(ns_width, iep->def_inc));
- regmap_write(iep->map, ICSS_IEP_SYNC0_PERIOD_REG, 0);
- regmap_write(iep->map, ICSS_IEP_SYNC_START_REG,
- div_u64(ns_start, iep->def_inc));
- regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG, 0); /* one-shot mode */
- /* Enable CMP 1 */
- regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
- IEP_CMP_CFG_CMP_EN(1), IEP_CMP_CFG_CMP_EN(1));
- } else {
- /* Disable CMP 1 */
- regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
- IEP_CMP_CFG_CMP_EN(1), 0);
-
- /* clear regs */
- regmap_write(iep->map, ICSS_IEP_CMP1_REG0, 0);
- if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
- regmap_write(iep->map, ICSS_IEP_CMP1_REG1, 0);
- }
+ /* Configure CMP */
+ regmap_write(iep->map, ICSS_IEP_CMP1_REG0, lower_32_bits(cmp));
+ if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
+ regmap_write(iep->map, ICSS_IEP_CMP1_REG1, upper_32_bits(cmp));
+ /* Configure SYNC, based on req on width */
+ regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG,
+ div_u64(ns_width, iep->def_inc));
+ regmap_write(iep->map, ICSS_IEP_SYNC0_PERIOD_REG, 0);
+ regmap_write(iep->map, ICSS_IEP_SYNC_START_REG,
+ div_u64(ns_start, iep->def_inc));
+ regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG, 0); /* one-shot mode */
+ /* Enable CMP 1 */
+ regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+ IEP_CMP_CFG_CMP_EN(1), IEP_CMP_CFG_CMP_EN(1));
} else {
- if (on) {
- u64 start_ns;
-
- iep->period = ((u64)req->period.sec * NSEC_PER_SEC) +
- req->period.nsec;
- start_ns = ((u64)req->period.sec * NSEC_PER_SEC)
- + req->period.nsec;
- icss_iep_update_to_next_boundary(iep, start_ns);
-
- regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG,
- div_u64(ns_width, iep->def_inc));
- regmap_write(iep->map, ICSS_IEP_SYNC_START_REG,
- div_u64(ns_start, iep->def_inc));
- /* Enable Sync in single shot mode */
- regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG,
- IEP_SYNC_CTRL_SYNC_N_EN(0) | IEP_SYNC_CTRL_SYNC_EN);
- /* Enable CMP 1 */
- regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
- IEP_CMP_CFG_CMP_EN(1), IEP_CMP_CFG_CMP_EN(1));
- } else {
- /* Disable CMP 1 */
- regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
- IEP_CMP_CFG_CMP_EN(1), 0);
-
- /* clear CMP regs */
- regmap_write(iep->map, ICSS_IEP_CMP1_REG0, 0);
- if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
- regmap_write(iep->map, ICSS_IEP_CMP1_REG1, 0);
-
- /* Disable sync */
- regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG, 0);
- }
+ u64 start_ns;
+
+ iep->period = ((u64)req->period.sec * NSEC_PER_SEC) +
+ req->period.nsec;
+ start_ns = ((u64)req->period.sec * NSEC_PER_SEC)
+ + req->period.nsec;
+ icss_iep_update_to_next_boundary(iep, start_ns);
+
+ regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG,
+ div_u64(ns_width, iep->def_inc));
+ regmap_write(iep->map, ICSS_IEP_SYNC_START_REG,
+ div_u64(ns_start, iep->def_inc));
+ /* Enable Sync in single shot mode */
+ regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG,
+ IEP_SYNC_CTRL_SYNC_N_EN(0) | IEP_SYNC_CTRL_SYNC_EN);
+ /* Enable CMP 1 */
+ regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+ IEP_CMP_CFG_CMP_EN(1), IEP_CMP_CFG_CMP_EN(1));
}
return 0;
@@ -498,11 +489,21 @@ static int icss_iep_perout_enable(struct icss_iep *iep,
{
int ret = 0;
+ if (!on)
+ goto disable;
+
/* Reject requests with unsupported flags */
if (req->flags & ~(PTP_PEROUT_DUTY_CYCLE |
PTP_PEROUT_PHASE))
return -EOPNOTSUPP;
+ /* Set default "on" time (1ms) for the signal if not passed by the app */
+ if (!(req->flags & PTP_PEROUT_DUTY_CYCLE)) {
+ req->on.sec = 0;
+ req->on.nsec = NSEC_PER_MSEC;
+ }
+
+disable:
mutex_lock(&iep->ptp_clk_mutex);
if (iep->pps_enabled) {
@@ -513,12 +514,6 @@ static int icss_iep_perout_enable(struct icss_iep *iep,
if (iep->perout_enabled == !!on)
goto exit;
- /* Set default "on" time (1ms) for the signal if not passed by the app */
- if (!(req->flags & PTP_PEROUT_DUTY_CYCLE)) {
- req->on.sec = 0;
- req->on.nsec = NSEC_PER_MSEC;
- }
-
ret = icss_iep_perout_enable_hw(iep, req, on);
if (!ret)
iep->perout_enabled = !!on;
--
2.43.0
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