linux-kernel - [PATCH v8 05/10] OPP: Add sanity checks in _read_opp

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Message-Id: <20200512125327.1868-6-georgi.djakov@linaro.org>
Date:   Tue, 12 May 2020 15:53:22 +0300
From:   Georgi Djakov <georgi.djakov@...aro.org>
To:     vireshk@...nel.org, nm@...com, sboyd@...nel.org, rjw@...ysocki.net,
        saravanak@...gle.com, sibis@...eaurora.org, mka@...omium.org
Cc:     robh+dt@...nel.org, rnayak@...eaurora.org,
        bjorn.andersson@...aro.org, vincent.guittot@...aro.org,
        jcrouse@...eaurora.org, evgreen@...omium.org,
        linux-pm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, georgi.djakov@...aro.org
Subject: [PATCH v8 05/10] OPP: Add sanity checks in _read_opp_key()

When we read the OPP keys, it would be nice to do some sanity checks
of the values we get from DT and see if they match with the information
that is populated in the OPP table. Let's pass a pointer of the table,
so that we can do some validation.

Reviewed-by: Matthias Kaehlcke <mka@...omium.org>
Reviewed-by: Sibi Sankar <sibis@...eaurora.org>
Signed-off-by: Georgi Djakov <georgi.djakov@...aro.org>
---
v8:
* Picked reviewed-by tags.

 drivers/opp/of.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index d139ad8c8f4f..3a64f2aa0f86 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -573,8 +573,8 @@ void dev_pm_opp_of_remove_table(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
 
-static int _read_opp_key(struct dev_pm_opp *new_opp, struct device_node *np,
-			 bool *rate_not_available)
+static int _read_opp_key(struct dev_pm_opp *new_opp, struct opp_table *table,
+			 struct device_node *np, bool *rate_not_available)
 {
 	struct property *peak, *avg;
 	u32 *peak_bw, *avg_bw;
@@ -602,6 +602,12 @@ static int _read_opp_key(struct dev_pm_opp *new_opp, struct device_node *np,
 		 * opp-avg-kBps = <path1_value path2_value>;
 		 */
 		count = peak->length / sizeof(u32);
+		if (table->path_count != count) {
+			pr_err("%s: Mismatch between opp-peak-kBps and paths (%d %d)\n",
+			       __func__, count, table->path_count);
+			return -EINVAL;
+		}
+
 		peak_bw = kmalloc_array(count, sizeof(*peak_bw), GFP_KERNEL);
 		if (!peak_bw)
 			return -ENOMEM;
@@ -624,6 +630,13 @@ static int _read_opp_key(struct dev_pm_opp *new_opp, struct device_node *np,
 	avg = of_find_property(np, "opp-avg-kBps", NULL);
 	if (peak && avg) {
 		count = avg->length / sizeof(u32);
+		if (table->path_count != count) {
+			pr_err("%s: Mismatch between opp-avg-kBps and paths (%d %d)\n",
+			       __func__, count, table->path_count);
+			ret = -EINVAL;
+			goto free_peak_bw;
+		}
+
 		avg_bw = kmalloc_array(count, sizeof(*avg_bw), GFP_KERNEL);
 		if (!avg_bw) {
 			ret = -ENOMEM;
@@ -697,7 +710,7 @@ static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
 	if (!new_opp)
 		return ERR_PTR(-ENOMEM);
 
-	ret = _read_opp_key(new_opp, np, &rate_not_available);
+	ret = _read_opp_key(new_opp, opp_table, np, &rate_not_available);
 	/* The key is optional for devices like power domains. */
 	if (ret < 0 && !opp_table->is_genpd) {
 		dev_err(dev, "%s: opp key field not found\n", __func__);