[PATCH 1/3] dev_pm_qos: Improve sysfs pm_qos_latency_tolerance validation

From	Andy Lutomirski <luto@kernel.org>
Newsgroups	linux.kernel
Subject	[PATCH 1/3] dev_pm_qos: Improve sysfs pm_qos_latency_tolerance validation
Date	2016-11-30 02:20 +0100
Message-ID	<sJ1IZ-7Hw-3@gated-at.bofh.it> (permalink)
References	<sJ1IZ-7Hw-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Negative values are special.  Don't let users write them directly.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 drivers/base/power/sysfs.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index a7b46798c81d..33b4b902741a 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -263,7 +263,11 @@ static ssize_t pm_qos_latency_tolerance_store(struct device *dev,
 	s32 value;
 	int ret;
 
-	if (kstrtos32(buf, 0, &value)) {
+	if (kstrtos32(buf, 0, &value) == 0) {
+		/* Users can't write negative values directly */
+		if (value < 0)
+			return -EINVAL;
+	} else {
 		if (!strcmp(buf, "auto") || !strcmp(buf, "auto\n"))
 			value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
 		else if (!strcmp(buf, "any") || !strcmp(buf, "any\n"))
-- 
2.9.3

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[PATCH 1/3] dev_pm_qos: Improve sysfs pm_qos_latency_tolerance validation Andy Lutomirski <luto@kernel.org> - 2016-11-30 02:20 +0100
  Re: [PATCH 1/3] dev_pm_qos: Improve sysfs pm_qos_latency_tolerance  validation Pavel Machek <pavel@ucw.cz> - 2016-12-05 12:20 +0100

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