From: Xunlei Pang <pang.xunlei@linaro.org>
Date: Mon, 31 Aug 2015 03:34:05 +0000 (+0800)
Subject: cpuidle/coupled: Add sanity check for safe_state_index
X-Git-Tag: omap-for-v4.3/fixes-rc1~23^2^3
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=abceaa9cded5f059f8c3b3b6f32730084fe5e39f;p=pandora-kernel.git

cpuidle/coupled: Add sanity check for safe_state_index

Since we are using cpuidle_driver::safe_state_index directly as the
target state index, it is better to add the sanity check at the point
of registering the driver.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index 1523e2d745eb..344058f8501a 100644
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c
@@ -186,6 +186,28 @@ bool cpuidle_state_is_coupled(struct cpuidle_driver *drv, int state)
 	return drv->states[state].flags & CPUIDLE_FLAG_COUPLED;
 }
 
+/**
+ * cpuidle_coupled_state_verify - check if the coupled states are correctly set.
+ * @drv: struct cpuidle_driver for the platform
+ *
+ * Returns 0 for valid state values, a negative error code otherwise:
+ *  * -EINVAL if any coupled state(safe_state_index) is wrongly set.
+ */
+int cpuidle_coupled_state_verify(struct cpuidle_driver *drv)
+{
+	int i;
+
+	for (i = drv->state_count - 1; i >= 0; i--) {
+		if (cpuidle_state_is_coupled(drv, i) &&
+		    (drv->safe_state_index == i ||
+		     drv->safe_state_index < 0 ||
+		     drv->safe_state_index >= drv->state_count))
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
 /**
  * cpuidle_coupled_set_ready - mark a cpu as ready
  * @coupled: the struct coupled that contains the current cpu
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