From abceaa9cded5f059f8c3b3b6f32730084fe5e39f Mon Sep 17 00:00:00 2001
From: Xunlei Pang <pang.xunlei@linaro.org>
Date: Mon, 31 Aug 2015 11:34:05 +0800
Subject: [PATCH] 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>
---
drivers/cpuidle/coupled.c | 22 ++++++++++++++++++++++
drivers/cpuidle/cpuidle.h | 6 ++++++
drivers/cpuidle/driver.c | 4 ++++
3 files changed, 32 insertions(+)
diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index 1523e2d745eb5..344058f8501a2 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
diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h
index 178c5ad3d5687..f87f399b0540c 100644
--- a/drivers/cpuidle/cpuidle.h
+++ b/drivers/cpuidle/cpuidle.h
@@ -35,6 +35,7 @@ extern void cpuidle_remove_sysfs(struct cpuidle_device *dev);
#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
bool cpuidle_state_is_coupled(struct cpuidle_driver *drv, int state);
+int cpuidle_coupled_state_verify(struct cpuidle_driver *drv);
int cpuidle_enter_state_coupled(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int next_state);
int cpuidle_coupled_register_device(struct cpuidle_device *dev);
@@ -46,6 +47,11 @@ bool cpuidle_state_is_coupled(struct cpuidle_driver *drv, int state)
return false;
}
+static inline int cpuidle_coupled_state_verify(struct cpuidle_driver *drv)
+{
+ return 0;
+}
+
static inline int cpuidle_enter_state_coupled(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int next_state)
{
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 5db147859b904..389ade4572beb 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -227,6 +227,10 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv)
if (!drv || !drv->state_count)
return -EINVAL;
+ ret = cpuidle_coupled_state_verify(drv);
+ if (ret)
+ return ret;
+
if (cpuidle_disabled())
return -ENODEV;
--
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