2015-05-05 22:25:13

by Jin Qian

Subject: [PATCH v2 1/3] power: validate wakeup source before activating it.

A rogue wakeup source not registered in wakeup_sources list is not visible
from wakeup_sources_stats_show. Check if the wakeup source is registered
properly by looking at the timer function.

Signed-off-by: Jin Qian <[email protected]>
---
drivers/base/power/wakeup.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 7726200..5d866b9 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -14,6 +14,7 @@
#include <linux/suspend.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
+#include <linux/types.h>
#include <trace/events/power.h>

#include "power.h"
@@ -351,6 +352,19 @@ int device_set_wakeup_enable(struct device *dev, bool enable)
}
EXPORT_SYMBOL_GPL(device_set_wakeup_enable);

+/**
+ * validate_wakeup_source - validate the given wakeup source.
+ * @ws: Wakeup source to be validated.
+ */
+static bool validate_wakeup_source(struct wakeup_source *ws)
+{
+ /*
+ * Use timer function to check if the given source is initialized
+ * by wakeup_source_add.
+ */
+ return ws->timer.function == pm_wakeup_timer_fn;
+}
+
/*
* The functions below use the observation that each wakeup event starts a
* period in which the system should not be suspended. The moment this period
@@ -391,6 +405,11 @@ static void wakeup_source_activate(struct wakeup_source *ws)
{
unsigned int cec;

+ if (WARN_ON(!validate_wakeup_source(ws))) {
+ pr_err("unregistered wakeup source: %s\n", ws->name);
+ return;
+ }
+
/*
* active wakeup source should bring the system
* out of PM_SUSPEND_FREEZE state
--
2.2.0.rc0.207.ga3a616c

2015-05-05 22:51:55

by Rafael J. Wysocki

Subject: Re: [PATCH v2 1/3] power: validate wakeup source before activating it.

On Tuesday, May 05, 2015 03:24:13 PM Jin Qian wrote:
> A rogue wakeup source not registered in wakeup_sources list is not visible
> from wakeup_sources_stats_show. Check if the wakeup source is registered
> properly by looking at the timer function.
>
> Signed-off-by: Jin Qian <[email protected]>
> ---
> drivers/base/power/wakeup.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> index 7726200..5d866b9 100644
> --- a/drivers/base/power/wakeup.c
> +++ b/drivers/base/power/wakeup.c
> @@ -14,6 +14,7 @@
> #include <linux/suspend.h>
> #include <linux/seq_file.h>
> #include <linux/debugfs.h>
> +#include <linux/types.h>

What's that for?

> #include <trace/events/power.h>
>
> #include "power.h"
> @@ -351,6 +352,19 @@ int device_set_wakeup_enable(struct device *dev, bool enable)
> }
> EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
>
> +/**
> + * validate_wakeup_source - validate the given wakeup source.
> + * @ws: Wakeup source to be validated.
> + */
> +static bool validate_wakeup_source(struct wakeup_source *ws)

I would call that wakeup_source_not_registered() and do the reverse check.
The extra logical negation below wouldn't be necessary then.

> +{
> + /*
> + * Use timer function to check if the given source is initialized
> + * by wakeup_source_add.
> + */
> + return ws->timer.function == pm_wakeup_timer_fn;

You can also verify if timer.data is equal to ws.

> +}
> +
> /*
> * The functions below use the observation that each wakeup event starts a
> * period in which the system should not be suspended. The moment this period
> @@ -391,6 +405,11 @@ static void wakeup_source_activate(struct wakeup_source *ws)
> {
> unsigned int cec;
>
> + if (WARN_ON(!validate_wakeup_source(ws))) {

WARN_ONCE() would be better, so you can make it print the message and you
won't need the extra statement.

> + pr_err("unregistered wakeup source: %s\n", ws->name);
> + return;
> + }
> +
> /*
> * active wakeup source should bring the system
> * out of PM_SUSPEND_FREEZE state
>

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.