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PM: sleep: Fix possible deadlocks in core system-wide PM code

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It is reported that in low-memory situations the system-wide resume core
code deadlocks, because async_schedule_dev() executes its argument
function synchronously if it cannot allocate memory (and not only in
that case) and that function attempts to acquire a mutex that is already
held.  Executing the argument function synchronously from within
dpm_async_fn() may also be problematic for ordering reasons (it may
cause a consumer device's resume callback to be invoked before a
requisite supplier device's one, for example).

Address this by changing the code in question to use
async_schedule_dev_nocall() for scheduling the asynchronous
execution of device suspend and resume functions and to directly
run them synchronously if async_schedule_dev_nocall() returns false.

Link: https://lore.kernel.org/linux-pm/ZYvjiqX6EsL15moe@perf/
Reported-by: Youngmin Nam <youngmin.nam@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Tested-by: Youngmin Nam <youngmin.nam@samsung.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: 5.7+ <stable@vger.kernel.org> # 5.7+: 6aa09a5bcc async: Split async_schedule_node_domain()
Cc: 5.7+ <stable@vger.kernel.org> # 5.7+: 7d4b5d7a37 async: Introduce async_schedule_dev_nocall()
Cc: 5.7+ <stable@vger.kernel.org> # 5.7+
This commit is contained in:
Rafael J. Wysocki 2023-12-27 21:41:06 +01:00
parent 7d4b5d7a37
commit 7839d0078e
1 changed files with 68 additions and 80 deletions
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148
drivers/base/power/main.c
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@ -579,7 +579,7 @@ bool dev_pm_skip_resume(struct device *dev)
}
/**
* device_resume_noirq - Execute a "noirq resume" callback for given device.
* __device_resume_noirq - Execute a "noirq resume" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being resumed asynchronously.
@ -587,7 +587,7 @@ bool dev_pm_skip_resume(struct device *dev)
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
static void __device_resume_noirq(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
const char *info = NULL;
@ -655,7 +655,13 @@ Skip:
Out:
complete_all(&dev->power.completion);
TRACE_RESUME(error);
return error;
if (error) {
suspend_stats.failed_resume_noirq++;
dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, async ? " async noirq" : " noirq", error);
}
}
static bool is_async(struct device *dev)
@ -668,11 +674,15 @@ static bool dpm_async_fn(struct device *dev, async_func_t func)
{
reinit_completion(&dev->power.completion);
if (is_async(dev)) {
get_device(dev);
async_schedule_dev(func, dev);
if (!is_async(dev))
return false;
get_device(dev);
if (async_schedule_dev_nocall(func, dev))
return true;
}
put_device(dev);
return false;
}
@ -680,15 +690,19 @@ static bool dpm_async_fn(struct device *dev, async_func_t func)
static void async_resume_noirq(void *data, async_cookie_t cookie)
{
struct device *dev = data;
int error;
error = device_resume_noirq(dev, pm_transition, true);
if (error)
pm_dev_err(dev, pm_transition, " async", error);
__device_resume_noirq(dev, pm_transition, true);
put_device(dev);
}
static void device_resume_noirq(struct device *dev)
{
if (dpm_async_fn(dev, async_resume_noirq))
return;
__device_resume_noirq(dev, pm_transition, false);
}
static void dpm_noirq_resume_devices(pm_message_t state)
{
struct device *dev;
@ -698,14 +712,6 @@ static void dpm_noirq_resume_devices(pm_message_t state)
mutex_lock(&dpm_list_mtx);
pm_transition = state;
/*
* Advanced the async threads upfront,
* in case the starting of async threads is
* delayed by non-async resuming devices.
*/
list_for_each_entry(dev, &dpm_noirq_list, power.entry)
dpm_async_fn(dev, async_resume_noirq);
while (!list_empty(&dpm_noirq_list)) {
dev = to_device(dpm_noirq_list.next);
get_device(dev);
@ -713,17 +719,7 @@ static void dpm_noirq_resume_devices(pm_message_t state)
mutex_unlock(&dpm_list_mtx);
if (!is_async(dev)) {
int error;
error = device_resume_noirq(dev, state, false);
if (error) {
suspend_stats.failed_resume_noirq++;
dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, " noirq", error);
}
}
device_resume_noirq(dev);
put_device(dev);
@ -751,14 +747,14 @@ void dpm_resume_noirq(pm_message_t state)
}
/**
* device_resume_early - Execute an "early resume" callback for given device.
* __device_resume_early - Execute an "early resume" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being resumed asynchronously.
*
* Runtime PM is disabled for @dev while this function is being executed.
*/
static int device_resume_early(struct device *dev, pm_message_t state, bool async)
static void __device_resume_early(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
const char *info = NULL;
@ -811,21 +807,31 @@ Out:
pm_runtime_enable(dev);
complete_all(&dev->power.completion);
return error;
if (error) {
suspend_stats.failed_resume_early++;
dpm_save_failed_step(SUSPEND_RESUME_EARLY);
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, async ? " async early" : " early", error);
}
}
static void async_resume_early(void *data, async_cookie_t cookie)
{
struct device *dev = data;
int error;
error = device_resume_early(dev, pm_transition, true);
if (error)
pm_dev_err(dev, pm_transition, " async", error);
__device_resume_early(dev, pm_transition, true);
put_device(dev);
}
static void device_resume_early(struct device *dev)
{
if (dpm_async_fn(dev, async_resume_early))
return;
__device_resume_early(dev, pm_transition, false);
}
/**
* dpm_resume_early - Execute "early resume" callbacks for all devices.
* @state: PM transition of the system being carried out.
@ -839,14 +845,6 @@ void dpm_resume_early(pm_message_t state)
mutex_lock(&dpm_list_mtx);
pm_transition = state;
/*
* Advanced the async threads upfront,
* in case the starting of async threads is
* delayed by non-async resuming devices.
*/
list_for_each_entry(dev, &dpm_late_early_list, power.entry)
dpm_async_fn(dev, async_resume_early);
while (!list_empty(&dpm_late_early_list)) {
dev = to_device(dpm_late_early_list.next);
get_device(dev);
@ -854,17 +852,7 @@ void dpm_resume_early(pm_message_t state)
mutex_unlock(&dpm_list_mtx);
if (!is_async(dev)) {
int error;
error = device_resume_early(dev, state, false);
if (error) {
suspend_stats.failed_resume_early++;
dpm_save_failed_step(SUSPEND_RESUME_EARLY);
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, " early", error);
}
}
device_resume_early(dev);
put_device(dev);
@ -888,12 +876,12 @@ void dpm_resume_start(pm_message_t state)
EXPORT_SYMBOL_GPL(dpm_resume_start);
/**
* device_resume - Execute "resume" callbacks for given device.
* __device_resume - Execute "resume" callbacks for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being resumed asynchronously.
*/
static int device_resume(struct device *dev, pm_message_t state, bool async)
static void __device_resume(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
const char *info = NULL;
@ -975,20 +963,30 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
TRACE_RESUME(error);
return error;
if (error) {
suspend_stats.failed_resume++;
dpm_save_failed_step(SUSPEND_RESUME);
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, async ? " async" : "", error);
}
}
static void async_resume(void *data, async_cookie_t cookie)
{
struct device *dev = data;
int error;
error = device_resume(dev, pm_transition, true);
if (error)
pm_dev_err(dev, pm_transition, " async", error);
__device_resume(dev, pm_transition, true);
put_device(dev);
}
static void device_resume(struct device *dev)
{
if (dpm_async_fn(dev, async_resume))
return;
__device_resume(dev, pm_transition, false);
}
/**
* dpm_resume - Execute "resume" callbacks for non-sysdev devices.
* @state: PM transition of the system being carried out.
@ -1008,27 +1006,17 @@ void dpm_resume(pm_message_t state)
pm_transition = state;
async_error = 0;
list_for_each_entry(dev, &dpm_suspended_list, power.entry)
dpm_async_fn(dev, async_resume);
while (!list_empty(&dpm_suspended_list)) {
dev = to_device(dpm_suspended_list.next);
get_device(dev);
if (!is_async(dev)) {
int error;
mutex_unlock(&dpm_list_mtx);
mutex_unlock(&dpm_list_mtx);
error = device_resume(dev, state, false);
if (error) {
suspend_stats.failed_resume++;
dpm_save_failed_step(SUSPEND_RESUME);
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, "", error);
}
device_resume(dev);
mutex_lock(&dpm_list_mtx);
mutex_lock(&dpm_list_mtx);
}
if (!list_empty(&dev->power.entry))
list_move_tail(&dev->power.entry, &dpm_prepared_list);