[PATCH] PM: sleep: Fix error handling in dpm_prepare()

[PATCH] PM: sleep: Fix error handling in dpm_prepare()

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 2aa36604e824 ("PM: sleep: Avoid calling put_device() under
dpm_list_mtx") forgot to update the while () loop termination
condition to also break the loop if error is nonzero, which
causes the loop to become infinite if device_prepare() returns
an error for one device.

Add the missing !error check.

Fixes: 2aa36604e824 ("PM: sleep: Avoid calling put_device() under dpm_list_mtx")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Thomas Hellström <thomas.hellstrom@linux.intel.com>
---
 drivers/base/power/main.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-pm/drivers/base/power/main.c
===================================================================
--- linux-pm.orig/drivers/base/power/main.c
+++ linux-pm/drivers/base/power/main.c
@@ -1902,7 +1902,7 @@ int dpm_prepare(pm_message_t state)
 	device_block_probing();
 
 	mutex_lock(&dpm_list_mtx);
-	while (!list_empty(&dpm_list)) {
+	while (!list_empty(&dpm_list) && !error) {
 		struct device *dev = to_device(dpm_list.next);
 
 		get_device(dev);

Re: [PATCH] PM: sleep: Fix error handling in dpm_prepare()

[Thomas Hellström]

On Thu, 2021-12-16 at 20:30 +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Commit 2aa36604e824 ("PM: sleep: Avoid calling put_device() under
> dpm_list_mtx") forgot to update the while () loop termination
> condition to also break the loop if error is nonzero, which
> causes the loop to become infinite if device_prepare() returns
> an error for one device.
> 
> Add the missing !error check.
> 
> Fixes: 2aa36604e824 ("PM: sleep: Avoid calling put_device() under
> dpm_list_mtx")
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Thomas Hellström <thomas.hellstrom@linux.intel.com>

Was this meant to be a Reported-by:?
Also Cc stable? IIRC 2aa36604e824 was.

In any case,
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

Thanks,
Thomas


> ---
>  drivers/base/power/main.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux-pm/drivers/base/power/main.c
> ===================================================================
> --- linux-pm.orig/drivers/base/power/main.c
> +++ linux-pm/drivers/base/power/main.c
> @@ -1902,7 +1902,7 @@ int dpm_prepare(pm_message_t state)
>         device_block_probing();
>  
>         mutex_lock(&dpm_list_mtx);
> -       while (!list_empty(&dpm_list)) {
> +       while (!list_empty(&dpm_list) && !error) {
>                 struct device *dev = to_device(dpm_list.next);
>  
>                 get_device(dev);
> 
> 
> 

Re: [PATCH] PM: sleep: Fix error handling in dpm_prepare()

[Rafael J. Wysocki]

On Thu, Dec 16, 2021 at 8:44 PM Thomas Hellström
<thomas.hellstrom@linux.intel.com> wrote:
>
> On Thu, 2021-12-16 at 20:30 +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > Commit 2aa36604e824 ("PM: sleep: Avoid calling put_device() under
> > dpm_list_mtx") forgot to update the while () loop termination
> > condition to also break the loop if error is nonzero, which
> > causes the loop to become infinite if device_prepare() returns
> > an error for one device.
> >
> > Add the missing !error check.
> >
> > Fixes: 2aa36604e824 ("PM: sleep: Avoid calling put_device() under
> > dpm_list_mtx")
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > Thomas Hellström <thomas.hellstrom@linux.intel.com>
>
> Was this meant to be a Reported-by:?

Yes, it was, sorry.

> Also Cc stable? IIRC 2aa36604e824 was.

That gets added later and -stable can figure it out.

> In any case,
> Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

Thanks!

> > ---
> >  drivers/base/power/main.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Index: linux-pm/drivers/base/power/main.c
> > ===================================================================
> > --- linux-pm.orig/drivers/base/power/main.c
> > +++ linux-pm/drivers/base/power/main.c
> > @@ -1902,7 +1902,7 @@ int dpm_prepare(pm_message_t state)
> >         device_block_probing();
> >
> >         mutex_lock(&dpm_list_mtx);
> > -       while (!list_empty(&dpm_list)) {
> > +       while (!list_empty(&dpm_list) && !error) {
> >                 struct device *dev = to_device(dpm_list.next);
> >
> >                 get_device(dev);
> >
> >
> >
>
>

Re: [PATCH] PM: sleep: Fix error handling in dpm_prepare()

[Ulf Hansson]

On Thu, 16 Dec 2021 at 20:30, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
>
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Commit 2aa36604e824 ("PM: sleep: Avoid calling put_device() under
> dpm_list_mtx") forgot to update the while () loop termination
> condition to also break the loop if error is nonzero, which
> causes the loop to become infinite if device_prepare() returns
> an error for one device.
>
> Add the missing !error check.
>
> Fixes: 2aa36604e824 ("PM: sleep: Avoid calling put_device() under dpm_list_mtx")
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Thomas Hellström <thomas.hellstrom@linux.intel.com>

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  drivers/base/power/main.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> Index: linux-pm/drivers/base/power/main.c
> ===================================================================
> --- linux-pm.orig/drivers/base/power/main.c
> +++ linux-pm/drivers/base/power/main.c
> @@ -1902,7 +1902,7 @@ int dpm_prepare(pm_message_t state)
>         device_block_probing();
>
>         mutex_lock(&dpm_list_mtx);
> -       while (!list_empty(&dpm_list)) {
> +       while (!list_empty(&dpm_list) && !error) {
>                 struct device *dev = to_device(dpm_list.next);
>
>                 get_device(dev);
>
>
>