stable.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH 1/2]Revert "SCSI: Fix NULL pointer dereference in runtime PM"
       [not found] <1441782131.5845.73.camel@kxue-X58A-UD3R>
@ 2015-09-10  2:23 ` Ken Xue
  2015-11-27  3:01   ` Xue, Ken
  0 siblings, 1 reply; 3+ messages in thread
From: Ken Xue @ 2015-09-10  2:23 UTC (permalink / raw)
  To: stern
  Cc: Shane.Huang, Xiangliang.Yu, aaron.lu, linux-scsi, JBottomley,
	SPG_Linux_Kernel, stable

Revert "SCSI: Fix NULL pointer dereference in runtime PM"

This reverts commit 49718f0fb8c9 ("SCSI: Fix NULL pointer dereference in
runtime PM")

The old commit may lead to a issue that blk_{pre|post}_runtime_suspend and
blk_{pre|post}_runtime_resume can not be called in pairs.

Take sr device as example, when sr device goes to runtime suspend, 
blk_{pre|post}_runtime_suspend will be called since sr device defined
pm->runtime_suspend. But blk_{pre|post}_runtime_resume will not be called
since sr device doesn't have pm->runtime_resume. Then sr device can not
resume correctly anymore.

Signed-off-by: Ken Xue <Ken.Xue@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org

---
 drivers/scsi/scsi_pm.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index e4b7998..459abe1 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -219,13 +219,13 @@ static int sdev_runtime_suspend(struct device *dev)
 	struct scsi_device *sdev = to_scsi_device(dev);
 	int err = 0;
 
-	if (pm && pm->runtime_suspend) {
-		err = blk_pre_runtime_suspend(sdev->request_queue);
-		if (err)
-			return err;
+	err = blk_pre_runtime_suspend(sdev->request_queue);
+	if (err)
+		return err;
+	if (pm && pm->runtime_suspend)
 		err = pm->runtime_suspend(dev);
-		blk_post_runtime_suspend(sdev->request_queue, err);
-	}
+	blk_post_runtime_suspend(sdev->request_queue, err);
+
 	return err;
 }
 
@@ -248,11 +248,11 @@ static int sdev_runtime_resume(struct device *dev)
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 	int err = 0;
 
-	if (pm && pm->runtime_resume) {
-		blk_pre_runtime_resume(sdev->request_queue);
+	blk_pre_runtime_resume(sdev->request_queue);
+	if (pm && pm->runtime_resume)
 		err = pm->runtime_resume(dev);
-		blk_post_runtime_resume(sdev->request_queue, err);
-	}
+	blk_post_runtime_resume(sdev->request_queue, err);
+
 	return err;
 }
 
-- 
1.9.1




^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH 1/2]Revert "SCSI: Fix NULL pointer dereference in runtime PM"
  2015-09-10  2:23 ` [PATCH 1/2]Revert "SCSI: Fix NULL pointer dereference in runtime PM" Ken Xue
@ 2015-11-27  3:01   ` Xue, Ken
  0 siblings, 0 replies; 3+ messages in thread
From: Xue, Ken @ 2015-11-27  3:01 UTC (permalink / raw)
  To: linux-kernel@vger.kernel.org, mlin@kernel.org,
	stern@rowland.harvard.edu
  Cc: linux-scsi@vger.kernel.org, Huang, Shane, SPG_Linux_Kernel,
	aaron.lu@intel.com, stable@vger.kernel.org, JBottomley@Odin.com,
	Yu, Xiangliang

On 四, 2015-09-10 at 10:23 +0800, Ken Xue wrote:

Can someone help to apply this patch series? Thanks.
http://marc.info/?l=linux-scsi&m=144185206825609&w=2
http://marc.info/?l=linux-scsi&m=144185208525611&w=2 

> Revert "SCSI: Fix NULL pointer dereference in runtime PM"
> 
> This reverts commit 49718f0fb8c9 ("SCSI: Fix NULL pointer dereference
> in
> runtime PM")
> 
> The old commit may lead to a issue that
> blk_{pre|post}_runtime_suspend and
> blk_{pre|post}_runtime_resume can not be called in pairs.
> 
> Take sr device as example, when sr device goes to runtime suspend, 
> blk_{pre|post}_runtime_suspend will be called since sr device defined
> pm->runtime_suspend. But blk_{pre|post}_runtime_resume will not be
> called
> since sr device doesn't have pm->runtime_resume. Then sr device can
> not
> resume correctly anymore.
> 
> Signed-off-by: Ken Xue <Ken.Xue@amd.com>
> Acked-by: Alan Stern <stern@rowland.harvard.edu>
> Cc: stable@vger.kernel.org
> 
> ---
>  drivers/scsi/scsi_pm.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
> index e4b7998..459abe1 100644
> --- a/drivers/scsi/scsi_pm.c
> +++ b/drivers/scsi/scsi_pm.c
> @@ -219,13 +219,13 @@ static int sdev_runtime_suspend(struct device
> *dev)
>  	struct scsi_device *sdev = to_scsi_device(dev);
>  	int err = 0;
>  
> -	if (pm && pm->runtime_suspend) {
> -		err = blk_pre_runtime_suspend(sdev->request_queue);
> -		if (err)
> -			return err;
> +	err = blk_pre_runtime_suspend(sdev->request_queue);
> +	if (err)
> +		return err;
> +	if (pm && pm->runtime_suspend)
>  		err = pm->runtime_suspend(dev);
> -		blk_post_runtime_suspend(sdev->request_queue, err);
> -	}
> +	blk_post_runtime_suspend(sdev->request_queue, err);
> +
>  	return err;
>  }
>  
> @@ -248,11 +248,11 @@ static int sdev_runtime_resume(struct device
> *dev)
>  	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm
> : NULL;
>  	int err = 0;
>  
> -	if (pm && pm->runtime_resume) {
> -		blk_pre_runtime_resume(sdev->request_queue);
> +	blk_pre_runtime_resume(sdev->request_queue);
> +	if (pm && pm->runtime_resume)
>  		err = pm->runtime_resume(dev);
> -		blk_post_runtime_resume(sdev->request_queue, err);
> -	}
> +	blk_post_runtime_resume(sdev->request_queue, err);
> +
>  	return err;
>  }
>  

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH 1/2]Revert "SCSI: Fix NULL pointer dereference in runtime PM"
@ 2015-12-01  6:45 Ken Xue
  0 siblings, 0 replies; 3+ messages in thread
From: Ken Xue @ 2015-12-01  6:45 UTC (permalink / raw)
  To: linux-scsi, linux-block, stable, linux-kernel
  Cc: Xiangliang.Yu, stern, JBottomley, SPG_Linux_Kernel, axboe,
	michael.terry

This reverts commit 49718f0fb8c9 ("SCSI: Fix NULL pointer dereference in
runtime PM")

The old commit may lead to a issue that blk_{pre|post}_runtime_suspend and
blk_{pre|post}_runtime_resume may not be called in pairs.

Take sr device as example, when sr device goes to runtime suspend, 
blk_{pre|post}_runtime_suspend will be called since sr device defined
pm->runtime_suspend. But blk_{pre|post}_runtime_resume will not be called
since sr device doesn't have pm->runtime_resume. so, sr device can not
resume correctly anymore.

More discussion can be found from below link.
http://marc.info/?l=linux-scsi&m=144163730531875&w=2

Signed-off-by: Ken Xue <Ken.Xue@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Xiangliang Yu <Xiangliang.Yu@amd.com>
Cc: James E.J. Bottomley <JBottomley@odin.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Terry <Michael.terry@canonical.com>
Cc: stable@vger.kernel.org

---
 drivers/scsi/scsi_pm.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index e4b7998..459abe1 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -219,13 +219,13 @@ static int sdev_runtime_suspend(struct device *dev)
 	struct scsi_device *sdev = to_scsi_device(dev);
 	int err = 0;
 
-	if (pm && pm->runtime_suspend) {
-		err = blk_pre_runtime_suspend(sdev->request_queue);
-		if (err)
-			return err;
+	err = blk_pre_runtime_suspend(sdev->request_queue);
+	if (err)
+		return err;
+	if (pm && pm->runtime_suspend)
 		err = pm->runtime_suspend(dev);
-		blk_post_runtime_suspend(sdev->request_queue, err);
-	}
+	blk_post_runtime_suspend(sdev->request_queue, err);
+
 	return err;
 }
 
@@ -248,11 +248,11 @@ static int sdev_runtime_resume(struct device *dev)
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 	int err = 0;
 
-	if (pm && pm->runtime_resume) {
-		blk_pre_runtime_resume(sdev->request_queue);
+	blk_pre_runtime_resume(sdev->request_queue);
+	if (pm && pm->runtime_resume)
 		err = pm->runtime_resume(dev);
-		blk_post_runtime_resume(sdev->request_queue, err);
-	}
+	blk_post_runtime_resume(sdev->request_queue, err);
+
 	return err;
 }
 
-- 
1.9.1




^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2015-12-01  7:06 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <1441782131.5845.73.camel@kxue-X58A-UD3R>
2015-09-10  2:23 ` [PATCH 1/2]Revert "SCSI: Fix NULL pointer dereference in runtime PM" Ken Xue
2015-11-27  3:01   ` Xue, Ken
2015-12-01  6:45 Ken Xue

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).