linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure
@ 2019-03-28 10:08 John Garry
  2019-04-03  8:02 ` John Garry
  0 siblings, 1 reply; 8+ messages in thread
From: John Garry @ 2019-03-28 10:08 UTC (permalink / raw)
  To: rafael, gregkh
  Cc: linuxarm, chenxiang66, robin.murphy, geert, linux-kernel, iommu,
	linux-arm-kernel, robh, hch, John Garry

In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after
devres release"), we changed the ordering of tearing down the device DMA
ops and releasing all the device's resources; this was because the DMA ops
should be maintained until we release the device's managed DMA memories.

However, we have seen another crash on an arm64 system when a
device driver probe fails:

  hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2
  scsi host1: hisi_sas_v3_hw
  BUG: Bad page state in process swapper/0  pfn:313f5
  page:ffff7e0000c4fd40 count:1 mapcount:0
  mapping:0000000000000000 index:0x0
  flags: 0xfffe00000001000(reserved)
  raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48
0000000000000000
  raw: 0000000000000000 0000000000000000 00000001ffffffff
0000000000000000
  page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
  bad because of flags: 0x1000(reserved)
  Modules linked in:
  CPU: 49 PID: 1 Comm: swapper/0 Not tainted
5.1.0-rc1-43081-g22d97fd-dirty #1433
  Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI
RC0 - V1.12.01 01/29/2019
  Call trace:
  dump_backtrace+0x0/0x118
  show_stack+0x14/0x1c
  dump_stack+0xa4/0xc8
  bad_page+0xe4/0x13c
  free_pages_check_bad+0x4c/0xc0
  __free_pages_ok+0x30c/0x340
  __free_pages+0x30/0x44
  __dma_direct_free_pages+0x30/0x38
  dma_direct_free+0x24/0x38
  dma_free_attrs+0x9c/0xd8
  dmam_release+0x20/0x28
  release_nodes+0x17c/0x220
  devres_release_all+0x34/0x54
  really_probe+0xc4/0x2c8
  driver_probe_device+0x58/0xfc
  device_driver_attach+0x68/0x70
  __driver_attach+0x94/0xdc
  bus_for_each_dev+0x5c/0xb4
  driver_attach+0x20/0x28
  bus_add_driver+0x14c/0x200
  driver_register+0x6c/0x124
  __pci_register_driver+0x48/0x50
  sas_v3_pci_driver_init+0x20/0x28
  do_one_initcall+0x40/0x25c
  kernel_init_freeable+0x2b8/0x3c0
  kernel_init+0x10/0x100
  ret_from_fork+0x10/0x18
  Disabling lock debugging due to kernel taint
  BUG: Bad page state in process swapper/0  pfn:313f6
  page:ffff7e0000c4fd80 count:1 mapcount:0
mapping:0000000000000000 index:0x0
[   89.322983] flags: 0xfffe00000001000(reserved)
  raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88
0000000000000000
  raw: 0000000000000000 0000000000000000 00000001ffffffff
0000000000000000

The crash occurs for the same reason.

In this case, on the really_probe() failure path, we are still clearing
the DMA ops prior to releasing the device's managed memories.

This patch fixes this issue by reordering the DMA ops teardown and the
call to devres_release_all() on the failure path.

Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---

For convenience, here is the 2nd half of really_probe() now:

	atomic_inc(&probe_count);
	pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
		 drv->bus->name, __func__, drv->name, dev_name(dev));
	WARN_ON(!list_empty(&dev->devres_head));

re_probe:
	dev->driver = drv;

	/* If using pinctrl, bind pins now before probing */
	ret = pinctrl_bind_pins(dev);
	if (ret)
		goto pinctrl_bind_failed;

	if (dev->bus->dma_configure) {
		ret = dev->bus->dma_configure(dev);
		if (ret)
			goto probe_failed;
	}

	if (driver_sysfs_add(dev)) {
		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
			__func__, dev_name(dev));
		goto probe_failed;
	}

	if (dev->pm_domain && dev->pm_domain->activate) {
		ret = dev->pm_domain->activate(dev);
		if (ret)
			goto probe_failed;
	}

	if (dev->bus->probe) {
		ret = dev->bus->probe(dev);
		if (ret)
			goto probe_failed;
	} else if (drv->probe) {
		ret = drv->probe(dev);
		if (ret)
			goto probe_failed;
	}

	if (test_remove) {
		test_remove = false;

		if (dev->bus->remove)
			dev->bus->remove(dev);
		else if (drv->remove)
			drv->remove(dev);

		devres_release_all(dev);
		driver_sysfs_remove(dev);
		dev->driver = NULL;
		dev_set_drvdata(dev, NULL);
		if (dev->pm_domain && dev->pm_domain->dismiss)
			dev->pm_domain->dismiss(dev);
		pm_runtime_reinit(dev);

		goto re_probe;
	}

	pinctrl_init_done(dev);

	if (dev->pm_domain && dev->pm_domain->sync)
		dev->pm_domain->sync(dev);

	driver_bound(dev);
	ret = 1;
	pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
		 drv->bus->name, __func__, dev_name(dev), drv->name);
	goto done;

probe_failed:
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
pinctrl_bind_failed:
	device_links_no_driver(dev);
	devres_release_all(dev);
	arch_teardown_dma_ops(dev);
	driver_sysfs_remove(dev);
	dev->driver = NULL;
	dev_set_drvdata(dev, NULL);
	if (dev->pm_domain && dev->pm_domain->dismiss)
		dev->pm_domain->dismiss(dev);
	pm_runtime_reinit(dev);
	dev_pm_set_driver_flags(dev, 0);

	switch (ret) {
	case -EPROBE_DEFER:
		/* Driver requested deferred probing */
		dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);
		driver_deferred_probe_add_trigger(dev, local_trigger_count);
		break;
	case -ENODEV:
	case -ENXIO:
		pr_debug("%s: probe of %s rejects match %d\n",
			 drv->name, dev_name(dev), ret);
		break;
	default:
		/* driver matched but the probe failed */
		printk(KERN_WARNING
		       "%s: probe of %s failed with error %d\n",
		       drv->name, dev_name(dev), ret);
	}
	/*
	 * Ignore errors returned by ->probe so that the next driver can try
	 * its luck.
	 */
	ret = 0;
done:
	atomic_dec(&probe_count);
	wake_up(&probe_waitqueue);
	return ret;
}

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index a823f469e53f..0df9b4461766 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -490,7 +490,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	if (dev->bus->dma_configure) {
 		ret = dev->bus->dma_configure(dev);
 		if (ret)
-			goto dma_failed;
+			goto probe_failed;
 	}
 
 	if (driver_sysfs_add(dev)) {
@@ -546,14 +546,13 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	goto done;
 
 probe_failed:
-	arch_teardown_dma_ops(dev);
-dma_failed:
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
 pinctrl_bind_failed:
 	device_links_no_driver(dev);
 	devres_release_all(dev);
+	arch_teardown_dma_ops(dev);
 	driver_sysfs_remove(dev);
 	dev->driver = NULL;
 	dev_set_drvdata(dev, NULL);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure
  2019-03-28 10:08 [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure John Garry
@ 2019-04-03  8:02 ` John Garry
  2019-04-03  8:14   ` Greg KH
  0 siblings, 1 reply; 8+ messages in thread
From: John Garry @ 2019-04-03  8:02 UTC (permalink / raw)
  To: rafael, gregkh
  Cc: linuxarm, chenxiang66, robin.murphy, geert, linux-kernel, iommu,
	linux-arm-kernel, robh, hch

On 28/03/2019 10:08, John Garry wrote:
> In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after
> devres release"), we changed the ordering of tearing down the device DMA
> ops and releasing all the device's resources; this was because the DMA ops
> should be maintained until we release the device's managed DMA memories.
>

Hi all,

A friendly reminder on this patch... I didn't see any update.

I thought that it had some importance.

Thanks,
John

> However, we have seen another crash on an arm64 system when a
> device driver probe fails:
>
>   hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2
>   scsi host1: hisi_sas_v3_hw
>   BUG: Bad page state in process swapper/0  pfn:313f5
>   page:ffff7e0000c4fd40 count:1 mapcount:0
>   mapping:0000000000000000 index:0x0
>   flags: 0xfffe00000001000(reserved)
>   raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48
> 0000000000000000
>   raw: 0000000000000000 0000000000000000 00000001ffffffff
> 0000000000000000
>   page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
>   bad because of flags: 0x1000(reserved)
>   Modules linked in:
>   CPU: 49 PID: 1 Comm: swapper/0 Not tainted
> 5.1.0-rc1-43081-g22d97fd-dirty #1433
>   Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI
> RC0 - V1.12.01 01/29/2019
>   Call trace:
>   dump_backtrace+0x0/0x118
>   show_stack+0x14/0x1c
>   dump_stack+0xa4/0xc8
>   bad_page+0xe4/0x13c
>   free_pages_check_bad+0x4c/0xc0
>   __free_pages_ok+0x30c/0x340
>   __free_pages+0x30/0x44
>   __dma_direct_free_pages+0x30/0x38
>   dma_direct_free+0x24/0x38
>   dma_free_attrs+0x9c/0xd8
>   dmam_release+0x20/0x28
>   release_nodes+0x17c/0x220
>   devres_release_all+0x34/0x54
>   really_probe+0xc4/0x2c8
>   driver_probe_device+0x58/0xfc
>   device_driver_attach+0x68/0x70
>   __driver_attach+0x94/0xdc
>   bus_for_each_dev+0x5c/0xb4
>   driver_attach+0x20/0x28
>   bus_add_driver+0x14c/0x200
>   driver_register+0x6c/0x124
>   __pci_register_driver+0x48/0x50
>   sas_v3_pci_driver_init+0x20/0x28
>   do_one_initcall+0x40/0x25c
>   kernel_init_freeable+0x2b8/0x3c0
>   kernel_init+0x10/0x100
>   ret_from_fork+0x10/0x18
>   Disabling lock debugging due to kernel taint
>   BUG: Bad page state in process swapper/0  pfn:313f6
>   page:ffff7e0000c4fd80 count:1 mapcount:0
> mapping:0000000000000000 index:0x0
> [   89.322983] flags: 0xfffe00000001000(reserved)
>   raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88
> 0000000000000000
>   raw: 0000000000000000 0000000000000000 00000001ffffffff
> 0000000000000000
>
> The crash occurs for the same reason.
>
> In this case, on the really_probe() failure path, we are still clearing
> the DMA ops prior to releasing the device's managed memories.
>
> This patch fixes this issue by reordering the DMA ops teardown and the
> call to devres_release_all() on the failure path.
>
> Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
> Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
> Signed-off-by: John Garry <john.garry@huawei.com>
> ---
>
> For convenience, here is the 2nd half of really_probe() now:
>
> 	atomic_inc(&probe_count);
> 	pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
> 		 drv->bus->name, __func__, drv->name, dev_name(dev));
> 	WARN_ON(!list_empty(&dev->devres_head));
>
> re_probe:
> 	dev->driver = drv;
>
> 	/* If using pinctrl, bind pins now before probing */
> 	ret = pinctrl_bind_pins(dev);
> 	if (ret)
> 		goto pinctrl_bind_failed;
>
> 	if (dev->bus->dma_configure) {
> 		ret = dev->bus->dma_configure(dev);
> 		if (ret)
> 			goto probe_failed;
> 	}
>
> 	if (driver_sysfs_add(dev)) {
> 		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
> 			__func__, dev_name(dev));
> 		goto probe_failed;
> 	}
>
> 	if (dev->pm_domain && dev->pm_domain->activate) {
> 		ret = dev->pm_domain->activate(dev);
> 		if (ret)
> 			goto probe_failed;
> 	}
>
> 	if (dev->bus->probe) {
> 		ret = dev->bus->probe(dev);
> 		if (ret)
> 			goto probe_failed;
> 	} else if (drv->probe) {
> 		ret = drv->probe(dev);
> 		if (ret)
> 			goto probe_failed;
> 	}
>
> 	if (test_remove) {
> 		test_remove = false;
>
> 		if (dev->bus->remove)
> 			dev->bus->remove(dev);
> 		else if (drv->remove)
> 			drv->remove(dev);
>
> 		devres_release_all(dev);
> 		driver_sysfs_remove(dev);
> 		dev->driver = NULL;
> 		dev_set_drvdata(dev, NULL);
> 		if (dev->pm_domain && dev->pm_domain->dismiss)
> 			dev->pm_domain->dismiss(dev);
> 		pm_runtime_reinit(dev);
>
> 		goto re_probe;
> 	}
>
> 	pinctrl_init_done(dev);
>
> 	if (dev->pm_domain && dev->pm_domain->sync)
> 		dev->pm_domain->sync(dev);
>
> 	driver_bound(dev);
> 	ret = 1;
> 	pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
> 		 drv->bus->name, __func__, dev_name(dev), drv->name);
> 	goto done;
>
> probe_failed:
> 	if (dev->bus)
> 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
> 					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
> pinctrl_bind_failed:
> 	device_links_no_driver(dev);
> 	devres_release_all(dev);
> 	arch_teardown_dma_ops(dev);
> 	driver_sysfs_remove(dev);
> 	dev->driver = NULL;
> 	dev_set_drvdata(dev, NULL);
> 	if (dev->pm_domain && dev->pm_domain->dismiss)
> 		dev->pm_domain->dismiss(dev);
> 	pm_runtime_reinit(dev);
> 	dev_pm_set_driver_flags(dev, 0);
>
> 	switch (ret) {
> 	case -EPROBE_DEFER:
> 		/* Driver requested deferred probing */
> 		dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);
> 		driver_deferred_probe_add_trigger(dev, local_trigger_count);
> 		break;
> 	case -ENODEV:
> 	case -ENXIO:
> 		pr_debug("%s: probe of %s rejects match %d\n",
> 			 drv->name, dev_name(dev), ret);
> 		break;
> 	default:
> 		/* driver matched but the probe failed */
> 		printk(KERN_WARNING
> 		       "%s: probe of %s failed with error %d\n",
> 		       drv->name, dev_name(dev), ret);
> 	}
> 	/*
> 	 * Ignore errors returned by ->probe so that the next driver can try
> 	 * its luck.
> 	 */
> 	ret = 0;
> done:
> 	atomic_dec(&probe_count);
> 	wake_up(&probe_waitqueue);
> 	return ret;
> }
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index a823f469e53f..0df9b4461766 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -490,7 +490,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	if (dev->bus->dma_configure) {
>  		ret = dev->bus->dma_configure(dev);
>  		if (ret)
> -			goto dma_failed;
> +			goto probe_failed;
>  	}
>
>  	if (driver_sysfs_add(dev)) {
> @@ -546,14 +546,13 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	goto done;
>
>  probe_failed:
> -	arch_teardown_dma_ops(dev);
> -dma_failed:
>  	if (dev->bus)
>  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
>  pinctrl_bind_failed:
>  	device_links_no_driver(dev);
>  	devres_release_all(dev);
> +	arch_teardown_dma_ops(dev);
>  	driver_sysfs_remove(dev);
>  	dev->driver = NULL;
>  	dev_set_drvdata(dev, NULL);
>



^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure
  2019-04-03  8:02 ` John Garry
@ 2019-04-03  8:14   ` Greg KH
  2019-04-03  9:20     ` John Garry
  0 siblings, 1 reply; 8+ messages in thread
From: Greg KH @ 2019-04-03  8:14 UTC (permalink / raw)
  To: John Garry
  Cc: rafael, linuxarm, chenxiang66, robin.murphy, geert, linux-kernel,
	iommu, linux-arm-kernel, robh, hch

On Wed, Apr 03, 2019 at 09:02:36AM +0100, John Garry wrote:
> On 28/03/2019 10:08, John Garry wrote:
> > In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after
> > devres release"), we changed the ordering of tearing down the device DMA
> > ops and releasing all the device's resources; this was because the DMA ops
> > should be maintained until we release the device's managed DMA memories.
> > 
> 
> Hi all,
> 
> A friendly reminder on this patch... I didn't see any update.
> 
> I thought that it had some importance.
> 
> Thanks,
> John
> 
> > However, we have seen another crash on an arm64 system when a
> > device driver probe fails:
> > 
> >   hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2
> >   scsi host1: hisi_sas_v3_hw
> >   BUG: Bad page state in process swapper/0  pfn:313f5
> >   page:ffff7e0000c4fd40 count:1 mapcount:0
> >   mapping:0000000000000000 index:0x0
> >   flags: 0xfffe00000001000(reserved)
> >   raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48
> > 0000000000000000
> >   raw: 0000000000000000 0000000000000000 00000001ffffffff
> > 0000000000000000
> >   page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
> >   bad because of flags: 0x1000(reserved)
> >   Modules linked in:
> >   CPU: 49 PID: 1 Comm: swapper/0 Not tainted
> > 5.1.0-rc1-43081-g22d97fd-dirty #1433
> >   Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI
> > RC0 - V1.12.01 01/29/2019
> >   Call trace:
> >   dump_backtrace+0x0/0x118
> >   show_stack+0x14/0x1c
> >   dump_stack+0xa4/0xc8
> >   bad_page+0xe4/0x13c
> >   free_pages_check_bad+0x4c/0xc0
> >   __free_pages_ok+0x30c/0x340
> >   __free_pages+0x30/0x44
> >   __dma_direct_free_pages+0x30/0x38
> >   dma_direct_free+0x24/0x38
> >   dma_free_attrs+0x9c/0xd8
> >   dmam_release+0x20/0x28
> >   release_nodes+0x17c/0x220
> >   devres_release_all+0x34/0x54
> >   really_probe+0xc4/0x2c8
> >   driver_probe_device+0x58/0xfc
> >   device_driver_attach+0x68/0x70
> >   __driver_attach+0x94/0xdc
> >   bus_for_each_dev+0x5c/0xb4
> >   driver_attach+0x20/0x28
> >   bus_add_driver+0x14c/0x200
> >   driver_register+0x6c/0x124
> >   __pci_register_driver+0x48/0x50
> >   sas_v3_pci_driver_init+0x20/0x28
> >   do_one_initcall+0x40/0x25c
> >   kernel_init_freeable+0x2b8/0x3c0
> >   kernel_init+0x10/0x100
> >   ret_from_fork+0x10/0x18
> >   Disabling lock debugging due to kernel taint
> >   BUG: Bad page state in process swapper/0  pfn:313f6
> >   page:ffff7e0000c4fd80 count:1 mapcount:0
> > mapping:0000000000000000 index:0x0
> > [   89.322983] flags: 0xfffe00000001000(reserved)
> >   raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88
> > 0000000000000000
> >   raw: 0000000000000000 0000000000000000 00000001ffffffff
> > 0000000000000000
> > 
> > The crash occurs for the same reason.
> > 
> > In this case, on the really_probe() failure path, we are still clearing
> > the DMA ops prior to releasing the device's managed memories.
> > 
> > This patch fixes this issue by reordering the DMA ops teardown and the
> > call to devres_release_all() on the failure path.
> > 
> > Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
> > Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
> > Signed-off-by: John Garry <john.garry@huawei.com>

So does this "fix" 376991db4b64?  If so, should this be added to the
patch and also backported to the stable trees?

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure
  2019-04-03  8:14   ` Greg KH
@ 2019-04-03  9:20     ` John Garry
  2019-04-04 11:17       ` John Garry
  0 siblings, 1 reply; 8+ messages in thread
From: John Garry @ 2019-04-03  9:20 UTC (permalink / raw)
  To: Greg KH
  Cc: rafael, linuxarm, chenxiang66, robin.murphy, geert, linux-kernel,
	iommu, linux-arm-kernel, robh, hch

On 03/04/2019 09:14, Greg KH wrote:
> On Wed, Apr 03, 2019 at 09:02:36AM +0100, John Garry wrote:
>> On 28/03/2019 10:08, John Garry wrote:
>>> In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after
>>> devres release"), we changed the ordering of tearing down the device DMA
>>> ops and releasing all the device's resources; this was because the DMA ops
>>> should be maintained until we release the device's managed DMA memories.
>>>
>>
>> Hi all,
>>
>> A friendly reminder on this patch... I didn't see any update.
>>
>> I thought that it had some importance.
>>
>> Thanks,
>> John
>>
>>> However, we have seen another crash on an arm64 system when a
>>> device driver probe fails:
>>>
>>>   hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2
>>>   scsi host1: hisi_sas_v3_hw
>>>   BUG: Bad page state in process swapper/0  pfn:313f5
>>>   page:ffff7e0000c4fd40 count:1 mapcount:0
>>>   mapping:0000000000000000 index:0x0
>>>   flags: 0xfffe00000001000(reserved)
>>>   raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48
>>> 0000000000000000
>>>   raw: 0000000000000000 0000000000000000 00000001ffffffff
>>> 0000000000000000
>>>   page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
>>>   bad because of flags: 0x1000(reserved)
>>>   Modules linked in:
>>>   CPU: 49 PID: 1 Comm: swapper/0 Not tainted
>>> 5.1.0-rc1-43081-g22d97fd-dirty #1433
>>>   Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI
>>> RC0 - V1.12.01 01/29/2019
>>>   Call trace:
>>>   dump_backtrace+0x0/0x118
>>>   show_stack+0x14/0x1c
>>>   dump_stack+0xa4/0xc8
>>>   bad_page+0xe4/0x13c
>>>   free_pages_check_bad+0x4c/0xc0
>>>   __free_pages_ok+0x30c/0x340
>>>   __free_pages+0x30/0x44
>>>   __dma_direct_free_pages+0x30/0x38
>>>   dma_direct_free+0x24/0x38
>>>   dma_free_attrs+0x9c/0xd8
>>>   dmam_release+0x20/0x28
>>>   release_nodes+0x17c/0x220
>>>   devres_release_all+0x34/0x54
>>>   really_probe+0xc4/0x2c8
>>>   driver_probe_device+0x58/0xfc
>>>   device_driver_attach+0x68/0x70
>>>   __driver_attach+0x94/0xdc
>>>   bus_for_each_dev+0x5c/0xb4
>>>   driver_attach+0x20/0x28
>>>   bus_add_driver+0x14c/0x200
>>>   driver_register+0x6c/0x124
>>>   __pci_register_driver+0x48/0x50
>>>   sas_v3_pci_driver_init+0x20/0x28
>>>   do_one_initcall+0x40/0x25c
>>>   kernel_init_freeable+0x2b8/0x3c0
>>>   kernel_init+0x10/0x100
>>>   ret_from_fork+0x10/0x18
>>>   Disabling lock debugging due to kernel taint
>>>   BUG: Bad page state in process swapper/0  pfn:313f6
>>>   page:ffff7e0000c4fd80 count:1 mapcount:0
>>> mapping:0000000000000000 index:0x0
>>> [   89.322983] flags: 0xfffe00000001000(reserved)
>>>   raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88
>>> 0000000000000000
>>>   raw: 0000000000000000 0000000000000000 00000001ffffffff
>>> 0000000000000000
>>>
>>> The crash occurs for the same reason.
>>>
>>> In this case, on the really_probe() failure path, we are still clearing
>>> the DMA ops prior to releasing the device's managed memories.
>>>
>>> This patch fixes this issue by reordering the DMA ops teardown and the
>>> call to devres_release_all() on the failure path.
>>>
>>> Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
>>> Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
>>> Signed-off-by: John Garry <john.garry@huawei.com>
>
> So does this "fix" 376991db4b64?  If so, should this be added to the
> patch and also backported to the stable trees?

Hi Greg,

No, I don't think so. I'd say it supplements it. Here I'm trying to fix 
up another path in which we tear down the DMA ops prior to releasing the 
device's resources.

I didn't add a fixes tag as 376991db4b64 didn't have one either. It will 
need to be backported to stable, I figure the same as 376991db4b64.

Thanks,
John

>
> thanks,
>
> greg k-h
>
> .
>



^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure
  2019-04-03  9:20     ` John Garry
@ 2019-04-04 11:17       ` John Garry
  2019-04-11  8:50         ` John Garry
  0 siblings, 1 reply; 8+ messages in thread
From: John Garry @ 2019-04-04 11:17 UTC (permalink / raw)
  To: Greg KH, robin.murphy
  Cc: rafael, linuxarm, chenxiang66, geert, linux-kernel, iommu,
	linux-arm-kernel, robh, hch

On 03/04/2019 10:20, John Garry wrote:
> On 03/04/2019 09:14, Greg KH wrote:
>> On Wed, Apr 03, 2019 at 09:02:36AM +0100, John Garry wrote:
>>> On 28/03/2019 10:08, John Garry wrote:
>>>> In commit 376991db4b64 ("driver core: Postpone DMA tear-down until
>>>> after
>>>> devres release"), we changed the ordering of tearing down the device
>>>> DMA
>>>> ops and releasing all the device's resources; this was because the
>>>> DMA ops
>>>> should be maintained until we release the device's managed DMA
>>>> memories.
>>>>
>>>
>>> Hi all,
>>>
>>> A friendly reminder on this patch... I didn't see any update.
>>>
>>> I thought that it had some importance.
>>>
>>> Thanks,
>>> John
>>>
>>>> However, we have seen another crash on an arm64 system when a
>>>> device driver probe fails:
>>>>
>>>>   hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2
>>>>   scsi host1: hisi_sas_v3_hw
>>>>   BUG: Bad page state in process swapper/0  pfn:313f5
>>>>   page:ffff7e0000c4fd40 count:1 mapcount:0
>>>>   mapping:0000000000000000 index:0x0
>>>>   flags: 0xfffe00000001000(reserved)
>>>>   raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48
>>>> 0000000000000000
>>>>   raw: 0000000000000000 0000000000000000 00000001ffffffff
>>>> 0000000000000000
>>>>   page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
>>>>   bad because of flags: 0x1000(reserved)
>>>>   Modules linked in:
>>>>   CPU: 49 PID: 1 Comm: swapper/0 Not tainted
>>>> 5.1.0-rc1-43081-g22d97fd-dirty #1433
>>>>   Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI
>>>> RC0 - V1.12.01 01/29/2019
>>>>   Call trace:
>>>>   dump_backtrace+0x0/0x118
>>>>   show_stack+0x14/0x1c
>>>>   dump_stack+0xa4/0xc8
>>>>   bad_page+0xe4/0x13c
>>>>   free_pages_check_bad+0x4c/0xc0
>>>>   __free_pages_ok+0x30c/0x340
>>>>   __free_pages+0x30/0x44
>>>>   __dma_direct_free_pages+0x30/0x38
>>>>   dma_direct_free+0x24/0x38
>>>>   dma_free_attrs+0x9c/0xd8
>>>>   dmam_release+0x20/0x28
>>>>   release_nodes+0x17c/0x220
>>>>   devres_release_all+0x34/0x54
>>>>   really_probe+0xc4/0x2c8
>>>>   driver_probe_device+0x58/0xfc
>>>>   device_driver_attach+0x68/0x70
>>>>   __driver_attach+0x94/0xdc
>>>>   bus_for_each_dev+0x5c/0xb4
>>>>   driver_attach+0x20/0x28
>>>>   bus_add_driver+0x14c/0x200
>>>>   driver_register+0x6c/0x124
>>>>   __pci_register_driver+0x48/0x50
>>>>   sas_v3_pci_driver_init+0x20/0x28
>>>>   do_one_initcall+0x40/0x25c
>>>>   kernel_init_freeable+0x2b8/0x3c0
>>>>   kernel_init+0x10/0x100
>>>>   ret_from_fork+0x10/0x18
>>>>   Disabling lock debugging due to kernel taint
>>>>   BUG: Bad page state in process swapper/0  pfn:313f6
>>>>   page:ffff7e0000c4fd80 count:1 mapcount:0
>>>> mapping:0000000000000000 index:0x0
>>>> [   89.322983] flags: 0xfffe00000001000(reserved)
>>>>   raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88
>>>> 0000000000000000
>>>>   raw: 0000000000000000 0000000000000000 00000001ffffffff
>>>> 0000000000000000
>>>>
>>>> The crash occurs for the same reason.
>>>>
>>>> In this case, on the really_probe() failure path, we are still clearing
>>>> the DMA ops prior to releasing the device's managed memories.
>>>>
>>>> This patch fixes this issue by reordering the DMA ops teardown and the
>>>> call to devres_release_all() on the failure path.
>>>>
>>>> Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
>>>> Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
>>>> Signed-off-by: John Garry <john.garry@huawei.com>
>>
>> So does this "fix" 376991db4b64?  If so, should this be added to the
>> patch and also backported to the stable trees?
>
> Hi Greg,
>
> No, I don't think so. I'd say it supplements it. Here I'm trying to fix
> up another path in which we tear down the DMA ops prior to releasing the
> device's resources.
>
> I didn't add a fixes tag as 376991db4b64 didn't have one either. It will
> need to be backported to stable, I figure the same as 376991db4b64.

So 376991db4b64 required manual backporting to stable, and this patch 
would require the same:

https://www.spinics.net/lists/stable/msg289685.html

Robin, any further comment?

Thanks,
John


>> thanks,
>>
>> greg k-h
>>
>> .
>>
>



^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure
  2019-04-04 11:17       ` John Garry
@ 2019-04-11  8:50         ` John Garry
  2019-04-11 11:01           ` Robin Murphy
  0 siblings, 1 reply; 8+ messages in thread
From: John Garry @ 2019-04-11  8:50 UTC (permalink / raw)
  To: Greg KH, robin.murphy
  Cc: rafael, linuxarm, chenxiang66, geert, linux-kernel, iommu,
	linux-arm-kernel, robh, hch

On 04/04/2019 12:17, John Garry wrote:
> On 03/04/2019 10:20, John Garry wrote:
>> On 03/04/2019 09:14, Greg KH wrote:
>>> On Wed, Apr 03, 2019 at 09:02:36AM +0100, John Garry wrote:
>>>> On 28/03/2019 10:08, John Garry wrote:
>>>>> In commit 376991db4b64 ("driver core: Postpone DMA tear-down until
>>>>> after
>>>>> devres release"), we changed the ordering of tearing down the device
>>>>> DMA
>>>>> ops and releasing all the device's resources; this was because the
>>>>> DMA ops
>>>>> should be maintained until we release the device's managed DMA
>>>>> memories.
>>>>>
>>>>
>>>> Hi all,
>>>>
>>>> A friendly reminder on this patch... I didn't see any update.
>>>>
>>>> I thought that it had some importance.
>>>>
>>>> Thanks,
>>>> John
>>>>
>>>>> However, we have seen another crash on an arm64 system when a
>>>>> device driver probe fails:
>>>>>
>>>>>   hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2
>>>>>   scsi host1: hisi_sas_v3_hw
>>>>>   BUG: Bad page state in process swapper/0  pfn:313f5
>>>>>   page:ffff7e0000c4fd40 count:1 mapcount:0
>>>>>   mapping:0000000000000000 index:0x0
>>>>>   flags: 0xfffe00000001000(reserved)
>>>>>   raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48
>>>>> 0000000000000000
>>>>>   raw: 0000000000000000 0000000000000000 00000001ffffffff
>>>>> 0000000000000000
>>>>>   page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
>>>>>   bad because of flags: 0x1000(reserved)
>>>>>   Modules linked in:
>>>>>   CPU: 49 PID: 1 Comm: swapper/0 Not tainted
>>>>> 5.1.0-rc1-43081-g22d97fd-dirty #1433
>>>>>   Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI
>>>>> RC0 - V1.12.01 01/29/2019
>>>>>   Call trace:
>>>>>   dump_backtrace+0x0/0x118
>>>>>   show_stack+0x14/0x1c
>>>>>   dump_stack+0xa4/0xc8
>>>>>   bad_page+0xe4/0x13c
>>>>>   free_pages_check_bad+0x4c/0xc0
>>>>>   __free_pages_ok+0x30c/0x340
>>>>>   __free_pages+0x30/0x44
>>>>>   __dma_direct_free_pages+0x30/0x38
>>>>>   dma_direct_free+0x24/0x38
>>>>>   dma_free_attrs+0x9c/0xd8
>>>>>   dmam_release+0x20/0x28
>>>>>   release_nodes+0x17c/0x220
>>>>>   devres_release_all+0x34/0x54
>>>>>   really_probe+0xc4/0x2c8
>>>>>   driver_probe_device+0x58/0xfc
>>>>>   device_driver_attach+0x68/0x70
>>>>>   __driver_attach+0x94/0xdc
>>>>>   bus_for_each_dev+0x5c/0xb4
>>>>>   driver_attach+0x20/0x28
>>>>>   bus_add_driver+0x14c/0x200
>>>>>   driver_register+0x6c/0x124
>>>>>   __pci_register_driver+0x48/0x50
>>>>>   sas_v3_pci_driver_init+0x20/0x28
>>>>>   do_one_initcall+0x40/0x25c
>>>>>   kernel_init_freeable+0x2b8/0x3c0
>>>>>   kernel_init+0x10/0x100
>>>>>   ret_from_fork+0x10/0x18
>>>>>   Disabling lock debugging due to kernel taint
>>>>>   BUG: Bad page state in process swapper/0  pfn:313f6
>>>>>   page:ffff7e0000c4fd80 count:1 mapcount:0
>>>>> mapping:0000000000000000 index:0x0
>>>>> [   89.322983] flags: 0xfffe00000001000(reserved)
>>>>>   raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88
>>>>> 0000000000000000
>>>>>   raw: 0000000000000000 0000000000000000 00000001ffffffff
>>>>> 0000000000000000
>>>>>
>>>>> The crash occurs for the same reason.
>>>>>
>>>>> In this case, on the really_probe() failure path, we are still
>>>>> clearing
>>>>> the DMA ops prior to releasing the device's managed memories.
>>>>>
>>>>> This patch fixes this issue by reordering the DMA ops teardown and the
>>>>> call to devres_release_all() on the failure path.
>>>>>
>>>>> Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
>>>>> Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
>>>>> Signed-off-by: John Garry <john.garry@huawei.com>
>>>
>>> So does this "fix" 376991db4b64?  If so, should this be added to the
>>> patch and also backported to the stable trees?
>>
>> Hi Greg,
>>
>> No, I don't think so. I'd say it supplements it. Here I'm trying to fix
>> up another path in which we tear down the DMA ops prior to releasing the
>> device's resources.
>>
>> I didn't add a fixes tag as 376991db4b64 didn't have one either. It will
>> need to be backported to stable, I figure the same as 376991db4b64.
>

Hi Greg,

I still think that we should consider merging this patch.

Thanks,
John

> So 376991db4b64 required manual backporting to stable, and this patch
> would require the same:
>
> https://www.spinics.net/lists/stable/msg289685.html
>
> Robin, any further comment?
>
> Thanks,
> John
>
>
>>> thanks,
>>>
>>> greg k-h
>>>
>>> .
>>>
>>
>



^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure
  2019-04-11  8:50         ` John Garry
@ 2019-04-11 11:01           ` Robin Murphy
  2019-04-11 12:13             ` John Garry
  0 siblings, 1 reply; 8+ messages in thread
From: Robin Murphy @ 2019-04-11 11:01 UTC (permalink / raw)
  To: John Garry, Greg KH
  Cc: rafael, linuxarm, chenxiang66, geert, linux-kernel, iommu,
	linux-arm-kernel, robh, hch

On 11/04/2019 09:50, John Garry wrote:
> On 04/04/2019 12:17, John Garry wrote:
>> On 03/04/2019 10:20, John Garry wrote:
>>> On 03/04/2019 09:14, Greg KH wrote:
>>>> On Wed, Apr 03, 2019 at 09:02:36AM +0100, John Garry wrote:
>>>>> On 28/03/2019 10:08, John Garry wrote:
>>>>>> In commit 376991db4b64 ("driver core: Postpone DMA tear-down until
>>>>>> after
>>>>>> devres release"), we changed the ordering of tearing down the device
>>>>>> DMA
>>>>>> ops and releasing all the device's resources; this was because the
>>>>>> DMA ops
>>>>>> should be maintained until we release the device's managed DMA
>>>>>> memories.
>>>>>>
>>>>>
>>>>> Hi all,
>>>>>
>>>>> A friendly reminder on this patch... I didn't see any update.
>>>>>
>>>>> I thought that it had some importance.
>>>>>
>>>>> Thanks,
>>>>> John
>>>>>
>>>>>> However, we have seen another crash on an arm64 system when a
>>>>>> device driver probe fails:
>>>>>>
>>>>>>   hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2
>>>>>>   scsi host1: hisi_sas_v3_hw
>>>>>>   BUG: Bad page state in process swapper/0  pfn:313f5
>>>>>>   page:ffff7e0000c4fd40 count:1 mapcount:0
>>>>>>   mapping:0000000000000000 index:0x0
>>>>>>   flags: 0xfffe00000001000(reserved)
>>>>>>   raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48
>>>>>> 0000000000000000
>>>>>>   raw: 0000000000000000 0000000000000000 00000001ffffffff
>>>>>> 0000000000000000
>>>>>>   page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
>>>>>>   bad because of flags: 0x1000(reserved)
>>>>>>   Modules linked in:
>>>>>>   CPU: 49 PID: 1 Comm: swapper/0 Not tainted
>>>>>> 5.1.0-rc1-43081-g22d97fd-dirty #1433
>>>>>>   Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI
>>>>>> RC0 - V1.12.01 01/29/2019
>>>>>>   Call trace:
>>>>>>   dump_backtrace+0x0/0x118
>>>>>>   show_stack+0x14/0x1c
>>>>>>   dump_stack+0xa4/0xc8
>>>>>>   bad_page+0xe4/0x13c
>>>>>>   free_pages_check_bad+0x4c/0xc0
>>>>>>   __free_pages_ok+0x30c/0x340
>>>>>>   __free_pages+0x30/0x44
>>>>>>   __dma_direct_free_pages+0x30/0x38
>>>>>>   dma_direct_free+0x24/0x38
>>>>>>   dma_free_attrs+0x9c/0xd8
>>>>>>   dmam_release+0x20/0x28
>>>>>>   release_nodes+0x17c/0x220
>>>>>>   devres_release_all+0x34/0x54
>>>>>>   really_probe+0xc4/0x2c8
>>>>>>   driver_probe_device+0x58/0xfc
>>>>>>   device_driver_attach+0x68/0x70
>>>>>>   __driver_attach+0x94/0xdc
>>>>>>   bus_for_each_dev+0x5c/0xb4
>>>>>>   driver_attach+0x20/0x28
>>>>>>   bus_add_driver+0x14c/0x200
>>>>>>   driver_register+0x6c/0x124
>>>>>>   __pci_register_driver+0x48/0x50
>>>>>>   sas_v3_pci_driver_init+0x20/0x28
>>>>>>   do_one_initcall+0x40/0x25c
>>>>>>   kernel_init_freeable+0x2b8/0x3c0
>>>>>>   kernel_init+0x10/0x100
>>>>>>   ret_from_fork+0x10/0x18
>>>>>>   Disabling lock debugging due to kernel taint
>>>>>>   BUG: Bad page state in process swapper/0  pfn:313f6
>>>>>>   page:ffff7e0000c4fd80 count:1 mapcount:0
>>>>>> mapping:0000000000000000 index:0x0
>>>>>> [   89.322983] flags: 0xfffe00000001000(reserved)
>>>>>>   raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88
>>>>>> 0000000000000000
>>>>>>   raw: 0000000000000000 0000000000000000 00000001ffffffff
>>>>>> 0000000000000000
>>>>>>
>>>>>> The crash occurs for the same reason.
>>>>>>
>>>>>> In this case, on the really_probe() failure path, we are still
>>>>>> clearing
>>>>>> the DMA ops prior to releasing the device's managed memories.
>>>>>>
>>>>>> This patch fixes this issue by reordering the DMA ops teardown and 
>>>>>> the
>>>>>> call to devres_release_all() on the failure path.
>>>>>>
>>>>>> Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
>>>>>> Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
>>>>>> Signed-off-by: John Garry <john.garry@huawei.com>
>>>>
>>>> So does this "fix" 376991db4b64?  If so, should this be added to the
>>>> patch and also backported to the stable trees?
>>>
>>> Hi Greg,
>>>
>>> No, I don't think so. I'd say it supplements it. Here I'm trying to fix
>>> up another path in which we tear down the DMA ops prior to releasing the
>>> device's resources.
>>>
>>> I didn't add a fixes tag as 376991db4b64 didn't have one either. It will
>>> need to be backported to stable, I figure the same as 376991db4b64.
>>
> 
> Hi Greg,
> 
> I still think that we should consider merging this patch.

Bah, sorry, I thought I'd replied to this thread already, but apparently 
not :(

I don't have a particularly strong opinion, but at the moment I am 
leaning slightly towards this being a parallel fix for another part of 
09515ef5ddad, rather than a specific fix of the other fix. Either way, 
you can have a:

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

Thanks,
Robin.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure
  2019-04-11 11:01           ` Robin Murphy
@ 2019-04-11 12:13             ` John Garry
  0 siblings, 0 replies; 8+ messages in thread
From: John Garry @ 2019-04-11 12:13 UTC (permalink / raw)
  To: Robin Murphy, Greg KH
  Cc: rafael, linuxarm, chenxiang66, geert, linux-kernel, iommu,
	linux-arm-kernel, robh, hch

On 11/04/2019 12:01, Robin Murphy wrote:
>>>>>>>
>>>>>>> The crash occurs for the same reason.
>>>>>>>
>>>>>>> In this case, on the really_probe() failure path, we are still
>>>>>>> clearing
>>>>>>> the DMA ops prior to releasing the device's managed memories.
>>>>>>>
>>>>>>> This patch fixes this issue by reordering the DMA ops teardown
>>>>>>> and the
>>>>>>> call to devres_release_all() on the failure path.
>>>>>>>
>>>>>>> Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
>>>>>>> Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
>>>>>>> Signed-off-by: John Garry <john.garry@huawei.com>
>>>>>
>>>>> So does this "fix" 376991db4b64?  If so, should this be added to the
>>>>> patch and also backported to the stable trees?
>>>>
>>>> Hi Greg,
>>>>
>>>> No, I don't think so. I'd say it supplements it. Here I'm trying to fix
>>>> up another path in which we tear down the DMA ops prior to releasing
>>>> the
>>>> device's resources.
>>>>
>>>> I didn't add a fixes tag as 376991db4b64 didn't have one either. It
>>>> will
>>>> need to be backported to stable, I figure the same as 376991db4b64.
>>>
>>
>> Hi Greg,
>>
>> I still think that we should consider merging this patch.
>
> Bah, sorry, I thought I'd replied to this thread already, but apparently
> not :(
>
> I don't have a particularly strong opinion, but at the moment I am
> leaning slightly towards this being a parallel fix for another part of
> 09515ef5ddad, rather than a specific fix of the other fix. Either way,
> you can have a:

I'd say a parallel fix of 09515ef5ddad.

>
> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
>

cheers Robin

> Thanks,
> Robin.



^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2019-04-11 12:13 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-28 10:08 [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure John Garry
2019-04-03  8:02 ` John Garry
2019-04-03  8:14   ` Greg KH
2019-04-03  9:20     ` John Garry
2019-04-04 11:17       ` John Garry
2019-04-11  8:50         ` John Garry
2019-04-11 11:01           ` Robin Murphy
2019-04-11 12:13             ` John Garry

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).