ACPI: scan: Fix DMA range assignment

[PATCH] ACPI: scan: Fix DMA range assignment

Posted by Robin Murphy 3 years, 5 months ago

Assigning the device's dma_range_map from the iterator variable after
the loop means it always points to the empty terminator at the end of
the map, which is not what we want. Similarly, freeing the iterator on
error when it points to somwhere in the middle of the allocated array
won't work either. Fix this.

Fixes: bf2ee8d0c385 ("ACPI: scan: Support multiple DMA windows with different offsets")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/acpi/scan.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 558664d169fc..024cc373a197 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1509,9 +1509,12 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
 			goto out;
 		}
 
+		*map = r;
+
 		list_for_each_entry(rentry, &list, node) {
 			if (rentry->res->start >= rentry->res->end) {
-				kfree(r);
+				kfree(*map);
+				*map = NULL;
 				ret = -EINVAL;
 				dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
 				goto out;
@@ -1523,8 +1526,6 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
 			r->offset = rentry->offset;
 			r++;
 		}
-
-		*map = r;
 	}
  out:
 	acpi_dev_free_resource_list(&list);
-- 
2.36.1.dirty

Re: [PATCH] ACPI: scan: Fix DMA range assignment

Posted by Lorenzo Pieralisi 3 years, 5 months ago

On Tue, Oct 18, 2022 at 02:14:04PM +0100, Robin Murphy wrote:
> Assigning the device's dma_range_map from the iterator variable after
> the loop means it always points to the empty terminator at the end of
> the map, which is not what we want. Similarly, freeing the iterator on
> error when it points to somwhere in the middle of the allocated array
> won't work either. Fix this.
> 
> Fixes: bf2ee8d0c385 ("ACPI: scan: Support multiple DMA windows with different offsets")
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>  drivers/acpi/scan.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)

A quick comment below, otherwise:

Reviewed-by: Lorenzo Pieralisi <lpieralisi@kernel.org>

> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 558664d169fc..024cc373a197 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1509,9 +1509,12 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
>  			goto out;
>  		}
>  
> +		*map = r;

I wonder whether having a local variable to stash the base pointer
would make code easier to read (so that we avoid using *map for that
purpose and also to return the array to the caller).

Thanks for fixing it so promptly.

Lorenzo

> +
>  		list_for_each_entry(rentry, &list, node) {
>  			if (rentry->res->start >= rentry->res->end) {
> -				kfree(r);
> +				kfree(*map);
> +				*map = NULL;
>  				ret = -EINVAL;
>  				dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
>  				goto out;
> @@ -1523,8 +1526,6 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
>  			r->offset = rentry->offset;
>  			r++;
>  		}
> -
> -		*map = r;
>  	}
>   out:
>  	acpi_dev_free_resource_list(&list);
> -- 
> 2.36.1.dirty
>

Re: [PATCH] ACPI: scan: Fix DMA range assignment

Posted by Rafael J. Wysocki 3 years, 5 months ago

On Wed, Oct 19, 2022 at 10:13 AM Lorenzo Pieralisi
<lpieralisi@kernel.org> wrote:
>
> On Tue, Oct 18, 2022 at 02:14:04PM +0100, Robin Murphy wrote:
> > Assigning the device's dma_range_map from the iterator variable after
> > the loop means it always points to the empty terminator at the end of
> > the map, which is not what we want. Similarly, freeing the iterator on
> > error when it points to somwhere in the middle of the allocated array
> > won't work either. Fix this.
> >
> > Fixes: bf2ee8d0c385 ("ACPI: scan: Support multiple DMA windows with different offsets")
> > Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> > ---
> >  drivers/acpi/scan.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
>
> A quick comment below, otherwise:
>
> Reviewed-by: Lorenzo Pieralisi <lpieralisi@kernel.org>

Applied as is and the code may be cleaned up later.

Thanks!

> > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> > index 558664d169fc..024cc373a197 100644
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -1509,9 +1509,12 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
> >                       goto out;
> >               }
> >
> > +             *map = r;
>
> I wonder whether having a local variable to stash the base pointer
> would make code easier to read (so that we avoid using *map for that
> purpose and also to return the array to the caller).
>
> Thanks for fixing it so promptly.
>
> Lorenzo
>
> > +
> >               list_for_each_entry(rentry, &list, node) {
> >                       if (rentry->res->start >= rentry->res->end) {
> > -                             kfree(r);
> > +                             kfree(*map);
> > +                             *map = NULL;
> >                               ret = -EINVAL;
> >                               dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
> >                               goto out;
> > @@ -1523,8 +1526,6 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
> >                       r->offset = rentry->offset;
> >                       r++;
> >               }
> > -
> > -             *map = r;
> >       }
> >   out:
> >       acpi_dev_free_resource_list(&list);
> > --
> > 2.36.1.dirty
> >

Re: [PATCH] ACPI: scan: Fix DMA range assignment

Posted by Yicong Yang 3 years, 5 months ago

On 2022/10/18 21:14, Robin Murphy wrote:
> Assigning the device's dma_range_map from the iterator variable after
> the loop means it always points to the empty terminator at the end of
> the map, which is not what we want. Similarly, freeing the iterator on
> error when it points to somwhere in the middle of the allocated array
> won't work either. Fix this.
> 
> Fixes: bf2ee8d0c385 ("ACPI: scan: Support multiple DMA windows with different offsets")

Thanks for fixing this. Works on my platform.

Tested-by: Yicong Yang <yangyicong@hisilicon.com>

> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>  drivers/acpi/scan.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 558664d169fc..024cc373a197 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1509,9 +1509,12 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
>  			goto out;
>  		}
>  
> +		*map = r;
> +
>  		list_for_each_entry(rentry, &list, node) {
>  			if (rentry->res->start >= rentry->res->end) {
> -				kfree(r);
> +				kfree(*map);
> +				*map = NULL;
>  				ret = -EINVAL;
>  				dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
>  				goto out;
> @@ -1523,8 +1526,6 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
>  			r->offset = rentry->offset;
>  			r++;
>  		}
> -
> -		*map = r;
>  	}
>   out:
>  	acpi_dev_free_resource_list(&list);
>

Re: [PATCH] ACPI: scan: Fix DMA range assignment

Posted by Jeremy Linton 3 years, 5 months ago

Hi,

On 10/18/22 08:14, Robin Murphy wrote:
> Assigning the device's dma_range_map from the iterator variable after
> the loop means it always points to the empty terminator at the end of
> the map, which is not what we want. Similarly, freeing the iterator on
> error when it points to somwhere in the middle of the allocated array
> won't work either. Fix this.

This fixes the boot problem on both SoC generations of the rpi4+ACPI,

Thanks,

Tested-by: Jeremy Linton <jeremy.linton@arm.com>

> 
> Fixes: bf2ee8d0c385 ("ACPI: scan: Support multiple DMA windows with different offsets")
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>   drivers/acpi/scan.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 558664d169fc..024cc373a197 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1509,9 +1509,12 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
>   			goto out;
>   		}
>   
> +		*map = r;
> +
>   		list_for_each_entry(rentry, &list, node) {
>   			if (rentry->res->start >= rentry->res->end) {
> -				kfree(r);
> +				kfree(*map);
> +				*map = NULL;
>   				ret = -EINVAL;
>   				dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
>   				goto out;
> @@ -1523,8 +1526,6 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
>   			r->offset = rentry->offset;
>   			r++;
>   		}
> -
> -		*map = r;
>   	}
>    out:
>   	acpi_dev_free_resource_list(&list);

Re: [PATCH] ACPI: scan: Fix DMA range assignment

Posted by Jianmin Lv 3 years, 5 months ago

Seems good. Thanks very much.

Reviewed-by: Jianmin Lv <lvjianmin@loongson.cn>

On 2022/10/18 下午9:14, Robin Murphy wrote:
> Assigning the device's dma_range_map from the iterator variable after
> the loop means it always points to the empty terminator at the end of
> the map, which is not what we want. Similarly, freeing the iterator on
> error when it points to somwhere in the middle of the allocated array
> won't work either. Fix this.
> 
> Fixes: bf2ee8d0c385 ("ACPI: scan: Support multiple DMA windows with different offsets")
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>   drivers/acpi/scan.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 558664d169fc..024cc373a197 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1509,9 +1509,12 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
>   			goto out;
>   		}
>   
> +		*map = r;
> +
>   		list_for_each_entry(rentry, &list, node) {
>   			if (rentry->res->start >= rentry->res->end) {
> -				kfree(r);
> +				kfree(*map);
> +				*map = NULL;
>   				ret = -EINVAL;
>   				dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
>   				goto out;
> @@ -1523,8 +1526,6 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
>   			r->offset = rentry->offset;
>   			r++;
>   		}
> -
> -		*map = r;
>   	}
>    out:
>   	acpi_dev_free_resource_list(&list);
>