diff mbox

vfio/platform: store mapped memory in region, instead of an on-stack copy

Message ID 1446137443-5387-1-git-send-email-james.morse@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

James Morse Oct. 29, 2015, 4:50 p.m. UTC
vfio_platform_{read,write}_mmio() call ioremap_nocache() to map
a region of io memory, which they store in struct vfio_platform_region to
be eventually re-used, or unmapped by vfio_platform_regions_cleanup().

These functions receive a copy of their struct vfio_platform_region
argument on the stack - so these mapped areas are always allocated, and
always leaked.

Pass this argument as a pointer instead.

Fixes: 6e3f26456009 "vfio/platform: read and write support for the device fd"
Signed-off-by: James Morse <james.morse@arm.com>
---
 drivers/vfio/platform/vfio_platform_common.c | 36 ++++++++++++++--------------
 1 file changed, 18 insertions(+), 18 deletions(-)

Comments

Baptiste Reynal Oct. 30, 2015, 8:51 a.m. UTC | #1
Hi James,

Thanks for this fix.

Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com>

On Thu, Oct 29, 2015 at 5:50 PM, James Morse <james.morse@arm.com> wrote:
> vfio_platform_{read,write}_mmio() call ioremap_nocache() to map
> a region of io memory, which they store in struct vfio_platform_region to
> be eventually re-used, or unmapped by vfio_platform_regions_cleanup().
>
> These functions receive a copy of their struct vfio_platform_region
> argument on the stack - so these mapped areas are always allocated, and
> always leaked.
>
> Pass this argument as a pointer instead.
>
> Fixes: 6e3f26456009 "vfio/platform: read and write support for the device fd"
> Signed-off-by: James Morse <james.morse@arm.com>
> ---
>  drivers/vfio/platform/vfio_platform_common.c | 36 ++++++++++++++--------------
>  1 file changed, 18 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> index f3b6299..ccf5da5 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -308,17 +308,17 @@ static long vfio_platform_ioctl(void *device_data,
>         return -ENOTTY;
>  }
>
> -static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
> +static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
>                                        char __user *buf, size_t count,
>                                        loff_t off)
>  {
>         unsigned int done = 0;
>
> -       if (!reg.ioaddr) {
> -               reg.ioaddr =
> -                       ioremap_nocache(reg.addr, reg.size);
> +       if (!reg->ioaddr) {
> +               reg->ioaddr =
> +                       ioremap_nocache(reg->addr, reg->size);
>
> -               if (!reg.ioaddr)
> +               if (!reg->ioaddr)
>                         return -ENOMEM;
>         }
>
> @@ -328,7 +328,7 @@ static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
>                 if (count >= 4 && !(off % 4)) {
>                         u32 val;
>
> -                       val = ioread32(reg.ioaddr + off);
> +                       val = ioread32(reg->ioaddr + off);
>                         if (copy_to_user(buf, &val, 4))
>                                 goto err;
>
> @@ -336,7 +336,7 @@ static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
>                 } else if (count >= 2 && !(off % 2)) {
>                         u16 val;
>
> -                       val = ioread16(reg.ioaddr + off);
> +                       val = ioread16(reg->ioaddr + off);
>                         if (copy_to_user(buf, &val, 2))
>                                 goto err;
>
> @@ -344,7 +344,7 @@ static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
>                 } else {
>                         u8 val;
>
> -                       val = ioread8(reg.ioaddr + off);
> +                       val = ioread8(reg->ioaddr + off);
>                         if (copy_to_user(buf, &val, 1))
>                                 goto err;
>
> @@ -377,7 +377,7 @@ static ssize_t vfio_platform_read(void *device_data, char __user *buf,
>                 return -EINVAL;
>
>         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
> -               return vfio_platform_read_mmio(vdev->regions[index],
> +               return vfio_platform_read_mmio(&vdev->regions[index],
>                                                         buf, count, off);
>         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
>                 return -EINVAL; /* not implemented */
> @@ -385,17 +385,17 @@ static ssize_t vfio_platform_read(void *device_data, char __user *buf,
>         return -EINVAL;
>  }
>
> -static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
> +static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
>                                         const char __user *buf, size_t count,
>                                         loff_t off)
>  {
>         unsigned int done = 0;
>
> -       if (!reg.ioaddr) {
> -               reg.ioaddr =
> -                       ioremap_nocache(reg.addr, reg.size);
> +       if (!reg->ioaddr) {
> +               reg->ioaddr =
> +                       ioremap_nocache(reg->addr, reg->size);
>
> -               if (!reg.ioaddr)
> +               if (!reg->ioaddr)
>                         return -ENOMEM;
>         }
>
> @@ -407,7 +407,7 @@ static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
>
>                         if (copy_from_user(&val, buf, 4))
>                                 goto err;
> -                       iowrite32(val, reg.ioaddr + off);
> +                       iowrite32(val, reg->ioaddr + off);
>
>                         filled = 4;
>                 } else if (count >= 2 && !(off % 2)) {
> @@ -415,7 +415,7 @@ static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
>
>                         if (copy_from_user(&val, buf, 2))
>                                 goto err;
> -                       iowrite16(val, reg.ioaddr + off);
> +                       iowrite16(val, reg->ioaddr + off);
>
>                         filled = 2;
>                 } else {
> @@ -423,7 +423,7 @@ static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
>
>                         if (copy_from_user(&val, buf, 1))
>                                 goto err;
> -                       iowrite8(val, reg.ioaddr + off);
> +                       iowrite8(val, reg->ioaddr + off);
>
>                         filled = 1;
>                 }
> @@ -453,7 +453,7 @@ static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
>                 return -EINVAL;
>
>         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
> -               return vfio_platform_write_mmio(vdev->regions[index],
> +               return vfio_platform_write_mmio(&vdev->regions[index],
>                                                         buf, count, off);
>         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
>                 return -EINVAL; /* not implemented */
> --
> 2.6.1
>
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Eric Auger Oct. 30, 2015, 9:19 a.m. UTC | #2
Hi,
On 10/30/2015 09:51 AM, Baptiste Reynal wrote:
> Hi James,
> 
> Thanks for this fix.
> 
> Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
> Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
> 
> On Thu, Oct 29, 2015 at 5:50 PM, James Morse <james.morse@arm.com> wrote:
>> vfio_platform_{read,write}_mmio() call ioremap_nocache() to map
>> a region of io memory, which they store in struct vfio_platform_region to
>> be eventually re-used, or unmapped by vfio_platform_regions_cleanup().
>>
>> These functions receive a copy of their struct vfio_platform_region
>> argument on the stack - so these mapped areas are always allocated, and
>> always leaked.
I just noticed I have a leak in reset modules too. I am going to correct
this.

Thanks

Eric
>>
>> Pass this argument as a pointer instead.
>>
>> Fixes: 6e3f26456009 "vfio/platform: read and write support for the device fd"
>> Signed-off-by: James Morse <james.morse@arm.com>
>> ---
>>  drivers/vfio/platform/vfio_platform_common.c | 36 ++++++++++++++--------------
>>  1 file changed, 18 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
>> index f3b6299..ccf5da5 100644
>> --- a/drivers/vfio/platform/vfio_platform_common.c
>> +++ b/drivers/vfio/platform/vfio_platform_common.c
>> @@ -308,17 +308,17 @@ static long vfio_platform_ioctl(void *device_data,
>>         return -ENOTTY;
>>  }
>>
>> -static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
>> +static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
>>                                        char __user *buf, size_t count,
>>                                        loff_t off)
>>  {
>>         unsigned int done = 0;
>>
>> -       if (!reg.ioaddr) {
>> -               reg.ioaddr =
>> -                       ioremap_nocache(reg.addr, reg.size);
>> +       if (!reg->ioaddr) {
>> +               reg->ioaddr =
>> +                       ioremap_nocache(reg->addr, reg->size);
>>
>> -               if (!reg.ioaddr)
>> +               if (!reg->ioaddr)
>>                         return -ENOMEM;
>>         }
>>
>> @@ -328,7 +328,7 @@ static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
>>                 if (count >= 4 && !(off % 4)) {
>>                         u32 val;
>>
>> -                       val = ioread32(reg.ioaddr + off);
>> +                       val = ioread32(reg->ioaddr + off);
>>                         if (copy_to_user(buf, &val, 4))
>>                                 goto err;
>>
>> @@ -336,7 +336,7 @@ static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
>>                 } else if (count >= 2 && !(off % 2)) {
>>                         u16 val;
>>
>> -                       val = ioread16(reg.ioaddr + off);
>> +                       val = ioread16(reg->ioaddr + off);
>>                         if (copy_to_user(buf, &val, 2))
>>                                 goto err;
>>
>> @@ -344,7 +344,7 @@ static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
>>                 } else {
>>                         u8 val;
>>
>> -                       val = ioread8(reg.ioaddr + off);
>> +                       val = ioread8(reg->ioaddr + off);
>>                         if (copy_to_user(buf, &val, 1))
>>                                 goto err;
>>
>> @@ -377,7 +377,7 @@ static ssize_t vfio_platform_read(void *device_data, char __user *buf,
>>                 return -EINVAL;
>>
>>         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
>> -               return vfio_platform_read_mmio(vdev->regions[index],
>> +               return vfio_platform_read_mmio(&vdev->regions[index],
>>                                                         buf, count, off);
>>         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
>>                 return -EINVAL; /* not implemented */
>> @@ -385,17 +385,17 @@ static ssize_t vfio_platform_read(void *device_data, char __user *buf,
>>         return -EINVAL;
>>  }
>>
>> -static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
>> +static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
>>                                         const char __user *buf, size_t count,
>>                                         loff_t off)
>>  {
>>         unsigned int done = 0;
>>
>> -       if (!reg.ioaddr) {
>> -               reg.ioaddr =
>> -                       ioremap_nocache(reg.addr, reg.size);
>> +       if (!reg->ioaddr) {
>> +               reg->ioaddr =
>> +                       ioremap_nocache(reg->addr, reg->size);
>>
>> -               if (!reg.ioaddr)
>> +               if (!reg->ioaddr)
>>                         return -ENOMEM;
>>         }
>>
>> @@ -407,7 +407,7 @@ static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
>>
>>                         if (copy_from_user(&val, buf, 4))
>>                                 goto err;
>> -                       iowrite32(val, reg.ioaddr + off);
>> +                       iowrite32(val, reg->ioaddr + off);
>>
>>                         filled = 4;
>>                 } else if (count >= 2 && !(off % 2)) {
>> @@ -415,7 +415,7 @@ static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
>>
>>                         if (copy_from_user(&val, buf, 2))
>>                                 goto err;
>> -                       iowrite16(val, reg.ioaddr + off);
>> +                       iowrite16(val, reg->ioaddr + off);
>>
>>                         filled = 2;
>>                 } else {
>> @@ -423,7 +423,7 @@ static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
>>
>>                         if (copy_from_user(&val, buf, 1))
>>                                 goto err;
>> -                       iowrite8(val, reg.ioaddr + off);
>> +                       iowrite8(val, reg->ioaddr + off);
>>
>>                         filled = 1;
>>                 }
>> @@ -453,7 +453,7 @@ static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
>>                 return -EINVAL;
>>
>>         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
>> -               return vfio_platform_write_mmio(vdev->regions[index],
>> +               return vfio_platform_write_mmio(&vdev->regions[index],
>>                                                         buf, count, off);
>>         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
>>                 return -EINVAL; /* not implemented */
>> --
>> 2.6.1
>>
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diff mbox

Patch

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index f3b6299..ccf5da5 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -308,17 +308,17 @@  static long vfio_platform_ioctl(void *device_data,
 	return -ENOTTY;
 }
 
-static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
+static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
 				       char __user *buf, size_t count,
 				       loff_t off)
 {
 	unsigned int done = 0;
 
-	if (!reg.ioaddr) {
-		reg.ioaddr =
-			ioremap_nocache(reg.addr, reg.size);
+	if (!reg->ioaddr) {
+		reg->ioaddr =
+			ioremap_nocache(reg->addr, reg->size);
 
-		if (!reg.ioaddr)
+		if (!reg->ioaddr)
 			return -ENOMEM;
 	}
 
@@ -328,7 +328,7 @@  static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
 		if (count >= 4 && !(off % 4)) {
 			u32 val;
 
-			val = ioread32(reg.ioaddr + off);
+			val = ioread32(reg->ioaddr + off);
 			if (copy_to_user(buf, &val, 4))
 				goto err;
 
@@ -336,7 +336,7 @@  static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
 		} else if (count >= 2 && !(off % 2)) {
 			u16 val;
 
-			val = ioread16(reg.ioaddr + off);
+			val = ioread16(reg->ioaddr + off);
 			if (copy_to_user(buf, &val, 2))
 				goto err;
 
@@ -344,7 +344,7 @@  static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg,
 		} else {
 			u8 val;
 
-			val = ioread8(reg.ioaddr + off);
+			val = ioread8(reg->ioaddr + off);
 			if (copy_to_user(buf, &val, 1))
 				goto err;
 
@@ -377,7 +377,7 @@  static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 		return -EINVAL;
 
 	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
-		return vfio_platform_read_mmio(vdev->regions[index],
+		return vfio_platform_read_mmio(&vdev->regions[index],
 							buf, count, off);
 	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 		return -EINVAL; /* not implemented */
@@ -385,17 +385,17 @@  static ssize_t vfio_platform_read(void *device_data, char __user *buf,
 	return -EINVAL;
 }
 
-static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
+static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
 					const char __user *buf, size_t count,
 					loff_t off)
 {
 	unsigned int done = 0;
 
-	if (!reg.ioaddr) {
-		reg.ioaddr =
-			ioremap_nocache(reg.addr, reg.size);
+	if (!reg->ioaddr) {
+		reg->ioaddr =
+			ioremap_nocache(reg->addr, reg->size);
 
-		if (!reg.ioaddr)
+		if (!reg->ioaddr)
 			return -ENOMEM;
 	}
 
@@ -407,7 +407,7 @@  static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
 
 			if (copy_from_user(&val, buf, 4))
 				goto err;
-			iowrite32(val, reg.ioaddr + off);
+			iowrite32(val, reg->ioaddr + off);
 
 			filled = 4;
 		} else if (count >= 2 && !(off % 2)) {
@@ -415,7 +415,7 @@  static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
 
 			if (copy_from_user(&val, buf, 2))
 				goto err;
-			iowrite16(val, reg.ioaddr + off);
+			iowrite16(val, reg->ioaddr + off);
 
 			filled = 2;
 		} else {
@@ -423,7 +423,7 @@  static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg,
 
 			if (copy_from_user(&val, buf, 1))
 				goto err;
-			iowrite8(val, reg.ioaddr + off);
+			iowrite8(val, reg->ioaddr + off);
 
 			filled = 1;
 		}
@@ -453,7 +453,7 @@  static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
 		return -EINVAL;
 
 	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
-		return vfio_platform_write_mmio(vdev->regions[index],
+		return vfio_platform_write_mmio(&vdev->regions[index],
 							buf, count, off);
 	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
 		return -EINVAL; /* not implemented */