2019-01-11 15:10:32

by Souptick Joarder

Subject: [PATCH 8/9] xen/gntdev.c: Convert to use vm_insert_range

Convert to use vm_insert_range() to map range of kernel
memory to user vma.

Signed-off-by: Souptick Joarder <[email protected]>
---
drivers/xen/gntdev.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index b0b02a5..ca4acee 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -1082,18 +1082,17 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
{
struct gntdev_priv *priv = flip->private_data;
int index = vma->vm_pgoff;
- int count = vma_pages(vma);
struct gntdev_grant_map *map;
- int i, err = -EINVAL;
+ int err = -EINVAL;

if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
return -EINVAL;

pr_debug("map %d+%d at %lx (pgoff %lx)\n",
- index, count, vma->vm_start, vma->vm_pgoff);
+ index, vma_pages(vma), vma->vm_start, vma->vm_pgoff);

mutex_lock(&priv->lock);
- map = gntdev_find_map_index(priv, index, count);
+ map = gntdev_find_map_index(priv, index, vma_pages(vma));
if (!map)
goto unlock_out;
if (use_ptemod && map->vma)
@@ -1145,12 +1144,9 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
goto out_put_map;

if (!use_ptemod) {
- for (i = 0; i < count; i++) {
- err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
- map->pages[i]);
- if (err)
- goto out_put_map;
- }
+ err = vm_insert_range(vma, map->pages, map->count);
+ if (err)
+ goto out_put_map;
} else {
#ifdef CONFIG_X86
/*
--
1.9.1

2019-01-14 23:30:57

by Boris Ostrovsky

Subject: Re: [PATCH 8/9] xen/gntdev.c: Convert to use vm_insert_range

On 1/11/19 10:12 AM, Souptick Joarder wrote:
> Convert to use vm_insert_range() to map range of kernel
> memory to user vma.
>
> Signed-off-by: Souptick Joarder <[email protected]>

Reviewed-by: Boris Ostrovsky <[email protected]>

(although it would be good to mention in the commit that you are also
replacing count with vma_pages(vma), and why)


> ---
> drivers/xen/gntdev.c | 16 ++++++----------
> 1 file changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index b0b02a5..ca4acee 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -1082,18 +1082,17 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
> {
> struct gntdev_priv *priv = flip->private_data;
> int index = vma->vm_pgoff;
> - int count = vma_pages(vma);
> struct gntdev_grant_map *map;
> - int i, err = -EINVAL;
> + int err = -EINVAL;
>
> if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
> return -EINVAL;
>
> pr_debug("map %d+%d at %lx (pgoff %lx)\n",
> - index, count, vma->vm_start, vma->vm_pgoff);
> + index, vma_pages(vma), vma->vm_start, vma->vm_pgoff);
>
> mutex_lock(&priv->lock);
> - map = gntdev_find_map_index(priv, index, count);
> + map = gntdev_find_map_index(priv, index, vma_pages(vma));
> if (!map)
> goto unlock_out;
> if (use_ptemod && map->vma)
> @@ -1145,12 +1144,9 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
> goto out_put_map;
>
> if (!use_ptemod) {
> - for (i = 0; i < count; i++) {
> - err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
> - map->pages[i]);
> - if (err)
> - goto out_put_map;
> - }
> + err = vm_insert_range(vma, map->pages, map->count);
> + if (err)
> + goto out_put_map;
> } else {
> #ifdef CONFIG_X86
> /*

2019-01-15 06:28:20

by Souptick Joarder

Subject: Re: [PATCH 8/9] xen/gntdev.c: Convert to use vm_insert_range

On Tue, Jan 15, 2019 at 4:58 AM Boris Ostrovsky
<[email protected]> wrote:
>
> On 1/11/19 10:12 AM, Souptick Joarder wrote:
> > Convert to use vm_insert_range() to map range of kernel
> > memory to user vma.
> >
> > Signed-off-by: Souptick Joarder <[email protected]>
>
> Reviewed-by: Boris Ostrovsky <[email protected]>
>
> (although it would be good to mention in the commit that you are also
> replacing count with vma_pages(vma), and why)

The original code was using count ( *count = vma_pages(vma)* )
which is same as this patch. Do I need capture it change log ?

>
>
> > ---
> > drivers/xen/gntdev.c | 16 ++++++----------
> > 1 file changed, 6 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> > index b0b02a5..ca4acee 100644
> > --- a/drivers/xen/gntdev.c
> > +++ b/drivers/xen/gntdev.c
> > @@ -1082,18 +1082,17 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
> > {
> > struct gntdev_priv *priv = flip->private_data;
> > int index = vma->vm_pgoff;
> > - int count = vma_pages(vma);
> > struct gntdev_grant_map *map;
> > - int i, err = -EINVAL;
> > + int err = -EINVAL;
> >
> > if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
> > return -EINVAL;
> >
> > pr_debug("map %d+%d at %lx (pgoff %lx)\n",
> > - index, count, vma->vm_start, vma->vm_pgoff);
> > + index, vma_pages(vma), vma->vm_start, vma->vm_pgoff);
> >
> > mutex_lock(&priv->lock);
> > - map = gntdev_find_map_index(priv, index, count);
> > + map = gntdev_find_map_index(priv, index, vma_pages(vma));
> > if (!map)
> > goto unlock_out;
> > if (use_ptemod && map->vma)
> > @@ -1145,12 +1144,9 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
> > goto out_put_map;
> >
> > if (!use_ptemod) {
> > - for (i = 0; i < count; i++) {
> > - err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
> > - map->pages[i]);
> > - if (err)
> > - goto out_put_map;
> > - }
> > + err = vm_insert_range(vma, map->pages, map->count);
> > + if (err)
> > + goto out_put_map;
> > } else {
> > #ifdef CONFIG_X86
> > /*
>

2019-01-15 17:52:33

by Boris Ostrovsky

Subject: Re: [PATCH 8/9] xen/gntdev.c: Convert to use vm_insert_range

On 1/14/19 11:49 PM, Souptick Joarder wrote:
> On Tue, Jan 15, 2019 at 4:58 AM Boris Ostrovsky
> <[email protected]> wrote:
>> On 1/11/19 10:12 AM, Souptick Joarder wrote:
>>> Convert to use vm_insert_range() to map range of kernel
>>> memory to user vma.
>>>
>>> Signed-off-by: Souptick Joarder <[email protected]>
>> Reviewed-by: Boris Ostrovsky <[email protected]>
>>
>> (although it would be good to mention in the commit that you are also
>> replacing count with vma_pages(vma), and why)
> The original code was using count ( *count = vma_pages(vma)* )
> which is same as this patch. Do I need capture it change log ?


I'd just say that because theoretically count might not be equal to
map->count we should use the latter as input to vm_insert_range().

Thanks.
-boris



>
>>
>>> ---
>>> drivers/xen/gntdev.c | 16 ++++++----------
>>> 1 file changed, 6 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
>>> index b0b02a5..ca4acee 100644
>>> --- a/drivers/xen/gntdev.c
>>> +++ b/drivers/xen/gntdev.c
>>> @@ -1082,18 +1082,17 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
>>> {
>>> struct gntdev_priv *priv = flip->private_data;
>>> int index = vma->vm_pgoff;
>>> - int count = vma_pages(vma);
>>> struct gntdev_grant_map *map;
>>> - int i, err = -EINVAL;
>>> + int err = -EINVAL;
>>>
>>> if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
>>> return -EINVAL;
>>>
>>> pr_debug("map %d+%d at %lx (pgoff %lx)\n",
>>> - index, count, vma->vm_start, vma->vm_pgoff);
>>> + index, vma_pages(vma), vma->vm_start, vma->vm_pgoff);
>>>
>>> mutex_lock(&priv->lock);
>>> - map = gntdev_find_map_index(priv, index, count);
>>> + map = gntdev_find_map_index(priv, index, vma_pages(vma));
>>> if (!map)
>>> goto unlock_out;
>>> if (use_ptemod && map->vma)
>>> @@ -1145,12 +1144,9 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
>>> goto out_put_map;
>>>
>>> if (!use_ptemod) {
>>> - for (i = 0; i < count; i++) {
>>> - err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
>>> - map->pages[i]);
>>> - if (err)
>>> - goto out_put_map;
>>> - }
>>> + err = vm_insert_range(vma, map->pages, map->count);
>>> + if (err)
>>> + goto out_put_map;
>>> } else {
>>> #ifdef CONFIG_X86
>>> /*