diff mbox series

[v13,15/20] drm/radeon, arm64: untag user pointers in radeon_ttm_tt_pin_userptr

Message ID 038360a0a9dc0abaaaf3ad84a2d07fd544abce1a.1553093421.git.andreyknvl@google.com (mailing list archive)
State New, archived
Headers show
Series arm64: untag user pointers passed to the kernel | expand

Commit Message

Andrey Konovalov March 20, 2019, 2:51 p.m. UTC
This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.

radeon_ttm_tt_pin_userptr() uses provided user pointers for vma
lookups, which can only by done with untagged pointers.

Untag user pointers in this function.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 drivers/gpu/drm/radeon/radeon_ttm.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Catalin Marinas March 22, 2019, 4 p.m. UTC | #1
On Wed, Mar 20, 2019 at 03:51:29PM +0100, Andrey Konovalov wrote:
> This patch is a part of a series that extends arm64 kernel ABI to allow to
> pass tagged user pointers (with the top byte set to something else other
> than 0x00) as syscall arguments.
> 
> radeon_ttm_tt_pin_userptr() uses provided user pointers for vma
> lookups, which can only by done with untagged pointers.
> 
> Untag user pointers in this function.
> 
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
>  drivers/gpu/drm/radeon/radeon_ttm.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
> index 9920a6fc11bf..872a98796117 100644
> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
> @@ -497,9 +497,10 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
>  	if (gtt->userflags & RADEON_GEM_USERPTR_ANONONLY) {
>  		/* check that we only pin down anonymous memory
>  		   to prevent problems with writeback */
> -		unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
> +		unsigned long userptr = untagged_addr(gtt->userptr);
> +		unsigned long end = userptr + ttm->num_pages * PAGE_SIZE;
>  		struct vm_area_struct *vma;
> -		vma = find_vma(gtt->usermm, gtt->userptr);
> +		vma = find_vma(gtt->usermm, userptr);
>  		if (!vma || vma->vm_file || vma->vm_end < end)
>  			return -EPERM;
>  	}

Same comment as on the previous patch.
Andrey Konovalov April 2, 2019, 2:17 p.m. UTC | #2
On Fri, Mar 22, 2019 at 5:01 PM Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Wed, Mar 20, 2019 at 03:51:29PM +0100, Andrey Konovalov wrote:
> > This patch is a part of a series that extends arm64 kernel ABI to allow to
> > pass tagged user pointers (with the top byte set to something else other
> > than 0x00) as syscall arguments.
> >
> > radeon_ttm_tt_pin_userptr() uses provided user pointers for vma
> > lookups, which can only by done with untagged pointers.
> >
> > Untag user pointers in this function.
> >
> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> > ---
> >  drivers/gpu/drm/radeon/radeon_ttm.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
> > index 9920a6fc11bf..872a98796117 100644
> > --- a/drivers/gpu/drm/radeon/radeon_ttm.c
> > +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
> > @@ -497,9 +497,10 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
> >       if (gtt->userflags & RADEON_GEM_USERPTR_ANONONLY) {
> >               /* check that we only pin down anonymous memory
> >                  to prevent problems with writeback */
> > -             unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
> > +             unsigned long userptr = untagged_addr(gtt->userptr);
> > +             unsigned long end = userptr + ttm->num_pages * PAGE_SIZE;
> >               struct vm_area_struct *vma;
> > -             vma = find_vma(gtt->usermm, gtt->userptr);
> > +             vma = find_vma(gtt->usermm, userptr);
> >               if (!vma || vma->vm_file || vma->vm_end < end)
> >                       return -EPERM;
> >       }
>
> Same comment as on the previous patch.

As Kevin wrote in the amd driver related thread, the call trace is:
radeon_gem_userptr_ioctl()->radeon_ttm_tt_set_userptr()->...->radeon_ttm_tt_pin_userptr()->find_vma()

>
> --
> Catalin
diff mbox series

Patch

diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 9920a6fc11bf..872a98796117 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -497,9 +497,10 @@  static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
 	if (gtt->userflags & RADEON_GEM_USERPTR_ANONONLY) {
 		/* check that we only pin down anonymous memory
 		   to prevent problems with writeback */
-		unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
+		unsigned long userptr = untagged_addr(gtt->userptr);
+		unsigned long end = userptr + ttm->num_pages * PAGE_SIZE;
 		struct vm_area_struct *vma;
-		vma = find_vma(gtt->usermm, gtt->userptr);
+		vma = find_vma(gtt->usermm, userptr);
 		if (!vma || vma->vm_file || vma->vm_end < end)
 			return -EPERM;
 	}