[v19,11/15] IB/mlx4: untag user pointers in mlx4_get_umem_mr
diff mbox series

Message ID 7969018013a67ddbbf784ac7afeea5a57b1e2bcb.1563904656.git.andreyknvl@google.com
State New
Headers show
Series
  • arm64: untag user pointers passed to the kernel
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Commit Message

Andrey Konovalov July 23, 2019, 5:58 p.m. UTC
This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

mlx4_get_umem_mr() uses provided user pointers for vma lookups, which can
only by done with untagged pointers.

Untag user pointers in this function.

Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 drivers/infiniband/hw/mlx4/mr.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Comments

Jason Gunthorpe July 24, 2019, 7:25 p.m. UTC | #1
On Tue, Jul 23, 2019 at 07:58:48PM +0200, Andrey Konovalov wrote:
> This patch is a part of a series that extends kernel ABI to allow to pass
> tagged user pointers (with the top byte set to something else other than
> 0x00) as syscall arguments.
> 
> mlx4_get_umem_mr() uses provided user pointers for vma lookups, which can
> only by done with untagged pointers.
> 
> Untag user pointers in this function.
> 
> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
>  drivers/infiniband/hw/mlx4/mr.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)

Applied to rdma-for next, please don't sent it via other trees :)

Thanks,
Jason
Andrey Konovalov July 25, 2019, 11:17 a.m. UTC | #2
On Wed, Jul 24, 2019 at 9:25 PM Jason Gunthorpe <jgg@ziepe.ca> wrote:
>
> On Tue, Jul 23, 2019 at 07:58:48PM +0200, Andrey Konovalov wrote:
> > This patch is a part of a series that extends kernel ABI to allow to pass
> > tagged user pointers (with the top byte set to something else other than
> > 0x00) as syscall arguments.
> >
> > mlx4_get_umem_mr() uses provided user pointers for vma lookups, which can
> > only by done with untagged pointers.
> >
> > Untag user pointers in this function.
> >
> > Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
> > Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> > ---
> >  drivers/infiniband/hw/mlx4/mr.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
>
> Applied to rdma-for next, please don't sent it via other trees :)

Sure, thanks!

>
> Thanks,
> Jason

Patch
diff mbox series

diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c
index 753479285ce9..6ae503cfc526 100644
--- a/drivers/infiniband/hw/mlx4/mr.c
+++ b/drivers/infiniband/hw/mlx4/mr.c
@@ -377,6 +377,7 @@  static struct ib_umem *mlx4_get_umem_mr(struct ib_udata *udata, u64 start,
 	 * again
 	 */
 	if (!ib_access_writable(access_flags)) {
+		unsigned long untagged_start = untagged_addr(start);
 		struct vm_area_struct *vma;
 
 		down_read(&current->mm->mmap_sem);
@@ -385,9 +386,9 @@  static struct ib_umem *mlx4_get_umem_mr(struct ib_udata *udata, u64 start,
 		 * cover the memory, but for now it requires a single vma to
 		 * entirely cover the MR to support RO mappings.
 		 */
-		vma = find_vma(current->mm, start);
-		if (vma && vma->vm_end >= start + length &&
-		    vma->vm_start <= start) {
+		vma = find_vma(current->mm, untagged_start);
+		if (vma && vma->vm_end >= untagged_start + length &&
+		    vma->vm_start <= untagged_start) {
 			if (vma->vm_flags & VM_WRITE)
 				access_flags |= IB_ACCESS_LOCAL_WRITE;
 		} else {