| Message ID | 05c0c078b8b5984af4cc3b105a58c711dcd83342.1556630205.git.andreyknvl@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: untag user pointers passed to the kernel | expand |
On Tue, Apr 30, 2019 at 03:25:09PM +0200, 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. > > 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. > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > Reviewed-by: Leon Romanovsky <leonro@mellanox.com> > --- > drivers/infiniband/hw/mlx4/mr.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c > index 395379a480cb..9a35ed2c6a6f 100644 > --- a/drivers/infiniband/hw/mlx4/mr.c > +++ b/drivers/infiniband/hw/mlx4/mr.c > @@ -378,6 +378,7 @@ 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(¤t->mm->mmap_sem); > @@ -386,9 +387,9 @@ 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 { Discussion ongoing on the previous version of the patch but I'm more inclined to do this in ib_uverbs_(re)reg_mr() on cmd.start.
On Fri, May 3, 2019 at 7:03 PM Catalin Marinas <catalin.marinas@arm.com> wrote: > > On Tue, Apr 30, 2019 at 03:25:09PM +0200, 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. > > > > 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. > > > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > > Reviewed-by: Leon Romanovsky <leonro@mellanox.com> > > --- > > drivers/infiniband/hw/mlx4/mr.c | 7 ++++--- > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c > > index 395379a480cb..9a35ed2c6a6f 100644 > > --- a/drivers/infiniband/hw/mlx4/mr.c > > +++ b/drivers/infiniband/hw/mlx4/mr.c > > @@ -378,6 +378,7 @@ 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(¤t->mm->mmap_sem); > > @@ -386,9 +387,9 @@ 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 { > > Discussion ongoing on the previous version of the patch but I'm more > inclined to do this in ib_uverbs_(re)reg_mr() on cmd.start. OK, I want to publish v15 sooner to fix the issue with emails addresses, so I'll implement this approach there for now. > > -- > Catalin
diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c index 395379a480cb..9a35ed2c6a6f 100644 --- a/drivers/infiniband/hw/mlx4/mr.c +++ b/drivers/infiniband/hw/mlx4/mr.c @@ -378,6 +378,7 @@ 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(¤t->mm->mmap_sem); @@ -386,9 +387,9 @@ 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 {