Re: [GIT PULL] Please pull RDMA subsystem changes

[Michal Kubecek <mkubecek@suse.cz>]

On Mon, Apr 29, 2019 at 08:40:37AM +0000, Jason Gunthorpe wrote:
> On Mon, Apr 29, 2019 at 08:09:47AM +0200, Heiko Carstens wrote:
> > On Sun, Apr 28, 2019 at 11:52:12AM +0000, Jason Gunthorpe wrote:
> > > Hi Linus,
> > > 
> > > Third rc pull request
> > > 
> > > Nothing particularly special here. There is a small merge conflict
> > > with Adrea's mm_still_valid patches which is resolved as below:
> > ...
> > > Jason Gunthorpe (3):
> > >       RDMA/mlx5: Do not allow the user to write to the clock page
> > >       RDMA/mlx5: Use rdma_user_map_io for mapping BAR pages
> > >       RDMA/ucontext: Fix regression with disassociate
> > 
> > This doesn't compile. The patch below would fix it, but not sure if
> > this is what is intended:
> > 
> > drivers/infiniband/core/uverbs_main.c: In function 'rdma_umap_fault':
> > drivers/infiniband/core/uverbs_main.c:898:28: error: 'struct vm_fault' has no member named 'vm_start'
> >    vmf->page = ZERO_PAGE(vmf->vm_start);
> >                             ^~
> > diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
> > index 7843e89235c3..65fe89b3fa2d 100644
> > +++ b/drivers/infiniband/core/uverbs_main.c
> > @@ -895,7 +895,7 @@ static vm_fault_t rdma_umap_fault(struct vm_fault *vmf)
> >  
> >  	/* Read only pages can just use the system zero page. */
> >  	if (!(vmf->vma->vm_flags & (VM_WRITE | VM_MAYWRITE))) {
> > -		vmf->page = ZERO_PAGE(vmf->vm_start);
> > +		vmf->page = ZERO_PAGE(vmf->vma->vm_start);
> >  		get_page(vmf->page);
> >  		return 0;
> >  	}
> > 
> 
> Thanks Heiko, this looks right to me. 
> 
> I'm surprised to be seeing this at this point, these patches should
> have been seen by 0 day for several days now, and they were in
> linux-next already too..

Most architectures have versions of ZERO_PAGE() which ignore the
argument so that the code builds anyway. I'm not sure if 0-day also
tests s390x builds (which is where I ran into this).

Michal Kubecek