Nouveau - Jun 2019 - [PATCH 08/25] memremap: move dev_pagemap callbacks into a separate structure

On Mon, Jun 17, 2019 at 5:27 AM Christoph Hellwig <hch at lst.de>
wrote:
>
> The dev_pagemap is a growing too many callbacks.  Move them into a
> separate ops structure so that they are not duplicated for multiple
> instances, and an attacker can't easily overwrite them.
>
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Reviewed-by: Logan Gunthorpe <logang at deltatee.com>
> Reviewed-by: Jason Gunthorpe <jgg at mellanox.com>
> ---
>  drivers/dax/device.c              | 11 ++++++----
>  drivers/dax/pmem/core.c           |  2 +-
>  drivers/nvdimm/pmem.c             | 19 +++++++++-------
>  drivers/pci/p2pdma.c              |  9 +++++---
>  include/linux/memremap.h          | 36 +++++++++++++++++--------------
>  kernel/memremap.c                 | 18 ++++++++--------
>  mm/hmm.c                          | 10 ++++++---
>  tools/testing/nvdimm/test/iomap.c |  9 ++++----
>  8 files changed, 65 insertions(+), 49 deletions(-)
>
[..]
> diff --git a/tools/testing/nvdimm/test/iomap.c
b/tools/testing/nvdimm/test/iomap.c
> index 219dd0a1cb08..a667d974155e 100644
> --- a/tools/testing/nvdimm/test/iomap.c
> +++ b/tools/testing/nvdimm/test/iomap.c
> @@ -106,11 +106,10 @@ EXPORT_SYMBOL(__wrap_devm_memremap);
>
>  static void nfit_test_kill(void *_pgmap)
>  {
> -       struct dev_pagemap *pgmap = _pgmap;
Whoops, needed to keep this line to avoid:

tools/testing/nvdimm/test/iomap.c:109:11: error: ‘pgmap’ undeclared
(first use in this function); did you mean ‘_pgmap’?

On Mon, Jun 17, 2019 at 10:51:35AM -0700, Dan Williams
wrote:
> > -       struct dev_pagemap *pgmap = _pgmap;
> 
> Whoops, needed to keep this line to avoid:
> 
> tools/testing/nvdimm/test/iomap.c:109:11: error: ‘pgmap’ undeclared
> (first use in this function); did you mean ‘_pgmap’?
So I really shouldn't be tripping over this anymore, but can we somehow
this mess?

 - at least add it to the normal build system and kconfig deps instead
   of stashing it away so that things like buildbot can build it?
 - at least allow building it (under COMPILE_TEST) if needed even when
   pmem.ko and friends are built in the kernel?

On Mon, Jun 17, 2019 at 12:59 PM Christoph Hellwig <hch at lst.de>
wrote:
>
> On Mon, Jun 17, 2019 at 10:51:35AM -0700, Dan Williams wrote:
> > > -       struct dev_pagemap *pgmap = _pgmap;
> >
> > Whoops, needed to keep this line to avoid:
> >
> > tools/testing/nvdimm/test/iomap.c:109:11: error: ‘pgmap’ undeclared
> > (first use in this function); did you mean ‘_pgmap’?
>
> So I really shouldn't be tripping over this anymore, but can we somehow
> this mess?
>
>  - at least add it to the normal build system and kconfig deps instead
>    of stashing it away so that things like buildbot can build it?
>  - at least allow building it (under COMPILE_TEST) if needed even when
>    pmem.ko and friends are built in the kernel?
Done: https://patchwork.kernel.org/patch/11000477/