[v1,bpf-next,0/5] Dynptr convenience helpers

Message

Joanne Koong April 9, 2023, 3:34 a.m. UTC

This patchset is the 3rd in the dynptr series. The 1st (dynptr
fundamentals) can be found here [0] and the second (skb + xdp dynptrs)
can be found here [1].

This patchset adds the following convenience helpers for interacting
with dynptrs:

int bpf_dynptr_trim(struct bpf_dynptr *ptr, __u32 len) __ksym;
int bpf_dynptr_advance(struct bpf_dynptr *ptr, __u32 len) __ksym;
int bpf_dynptr_is_null(const struct bpf_dynptr *ptr) __ksym;
int bpf_dynptr_is_rdonly(const struct bpf_dynptr *ptr) __ksym;
__u32 bpf_dynptr_get_size(const struct bpf_dynptr *ptr) __ksym;
__u32 bpf_dynptr_get_offset(const struct bpf_dynptr *ptr) __ksym;
int bpf_dynptr_clone(const struct bpf_dynptr *ptr, struct bpf_dynptr *clone__init) __ksym;

[0] https://lore.kernel.org/bpf/[e-mail]/
[1] https://lore.kernel.org/bpf/[e-mail]/

Joanne Koong (5):
  bpf: Add bpf_dynptr_trim and bpf_dynptr_advance
  bpf: Add bpf_dynptr_is_null and bpf_dynptr_is_rdonly
  bpf: Add bpf_dynptr_get_size and bpf_dynptr_get_offset
  bpf: Add bpf_dynptr_clone
  selftests/bpf: add tests for dynptr convenience helpers

 include/linux/bpf.h                           |   2 +-
 kernel/bpf/helpers.c                          | 108 +++++-
 kernel/bpf/verifier.c                         | 125 ++++++-
 kernel/trace/bpf_trace.c                      |   4 +-
 tools/testing/selftests/bpf/bpf_kfuncs.h      |   8 +
 .../testing/selftests/bpf/prog_tests/dynptr.c |   6 +
 .../testing/selftests/bpf/progs/dynptr_fail.c | 313 +++++++++++++++++
 .../selftests/bpf/progs/dynptr_success.c      | 320 ++++++++++++++++++
 8 files changed, 864 insertions(+), 22 deletions(-)

Comments

Andrii Nakryiko April 12, 2023, 9:48 p.m. UTC | #1

On Sat, Apr 8, 2023 at 8:34 PM Joanne Koong <[e-mail]> wrote:
>
> This patchset is the 3rd in the dynptr series. The 1st (dynptr
> fundamentals) can be found here [0] and the second (skb + xdp dynptrs)
> can be found here [1].
>
> This patchset adds the following convenience helpers for interacting
> with dynptrs:

"convenience helpers" doesn't do these APIs justice. They are
necessary APIs to make dynptrs a generic interface for working with
memory ranges. So it's dynptr cloning and adjustment helpers, but not
just a convenience APIs.

>
> int bpf_dynptr_trim(struct bpf_dynptr *ptr, __u32 len) __ksym;
> int bpf_dynptr_advance(struct bpf_dynptr *ptr, __u32 len) __ksym;
> int bpf_dynptr_is_null(const struct bpf_dynptr *ptr) __ksym;
> int bpf_dynptr_is_rdonly(const struct bpf_dynptr *ptr) __ksym;
> __u32 bpf_dynptr_get_size(const struct bpf_dynptr *ptr) __ksym;
> __u32 bpf_dynptr_get_offset(const struct bpf_dynptr *ptr) __ksym;
> int bpf_dynptr_clone(const struct bpf_dynptr *ptr, struct bpf_dynptr *clone__init) __ksym;
>
> [0] https://lore.kernel.org/bpf/[e-mail]/
> [1] https://lore.kernel.org/bpf/[e-mail]/
>
> Joanne Koong (5):
>   bpf: Add bpf_dynptr_trim and bpf_dynptr_advance
>   bpf: Add bpf_dynptr_is_null and bpf_dynptr_is_rdonly
>   bpf: Add bpf_dynptr_get_size and bpf_dynptr_get_offset
>   bpf: Add bpf_dynptr_clone
>   selftests/bpf: add tests for dynptr convenience helpers
>
>  include/linux/bpf.h                           |   2 +-
>  kernel/bpf/helpers.c                          | 108 +++++-
>  kernel/bpf/verifier.c                         | 125 ++++++-
>  kernel/trace/bpf_trace.c                      |   4 +-
>  tools/testing/selftests/bpf/bpf_kfuncs.h      |   8 +
>  .../testing/selftests/bpf/prog_tests/dynptr.c |   6 +
>  .../testing/selftests/bpf/progs/dynptr_fail.c | 313 +++++++++++++++++
>  .../selftests/bpf/progs/dynptr_success.c      | 320 ++++++++++++++++++
>  8 files changed, 864 insertions(+), 22 deletions(-)
>
> --
> 2.34.1
>