On Thu, Oct 3, 2019 at 10:29 PM Andrii Nakryiko <andriin@xxxxxx> wrote:
>
> Add bpf_object__open_file() and bpf_object__open_mem() APIs that use a new
> approach to providing future-proof non-ABI-breaking API changes. It relies on
> APIs accepting optional self-describing "opts" struct, containing its own
> size, filled out and provided by potentially outdated (as well as
> newer-than-libbpf) user application. A set of internal helper macros
> (OPTS_VALID, OPTS_HAS, and OPTS_GET) streamline and simplify a graceful
> handling forward and backward compatibility for user applications dynamically
> linked against different versions of libbpf shared library.
>
> Users of libbpf are provided with convenience macro LIBBPF_OPTS that takes
> care of populating correct structure size and zero-initializes options struct,
> which helps avoid obscure issues of unitialized padding. Uninitialized padding
> in a struct might turn into garbage-populated new fields understood by future
> versions of libbpf.
>
> Patch #3 switches two of test_progs' tests to use new APIs as a validation
> that they work as expected.
>
> v1->v2:
> - use better approach for tracking last field in opts struct;
> - convert few tests to new APIs for validation;
> - fix bug with using offsetof(last_field) instead of offsetofend(last_field).
>
> Andrii Nakryiko (3):
> libbpf: stop enforcing kern_version, populate it for users
> libbpf: add bpf_object__open_{file,mem} w/ extensible opts
> selftests/bpf: switch tests to new bpf_object__open_{file,mem}() APIs
>
> tools/lib/bpf/libbpf.c | 128 +++++++++---------
> tools/lib/bpf/libbpf.h | 38 +++++-
> tools/lib/bpf/libbpf.map | 3 +
> tools/lib/bpf/libbpf_internal.h | 32 +++++
> tools/testing/selftests/bpf/Makefile | 2 +-
> .../selftests/bpf/prog_tests/attach_probe.c | 42 +++++-
> .../bpf/prog_tests/reference_tracking.c | 7 +-
> .../selftests/bpf/progs/test_attach_probe.c | 1 -
> .../bpf/progs/test_get_stack_rawtp.c | 1 -
> .../selftests/bpf/progs/test_perf_buffer.c | 1 -
> .../selftests/bpf/progs/test_stacktrace_map.c | 1 -
> 11 files changed, 176 insertions(+), 80 deletions(-)
>
> --
> 2.17.1
>
Sorry for the spam! Forgot to bump to v2 in subject prefix, re-sending
v2 with correct prefix.
