Tweak struct_ops related APIs to allow the following features:
- specify version suffixes for stuct_ops map types;
- share same BPF program between several map definitions with
different local BTF types, assuming only maps with same
kernel BTF type would be selected for load;
- toggle autocreate flag for struct_ops maps;
- toggle autoload for referenced struct_ops programs
when autocreate flag of struct_ops maps is toggled.
This would allow loading programs like below:
SEC("struct_ops/foo") int BPF_PROG(foo) { ... }
SEC("struct_ops/bar") int BPF_PROG(bar) { ... }
struct bpf_testmod_ops___v1 {
int (*foo)(void);
};
struct bpf_testmod_ops___v2 {
int (*foo)(void);
int (*bar)(void);
};
/* Assume kernel type name to be 'test_ops' */
SEC(".struct_ops.link")
struct test_ops___v1 map_v1 = {
/* Program 'foo' shared by maps with
* different local BTF type
*/
.foo = (void *)foo
};
SEC(".struct_ops.link")
struct test_ops___v2 map_v2 = {
.foo = (void *)foo,
.bar = (void *)bar
};
Assuming the following tweaks are done before loading:
/* to load v1 */
bpf_map__set_autocreate(skel->maps.map_v1, true);
bpf_map__set_autocreate(skel->maps.map_v2, false);
/* to load v2 */
bpf_map__set_autocreate(skel->maps.map_v1, false);
bpf_map__set_autocreate(skel->maps.map_v2, true);
Patch #7 ties autocreate and autoload flags for struct_ops maps and
programs, I'm curious if people find such bundling useful and in line
with other libbpf APIs.
Eduard Zingerman (8):
libbpf: allow version suffixes (___smth) for struct_ops types
libbpf: tie struct_ops programs to kernel BTF ids, not to local ids
libbpf: honor autocreate flag for struct_ops maps
selftests/bpf: test struct_ops map definition with type suffix
selftests/bpf: bad_struct_ops test
selftests/bpf: test autocreate behavior for struct_ops maps
libbpf: sync progs autoload with maps autocreate for struct_ops maps
selftests/bpf: tests for struct_ops autoload/autocreate toggling
tools/lib/bpf/libbpf.c | 105 ++++++++++----
.../selftests/bpf/bpf_testmod/bpf_testmod.c | 25 ++++
.../selftests/bpf/bpf_testmod/bpf_testmod.h | 4 +
.../selftests/bpf/prog_tests/bad_struct_ops.c | 42 ++++++
.../bpf/prog_tests/struct_ops_autocreate.c | 136 ++++++++++++++++++
.../bpf/prog_tests/test_struct_ops_module.c | 32 +++--
.../selftests/bpf/progs/bad_struct_ops.c | 17 +++
.../bpf/progs/struct_ops_autocreate.c | 42 ++++++
.../selftests/bpf/progs/struct_ops_module.c | 21 ++-
9 files changed, 383 insertions(+), 41 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/bad_struct_ops.c
create mode 100644 tools/testing/selftests/bpf/prog_tests/struct_ops_autocreate.c
create mode 100644 tools/testing/selftests/bpf/progs/bad_struct_ops.c
create mode 100644 tools/testing/selftests/bpf/progs/struct_ops_autocreate.c
--
2.43.0
