v1->v2:
- move btf id cache to a new bpf_map_ops.map_btf_id field (Martin, Andrii);
- don't check btf names for collisions (Martin);
- drop btf_find_by_name_kind_next() patch since it was needed only for
collision check;
- don't fall back to `struct bpf_map` if a map type doesn't specify both
map_btf_name and map_btf_id;
This patch set adds support to access bpf map fields from bpf programs
using btf_struct_access().
That way a program can cast a pointer to map to either `struct bpf_map *`
or map type specific struct pointer such as `struct bpf_array *` or
`struct bpf_htab *`, and access necessary fields, e.g. map->max_entries.
The fields, in turn, should be defined by a user provided struct with
preserve_access_index attribute or included from vmlinux.h.
Please see patch 3 for more details on the feature and use-cases.
Other patches:
Patch 1 is refactoring to simplify btf_parse_vmlinux().
Patch 2 is a rename to avoid having two different `struct bpf_htab`.
Patch 4 enables access to map fields for all map types.
Patch 5 adds selftests.
Andrey Ignatov (5):
bpf: Switch btf_parse_vmlinux to btf_find_by_name_kind
bpf: Rename bpf_htab to bpf_shtab in sock_map
bpf: Support access to bpf map fields
bpf: Set map_btf_{name,id} for all map types
selftests/bpf: Test access to bpf map pointer
include/linux/bpf.h | 9 +
include/linux/bpf_verifier.h | 1 +
kernel/bpf/arraymap.c | 18 +
kernel/bpf/bpf_struct_ops.c | 3 +
kernel/bpf/btf.c | 63 +-
kernel/bpf/cpumap.c | 3 +
kernel/bpf/devmap.c | 6 +
kernel/bpf/hashtab.c | 15 +
kernel/bpf/local_storage.c | 3 +
kernel/bpf/lpm_trie.c | 3 +
kernel/bpf/queue_stack_maps.c | 6 +
kernel/bpf/reuseport_array.c | 3 +
kernel/bpf/ringbuf.c | 3 +
kernel/bpf/stackmap.c | 3 +
kernel/bpf/verifier.c | 82 ++-
net/core/bpf_sk_storage.c | 3 +
net/core/sock_map.c | 88 +--
net/xdp/xskmap.c | 3 +
.../selftests/bpf/prog_tests/map_ptr.c | 32 +
.../selftests/bpf/progs/map_ptr_kern.c | 686 ++++++++++++++++++
.../testing/selftests/bpf/verifier/map_ptr.c | 62 ++
.../selftests/bpf/verifier/map_ptr_mixing.c | 2 +-
22 files changed, 1030 insertions(+), 67 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/map_ptr.c
create mode 100644 tools/testing/selftests/bpf/progs/map_ptr_kern.c
create mode 100644 tools/testing/selftests/bpf/verifier/map_ptr.c
--
2.24.1
