diff options
| author | KP Singh <kpsingh@kernel.org> | 2025-09-14 23:51:35 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-09-18 19:11:42 -0700 |
| commit | ea2e6467ac36bf3d785defc89e58269b15d182f7 (patch) | |
| tree | 36a844dc8effdd72fbbf357961b67783f9abd052 /tools/testing/selftests/bpf/progs | |
| parent | selftests/bpf: Add tests for exclusive maps (diff) | |
| download | linux-ea2e6467ac36bf3d785defc89e58269b15d182f7.tar.gz linux-ea2e6467ac36bf3d785defc89e58269b15d182f7.zip | |
bpf: Return hashes of maps in BPF_OBJ_GET_INFO_BY_FD
Currently only array maps are supported, but the implementation can be
extended for other maps and objects. The hash is memoized only for
exclusive and frozen maps as their content is stable until the exclusive
program modifies the map.
This is required for BPF signing, enabling a trusted loader program to
verify a map's integrity. The loader retrieves
the map's runtime hash from the kernel and compares it against an
expected hash computed at build time.
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-7-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_map_ptr.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_map_ptr.c b/tools/testing/selftests/bpf/progs/verifier_map_ptr.c index 11a079145966..e2767d27d8aa 100644 --- a/tools/testing/selftests/bpf/progs/verifier_map_ptr.c +++ b/tools/testing/selftests/bpf/progs/verifier_map_ptr.c @@ -70,10 +70,13 @@ __naked void bpf_map_ptr_write_rejected(void) : __clobber_all); } +/* The first element of struct bpf_map is a SHA256 hash of 32 bytes, accessing + * into this array is valid. The opts field is now at offset 33. + */ SEC("socket") __description("bpf_map_ptr: read non-existent field rejected") __failure -__msg("cannot access ptr member ops with moff 0 in struct bpf_map with off 1 size 4") +__msg("cannot access ptr member ops with moff 32 in struct bpf_map with off 33 size 4") __failure_unpriv __msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN") __flag(BPF_F_ANY_ALIGNMENT) @@ -82,7 +85,7 @@ __naked void read_non_existent_field_rejected(void) asm volatile (" \ r6 = 0; \ r1 = %[map_array_48b] ll; \ - r6 = *(u32*)(r1 + 1); \ + r6 = *(u32*)(r1 + 33); \ r0 = 1; \ exit; \ " : |