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| author |   Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2021-10-28 12:04:55 +0530 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2021-10-28 16:30:06 -0700 |
| commit | c24941cd3766b6de682dbe6809bd6af12271ab5b (patch) | |
| tree | 986c39d2900886f2dc7b7eb2366dc946020fd548 /tools/lib/bpf/libbpf.c | |
| parent | bpf: Add bpf_kallsyms_lookup_name helper (diff) | |
| download | linux-dev-c24941cd3766b6de682dbe6809bd6af12271ab5b.tar.xz linux-dev-c24941cd3766b6de682dbe6809bd6af12271ab5b.zip | |
libbpf: Add typeless ksym support to gen_loader
This uses the bpf_kallsyms_lookup_name helper added in previous patches
to relocate typeless ksyms. The return value ENOENT can be ignored, and
the value written to 'res' can be directly stored to the insn, as it is
overwritten to 0 on lookup failure. For repeating symbols, we can simply
copy the previously populated bpf_insn.
Also, we need to take care to not close fds for typeless ksym_desc, so
reuse the 'off' member's space to add a marker for typeless ksym and use
that to skip them in cleanup_relos.
We add a emit_ksym_relo_log helper that avoids duplicating common
logging instructions between typeless and weak ksym (for future commit).
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-3-memxor@gmail.com
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 232e4efe82e9..73e1e70a722f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -6575,17 +6575,14 @@ static int bpf_program__record_externs(struct bpf_program *prog) case RELO_EXTERN_VAR: if (ext->type != EXT_KSYM) continue; - if (!ext->ksym.type_id) { - pr_warn("typeless ksym %s is not supported yet\n", - ext->name); - return -ENOTSUP; - } - bpf_gen__record_extern(obj->gen_loader, ext->name, ext->is_weak, + bpf_gen__record_extern(obj->gen_loader, ext->name, + ext->is_weak, !ext->ksym.type_id, BTF_KIND_VAR, relo->insn_idx); break; case RELO_EXTERN_FUNC: - bpf_gen__record_extern(obj->gen_loader, ext->name, ext->is_weak, - BTF_KIND_FUNC, relo->insn_idx); + bpf_gen__record_extern(obj->gen_loader, ext->name, + ext->is_weak, false, BTF_KIND_FUNC, + relo->insn_idx); break; default: continue; |