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| author | Alexei Starovoitov <ast@kernel.org> | 2020-07-13 17:07:43 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-07-13 17:08:44 -0700 |
| commit | 8afb259a9840fa953efb9a7835356a083ac8ec74 (patch) | |
| tree | 79a7e9cabc285400476b921dbdaa4bba220fa46e /tools/lib | |
| parent | 207a573c04755d5ef83e89ee1b3e4941f000acbd (diff) | |
| parent | 0b20933d8cfe2bf6473e9b581b5d1ed9a2117ecc (diff) | |
Merge branch 'strip-mods-from-global-vars'
Andrii Nakryiko says:
====================
Fix bpftool logic of stripping away const/volatile modifiers for all global
variables during BPF skeleton generation. See patch #1 for details on when
existing logic breaks and why it's important. Support special .strip_mods=true
mode in btf_dump__emit_type_decl.
Recent example of when this has caused problems can be found in [0].
[0] https://github.com/iovisor/bcc/pull/2994#issuecomment-650588533
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/btf.h | 4 | ||||
| -rw-r--r-- | tools/lib/bpf/btf_dump.c | 10 |
2 files changed, 11 insertions, 3 deletions
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index a3b7ef9b737f..491c7b41ffdc 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -144,8 +144,10 @@ struct btf_dump_emit_type_decl_opts { * necessary indentation already */ int indent_level; + /* strip all the const/volatile/restrict mods */ + bool strip_mods; }; -#define btf_dump_emit_type_decl_opts__last_field indent_level +#define btf_dump_emit_type_decl_opts__last_field strip_mods LIBBPF_API int btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index bbb430317260..e1c344504cae 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -60,6 +60,7 @@ struct btf_dump { const struct btf_ext *btf_ext; btf_dump_printf_fn_t printf_fn; struct btf_dump_opts opts; + bool strip_mods; /* per-type auxiliary state */ struct btf_dump_type_aux_state *type_states; @@ -1032,7 +1033,9 @@ int btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, fname = OPTS_GET(opts, field_name, ""); lvl = OPTS_GET(opts, indent_level, 0); + d->strip_mods = OPTS_GET(opts, strip_mods, false); btf_dump_emit_type_decl(d, id, fname, lvl); + d->strip_mods = false; return 0; } @@ -1045,6 +1048,10 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id, stack_start = d->decl_stack_cnt; for (;;) { + t = btf__type_by_id(d->btf, id); + if (d->strip_mods && btf_is_mod(t)) + goto skip_mod; + err = btf_dump_push_decl_stack_id(d, id); if (err < 0) { /* @@ -1056,12 +1063,11 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id, d->decl_stack_cnt = stack_start; return; } - +skip_mod: /* VOID */ if (id == 0) break; - t = btf__type_by_id(d->btf, id); switch (btf_kind(t)) { case BTF_KIND_PTR: case BTF_KIND_VOLATILE: |