| Message ID | 20210927205810.715656-1-toke@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next] libbpf: ignore STT_SECTION symbols in 'maps' section | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 1 maintainers not CCed: netdev@vger.kernel.org |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 17 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
| bpf/vmtest-bpf-next-PR | success | PR summary |
| bpf/vmtest-bpf-next | success | VM_Test |
On Mon, Sep 27, 2021 at 1:58 PM Toke Høiland-Jørgensen <toke@redhat.com> wrote: > > When parsing legacy map definitions, libbpf would error out when > encountering an STT_SECTION symbol. This becomes a problem because some > versions of binutils will produce SECTION symbols for every section when > processing an ELF file, so BPF files run through 'strip' will end up with > such symbols, making libbpf refuse to load them. > > There's not really any reason why erroring out is strictly necessary, so > change libbpf to just ignore SECTION symbols when parsing the ELF. > > Cc: Jiri Benc <jbenc@redhat.com> > Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> > --- Applied to bpf-next, thanks. [...]
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ef5db34bf913..453148fe8b4b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1869,6 +1869,8 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) continue; if (sym.st_shndx != obj->efile.maps_shndx) continue; + if (GELF_ST_TYPE(sym.st_info) == STT_SECTION) + continue; map = bpf_object__add_map(obj); if (IS_ERR(map)) @@ -1881,8 +1883,7 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) return -LIBBPF_ERRNO__FORMAT; } - if (GELF_ST_TYPE(sym.st_info) == STT_SECTION - || GELF_ST_BIND(sym.st_info) == STB_LOCAL) { + if (GELF_ST_BIND(sym.st_info) == STB_LOCAL) { pr_warn("map '%s' (legacy): static maps are not supported\n", map_name); return -ENOTSUP; }
When parsing legacy map definitions, libbpf would error out when encountering an STT_SECTION symbol. This becomes a problem because some versions of binutils will produce SECTION symbols for every section when processing an ELF file, so BPF files run through 'strip' will end up with such symbols, making libbpf refuse to load them. There's not really any reason why erroring out is strictly necessary, so change libbpf to just ignore SECTION symbols when parsing the ELF. Cc: Jiri Benc <jbenc@redhat.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> --- tools/lib/bpf/libbpf.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)