Kumar Kartikeya Dwivedi 3345193f6f tools/resolve_btfids: Skip unresolved symbol warning for empty BTF sets ... resolve_btfids prints a warning when it finds an unresolved symbol, (id == 0) in id_patch. This can be the case for BTF sets that are empty (due to disabled config options), hence printing warnings for certain builds, most recently seen in [0]. The reason behind this is because id->cnt aliases id->id in btf_id struct, leading to empty set showing up as ID 0 when we get to id_patch, which triggers the warning. Since sets are an exception here, accomodate by reusing hole in btf_id for bool is_set member, setting it to true for BTF set when setting id->cnt, and use that to skip extraneous warning. [0]: https://lore.kernel.org/all/1b99ae14-abb4-d18f-cc6a-d7e523b25542@gmail.com Before: ; ./tools/bpf/resolve_btfids/resolve_btfids -v -b vmlinux net/ipv4/tcp_cubic.ko adding symbol tcp_cubic_kfunc_ids WARN: resolve_btfids: unresolved symbol tcp_cubic_kfunc_ids patching addr 0: ID 0 [tcp_cubic_kfunc_ids] sorting addr 4: cnt 0 [tcp_cubic_kfunc_ids] update ok for net/ipv4/tcp_cubic.ko After: ; ./tools/bpf/resolve_btfids/resolve_btfids -v -b vmlinux net/ipv4/tcp_cubic.ko adding symbol tcp_cubic_kfunc_ids patching addr 0: ID 0 [tcp_cubic_kfunc_ids] sorting addr 4: cnt 0 [tcp_cubic_kfunc_ids] update ok for net/ipv4/tcp_cubic.ko Fixes: 0e32dfc80b ("bpf: Enable TCP congestion control kfunc from modules") Reported-by: Pavel Skripkin <paskripkin@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20211122144742.477787-4-memxor@gmail.com		2021-12-02 13:39:46 -08:00
..
bpftool	bpftool: Install libbpf headers for the bootstrap version, too	2021-11-05 16:19:48 +01:00
resolve_btfids	tools/resolve_btfids: Skip unresolved symbol warning for empty BTF sets	2021-12-02 13:39:46 -08:00
runqslower	tools/runqslower: Fix cross-build	2021-11-12 17:23:16 -08:00
.gitignore
bpf_asm.c
bpf_dbg.c
bpf_exp.l
bpf_exp.y
bpf_jit_disasm.c
Makefile