tools/resolve_btfids: Warn when having multiple IDs for single type
The kernel image can contain multiple types (structs/unions)
with the same name. This causes distinct type hierarchies in
BTF data and makes resolve_btfids fail with error like:
BTFIDS vmlinux
FAILED unresolved symbol udp6_sock
as reported by Qais Yousef [1].
This change adds warning when multiple types of the same name
are detected:
BTFIDS vmlinux
WARN: multiple IDs found for 'file': 526, 113351 - using 526
WARN: multiple IDs found for 'sk_buff': 2744, 113958 - using 2744
We keep the lower ID for the given type instance and let the
build continue.
Also changing the 'nr' variable name to 'nr_types' to avoid confusion.
[1] https://lore.kernel.org/lkml/
20201229151352.6hzmjvu3qh6p2qgg@
e107158-lin/
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210105234219.970039-1-jolsa@kernel.org