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) WARN: multiple IDs found for 'sk_buff' (2744, 113958) We keep the lower ID for the given type instance and let the build continue. [1] https://lore.kernel.org/lkml/20201229151352.6hzmjvu3qh6p2qgg@e107158-lin/ Reported-by: Qais Yousef <[email protected]> Signed-off-by: Jiri Olsa <[email protected]> --- tools/bpf/resolve_btfids/main.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c index e3ea569ee125..36a3b1024cdc 100644 --- a/tools/bpf/resolve_btfids/main.c +++ b/tools/bpf/resolve_btfids/main.c @@ -139,6 +139,8 @@ int eprintf(int level, int var, const char *fmt, ...) #define pr_debug2(fmt, ...) pr_debugN(2, pr_fmt(fmt), ##__VA_ARGS__) #define pr_err(fmt, ...) \ eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__) +#define pr_info(fmt, ...) \ + eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__) static bool is_btf_id(const char *name) { @@ -526,8 +528,13 @@ static int symbols_resolve(struct object *obj) id = btf_id__find(root, str); if (id) { - id->id = type_id; - (*nr)--; + if (id->id) { + pr_info("WARN: multiple IDs found for '%s' (%d, %d)\n", + str, id->id, type_id); + } else { + id->id = type_id; + (*nr)--; + } } } -- 2.26.2
