When building bpftool with !CONFIG_PERF_EVENTS:
skeleton/pid_iter.bpf.c:47:14: error: incomplete definition of type 'struct bpf_perf_link'
perf_link = container_of(link, struct bpf_perf_link, link);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helpers.h:74:22: note: expanded from macro 'container_of'
((type *)(__mptr - offsetof(type, member))); \
^~~~~~~~~~~~~~~~~~~~~~
tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helpers.h:68:60: note: expanded from macro 'offsetof'
#define offsetof(TYPE, MEMBER) ((unsigned long)&((TYPE *)0)->MEMBER)
~~~~~~~~~~~^
skeleton/pid_iter.bpf.c:44:9: note: forward declaration of 'struct bpf_perf_link'
struct bpf_perf_link *perf_link;
^
&bpf_perf_link is being defined and used only under the ifdef.
Move it out of the block and explicitly emit a BTF to fix
compilation.
Fixes: cbdaf71f7e65 ("bpftool: Add bpf_cookie to link output")
Signed-off-by: Alexander Lobakin <alobakin@xxxxx>
---
kernel/bpf/syscall.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index e9621cfa09f2..34fdf27d14cf 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2952,12 +2952,12 @@ static const struct bpf_link_ops bpf_raw_tp_link_lops = {
.fill_link_info = bpf_raw_tp_link_fill_link_info,
};
-#ifdef CONFIG_PERF_EVENTS
struct bpf_perf_link {
struct bpf_link link;
struct file *perf_file;
};
+#ifdef CONFIG_PERF_EVENTS
static void bpf_perf_link_release(struct bpf_link *link)
{
struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
@@ -4333,6 +4333,7 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr)
#endif
case BPF_PROG_TYPE_PERF_EVENT:
case BPF_PROG_TYPE_TRACEPOINT:
+ BTF_TYPE_EMIT(struct bpf_perf_link);
ret = bpf_perf_link_attach(attr, prog);
break;
case BPF_PROG_TYPE_KPROBE:
--
2.35.2
