To support epoll, a new instance of file_operations, bpf_link_fops_poll,
has been added for links that support epoll. The pid_iter.bpf.c checks
f_ops for links and other BPF objects. The check should fail for struct_ops
links without this patch.
Cc: Quentin Monnet <qmo@xxxxxxxxxx>
Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx>
---
tools/bpf/bpftool/skeleton/pid_iter.bpf.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
index 7bdbcac3cf62..948dde25034e 100644
--- a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
+++ b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
@@ -29,6 +29,7 @@ enum bpf_link_type___local {
};
extern const void bpf_link_fops __ksym;
+extern const void bpf_link_fops_poll __ksym __weak;
extern const void bpf_map_fops __ksym;
extern const void bpf_prog_fops __ksym;
extern const void btf_fops __ksym;
@@ -84,7 +85,11 @@ int iter(struct bpf_iter__task_file *ctx)
fops = &btf_fops;
break;
case BPF_OBJ_LINK:
- fops = &bpf_link_fops;
+ if (&bpf_link_fops_poll &&
+ file->f_op == &bpf_link_fops_poll)
+ fops = &bpf_link_fops_poll;
+ else
+ fops = &bpf_link_fops;
break;
default:
return 0;
--
2.34.1
