bpf: support raw tracepoints in modules

Distributions build drivers as modules, including network and filesystem
drivers which export numerous tracepoints.  This enables
bpf(BPF_RAW_TRACEPOINT_OPEN) to attach to those tracepoints.

Signed-off-by: Matt Mullins <mmullins@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 5db31067d85e..0607db304def 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1604,6 +1604,7 @@ static int bpf_raw_tracepoint_release(struct inode *inode, struct file *filp)
                 bpf_probe_unregister(raw_tp->btp, raw_tp->prog);
                 bpf_prog_put(raw_tp->prog);
         }
+        bpf_put_raw_tracepoint(raw_tp->btp);
         kfree(raw_tp);
         return 0;
 }
@@ -1629,13 +1630,15 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
                 return -EFAULT;
         tp_name[sizeof(tp_name) - 1] = 0;
 
-        btp = bpf_find_raw_tracepoint(tp_name);
+        btp = bpf_get_raw_tracepoint(tp_name);
         if (!btp)
                 return -ENOENT;
 
         raw_tp = kzalloc(sizeof(*raw_tp), GFP_USER);
-        if (!raw_tp)
-                return -ENOMEM;
+        if (!raw_tp) {
+                err = -ENOMEM;
+                goto out_put_btp;
+        }
         raw_tp->btp = btp;
 
         prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd,
@@ -1663,6 +1666,8 @@ out_put_prog:
         bpf_prog_put(prog);
 out_free_tp:
         kfree(raw_tp);
+out_put_btp:
+        bpf_put_raw_tracepoint(btp);
         return err;
 }