find_local_syms: 175: find_local_syms for af_packet.c: couldn't find in vmlinux symbol table

[disaster123]

While using kpatch-build 0.9.1 and building the following patch:

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 1d63ab3a8..f9e5fa9ba 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1999,6 +1999,54 @@ out_free:
        return err;
 }

+
+#define BPF_PROG_RUN2(prog, ctx)       ({                              \
+       u32 ret;                                                \
+       cant_sleep();                                           \
+       if (static_key_enabled(&bpf_stats_enabled_key)) {       \
+               struct bpf_prog_stats *stats;                   \
+               u64 start = sched_clock();                      \
+               ret = (*(prog)->bpf_func)(ctx, (prog)->insnsi); \
+               stats = this_cpu_ptr(prog->aux->stats);         \
+               u64_stats_update_begin(&stats->syncp);          \
+               stats->cnt++;                                   \
+               stats->nsecs += sched_clock() - start;          \
+               u64_stats_update_end(&stats->syncp);            \
+       } else {                                                \
+               ret = (*(prog)->bpf_func)(ctx, (prog)->insnsi); \
+       }                                                       \
+       ret; })
+
+static inline u32 bpf_prog_run_clear_cb2(const struct bpf_prog *prog,
+                                        struct sk_buff *skb)
+{
+        u8 *cb_data = bpf_skb_cb(skb);
+        u32 res; 
+
+        if (unlikely(prog->cb_access))
+                memset(cb_data, 0, BPF_SKB_CB_LEN);
+
+        preempt_disable();
+        res = BPF_PROG_RUN2(prog, skb);
+        preempt_enable();
+        return res; 
+}
+
+static unsigned int run_filter2(struct sk_buff *skb,
+                              const struct sock *sk,
+                              unsigned int res)
+{
+       struct sk_filter *filter;
+
+       rcu_read_lock();
+       filter = rcu_dereference(sk->sk_filter);
+       if (filter != NULL)
+               res = bpf_prog_run_clear_cb2(filter->prog, skb);
+       rcu_read_unlock();
+
+       return res;
+}
+
 static unsigned int run_filter(struct sk_buff *skb,
                               const struct sock *sk,
                               unsigned int res)
@@ -2167,7 +2215,8 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
        int skb_len = skb->len;
        unsigned int snaplen, res;
        unsigned long status = TP_STATUS_USER;
-       unsigned short macoff, netoff, hdrlen;
+       unsigned short macoff, hdrlen;
+       unsigned int netoff;
        struct sk_buff *copy_skb = NULL;
        struct timespec ts;
        __u32 ts_status;
@@ -2202,7 +2251,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,

        snaplen = skb->len;

-       res = run_filter(skb, sk, snaplen);
+       res = run_filter2(skb, sk, snaplen);
        if (!res)
                goto drop_n_restore;

@@ -2236,6 +2285,10 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
                }
                macoff = netoff - maclen;
        }
+       if (netoff > USHRT_MAX) {
+               atomic_inc(&po->tp_drops);
+               goto drop_n_restore;
+       }
        if (po->tp_version <= TPACKET_V2) {
                if (macoff + snaplen > po->rx_ring.frame_size) {
                        if (po->copy_thresh &&

against 5.4.48 - kpatch-build fails with:

Extracting new and modified ELF sections
af_packet.o: changed function: tpacket_rcv
/usr/lib/kpatch/create-diff-object: ERROR: af_packet.o: find_local_syms: 175: find_local_syms for af_packet.c: couldn't find in vmlinux symbol table

[disaster123]

OK this is solved by upcoming 0.9.2

[msupinodn]

This still doesnt work, with 0.9.2 and 0.9.3, on ubuntu 18, same error, almost same patch, any idea why ?