[DTrace-devel] [PATCH 1/5] udp: new provider

[Eugene Loh]

On 8/28/25 13:56, Eugene Loh wrote:

> Anyhow, testing x86 and arm for OL8/UEK6 OL8/UEK7 OL9/UEK7 OL9/UEK8 
> OL10/UEK8, I get
>     test/unittest/udp/tst.ipv6localudp.sh: FAIL: expected results differ.
> for
>     x86/OL8/UEK7
>     x86/OL9/UEK7
>     x86/OL9/UEK8
>     x86/OL10/UEK8
>     arm/OL10/UEK8
> If you like, I can investigate more or report more details.  I just 
> didn't want to dive in too deep without checking in with you first.

I took a quick and sloppy look at this.  I looked at only one VM. The 
failure was:

     test/unittest/udp/tst.ipv6localudp.sh
     Diff against expected:
      Minimum UDP events seen

     -ip:::send - yes
     +ip:::send - no
     -ip:::receive - yes
     +ip:::receive - no
     -udp:::send - yes
     +udp:::send - no
      udp:::receive - yes

I tried:

     diff --git a/libdtrace/dt_prov_udp.c b/libdtrace/dt_prov_udp.c
     @@ -31,7 +31,7 @@ static probe_dep_t probes[] = {
              { "send",
                DTRACE_PROBESPEC_NAME,   "fbt::ip_send_skb:entry" },
              { "send",
     -          DTRACE_PROBESPEC_NAME,   "fbt::ip6_send_skb:entry" },
     +          DTRACE_PROBESPEC_NAME,   "rawfbt::ip6_send_skb:entry" },
              { NULL, }
      };

     diff --git a/libdtrace/dt_prov_ip.c b/libdtrace/dt_prov_ip.c
     @@ -21,11 +21,11 @@ static probe_dep_t probes[] = {
              { "receive",
                DTRACE_PROBESPEC_NAME, "fbt::ip_local_deliver:entry" },
              { "receive",
     -          DTRACE_PROBESPEC_NAME,   "fbt::ip6_input:entry" },
     +          DTRACE_PROBESPEC_NAME,   "rawfbt::ip6_input:entry" },
              { "send",
                DTRACE_PROBESPEC_NAME, "fbt::ip_finish_output:entry" },
              { "send",
     -          DTRACE_PROBESPEC_NAME, "fbt::ip6_finish_output:entry" },
     +          DTRACE_PROBESPEC_NAME, "rawfbt::ip6_finish_output:entry" },
              { NULL, }
      };

(The last change is also in another patch I recently posted and you 
R-b.)  With these changes on that VM, the test passes.

The whole thing suggests to me that we need a better audit of such 
issues, better understanding, and more/better tests.