------- Comment From [email protected] 2020-08-04 18:45 EDT-------
Hi,
I fixed the skydive header as follows:
--- a/ebpf/defs.h
+++ b/ebpf/defs.h
@@ -56,7 +56,7 @@ static __inline int discret_memcmp(char *s1, char *s2, int n)
/* helper marcro to define a map, socket, kprobe section in the
* eBPF elf file.
*/
-#define MAP(NAME) struct bpf_map_def __section("maps/" #NAME) NAME =
+#define MAP(NAME) struct bpf_map_def __section("maps") NAME =
#define SOCKET(NAME) __section("socket_" #NAME)
#define LICENSE __section("license")
and also tried to cherry-pick some of the older kernel patches I wrote, e.g.:
https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=88aa8939c96781089e5ace3492d818074c5c6fe9
https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=05a68e892e89c97df6650cd8cc55058002657cbc
https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=3f161e0ae863a0456d00e5a6c9c81098c62ab7fe
- the new ones I linked here fix samples and aren't relevant for skydive
- but then I found out that quite some common code is missing as well.
For example, on 20.04 LLVM 10 is default. It contains the following
commit:
commit fbb64aa69835c8e3e9efe0afc8a73058b5a0fb3c # llvmorg-10.0.0
Author: Yonghong Song <[email protected]>
Date: Tue Dec 17 16:24:23 2019 -0800
[BPF] extend BTF_KIND_FUNC to cover global, static and extern funcs
which makes clang produce non-backwards-compatible BTF. This leads to:
[14] FUNC bpf_flow_table type_id=12 vlen != 0
libbpf: Error loading .BTF into kernel: -22.
when loading. It's not that BPF devs did not think about this: in case
kernel cannot handle the new BTF_KIND_FUNC bits, they are supposed to be
sanitized by libbpf. However, Ubuntu 20.04 does not ship the newest
libbpf:
# /usr/sbin/bpftool --version
/usr/lib/linux-tools/5.4.0-42-generic/bpftool v5.4.44
whereas the commit that introduced sanitization is in v5.6:
commit 2d3eb67f64ec317bbfe340cfcc8325d40a6ff317 # v5.6
Author: Alexei Starovoitov <[email protected]>
Date: Thu Jan 9 22:41:19 2020 -0800
libbpf: Sanitize global functions
Since this now turns into quite an adventure w.r.t. backporting, can't
we try an easier path first? Namely: use clang-8, which is also
available in Ubuntu 20.04, but doesn't include any fancy stuff!
skydive# CLANG=clang-8 GOPATH=$HOME/go make -C ebpf
skydive# bpftool prog load ebpf/flow.o /sys/fs/bpf/flow ; echo $?
0
# bpftool prog load ebpf/flow-gre.o /sys/fs/bpf/flow-gre ; echo $?
0
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1888507
Title:
[UBUNTU 18.04] BPF programs fail on Ubuntu s390x
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu-z-systems/+bug/1888507/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
