From: Jonathan Edwards jonathan.edwards@165gc.onmicrosoft.com
mainline inclusion from mainline-5.14-rc1 commit 5c10a3dbe9220ca7bcee716c13c8a8563bcb010a category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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eBPF has been backported for RHEL 7 w/ kernel 3.10-940+ [0]. However only the following program types are supported [1]:
BPF_PROG_TYPE_KPROBE BPF_PROG_TYPE_TRACEPOINT BPF_PROG_TYPE_PERF_EVENT
For libbpf this causes an EINVAL return during the bpf_object__probe_loading call which only checks to see if programs of type BPF_PROG_TYPE_SOCKET_FILTER can load.
The following will try BPF_PROG_TYPE_TRACEPOINT as a fallback attempt before erroring out. BPF_PROG_TYPE_KPROBE was not a good candidate because on some kernels it requires knowledge of the LINUX_VERSION_CODE.
[0] https://www.redhat.com/en/blog/introduction-ebpf-red-hat-enterprise-linux-7 [1] https://access.redhat.com/articles/3550581
Signed-off-by: Jonathan Edwards jonathan.edwards@165gc.onmicrosoft.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20210619151007.GA6963@165gc.onmicrosoft.com (cherry picked from commit 5c10a3dbe9220ca7bcee716c13c8a8563bcb010a) Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/lib/bpf/libbpf.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 64dd637af7db..176c06a51461 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4039,6 +4039,10 @@ bpf_object__probe_loading(struct bpf_object *obj) attr.license = "GPL";
ret = bpf_load_program_xattr(&attr, NULL, 0); + if (ret < 0) { + attr.prog_type = BPF_PROG_TYPE_TRACEPOINT; + ret = bpf_load_program_xattr(&attr, NULL, 0); + } if (ret < 0) { ret = errno; cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));