| Message ID | 20220204225823.339548-3-jolsa@kernel.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next,1/3] libbpf: Add names for auxiliary maps | expand |
On Fri, Feb 4, 2022 at 2:58 PM Jiri Olsa <jolsa@redhat.com> wrote: > > The commit e5043894b21f ("bpftool: Use libbpf_get_error() to check > error") forced map dump with pretty print enabled to has BTF loaded, > which is not necessarily needed. > > Keeping the libbpf_get_error call, but setting errno to 0 because > get_map_kv_btf does nothing for this case. > > This fixes test_offload.py for me, which failed because of the > pretty print fails with: > > Test map dump... > Traceback (most recent call last): > File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 1251, in <module> > _, entries = bpftool("map dump id %d" % (m["id"])) > File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 169, in bpftool > return tool("bpftool", args, {"json":"-p"}, JSON=JSON, ns=ns, > File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 155, in tool > ret, stdout = cmd(ns + name + " " + params + args, > File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 109, in cmd > return cmd_result(proc, include_stderr=include_stderr, fail=fail) > File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 131, in cmd_result > raise Exception("Command failed: %s\n%s" % (proc.args, stderr)) > Exception: Command failed: bpftool -p map dump id 4325 > > Fixes: e5043894b21f ("bpftool: Use libbpf_get_error() to check error") > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > tools/bpf/bpftool/map.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c > index c66a3c979b7a..2ccf85042e75 100644 > --- a/tools/bpf/bpftool/map.c > +++ b/tools/bpf/bpftool/map.c > @@ -862,6 +862,7 @@ map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr, > prev_key = NULL; > > if (wtr) { > + errno = 0; I don't think that's right. errno can be modified by something inside get_map_kv_btf() so this is unreliable approach. It's better to change get_map_kv_btf() to return an error explicitly and a btf pointer separate from error. Because btf == NULL isn't necessarily due to an error anymore. > btf = get_map_kv_btf(info); > err = libbpf_get_error(btf); > if (err) { > -- > 2.34.1 >
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index c66a3c979b7a..2ccf85042e75 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -862,6 +862,7 @@ map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr, prev_key = NULL; if (wtr) { + errno = 0; btf = get_map_kv_btf(info); err = libbpf_get_error(btf); if (err) {
The commit e5043894b21f ("bpftool: Use libbpf_get_error() to check error") forced map dump with pretty print enabled to has BTF loaded, which is not necessarily needed. Keeping the libbpf_get_error call, but setting errno to 0 because get_map_kv_btf does nothing for this case. This fixes test_offload.py for me, which failed because of the pretty print fails with: Test map dump... Traceback (most recent call last): File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 1251, in <module> _, entries = bpftool("map dump id %d" % (m["id"])) File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 169, in bpftool return tool("bpftool", args, {"json":"-p"}, JSON=JSON, ns=ns, File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 155, in tool ret, stdout = cmd(ns + name + " " + params + args, File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 109, in cmd return cmd_result(proc, include_stderr=include_stderr, fail=fail) File "/root/bpf-next/tools/testing/selftests/bpf/./test_offload.py", line 131, in cmd_result raise Exception("Command failed: %s\n%s" % (proc.args, stderr)) Exception: Command failed: bpftool -p map dump id 4325 Fixes: e5043894b21f ("bpftool: Use libbpf_get_error() to check error") Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- tools/bpf/bpftool/map.c | 1 + 1 file changed, 1 insertion(+)