Currently bpftool contains a mix of GPL-only and GPL or BSD2
licensed files. Make sure all files are dual licensed under
GPLv2 and BSD-2-Clause.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Sean Young <sean@mess.org>
Acked-by: Jiri Benc <jbenc@redhat.com>
Acked-by: David Calavera <david.calavera@gmail.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Joe Stringer <joe@wand.net.nz>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Acked-by: Petar Penkov <ppenkov@stanford.edu>
Acked-by: Sandipan Das <sandipan@linux.ibm.com>
Acked-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
CC: okash.khawaja@gmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Commit b04df400c3 ("tools/bpftool: add perf subcommand")
introduced bpftool subcommand perf to query bpf program
kuprobe and tracepoint attachments.
The perf subcommand will first test whether bpf subcommand
BPF_TASK_FD_QUERY is supported in kernel or not. It does it
by opening a file with argv[0] and feeds the file descriptor
and current task pid to the kernel for querying.
Such an approach won't work if the argv[0] cannot be opened
successfully in the current directory. This is especially
true when bpftool is accessible through PATH env variable.
The error below reflects the open failure for file argv[0]
at home directory.
[yhs@localhost ~]$ which bpftool
/usr/local/sbin/bpftool
[yhs@localhost ~]$ bpftool perf
Error: perf_query_support: No such file or directory
To fix the issue, let us open root directory ("/")
which exists in every linux system. With the fix, the
error message will correctly reflect the permission issue.
[yhs@localhost ~]$ which bpftool
/usr/local/sbin/bpftool
[yhs@localhost ~]$ bpftool perf
Error: perf_query_support: Operation not permitted
HINT: non root or kernel doesn't support TASK_FD_QUERY
Fixes: b04df400c3 ("tools/bpftool: add perf subcommand")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>