Commit Graph

3 Commits

Author SHA1 Message Date
Stanislav Fomichev
a8a1f7d09c libbpf: fix libbpf_print
With the recent print rework we now have the following problem:
pr_{warning,info,debug} expand to __pr which calls libbpf_print.
libbpf_print does va_start and calls __libbpf_pr with va_list argument.
In __base_pr we again do va_start. Because the next argument is a
va_list, we don't get correct pointer to the argument (and print noting
in my case, I don't know why it doesn't crash tbh).

Fix this by changing libbpf_print_fn_t signature to accept va_list and
remove unneeded calls to va_start in the existing users.

Alternatively, this can we solved by exporting __libbpf_pr and
changing __pr macro to (and killing libbpf_print):
{
	if (__libbpf_pr)
		__libbpf_pr(level, "libbpf: " fmt, ##__VA_ARGS__)
}

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-02-04 17:45:31 -08:00
Yonghong Song
6f1ae8b662 tools/bpf: simplify libbpf API function libbpf_set_print()
Currently, the libbpf API function libbpf_set_print()
takes three function pointer parameters for warning, info
and debug printout respectively.

This patch changes the API to have just one function pointer
parameter and the function pointer has one additional
parameter "debugging level". So if in the future, if
the debug level is increased, the function signature
won't change.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-02-04 09:40:59 -08:00
Jesper Dangaard Brouer
864db336c6 selftests/bpf: add test program for loading BPF ELF files
V2: Moved program into selftests/bpf from tools/libbpf

This program can be used on its own for testing/debugging if a
BPF ELF-object file can be loaded with libbpf (from tools/lib/bpf).

If something is wrong with the ELF object, the program have
a --debug mode that will display the ELF sections and especially
the skipped sections.  This allows for quickly identifying the
problematic ELF section number, which can be corrolated with the
readelf tool.

The program signal error via return codes, and also have
a --quiet mode, which is practical for use in scripts like
selftests/bpf.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-09 00:24:38 +01:00