From 705fa2190dfb3d02f83adcd1abdb4e7dc3434597 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 13 Jul 2016 10:44:02 +0000 Subject: tools lib bpf: Report error when kernel doesn't support program type Now libbpf support tracepoint program type. Report meaningful error when kernel version is less than 4.7. Signed-off-by: Wang Nan Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1468406646-21642-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/libbpf.c | 27 ++++++++++++++++++++------- tools/lib/bpf/libbpf.h | 1 + 2 files changed, 21 insertions(+), 7 deletions(-) (limited to 'tools/lib/bpf') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4751936831d7..32e6b6bc6f7d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -90,6 +90,7 @@ static const char *libbpf_strerror_table[NR_ERRNO] = { [ERRCODE_OFFSET(VERIFY)] = "Kernel verifier blocks program loading", [ERRCODE_OFFSET(PROG2BIG)] = "Program too big", [ERRCODE_OFFSET(KVER)] = "Incorrect kernel version", + [ERRCODE_OFFSET(PROGTYPE)] = "Kernel doesn't support this program type", }; int libbpf_strerror(int err, char *buf, size_t size) @@ -926,15 +927,27 @@ load_program(enum bpf_prog_type type, struct bpf_insn *insns, pr_warning("-- BEGIN DUMP LOG ---\n"); pr_warning("\n%s\n", log_buf); pr_warning("-- END LOG --\n"); + } else if (insns_cnt >= BPF_MAXINSNS) { + pr_warning("Program too large (%d insns), at most %d insns\n", + insns_cnt, BPF_MAXINSNS); + ret = -LIBBPF_ERRNO__PROG2BIG; } else { - if (insns_cnt >= BPF_MAXINSNS) { - pr_warning("Program too large (%d insns), at most %d insns\n", - insns_cnt, BPF_MAXINSNS); - ret = -LIBBPF_ERRNO__PROG2BIG; - } else if (log_buf) { - pr_warning("log buffer is empty\n"); - ret = -LIBBPF_ERRNO__KVER; + /* Wrong program type? */ + if (type != BPF_PROG_TYPE_KPROBE) { + int fd; + + fd = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns, + insns_cnt, license, kern_version, + NULL, 0); + if (fd >= 0) { + close(fd); + ret = -LIBBPF_ERRNO__PROGTYPE; + goto out; + } } + + if (log_buf) + ret = -LIBBPF_ERRNO__KVER; } out: diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index eb2a4c45f6b6..dd7a513efb10 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -39,6 +39,7 @@ enum libbpf_errno { LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ LIBBPF_ERRNO__PROG2BIG, /* Program too big */ LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ + LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ __LIBBPF_ERRNO__END, }; -- cgit v1.2.3-59-g8ed1b