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Commit 705fa219 authored by Wang Nan's avatar Wang Nan Committed by Arnaldo Carvalho de Melo
Browse files

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: default avatarWang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468406646-21642-3-git-send-email-wangnan0@huawei.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 5f44e4c8

tools/lib/bpf/libbpf.c

+20 −7
Original line number Diff line number Diff line
@@ -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) {

	} 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;

	} else {

		/* 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:

tools/lib/bpf/libbpf.h

+1 −0
Original line number Diff line number Diff line
@@ -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,

};