This patch utilizes bpf_object__load() provided by libbpf to load all
objects into kernel.
Committer notes:
Testing it:
When using an incorrect kernel version number, i.e., having this in your
eBPF proggie:
int _version __attribute__((section("version"), used)) = 0x40100;
For a 4.3.0-rc6+ kernel, say, this happens and needs checking at event
parsing time, to provide a better error report to the user:
# perf record --event /tmp/foo.o sleep 1
libbpf: load bpf program failed: Invalid argument
libbpf: -- BEGIN DUMP LOG ---
libbpf:
libbpf: -- END LOG --
libbpf: failed to load program 'fork=_do_fork'
libbpf: failed to load object '/tmp/foo.o'
event syntax error: '/tmp/foo.o'
\___ Invalid argument: Are you root and runing a CONFIG_BPF_SYSCALL kernel?
(add -v to see detail)
Run 'perf list' for a list of valid events
Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]
-e, --event <event> event selector. use 'perf list' to list available events
If we instead make it match, i.e. use 0x40300 on this v4.3.0-rc6+
kernel, the whole process goes thru:
# perf record --event /tmp/foo.o -a usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.202 MB perf.data ]
# perf evlist -v
/tmp/foo.o: type: 1, size: 112, config: 0x9, { sample_period,
sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD, disabled: 1,
inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, sample_id_all: 1,
exclude_guest: 1, mmap2: 1, comm_exec: 1
#
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1444826502-49291-6-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
71 lines
1.7 KiB
C
71 lines
1.7 KiB
C
/*
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* Copyright (C) 2015, Wang Nan <wangnan0@huawei.com>
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* Copyright (C) 2015, Huawei Inc.
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*/
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#ifndef __BPF_LOADER_H
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#define __BPF_LOADER_H
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#include <linux/compiler.h>
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#include <linux/err.h>
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#include <string.h>
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#include "debug.h"
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struct bpf_object;
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#define PERF_BPF_PROBE_GROUP "perf_bpf_probe"
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#ifdef HAVE_LIBBPF_SUPPORT
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struct bpf_object *bpf__prepare_load(const char *filename);
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void bpf__clear(void);
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int bpf__probe(struct bpf_object *obj);
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int bpf__unprobe(struct bpf_object *obj);
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int bpf__strerror_probe(struct bpf_object *obj, int err,
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char *buf, size_t size);
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int bpf__load(struct bpf_object *obj);
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int bpf__strerror_load(struct bpf_object *obj, int err,
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char *buf, size_t size);
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#else
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static inline struct bpf_object *
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bpf__prepare_load(const char *filename __maybe_unused)
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{
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pr_debug("ERROR: eBPF object loading is disabled during compiling.\n");
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return ERR_PTR(-ENOTSUP);
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}
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static inline void bpf__clear(void) { }
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static inline int bpf__probe(struct bpf_object *obj __maybe_unused) { return 0;}
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static inline int bpf__unprobe(struct bpf_object *obj __maybe_unused) { return 0;}
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static inline int bpf__load(struct bpf_object *obj __maybe_unused) { return 0; }
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static inline int
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__bpf_strerror(char *buf, size_t size)
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{
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if (!size)
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return 0;
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strncpy(buf,
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"ERROR: eBPF object loading is disabled during compiling.\n",
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size);
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buf[size - 1] = '\0';
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return 0;
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}
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static inline int
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bpf__strerror_probe(struct bpf_object *obj __maybe_unused,
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int err __maybe_unused,
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char *buf, size_t size)
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{
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return __bpf_strerror(buf, size);
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}
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static inline int bpf__strerror_load(struct bpf_object *obj __maybe_unused,
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int err __maybe_unused,
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char *buf, size_t size)
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{
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return __bpf_strerror(buf, size);
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}
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#endif
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#endif
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