Messages in this thread Patch in this message | | | From | Wang Nan <> | Subject | [PATCH 05/31] perf ebpf: Add the libbpf glue | Date | Sat, 29 Aug 2015 04:21:39 +0000 |
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The 'bpf-loader.[ch]' files are introduced in this patch. Which will be the interface between perf and libbpf. bpf__prepare_load() resides in bpf-loader.c. Dummy functions should be used because bpf-loader.c is available only when CONFIG_LIBBPF is on.
Functions in bpf-loader.c should not report error explicitly. Instead, strerror style error reporting should be used.
Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: 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: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/n/1436445342-1402-19-git-send-email-wangnan0@huawei.com [ split from a larger patch ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/bpf-loader.c | 92 ++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/bpf-loader.h | 47 ++++++++++++++++++++++ 2 files changed, 139 insertions(+) create mode 100644 tools/perf/util/bpf-loader.c create mode 100644 tools/perf/util/bpf-loader.h
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c new file mode 100644 index 0000000..88531ea --- /dev/null +++ b/tools/perf/util/bpf-loader.c @@ -0,0 +1,92 @@ +/* + * bpf-loader.c + * + * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> + * Copyright (C) 2015 Huawei Inc. + */ + +#include <bpf/libbpf.h> +#include "perf.h" +#include "debug.h" +#include "bpf-loader.h" + +#define DEFINE_PRINT_FN(name, level) \ +static int libbpf_##name(const char *fmt, ...) \ +{ \ + va_list args; \ + int ret; \ + \ + va_start(args, fmt); \ + ret = veprintf(level, verbose, pr_fmt(fmt), args);\ + va_end(args); \ + return ret; \ +} + +DEFINE_PRINT_FN(warning, 0) +DEFINE_PRINT_FN(info, 0) +DEFINE_PRINT_FN(debug, 1) + +static bool libbpf_initialized; + +int bpf__prepare_load(const char *filename) +{ + struct bpf_object *obj; + + if (!libbpf_initialized) + libbpf_set_print(libbpf_warning, + libbpf_info, + libbpf_debug); + + obj = bpf_object__open(filename); + if (!obj) { + pr_debug("bpf: failed to load %s\n", filename); + return -EINVAL; + } + + /* + * Throw object pointer away: it will be retrived using + * bpf_objects iterater. + */ + + return 0; +} + +void bpf__clear(void) +{ + struct bpf_object *obj, *tmp; + + bpf_object__for_each_safe(obj, tmp) + bpf_object__close(obj); +} + +#define bpf__strerror_head(err, buf, size) \ + char sbuf[STRERR_BUFSIZE], *emsg;\ + if (!size)\ + return 0;\ + if (err < 0)\ + err = -err;\ + emsg = strerror_r(err, sbuf, sizeof(sbuf));\ + switch (err) {\ + default:\ + scnprintf(buf, size, "%s", emsg);\ + break; + +#define bpf__strerror_entry(val, fmt...)\ + case val: {\ + scnprintf(buf, size, fmt);\ + break;\ + } + +#define bpf__strerror_end(buf, size)\ + }\ + buf[size - 1] = '\0'; + +int bpf__strerror_prepare_load(const char *filename, int err, + char *buf, size_t size) +{ + bpf__strerror_head(err, buf, size); + bpf__strerror_entry(EINVAL, "%s: BPF object file '%s' is invalid", + emsg, filename) + bpf__strerror_end(buf, size); + return 0; +} diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h new file mode 100644 index 0000000..12be630 --- /dev/null +++ b/tools/perf/util/bpf-loader.h @@ -0,0 +1,47 @@ +/* + * Copyright (C) 2015, Wang Nan <wangnan0@huawei.com> + * Copyright (C) 2015, Huawei Inc. + */ +#ifndef __BPF_LOADER_H +#define __BPF_LOADER_H + +#include <linux/compiler.h> +#include <string.h> +#include "debug.h" + +#ifdef HAVE_LIBBPF_SUPPORT +int bpf__prepare_load(const char *filename); +int bpf__strerror_prepare_load(const char *filename, int err, + char *buf, size_t size); + +void bpf__clear(void); +#else +static inline int bpf__prepare_load(const char *filename __maybe_unused) +{ + pr_debug("ERROR: eBPF object loading is disabled during compiling.\n"); + return -1; +} + +static inline void bpf__clear(void) { } + +static inline int +__bpf_strerror(char *buf, size_t size) +{ + if (!size) + return 0; + strncpy(buf, + "ERROR: eBPF object loading is disabled during compiling.\n", + size); + buf[size - 1] = '\0'; + return 0; +} + +static inline int +bpf__strerror_prepare_load(const char *filename __maybe_unused, + int err __maybe_unused, + char *buf, size_t size) +{ + return __bpf_strerror(buf, size); +} +#endif +#endif -- 2.1.0
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