diff options
author | Yonghong Song <yhs@fb.com> | 2018-05-24 21:21:58 +0300 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2018-05-25 04:18:20 +0300 |
commit | b04df400c30235fa347313c9e2a0695549bd2c8e (patch) | |
tree | de94bbbf01500ee35347b4351c2934e88ae710e5 /tools/bpf/bpftool/perf.c | |
parent | f699cf7aa41f7b5a48316c0d21b76861b45e46e8 (diff) | |
download | linux-b04df400c30235fa347313c9e2a0695549bd2c8e.tar.xz |
tools/bpftool: add perf subcommand
The new command "bpftool perf [show | list]" will traverse
all processes under /proc, and if any fd is associated
with a perf event, it will print out related perf event
information. Documentation is also added.
Below is an example to show the results using bcc commands.
Running the following 4 bcc commands:
kprobe: trace.py '__x64_sys_nanosleep'
kretprobe: trace.py 'r::__x64_sys_nanosleep'
tracepoint: trace.py 't:syscalls:sys_enter_nanosleep'
uprobe: trace.py 'p:/home/yhs/a.out:main'
The bpftool command line and result:
$ bpftool perf
pid 21711 fd 5: prog_id 5 kprobe func __x64_sys_write offset 0
pid 21765 fd 5: prog_id 7 kretprobe func __x64_sys_nanosleep offset 0
pid 21767 fd 5: prog_id 8 tracepoint sys_enter_nanosleep
pid 21800 fd 5: prog_id 9 uprobe filename /home/yhs/a.out offset 1159
$ bpftool -j perf
[{"pid":21711,"fd":5,"prog_id":5,"fd_type":"kprobe","func":"__x64_sys_write","offset":0}, \
{"pid":21765,"fd":5,"prog_id":7,"fd_type":"kretprobe","func":"__x64_sys_nanosleep","offset":0}, \
{"pid":21767,"fd":5,"prog_id":8,"fd_type":"tracepoint","tracepoint":"sys_enter_nanosleep"}, \
{"pid":21800,"fd":5,"prog_id":9,"fd_type":"uprobe","filename":"/home/yhs/a.out","offset":1159}]
$ bpftool prog
5: kprobe name probe___x64_sys tag e495a0c82f2c7a8d gpl
loaded_at 2018-05-15T04:46:37-0700 uid 0
xlated 200B not jited memlock 4096B map_ids 4
7: kprobe name probe___x64_sys tag f2fdee479a503abf gpl
loaded_at 2018-05-15T04:48:32-0700 uid 0
xlated 200B not jited memlock 4096B map_ids 7
8: tracepoint name tracepoint__sys tag 5390badef2395fcf gpl
loaded_at 2018-05-15T04:48:48-0700 uid 0
xlated 200B not jited memlock 4096B map_ids 8
9: kprobe name probe_main_1 tag 0a87bdc2e2953b6d gpl
loaded_at 2018-05-15T04:49:52-0700 uid 0
xlated 200B not jited memlock 4096B map_ids 9
$ ps ax | grep "python ./trace.py"
21711 pts/0 T 0:03 python ./trace.py __x64_sys_write
21765 pts/0 S+ 0:00 python ./trace.py r::__x64_sys_nanosleep
21767 pts/2 S+ 0:00 python ./trace.py t:syscalls:sys_enter_nanosleep
21800 pts/3 S+ 0:00 python ./trace.py p:/home/yhs/a.out:main
22374 pts/1 S+ 0:00 grep --color=auto python ./trace.py
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/bpf/bpftool/perf.c')
-rw-r--r-- | tools/bpf/bpftool/perf.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/perf.c b/tools/bpf/bpftool/perf.c new file mode 100644 index 000000000000..ac6b1a12c9b7 --- /dev/null +++ b/tools/bpf/bpftool/perf.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright (C) 2018 Facebook +// Author: Yonghong Song <yhs@fb.com> + +#define _GNU_SOURCE +#include <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#include <ftw.h> + +#include <bpf.h> + +#include "main.h" + +/* 0: undecided, 1: supported, 2: not supported */ +static int perf_query_supported; +static bool has_perf_query_support(void) +{ + __u64 probe_offset, probe_addr; + __u32 len, prog_id, fd_type; + char buf[256]; + int fd; + + if (perf_query_supported) + goto out; + + fd = open(bin_name, O_RDONLY); + if (fd < 0) { + p_err("perf_query_support: %s", strerror(errno)); + goto out; + } + + /* the following query will fail as no bpf attachment, + * the expected errno is ENOTSUPP + */ + errno = 0; + len = sizeof(buf); + bpf_task_fd_query(getpid(), fd, 0, buf, &len, &prog_id, + &fd_type, &probe_offset, &probe_addr); + + if (errno == 524 /* ENOTSUPP */) { + perf_query_supported = 1; + goto close_fd; + } + + perf_query_supported = 2; + p_err("perf_query_support: %s", strerror(errno)); + fprintf(stderr, + "HINT: non root or kernel doesn't support TASK_FD_QUERY\n"); + +close_fd: + close(fd); +out: + return perf_query_supported == 1; +} + +static void print_perf_json(int pid, int fd, __u32 prog_id, __u32 fd_type, + char *buf, __u64 probe_offset, __u64 probe_addr) +{ + jsonw_start_object(json_wtr); + jsonw_int_field(json_wtr, "pid", pid); + jsonw_int_field(json_wtr, "fd", fd); + jsonw_uint_field(json_wtr, "prog_id", prog_id); + switch (fd_type) { + case BPF_FD_TYPE_RAW_TRACEPOINT: + jsonw_string_field(json_wtr, "fd_type", "raw_tracepoint"); + jsonw_string_field(json_wtr, "tracepoint", buf); + break; + case BPF_FD_TYPE_TRACEPOINT: + jsonw_string_field(json_wtr, "fd_type", "tracepoint"); + jsonw_string_field(json_wtr, "tracepoint", buf); + break; + case BPF_FD_TYPE_KPROBE: + jsonw_string_field(json_wtr, "fd_type", "kprobe"); + if (buf[0] != '\0') { + jsonw_string_field(json_wtr, "func", buf); + jsonw_lluint_field(json_wtr, "offset", probe_offset); + } else { + jsonw_lluint_field(json_wtr, "addr", probe_addr); + } + break; + case BPF_FD_TYPE_KRETPROBE: + jsonw_string_field(json_wtr, "fd_type", "kretprobe"); + if (buf[0] != '\0') { + jsonw_string_field(json_wtr, "func", buf); + jsonw_lluint_field(json_wtr, "offset", probe_offset); + } else { + jsonw_lluint_field(json_wtr, "addr", probe_addr); + } + break; + case BPF_FD_TYPE_UPROBE: + jsonw_string_field(json_wtr, "fd_type", "uprobe"); + jsonw_string_field(json_wtr, "filename", buf); + jsonw_lluint_field(json_wtr, "offset", probe_offset); + break; + case BPF_FD_TYPE_URETPROBE: + jsonw_string_field(json_wtr, "fd_type", "uretprobe"); + jsonw_string_field(json_wtr, "filename", buf); + jsonw_lluint_field(json_wtr, "offset", probe_offset); + break; + } + jsonw_end_object(json_wtr); +} + +static void print_perf_plain(int pid, int fd, __u32 prog_id, __u32 fd_type, + char *buf, __u64 probe_offset, __u64 probe_addr) +{ + printf("pid %d fd %d: prog_id %u ", pid, fd, prog_id); + switch (fd_type) { + case BPF_FD_TYPE_RAW_TRACEPOINT: + printf("raw_tracepoint %s\n", buf); + break; + case BPF_FD_TYPE_TRACEPOINT: + printf("tracepoint %s\n", buf); + break; + case BPF_FD_TYPE_KPROBE: + if (buf[0] != '\0') + printf("kprobe func %s offset %llu\n", buf, + probe_offset); + else + printf("kprobe addr %llu\n", probe_addr); + break; + case BPF_FD_TYPE_KRETPROBE: + if (buf[0] != '\0') + printf("kretprobe func %s offset %llu\n", buf, + probe_offset); + else + printf("kretprobe addr %llu\n", probe_addr); + break; + case BPF_FD_TYPE_UPROBE: + printf("uprobe filename %s offset %llu\n", buf, probe_offset); + break; + case BPF_FD_TYPE_URETPROBE: + printf("uretprobe filename %s offset %llu\n", buf, + probe_offset); + break; + } +} + +static int show_proc(const char *fpath, const struct stat *sb, + int tflag, struct FTW *ftwbuf) +{ + __u64 probe_offset, probe_addr; + __u32 len, prog_id, fd_type; + int err, pid = 0, fd = 0; + const char *pch; + char buf[4096]; + + /* prefix always /proc */ + pch = fpath + 5; + if (*pch == '\0') + return 0; + + /* pid should be all numbers */ + pch++; + while (isdigit(*pch)) { + pid = pid * 10 + *pch - '0'; + pch++; + } + if (*pch == '\0') + return 0; + if (*pch != '/') + return FTW_SKIP_SUBTREE; + + /* check /proc/<pid>/fd directory */ + pch++; + if (strncmp(pch, "fd", 2)) + return FTW_SKIP_SUBTREE; + pch += 2; + if (*pch == '\0') + return 0; + if (*pch != '/') + return FTW_SKIP_SUBTREE; + + /* check /proc/<pid>/fd/<fd_num> */ + pch++; + while (isdigit(*pch)) { + fd = fd * 10 + *pch - '0'; + pch++; + } + if (*pch != '\0') + return FTW_SKIP_SUBTREE; + + /* query (pid, fd) for potential perf events */ + len = sizeof(buf); + err = bpf_task_fd_query(pid, fd, 0, buf, &len, &prog_id, &fd_type, + &probe_offset, &probe_addr); + if (err < 0) + return 0; + + if (json_output) + print_perf_json(pid, fd, prog_id, fd_type, buf, probe_offset, + probe_addr); + else + print_perf_plain(pid, fd, prog_id, fd_type, buf, probe_offset, + probe_addr); + + return 0; +} + +static int do_show(int argc, char **argv) +{ + int flags = FTW_ACTIONRETVAL | FTW_PHYS; + int err = 0, nopenfd = 16; + + if (!has_perf_query_support()) + return -1; + + if (json_output) + jsonw_start_array(json_wtr); + if (nftw("/proc", show_proc, nopenfd, flags) == -1) { + p_err("%s", strerror(errno)); + err = -1; + } + if (json_output) + jsonw_end_array(json_wtr); + + return err; +} + +static int do_help(int argc, char **argv) +{ + fprintf(stderr, + "Usage: %s %s { show | list | help }\n" + "", + bin_name, argv[-2]); + + return 0; +} + +static const struct cmd cmds[] = { + { "show", do_show }, + { "list", do_show }, + { "help", do_help }, + { 0 } +}; + +int do_perf(int argc, char **argv) +{ + return cmd_select(cmds, argc, argv, do_help); +} |