1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2 // Copyright (c) 2022 Jingxiang Zeng
3 // Copyright (c) 2022 Krisztian Fekete
4 //
5 // Based on oomkill(8) from BCC by Brendan Gregg.
6 // 13-Jan-2022 Jingxiang Zeng Created this.
7 // 17-Oct-2022 Krisztian Fekete Edited this.
8 #include <argp.h>
9 #include <errno.h>
10 #include <signal.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <time.h>
15 #include <unistd.h>
16
17 #include <bpf/bpf.h>
18 #include <bpf/libbpf.h>
19 #include "oomkill.skel.h"
20 #include "compat.h"
21 #include "oomkill.h"
22 #include "btf_helpers.h"
23 #include "trace_helpers.h"
24
25 static volatile sig_atomic_t exiting = 0;
26
27 static bool verbose = false;
28
29 const char *argp_program_version = "oomkill 0.1";
30 const char *argp_program_bug_address =
31 "https://github.com/iovisor/bcc/tree/master/libbpf-tools";
32 const char argp_program_doc[] =
33 "Trace OOM kills.\n"
34 "\n"
35 "USAGE: oomkill [-h]\n"
36 "\n"
37 "EXAMPLES:\n"
38 " oomkill # trace OOM kills\n";
39
40 static const struct argp_option opts[] = {
41 { "verbose", 'v', NULL, 0, "Verbose debug output" },
42 { NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
43 {},
44 };
45
parse_arg(int key,char * arg,struct argp_state * state)46 static error_t parse_arg(int key, char *arg, struct argp_state *state)
47 {
48 switch (key) {
49 case 'v':
50 verbose = true;
51 break;
52 case 'h':
53 argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
54 break;
55 default:
56 return ARGP_ERR_UNKNOWN;
57 }
58 return 0;
59 }
60
handle_event(void * ctx,void * data,size_t len)61 static int handle_event(void *ctx, void *data, size_t len)
62 {
63 FILE *f;
64 char buf[256];
65 int n = 0;
66 struct tm *tm;
67 char ts[32];
68 time_t t;
69 struct data_t *e = data;
70
71 f = fopen("/proc/loadavg", "r");
72 if (f) {
73 memset(buf, 0, sizeof(buf));
74 n = fread(buf, 1, sizeof(buf), f);
75 fclose(f);
76 }
77 time(&t);
78 tm = localtime(&t);
79 strftime(ts, sizeof(ts), "%H:%M:%S", tm);
80
81 if (n)
82 printf("%s Triggered by PID %d (\"%s\"), OOM kill of PID %d (\"%s\"), %lld pages, loadavg: %s",
83 ts, e->fpid, e->fcomm, e->tpid, e->tcomm, e->pages, buf);
84 else
85 printf("%s Triggered by PID %d (\"%s\"), OOM kill of PID %d (\"%s\"), %lld pages\n",
86 ts, e->fpid, e->fcomm, e->tpid, e->tcomm, e->pages);
87
88 return 0;
89 }
90
handle_lost_events(void * ctx,int cpu,__u64 lost_cnt)91 static void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
92 {
93 printf("Lost %llu events on CPU #%d!\n", lost_cnt, cpu);
94 }
95
sig_int(int signo)96 static void sig_int(int signo)
97 {
98 exiting = 1;
99 }
100
libbpf_print_fn(enum libbpf_print_level level,const char * format,va_list args)101 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
102 {
103 if (level == LIBBPF_DEBUG && !verbose)
104 return 0;
105 return vfprintf(stderr, format, args);
106 }
107
main(int argc,char ** argv)108 int main(int argc, char **argv)
109 {
110 LIBBPF_OPTS(bpf_object_open_opts, open_opts);
111 static const struct argp argp = {
112 .options = opts,
113 .parser = parse_arg,
114 .doc = argp_program_doc,
115 };
116 struct bpf_buffer *buf = NULL;
117 struct oomkill_bpf *obj;
118 int err;
119
120 err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
121 if (err)
122 return err;
123
124 libbpf_set_print(libbpf_print_fn);
125
126 err = ensure_core_btf(&open_opts);
127 if (err) {
128 fprintf(stderr, "failed to fetch necessary BTF for CO-RE: %s\n", strerror(-err));
129 return 1;
130 }
131
132 obj = oomkill_bpf__open_opts(&open_opts);
133 if (!obj) {
134 fprintf(stderr, "failed to load and open BPF object\n");
135 return 1;
136 }
137
138 buf = bpf_buffer__new(obj->maps.events, obj->maps.heap);
139 if (!buf) {
140 err = -errno;
141 fprintf(stderr, "failed to create ring/perf buffer: %d\n", err);
142 goto cleanup;
143 }
144
145 err = oomkill_bpf__load(obj);
146 if (err) {
147 fprintf(stderr, "failed to load BPF object: %d\n", err);
148 goto cleanup;
149 }
150
151 err = oomkill_bpf__attach(obj);
152 if (err) {
153 fprintf(stderr, "failed to attach BPF programs\n");
154 goto cleanup;
155 }
156
157 err = bpf_buffer__open(buf, handle_event, handle_lost_events, NULL);
158 if (err) {
159 fprintf(stderr, "failed to open ring/perf buffer: %d\n", err);
160 goto cleanup;
161 }
162
163 if (signal(SIGINT, sig_int) == SIG_ERR) {
164 fprintf(stderr, "can't set signal handler: %d\n", err);
165 err = 1;
166 goto cleanup;
167 }
168
169 printf("Tracing OOM kills... Ctrl-C to stop.\n");
170
171 while (!exiting) {
172 err = bpf_buffer__poll(buf, POLL_TIMEOUT_MS);
173 if (err < 0 && err != -EINTR) {
174 fprintf(stderr, "error polling ring/perf buffer: %d\n", err);
175 goto cleanup;
176 }
177 /* reset err to return 0 if exiting */
178 err = 0;
179 }
180
181 cleanup:
182 bpf_buffer__free(buf);
183 oomkill_bpf__destroy(obj);
184 cleanup_core_btf(&open_opts);
185
186 return err != 0;
187 }
188