2 * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU Lesser General Public License version 2.1
6 * as published by the Free Software Foundation
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
16 #include <sys/ptrace.h>
17 #include <sys/types.h>
28 #include <libubox/uloop.h>
29 #include <libubox/blobmsg.h>
30 #include <libubox/blobmsg_json.h>
32 #include "../syscall-names.h"
34 #define _offsetof(a, b) __builtin_offsetof(a,b)
35 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
38 #define reg_syscall_nr _offsetof(struct user, regs.orig_rax)
39 #elif defined(__i386__)
40 #define reg_syscall_nr _offsetof(struct user, regs.orig_eax)
45 #define reg_syscall_nr (EF_REG2 / 4)
46 #elif defined(__arm__)
47 #define reg_syscall_nr _offsetof(struct user, regs.uregs[7])
49 #error tracing is not supported on this architecture
52 #define INFO(fmt, ...) do { \
53 fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
56 #define ERROR(fmt, ...) do { \
57 syslog(LOG_ERR, "utrace: "fmt, ## __VA_ARGS__); \
58 fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
61 static struct uloop_process tracer;
62 static int *syscall_count;
63 static struct blob_buf b;
64 static int syscall_max;
65 static int in_syscall;
68 static int max_syscall = ARRAY_SIZE(syscall_names);
70 static void set_syscall(const char *name, int val)
74 for (i = 0; i < max_syscall; i++)
75 if (syscall_names[i] && !strcmp(syscall_names[i], name)) {
76 syscall_count[i] = val;
81 static void print_syscalls(int policy, const char *json)
86 set_syscall("rt_sigaction", 1);
87 set_syscall("sigreturn", 1);
88 set_syscall("rt_sigreturn", 1);
89 set_syscall("exit_group", 1);
90 set_syscall("exit", 1);
93 c = blobmsg_open_array(&b, "whitelist");
95 for (i = 0; i < ARRAY_SIZE(syscall_names); i++) {
96 if (!syscall_count[i])
98 if (syscall_names[i]) {
100 printf("syscall %d (%s) was called %d times\n",
101 i, syscall_names[i], syscall_count[i]);
102 blobmsg_add_string(&b, NULL, syscall_names[i]);
104 ERROR("no name found for syscall(%d)\n", i);
107 blobmsg_close_array(&b, c);
108 blobmsg_add_u32(&b, "policy", policy);
110 FILE *fp = fopen(json, "w");
112 fprintf(fp, "%s", blobmsg_format_json_indent(b.head, true, 0));
114 INFO("saving syscall trace to %s\n", json);
116 ERROR("failed to open %s\n", json);
120 blobmsg_format_json_indent(b.head, true, 0));
125 static void tracer_cb(struct uloop_process *c, int ret)
127 if (WIFSTOPPED(ret) && WSTOPSIG(ret) & 0x80) {
129 int syscall = ptrace(PTRACE_PEEKUSER, c->pid, reg_syscall_nr);
131 if (syscall < syscall_max) {
132 syscall_count[syscall]++;
134 fprintf(stderr, "%s()\n", syscall_names[syscall]);
136 fprintf(stderr, "syscal(%d)\n", syscall);
139 in_syscall = !in_syscall;
140 } else if (WIFEXITED(ret)) {
144 ptrace(PTRACE_SYSCALL, c->pid, 0, 0);
145 uloop_process_add(&tracer);
148 int main(int argc, char **argv, char **envp)
151 int status, ch, policy = EPERM;
154 while ((ch = getopt(argc, argv, "f:p:")) != -1) {
160 policy = atoi(optarg);
171 if (getenv("TRACE_DEBUG"))
173 unsetenv("TRACE_DEBUG");
178 char **_argv = calloc(argc + 1, sizeof(char *));
180 char *preload = "LD_PRELOAD=/lib/libpreload-trace.so";
184 memcpy(_argv, argv, argc * sizeof(char *));
189 _envp = calloc(envc, sizeof(char *));
190 memcpy(&_envp[1], _envp, envc * sizeof(char *));
193 ret = execve(_argv[0], _argv, _envp);
194 ERROR("failed to exec %s: %s\n", _argv[0], strerror(errno));
204 syscall_max = ARRAY_SIZE(syscall_names);
205 syscall_count = calloc(syscall_max, sizeof(int));
206 waitpid(child, &status, 0);
207 if (!WIFSTOPPED(status)) {
208 ERROR("failed to start %s\n", *argv);
212 ptrace(PTRACE_SETOPTIONS, child, 0, PTRACE_O_TRACESYSGOOD);
213 ptrace(PTRACE_SYSCALL, child, 0, 0);
217 tracer.cb = tracer_cb;
218 uloop_process_add(&tracer);
223 if (asprintf(&json, "/tmp/%s.%u.json", basename(*argv), child) < 0)
224 ERROR("failed to allocate output path: %s\n", strerror(errno));
226 print_syscalls(policy, json);