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>
27 #include <libubox/uloop.h>
28 #include <libubox/blobmsg.h>
29 #include <libubox/blobmsg_json.h>
31 #include "../syscall-names.h"
33 #define _offsetof(a, b) __builtin_offsetof(a,b)
34 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
37 #define reg_syscall_nr _offsetof(struct user, regs.orig_rax)
38 #elif defined(__i386__)
39 #define reg_syscall_nr _offsetof(struct user, regs.orig_eax)
44 #define reg_syscall_nr (EF_REG2 / 4)
45 #elif defined(__arm__)
46 #define reg_syscall_nr _offsetof(struct user, regs.uregs[7])
48 #error tracing is not supported on this architecture
51 #define INFO(fmt, ...) do { \
52 fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
55 #define ERROR(fmt, ...) do { \
56 syslog(LOG_ERR, "utrace: "fmt, ## __VA_ARGS__); \
57 fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
60 static struct uloop_process tracer
;
61 static int *syscall_count
;
62 static struct blob_buf b
;
63 static int syscall_max
;
64 static int in_syscall
;
67 static int max_syscall
= ARRAY_SIZE(syscall_names
);
69 static void set_syscall(const char *name
, int val
)
73 for (i
= 0; i
< max_syscall
; i
++)
74 if (syscall_names
[i
] && !strcmp(syscall_names
[i
], name
)) {
75 syscall_count
[i
] = val
;
85 static int cmp_count(const void *a
, const void *b
)
87 return ((struct syscall
*)b
)->count
- ((struct syscall
*)a
)->count
;
90 static void print_syscalls(int policy
, const char *json
)
95 set_syscall("rt_sigaction", 1);
96 set_syscall("sigreturn", 1);
97 set_syscall("rt_sigreturn", 1);
98 set_syscall("exit_group", 1);
99 set_syscall("exit", 1);
101 struct syscall sorted
[ARRAY_SIZE(syscall_names
)];
103 for (i
= 0; i
< ARRAY_SIZE(syscall_names
); i
++) {
104 sorted
[i
].syscall
= i
;
105 sorted
[i
].count
= syscall_count
[i
];
108 qsort(sorted
, ARRAY_SIZE(syscall_names
), sizeof(sorted
[0]), cmp_count
);
110 blob_buf_init(&b
, 0);
111 c
= blobmsg_open_array(&b
, "whitelist");
113 for (i
= 0; i
< ARRAY_SIZE(syscall_names
); i
++) {
114 int sc
= sorted
[i
].syscall
;
115 if (!sorted
[i
].count
)
117 if (syscall_names
[sc
]) {
119 printf("syscall %d (%s) was called %d times\n",
120 sc
, syscall_names
[sc
], sorted
[i
].count
);
121 blobmsg_add_string(&b
, NULL
, syscall_names
[sc
]);
123 ERROR("no name found for syscall(%d)\n", sc
);
126 blobmsg_close_array(&b
, c
);
127 blobmsg_add_u32(&b
, "policy", policy
);
129 FILE *fp
= fopen(json
, "w");
131 fprintf(fp
, "%s", blobmsg_format_json_indent(b
.head
, true, 0));
133 INFO("saving syscall trace to %s\n", json
);
135 ERROR("failed to open %s\n", json
);
139 blobmsg_format_json_indent(b
.head
, true, 0));
144 static void tracer_cb(struct uloop_process
*c
, int ret
)
146 if (WIFSTOPPED(ret
) && WSTOPSIG(ret
) & 0x80) {
148 int syscall
= ptrace(PTRACE_PEEKUSER
, c
->pid
, reg_syscall_nr
);
150 if (syscall
< syscall_max
) {
151 syscall_count
[syscall
]++;
153 fprintf(stderr
, "%s()\n", syscall_names
[syscall
]);
155 fprintf(stderr
, "syscal(%d)\n", syscall
);
158 in_syscall
= !in_syscall
;
159 } else if (WIFEXITED(ret
)) {
163 ptrace(PTRACE_SYSCALL
, c
->pid
, 0, 0);
164 uloop_process_add(&tracer
);
167 int main(int argc
, char **argv
, char **envp
)
170 int status
, ch
, policy
= EPERM
;
173 while ((ch
= getopt(argc
, argv
, "f:p:")) != -1) {
179 policy
= atoi(optarg
);
190 if (getenv("TRACE_DEBUG"))
192 unsetenv("TRACE_DEBUG");
197 char **_argv
= calloc(argc
+ 1, sizeof(char *));
199 char *preload
= "LD_PRELOAD=/lib/libpreload-trace.so";
203 memcpy(_argv
, argv
, argc
* sizeof(char *));
208 _envp
= calloc(envc
+ 1, sizeof(char *));
209 memcpy(&_envp
[1], envp
, envc
* sizeof(char *));
212 ret
= execve(_argv
[0], _argv
, _envp
);
213 ERROR("failed to exec %s: %s\n", _argv
[0], strerror(errno
));
223 syscall_max
= ARRAY_SIZE(syscall_names
);
224 syscall_count
= calloc(syscall_max
, sizeof(int));
225 waitpid(child
, &status
, 0);
226 if (!WIFSTOPPED(status
)) {
227 ERROR("failed to start %s\n", *argv
);
231 ptrace(PTRACE_SETOPTIONS
, child
, 0, PTRACE_O_TRACESYSGOOD
);
232 ptrace(PTRACE_SYSCALL
, child
, 0, 0);
236 tracer
.cb
= tracer_cb
;
237 uloop_process_add(&tracer
);
242 if (asprintf(&json
, "/tmp/%s.%u.json", basename(*argv
), child
) < 0)
243 ERROR("failed to allocate output path: %s\n", strerror(errno
));
245 print_syscalls(policy
, json
);