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
;
80 static void print_syscalls(int policy
, const char *json
)
85 set_syscall("rt_sigaction", 1);
86 set_syscall("sigreturn", 1);
87 set_syscall("rt_sigreturn", 1);
88 set_syscall("exit_group", 1);
89 set_syscall("exit", 1);
92 c
= blobmsg_open_array(&b
, "whitelist");
94 for (i
= 0; i
< ARRAY_SIZE(syscall_names
); i
++) {
95 if (!syscall_count
[i
])
97 if (syscall_names
[i
]) {
99 printf("syscall %d (%s) was called %d times\n",
100 i
, syscall_names
[i
], syscall_count
[i
]);
101 blobmsg_add_string(&b
, NULL
, syscall_names
[i
]);
103 ERROR("no name found for syscall(%d)\n", i
);
106 blobmsg_close_array(&b
, c
);
107 blobmsg_add_u32(&b
, "policy", policy
);
109 FILE *fp
= fopen(json
, "w");
111 fprintf(fp
, "%s", blobmsg_format_json_indent(b
.head
, true, 0));
113 INFO("saving syscall trace to %s\n", json
);
115 ERROR("failed to open %s\n", json
);
119 blobmsg_format_json_indent(b
.head
, true, 0));
124 static void tracer_cb(struct uloop_process
*c
, int ret
)
126 if (WIFSTOPPED(ret
) && WSTOPSIG(ret
) & 0x80) {
128 int syscall
= ptrace(PTRACE_PEEKUSER
, c
->pid
, reg_syscall_nr
);
130 if (syscall
< syscall_max
) {
131 syscall_count
[syscall
]++;
133 fprintf(stderr
, "%s()\n", syscall_names
[syscall
]);
135 fprintf(stderr
, "syscal(%d)\n", syscall
);
138 in_syscall
= !in_syscall
;
139 } else if (WIFEXITED(ret
)) {
143 ptrace(PTRACE_SYSCALL
, c
->pid
, 0, 0);
144 uloop_process_add(&tracer
);
147 int main(int argc
, char **argv
, char **envp
)
150 int status
, ch
, policy
= EPERM
;
153 while ((ch
= getopt(argc
, argv
, "f:p:")) != -1) {
159 policy
= atoi(optarg
);
170 if (getenv("TRACE_DEBUG"))
172 unsetenv("TRACE_DEBUG");
177 char **_argv
= calloc(argc
+ 1, sizeof(char *));
179 char preload
[] = "LD_PRELOAD=/lib/libpreload-trace.so";
183 memcpy(_argv
, argv
, argc
* sizeof(char *));
188 _envp
= calloc(envc
, sizeof(char *));
189 memcpy(&_envp
[1], _envp
, envc
* sizeof(char *));
192 ret
= execve(_argv
[0], _argv
, envp
);
193 ERROR("failed to exec %s: %s\n", _argv
[0], strerror(errno
));
200 syscall_max
= ARRAY_SIZE(syscall_names
);
201 syscall_count
= calloc(syscall_max
, sizeof(int));
202 waitpid(child
, &status
, 0);
203 if (!WIFSTOPPED(status
)) {
204 ERROR("failed to start %s\n", *argv
);
208 ptrace(PTRACE_SETOPTIONS
, child
, 0, PTRACE_O_TRACESYSGOOD
);
209 ptrace(PTRACE_SYSCALL
, child
, 0, 0);
213 tracer
.cb
= tracer_cb
;
214 uloop_process_add(&tracer
);
219 if (asprintf(&json
, "/tmp/%s.%u.json", basename(*argv
), child
) < 0)
220 ERROR("failed to allocate output path: %s\n", strerror(errno
));
222 print_syscalls(policy
, json
);