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>
19 #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)
46 #error tracing is not supported on this architecture
49 #define INFO(fmt, ...) do { \
50 fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
53 #define ERROR(fmt, ...) do { \
54 syslog(0, "utrace: "fmt, ## __VA_ARGS__); \
55 fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
58 static struct uloop_process tracer
;
59 static int *syscall_count
;
60 static struct blob_buf b
;
61 static int syscall_max
;
62 static int in_syscall
;
65 static int max_syscall
= ARRAY_SIZE(syscall_names
);
67 static void set_syscall(const char *name
, int val
)
71 for (i
= 0; i
< max_syscall
; i
++)
72 if (syscall_names
[i
] && !strcmp(syscall_names
[i
], name
)) {
73 syscall_count
[i
] = val
;
78 static void print_syscalls(int policy
, const char *json
)
83 set_syscall("rt_sigaction", 1);
84 set_syscall("sigreturn", 1);
85 set_syscall("rt_sigreturn", 1);
86 set_syscall("exit_group", 1);
87 set_syscall("exit", 1);
90 c
= blobmsg_open_array(&b
, "whitelist");
92 for (i
= 0; i
< ARRAY_SIZE(syscall_names
); i
++) {
93 if (!syscall_count
[i
])
95 if (syscall_names
[i
]) {
97 printf("syscall %d (%s) was called %d times\n",
98 i
, syscall_names
[i
], syscall_count
[i
]);
99 blobmsg_add_string(&b
, NULL
, syscall_names
[i
]);
101 ERROR("no name found for syscall(%d)\n", i
);
104 blobmsg_close_array(&b
, c
);
105 blobmsg_add_u32(&b
, "policy", policy
);
107 FILE *fp
= fopen(json
, "w");
109 fprintf(fp
, "%s", blobmsg_format_json_indent(b
.head
, true, 0));
111 INFO("saving syscall trace to %s\n", json
);
113 ERROR("failed to open %s\n", json
);
117 blobmsg_format_json_indent(b
.head
, true, 0));
122 static void tracer_cb(struct uloop_process
*c
, int ret
)
124 if (WIFSTOPPED(ret
) && WSTOPSIG(ret
) & 0x80) {
126 int syscall
= ptrace(PTRACE_PEEKUSER
, c
->pid
, reg_syscall_nr
);
128 if (syscall
< syscall_max
) {
129 syscall_count
[syscall
]++;
131 fprintf(stderr
, "%s()\n", syscall_names
[syscall
]);
133 fprintf(stderr
, "syscal(%d)\n", syscall
);
136 in_syscall
= !in_syscall
;
137 } else if (WIFEXITED(ret
)) {
141 ptrace(PTRACE_SYSCALL
, c
->pid
, 0, 0);
142 uloop_process_add(&tracer
);
145 int main(int argc
, char **argv
, char **envp
)
148 int status
, ch
, policy
= EPERM
;
151 while ((ch
= getopt(argc
, argv
, "f:p:")) != -1) {
157 policy
= atoi(optarg
);
168 if (getenv("TRACE_DEBUG"))
170 unsetenv("TRACE_DEBUG");
175 char **_argv
= calloc(argc
+ 1, sizeof(char *));
177 char preload
[] = "LD_PRELOAD=/lib/libpreload-trace.so";
181 memcpy(_argv
, argv
, argc
* sizeof(char *));
186 _envp
= calloc(envc
, sizeof(char *));
187 memcpy(&_envp
[1], _envp
, envc
* sizeof(char *));
190 ret
= execve(_argv
[0], _argv
, envp
);
191 ERROR("failed to exec %s: %s\n", _argv
[0], strerror(errno
));
198 syscall_max
= ARRAY_SIZE(syscall_names
);
199 syscall_count
= calloc(syscall_max
, sizeof(int));
200 waitpid(child
, &status
, 0);
201 if (!WIFSTOPPED(status
)) {
202 ERROR("failed to start %s\n", *argv
);
206 ptrace(PTRACE_SETOPTIONS
, child
, 0, PTRACE_O_TRACESYSGOOD
);
207 ptrace(PTRACE_SYSCALL
, child
, 0, 0);
211 tracer
.cb
= tracer_cb
;
212 uloop_process_add(&tracer
);
217 if (asprintf(&json
, "/tmp/%s.%u.json", basename(*argv
), child
) < 0)
218 ERROR("failed to allocate output path: %s\n", strerror(errno
));
220 print_syscalls(policy
, json
);