# define EF_REG2 8
# endif
#define reg_syscall_nr (EF_REG2 / 4)
+#elif defined(__arm__)
+#define reg_syscall_nr _offsetof(struct user, regs.uregs[7])
#else
#error tracing is not supported on this architecture
#endif
} while (0)
#define ERROR(fmt, ...) do { \
- syslog(0, "utrace: "fmt, ## __VA_ARGS__); \
+ syslog(LOG_ERR, "utrace: "fmt, ## __VA_ARGS__); \
fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
} while (0)
-static struct uloop_process tracer;
+struct tracee {
+ struct uloop_process proc;
+ int in_syscall;
+};
+
+static struct tracee tracer;
static int *syscall_count;
static struct blob_buf b;
static int syscall_max;
-static int in_syscall;
static int debug;
static int max_syscall = ARRAY_SIZE(syscall_names);
}
}
+struct syscall {
+ int syscall;
+ int count;
+};
+
+static int cmp_count(const void *a, const void *b)
+{
+ return ((struct syscall*)b)->count - ((struct syscall*)a)->count;
+}
+
static void print_syscalls(int policy, const char *json)
{
void *c;
set_syscall("exit_group", 1);
set_syscall("exit", 1);
+ struct syscall sorted[ARRAY_SIZE(syscall_names)];
+
+ for (i = 0; i < ARRAY_SIZE(syscall_names); i++) {
+ sorted[i].syscall = i;
+ sorted[i].count = syscall_count[i];
+ }
+
+ qsort(sorted, ARRAY_SIZE(syscall_names), sizeof(sorted[0]), cmp_count);
+
blob_buf_init(&b, 0);
c = blobmsg_open_array(&b, "whitelist");
for (i = 0; i < ARRAY_SIZE(syscall_names); i++) {
- if (!syscall_count[i])
- continue;
- if (syscall_names[i]) {
+ int sc = sorted[i].syscall;
+ if (!sorted[i].count)
+ break;
+ if (syscall_names[sc]) {
if (debug)
printf("syscall %d (%s) was called %d times\n",
- i, syscall_names[i], syscall_count[i]);
- blobmsg_add_string(&b, NULL, syscall_names[i]);
+ sc, syscall_names[sc], sorted[i].count);
+ blobmsg_add_string(&b, NULL, syscall_names[sc]);
} else {
- ERROR("no name found for syscall(%d)\n", i);
+ ERROR("no name found for syscall(%d)\n", sc);
}
}
blobmsg_close_array(&b, c);
static void tracer_cb(struct uloop_process *c, int ret)
{
- if (WIFSTOPPED(ret) && WSTOPSIG(ret) & 0x80) {
- if (!in_syscall) {
- int syscall = ptrace(PTRACE_PEEKUSER, c->pid, reg_syscall_nr);
-
- if (syscall < syscall_max) {
- syscall_count[syscall]++;
- if (debug)
- fprintf(stderr, "%s()\n", syscall_names[syscall]);
- } else if (debug) {
- fprintf(stderr, "syscal(%d)\n", syscall);
+ struct tracee *tracee = container_of(c, struct tracee, proc);
+
+ if (WIFSTOPPED(ret)) {
+ if (WSTOPSIG(ret) & 0x80) {
+ if (!tracee->in_syscall) {
+ int syscall = ptrace(PTRACE_PEEKUSER, c->pid, reg_syscall_nr);
+
+ if (syscall < syscall_max) {
+ syscall_count[syscall]++;
+ if (debug)
+ fprintf(stderr, "%s()\n", syscall_names[syscall]);
+ } else if (debug) {
+ fprintf(stderr, "syscal(%d)\n", syscall);
+ }
}
+ tracee->in_syscall = !tracee->in_syscall;
+ } else if ((ret >> 8) == (SIGTRAP | (PTRACE_EVENT_FORK << 8))) {
+ struct tracee *child = calloc(1, sizeof(struct tracee));
+
+ ptrace(PTRACE_GETEVENTMSG, c->pid, 0, &child->proc.pid);
+ child->proc.cb = tracer_cb;
+ ptrace(PTRACE_SYSCALL, child->proc.pid, 0, 0);
+ uloop_process_add(&child->proc);
+ if (debug)
+ fprintf(stderr, "Tracing new child %d\n", child->proc.pid);
}
- in_syscall = !in_syscall;
} else if (WIFEXITED(ret)) {
- uloop_end();
+ if (tracee == &tracer) {
+ uloop_end(); /* Main process exit */
+ } else {
+ if (debug)
+ fprintf(stderr, "Child %d exited\n", tracee->proc.pid);
+ free(tracee);
+ }
return;
}
+
ptrace(PTRACE_SYSCALL, c->pid, 0, 0);
- uloop_process_add(&tracer);
+ uloop_process_add(c);
}
int main(int argc, char **argv, char **envp)
if (child == 0) {
char **_argv = calloc(argc + 1, sizeof(char *));
char **_envp;
- char preload[] = "LD_PRELOAD=/lib/libpreload-trace.so";
- int envc = 1;
+ char *preload = "LD_PRELOAD=/lib/libpreload-trace.so";
+ int envc = 0;
int ret;
memcpy(_argv, argv, argc * sizeof(char *));
while (envp[envc++])
;
- _envp = calloc(envc, sizeof(char *));
- memcpy(&_envp[1], _envp, envc * sizeof(char *));
- *envp = preload;
+ _envp = calloc(envc + 1, sizeof(char *));
+ memcpy(&_envp[1], envp, envc * sizeof(char *));
+ *_envp = preload;
- ret = execve(_argv[0], _argv, envp);
+ ret = execve(_argv[0], _argv, _envp);
ERROR("failed to exec %s: %s\n", _argv[0], strerror(errno));
+
+ free(_argv);
+ free(_envp);
return ret;
}
return -1;
}
- ptrace(PTRACE_SETOPTIONS, child, 0, PTRACE_O_TRACESYSGOOD);
+ ptrace(PTRACE_SETOPTIONS, child, 0,
+ PTRACE_O_TRACESYSGOOD |
+ PTRACE_O_TRACEFORK);
ptrace(PTRACE_SYSCALL, child, 0, 0);
uloop_init();
- tracer.pid = child;
- tracer.cb = tracer_cb;
- uloop_process_add(&tracer);
+ tracer.proc.pid = child;
+ tracer.proc.cb = tracer_cb;
+ uloop_process_add(&tracer.proc);
uloop_run();
uloop_done();