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/* See LICENSE file for copyright and license details. */
#include "common.h"
char *argv0;
static void
usage(void)
{
fprintf(stderr, "usage: %s [-f trace-output-file] [-CFV] command ...\n", argv0);
exit(1);
}
static void
handle_syscall(struct process *proc)
{
struct user_regs_struct regs;
switch (proc->state) {
default:
/* Get systemcall arguments */
if (ptrace(PTRACE_GETREGS, proc->pid, NULL, ®s))
eprintf("ptrace PTRACE_GETREGS %ju NULL <buffer>:", (uintmax_t)proc->pid);
proc->scall = regs.orig_rax;
proc->args[0] = regs.rdi;
proc->args[1] = regs.rsi;
proc->args[2] = regs.rdx;
proc->args[3] = regs.r10;
proc->args[4] = regs.r8;
proc->args[5] = regs.r9;
/* Print system call */
print_systemcall(proc);
/* Run system call */
if (ptrace(PTRACE_SYSCALL, proc->pid, NULL, 0))
eprintf("ptrace PTRACE_SYSCALL %ju NULL 0:", (uintmax_t)proc->pid);
proc->state = Syscall;
break;
case Syscall:
/* Get system call result */
if (ptrace(PTRACE_GETREGS, proc->pid, NULL, ®s))
eprintf("ptrace PTRACE_GETREGS %ju NULL <buffer>:", (uintmax_t)proc->pid);
proc->ret = regs.rax;
/* Print system call result */
print_systemcall_exit(proc);
/* Make process continue and stop at next syscall */
if (ptrace(PTRACE_SYSCALL, proc->pid, NULL, 0))
eprintf("ptrace PTRACE_SYSCALL %ju NULL 0", (uintmax_t)proc->pid);
proc->state = Normal;
break;
}
}
int
main(int argc, char **argv)
{
pid_t pid, orig_pid;
long int tmp;
char *outfile = NULL;
FILE *outfp = stderr;
const char *num = NULL;
int status, exit_value = 0;
unsigned long int trace_options = PTRACE_O_EXITKILL | PTRACE_O_TRACESYSGOOD;
struct process *proc;
unsigned long int event;
/* TODO add support for exec */
/* TODO add option to trace threads */
/* TODO add option to trace vforks */
/* TODO add option to trace signals */
/* TODO add option to specify argv[0] */
ARGBEGIN {
case 'f':
if (outfile)
usage();
outfile = EARGF(usage());
break;
case 'F':
trace_options |= PTRACE_O_TRACEFORK;
break;
default:
usage();
} ARGEND;
if (!argc)
usage();
init_process_list();
/* Start program to trace */
pid = fork();
switch (pid) {
case -1:
eprintf("fork:");
return 1;
case 0:
if (ptrace(PTRACE_TRACEME, 0, NULL, 0)) {
eprintf("ptrace PTRACE_TRACEME 0 NULL 0:");
return 1;
}
/* exec will block until parent attaches */
execvp(*argv, argv);
eprintf("execvp %s:", *argv);
default:
orig_pid = pid;
add_process(pid, trace_options);
break;
}
/* Open trace output file */
if (outfile) {
if (!strncmp(outfile, "/dev/fd/", sizeof("/dev/fd/") - 1))
num = &outfile[sizeof("/dev/fd/") - 1];
else if (!strncmp(outfile, "/proc/self/fd/", sizeof("/proc/self/fd/") - 1))
num = &outfile[sizeof("/proc/self/fd/") - 1];
else if (!strcmp(outfile, "/dev/stdin"))
num = "0";
else if (!strcmp(outfile, "/dev/stdout"))
num = "1";
else if (!strcmp(outfile, "/dev/stderr"))
num = "2";
if (num && isdigit(*num)) {
errno = 0;
tmp = strtol(num, (void *)&num, 10);
if (!errno && tmp >= 0 &&
#if INT_MAX < LONG_MAX
tmp < INT_MAX &&
#endif
!*num) {
outfp = fdopen((int)tmp, "wb");
if (!outfp) {
eprintf("fdopen %li wb:", tmp);
return 1;
}
goto have_outfp;
}
}
outfp = fopen(outfile, "wb");
if (!outfp) {
eprintf("fopen %s wb:", outfile);
return 1;
}
}
have_outfp:
set_trace_output(outfp);
for (;;) {
/* Wait for next syscall enter/exit */
pid = wait(&status);
if (pid < 0) {
if (errno == ECHILD)
return exit_value;
eprintf("wait <buffer>:");
return 1;
}
proc = find_process(pid);
if (!proc)
continue;
if (WIFEXITED(status)) {
if (pid == orig_pid)
exit_value = WEXITSTATUS(status);
tprintf(proc, "\nProcess exited with value %i\n", WEXITSTATUS(status));
} else if (WIFSIGNALED(status)) {
tprintf(proc, "\nProcess terminated by signal %i (%s)\n", WTERMSIG(status), strsignal(WTERMSIG(status)));
/* TODO print signal name */
} else if (WIFSTOPPED(status)) {
if (WSTOPSIG(status) == (SIGTRAP | 0x80)) {
handle_syscall(proc);
} else if (WSTOPSIG(status) == SIGTRAP) {
switch (((status >> 8) ^ SIGTRAP) >> 8) {
case PTRACE_EVENT_FORK:
if (ptrace(PTRACE_GETEVENTMSG, proc->pid, NULL, &event))
eprintf("ptrace PTRACE_GETEVENTMSG %ju NULL <buffer>:", (uintmax_t)proc->pid);
add_process((pid_t)event, trace_options);
handle_syscall(proc);
break;
default:
goto print_signal;
}
} else {
print_signal:
tprintf(proc, "\nProcess stopped by signal %i (%s)\n", WSTOPSIG(status), strsignal(WSTOPSIG(status)));
/* TODO print signal name */
}
} else if (WIFCONTINUED(status)) {
tprintf(proc, "\nProcess continued\n", (uintmax_t)pid);
}
}
fclose(outfp);
return 0;
}
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