source: mainline/uspace/app/trace/trace.c@ c7325dd6

/*
 * Copyright (c) 2008 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup trace
 * @{
 */
/** @file
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fibril.h>
#include <errno.h>
#include <udebug.h>
#include <async.h>
#include <task.h>
#include <mem.h>
#include <str.h>
#include <bool.h>
#include <loader/loader.h>
#include <io/console.h>
#include <io/keycode.h>
#include <fibril_synch.h>
#include <sys/types.h>
#include <sys/typefmt.h>
#include <vfs/vfs.h>

#include <libc.h>

/* Temporary: service and method names */
#include "proto.h"
#include <ipc/services.h>
#include "../../srv/vfs/vfs.h"
#include <ipc/console.h>

#include "syscalls.h"
#include "ipcp.h"
#include "errors.h"
#include "trace.h"

#define THBUF_SIZE 64
uintptr_t thread_hash_buf[THBUF_SIZE];
int n_threads;

int next_thread_id;

ipc_call_t thread_ipc_req[THBUF_SIZE];

async_sess_t *sess;
bool abort_trace;

uintptr_t thash;
static bool paused;
static fibril_condvar_t state_cv;
static fibril_mutex_t state_lock;

static bool cev_valid;
static kbd_event_t cev;

void thread_trace_start(uintptr_t thread_hash);

static task_id_t task_id;
static loader_t *task_ldr;
static bool task_wait_for;

/** Combination of events/data to print. */
display_mask_t display_mask;

static int program_run_fibril(void *arg);
static int cev_fibril(void *arg);

static void program_run(void)
{
        fid_t fid;

        fid = fibril_create(program_run_fibril, NULL);
        if (fid == 0) {
                printf("Error creating fibril\n");
                exit(1);
        }

        fibril_add_ready(fid);
}

static void cev_fibril_start(void)
{
        fid_t fid;

        fid = fibril_create(cev_fibril, NULL);
        if (fid == 0) {
                printf("Error creating fibril\n");
                exit(1);
        }

        fibril_add_ready(fid);
}

static int program_run_fibril(void *arg)
{
        int rc;

        /*
         * This must be done in background as it will block until
         * we let the task reply to this call.
         */
        rc = loader_run(task_ldr);
        if (rc != 0) {
                printf("Error running program\n");
                exit(1);
        }

        free(task_ldr);
        task_ldr = NULL;

        printf("program_run_fibril exiting\n");
        return 0;
}


static int connect_task(task_id_t task_id)
{
        async_sess_t *ksess = async_connect_kbox(task_id);
        
        if (!ksess) {
                if (errno == ENOTSUP) {
                        printf("You do not have userspace debugging support "
                            "compiled in the kernel.\n");
                        printf("Compile kernel with 'Support for userspace debuggers' "
                            "(CONFIG_UDEBUG) enabled.\n");
                        return errno;
                }
                
                printf("Error connecting\n");
                printf("ipc_connect_task(%" PRIu64 ") -> %d ", task_id, errno);
                return errno;
        }
        
        int rc = udebug_begin(ksess);
        if (rc < 0) {
                printf("udebug_begin() -> %d\n", rc);
                return rc;
        }
        
        rc = udebug_set_evmask(ksess, UDEBUG_EM_ALL);
        if (rc < 0) {
                printf("udebug_set_evmask(0x%x) -> %d\n ", UDEBUG_EM_ALL, rc);
                return rc;
        }
        
        sess = ksess;
        return 0;
}

static int get_thread_list(void)
{
        int rc;
        size_t tb_copied;
        size_t tb_needed;
        int i;

        rc = udebug_thread_read(sess, thread_hash_buf,
                THBUF_SIZE*sizeof(unsigned), &tb_copied, &tb_needed);
        if (rc < 0) {
                printf("udebug_thread_read() -> %d\n", rc);
                return rc;
        }

        n_threads = tb_copied / sizeof(uintptr_t);

        printf("Threads:");
        for (i = 0; i < n_threads; i++) {
                printf(" [%d] (hash %p)", 1 + i, (void *) thread_hash_buf[i]);
        }
        printf("\ntotal of %zu threads\n", tb_needed / sizeof(uintptr_t));

        return 0;
}

void val_print(sysarg_t val, val_type_t v_type)
{
        long sval;

        sval = (long) val;

        switch (v_type) {
        case V_VOID:
                printf("<void>");
                break;

        case V_INTEGER:
                printf("%ld", sval);
                break;

        case V_HASH:
        case V_PTR:
                printf("%p", (void *) val);
                break;

        case V_ERRNO:
                if (sval >= -15 && sval <= 0) {
                        printf("%ld %s (%s)", sval,
                            err_desc[-sval].name,
                            err_desc[-sval].desc);
                } else {
                        printf("%ld", sval);
                }
                break;
        case V_INT_ERRNO:
                if (sval >= -15 && sval < 0) {
                        printf("%ld %s (%s)", sval,
                            err_desc[-sval].name,
                            err_desc[-sval].desc);
                } else {
                        printf("%ld", sval);
                }
                break;

        case V_CHAR:
                if (sval >= 0x20 && sval < 0x7f) {
                        printf("'%c'", (char) sval);
                } else {
                        switch (sval) {
                        case '\a': printf("'\\a'"); break;
                        case '\b': printf("'\\b'"); break;
                        case '\n': printf("'\\n'"); break;
                        case '\r': printf("'\\r'"); break;
                        case '\t': printf("'\\t'"); break;
                        case '\\': printf("'\\\\'"); break;
                        default: printf("'\\x%02" PRIxn "'", val); break;
                        }
                }
                break;
        }
}


static void print_sc_retval(sysarg_t retval, val_type_t val_type)
{
        printf(" -> ");
        val_print(retval, val_type);
        putchar('\n');
}

static void print_sc_args(sysarg_t *sc_args, int n)
{
        int i;

        putchar('(');
        if (n > 0) printf("%" PRIun, sc_args[0]);
        for (i = 1; i < n; i++) {
                printf(", %" PRIun, sc_args[i]);
        }
        putchar(')');
}

static void sc_ipc_call_async_fast(sysarg_t *sc_args, sysarg_t sc_rc)
{
        ipc_call_t call;
        sysarg_t phoneid;
        
        if (sc_rc == (sysarg_t) IPC_CALLRET_FATAL ||
            sc_rc == (sysarg_t) IPC_CALLRET_TEMPORARY)
                return;

        phoneid = sc_args[0];

        IPC_SET_IMETHOD(call, sc_args[1]);
        IPC_SET_ARG1(call, sc_args[2]);
        IPC_SET_ARG2(call, sc_args[3]);
        IPC_SET_ARG3(call, sc_args[4]);
        IPC_SET_ARG4(call, sc_args[5]);
        IPC_SET_ARG5(call, 0);

        ipcp_call_out(phoneid, &call, sc_rc);
}

static void sc_ipc_call_async_slow(sysarg_t *sc_args, sysarg_t sc_rc)
{
        ipc_call_t call;
        int rc;

        if (sc_rc == (sysarg_t) IPC_CALLRET_FATAL ||
            sc_rc == (sysarg_t) IPC_CALLRET_TEMPORARY)
                return;

        memset(&call, 0, sizeof(call));
        rc = udebug_mem_read(sess, &call.args, sc_args[1], sizeof(call.args));

        if (rc >= 0) {
                ipcp_call_out(sc_args[0], &call, sc_rc);
        }
}

static void sc_ipc_call_sync_fast(sysarg_t *sc_args)
{
        ipc_call_t question, reply;
        int rc;
        int phoneid;

        phoneid = sc_args[0];

        IPC_SET_IMETHOD(question, sc_args[1]);
        IPC_SET_ARG1(question, sc_args[2]);
        IPC_SET_ARG2(question, sc_args[3]);
        IPC_SET_ARG3(question, sc_args[4]);
        IPC_SET_ARG4(question, 0);
        IPC_SET_ARG5(question, 0);

        memset(&reply, 0, sizeof(reply));
        rc = udebug_mem_read(sess, &reply.args, sc_args[5], sizeof(reply.args));
        if (rc < 0)
                return;
        
        ipcp_call_sync(phoneid, &question, &reply);
}

static void sc_ipc_call_sync_slow_b(unsigned thread_id, sysarg_t *sc_args)
{
        ipc_call_t question;
        int rc;

        memset(&question, 0, sizeof(question));
        rc = udebug_mem_read(sess, &question.args, sc_args[1],
            sizeof(question.args));

        if (rc < 0) {
                printf("Error: mem_read->%d\n", rc);
                return;
        }

        thread_ipc_req[thread_id] = question;
}

static void sc_ipc_call_sync_slow_e(unsigned thread_id, sysarg_t *sc_args)
{
        ipc_call_t reply;
        int rc;

        memset(&reply, 0, sizeof(reply));
        rc = udebug_mem_read(sess, &reply.args, sc_args[2],
            sizeof(reply.args));

        if (rc < 0) {
                printf("Error: mem_read->%d\n", rc);
                return;
        }

        ipcp_call_sync(sc_args[0], &thread_ipc_req[thread_id], &reply);
}

static void sc_ipc_wait(sysarg_t *sc_args, int sc_rc)
{
        ipc_call_t call;
        int rc;

        if (sc_rc == 0) return;

        memset(&call, 0, sizeof(call));
        rc = udebug_mem_read(sess, &call, sc_args[0], sizeof(call));
        
        if (rc >= 0)
                ipcp_call_in(&call, sc_rc);
}

static void event_syscall_b(unsigned thread_id, uintptr_t thread_hash,
    unsigned sc_id, sysarg_t sc_rc)
{
        sysarg_t sc_args[6];
        int rc;

        /* Read syscall arguments */
        rc = udebug_args_read(sess, thread_hash, sc_args);

        if (rc < 0) {
                printf("error\n");
                return;
        }

        if ((display_mask & DM_SYSCALL) != 0) {
                /* Print syscall name and arguments */
                printf("%s", syscall_desc[sc_id].name);
                print_sc_args(sc_args, syscall_desc[sc_id].n_args);
        }

        switch (sc_id) {
        case SYS_IPC_CALL_SYNC_SLOW:
                sc_ipc_call_sync_slow_b(thread_id, sc_args);
                break;
        default:
                break;
        }
}

static void event_syscall_e(unsigned thread_id, uintptr_t thread_hash,
    unsigned sc_id, sysarg_t sc_rc)
{
        sysarg_t sc_args[6];
        int rv_type;
        int rc;

        /* Read syscall arguments */
        rc = udebug_args_read(sess, thread_hash, sc_args);

//      printf("[%d] ", thread_id);

        if (rc < 0) {
                printf("error\n");
                return;
        }

        if ((display_mask & DM_SYSCALL) != 0) {
                /* Print syscall return value */
                rv_type = syscall_desc[sc_id].rv_type;
                print_sc_retval(sc_rc, rv_type);
        }

        switch (sc_id) {
        case SYS_IPC_CALL_ASYNC_FAST:
                sc_ipc_call_async_fast(sc_args, sc_rc);
                break;
        case SYS_IPC_CALL_ASYNC_SLOW:
                sc_ipc_call_async_slow(sc_args, sc_rc);
                break;
        case SYS_IPC_CALL_SYNC_FAST:
                sc_ipc_call_sync_fast(sc_args);
                break;
        case SYS_IPC_CALL_SYNC_SLOW:
                sc_ipc_call_sync_slow_e(thread_id, sc_args);
                break;
        case SYS_IPC_WAIT:
                sc_ipc_wait(sc_args, sc_rc);
                break;
        default:
                break;
        }
}

static void event_thread_b(uintptr_t hash)
{
        printf("New thread, hash %p\n", (void *) hash);
        thread_trace_start(hash);
}

static int trace_loop(void *thread_hash_arg)
{
        int rc;
        unsigned ev_type;
        uintptr_t thread_hash;
        unsigned thread_id;
        sysarg_t val0, val1;

        thread_hash = (uintptr_t)thread_hash_arg;
        thread_id = next_thread_id++;
        if (thread_id >= THBUF_SIZE) {
                printf("Too many threads.\n");
                return ELIMIT;
        }

        printf("Start tracing thread [%u] (hash %p).\n",
            thread_id, (void *) thread_hash);

        while (!abort_trace) {

                fibril_mutex_lock(&state_lock);
                if (paused) {
                        printf("Thread [%u] paused. Press R to resume.\n",
                            thread_id);

                        while (paused)
                                fibril_condvar_wait(&state_cv, &state_lock);

                        printf("Thread [%u] resumed.\n", thread_id);
                }
                fibril_mutex_unlock(&state_lock);

                /* Run thread until an event occurs */
                rc = udebug_go(sess, thread_hash,
                    &ev_type, &val0, &val1);

//              printf("rc = %d, ev_type=%d\n", rc, ev_type);
                if (ev_type == UDEBUG_EVENT_FINISHED) {
                        /* Done tracing this thread */
                        break;
                }

                if (rc >= 0) {
                        switch (ev_type) {
                        case UDEBUG_EVENT_SYSCALL_B:
                                event_syscall_b(thread_id, thread_hash, val0, (int)val1);
                                break;
                        case UDEBUG_EVENT_SYSCALL_E:
                                event_syscall_e(thread_id, thread_hash, val0, (int)val1);
                                break;
                        case UDEBUG_EVENT_STOP:
                                printf("Stop event\n");
                                fibril_mutex_lock(&state_lock);
                                paused = true;
                                fibril_mutex_unlock(&state_lock);
                                break;
                        case UDEBUG_EVENT_THREAD_B:
                                event_thread_b(val0);
                                break;
                        case UDEBUG_EVENT_THREAD_E:
                                printf("Thread %" PRIun " exited.\n", val0);
                                fibril_mutex_lock(&state_lock);
                                abort_trace = true;
                                fibril_condvar_broadcast(&state_cv);
                                fibril_mutex_unlock(&state_lock);
                                break;
                        default:
                                printf("Unknown event type %d.\n", ev_type);
                                break;
                        }
                }

        }

        printf("Finished tracing thread [%d].\n", thread_id);
        return 0;
}

void thread_trace_start(uintptr_t thread_hash)
{
        fid_t fid;

        thash = thread_hash;

        fid = fibril_create(trace_loop, (void *)thread_hash);
        if (fid == 0) {
                printf("Warning: Failed creating fibril\n");
        }
        fibril_add_ready(fid);
}

static loader_t *preload_task(const char *path, char **argv,
    task_id_t *task_id)
{
        loader_t *ldr;
        int rc;

        /* Spawn a program loader */
        ldr = loader_connect();
        if (ldr == NULL)
                return 0;

        /* Get task ID. */
        rc = loader_get_task_id(ldr, task_id);
        if (rc != EOK)
                goto error;

        /* Send program pathname */
        rc = loader_set_pathname(ldr, path);
        if (rc != EOK)
                goto error;

        /* Send arguments */
        rc = loader_set_args(ldr, (const char **) argv);
        if (rc != EOK)
                goto error;

        /* Send default files */
        int *files[4];
        int fd_stdin;
        int fd_stdout;
        int fd_stderr;
        
        if ((stdin != NULL) && (fhandle(stdin, &fd_stdin) == EOK))
                files[0] = &fd_stdin;
        else
                files[0] = NULL;
        
        if ((stdout != NULL) && (fhandle(stdout, &fd_stdout) == EOK))
                files[1] = &fd_stdout;
        else
                files[1] = NULL;
        
        if ((stderr != NULL) && (fhandle(stderr, &fd_stderr) == EOK))
                files[2] = &fd_stderr;
        else
                files[2] = NULL;
        
        files[3] = NULL;
        
        rc = loader_set_files(ldr, files);
        if (rc != EOK)
                goto error;

        /* Load the program. */
        rc = loader_load_program(ldr);
        if (rc != EOK)
                goto error;

        /* Success */
        return ldr;

        /* Error exit */
error:
        loader_abort(ldr);
        free(ldr);
        return NULL;
}

static int cev_fibril(void *arg)
{
        (void) arg;
        
        console_ctrl_t *console = console_init(stdin, stdout);
        
        while (true) {
                fibril_mutex_lock(&state_lock);
                while (cev_valid)
                        fibril_condvar_wait(&state_cv, &state_lock);
                fibril_mutex_unlock(&state_lock);
                
                if (!console_get_kbd_event(console, &cev))
                        return -1;
                
                fibril_mutex_lock(&state_lock);
                cev_valid = true;
                fibril_condvar_broadcast(&state_cv);
                fibril_mutex_unlock(&state_lock);
        }
}

static void trace_task(task_id_t task_id)
{
        kbd_event_t ev;
        bool done;
        int i;
        int rc;

        ipcp_init();

        rc = get_thread_list();
        if (rc < 0) {
                printf("Failed to get thread list (error %d)\n", rc);
                return;
        }

        abort_trace = false;

        for (i = 0; i < n_threads; i++) {
                thread_trace_start(thread_hash_buf[i]);
        }

        done = false;

        while (!done) {
                fibril_mutex_lock(&state_lock);
                while (!cev_valid && !abort_trace)
                        fibril_condvar_wait(&state_cv, &state_lock);
                fibril_mutex_unlock(&state_lock);

                ev = cev;

                fibril_mutex_lock(&state_lock);
                cev_valid = false;
                fibril_condvar_broadcast(&state_cv);
                fibril_mutex_unlock(&state_lock);

                if (abort_trace)
                        break;

                if (ev.type != KEY_PRESS)
                        continue;

                switch (ev.key) {
                case KC_Q:
                        done = true;
                        break;
                case KC_P:
                        printf("Pause...\n");
                        rc = udebug_stop(sess, thash);
                        if (rc != EOK)
                                printf("Error: stop -> %d\n", rc);
                        break;
                case KC_R:
                        fibril_mutex_lock(&state_lock);
                        paused = false;
                        fibril_condvar_broadcast(&state_cv);
                        fibril_mutex_unlock(&state_lock);
                        printf("Resume...\n");
                        break;
                default:
                        break;
                }
        }

        printf("\nTerminate debugging session...\n");
        abort_trace = true;
        udebug_end(sess);
        async_hangup(sess);

        ipcp_cleanup();

        printf("Done\n");
        return;
}

static void main_init(void)
{
        proto_t *p;
        oper_t *o;

        val_type_t arg_def[OPER_MAX_ARGS] = {
                V_INTEGER,
                V_INTEGER,
                V_INTEGER,
                V_INTEGER,
                V_INTEGER               
        };

        val_type_t resp_def[OPER_MAX_ARGS] = {
                V_INTEGER,
                V_INTEGER,
                V_INTEGER,
                V_INTEGER,
                V_INTEGER
        };

        next_thread_id = 1;
        paused = false;
        cev_valid = false;

        fibril_mutex_initialize(&state_lock);
        fibril_condvar_initialize(&state_cv);

        proto_init();

        p = proto_new("vfs");
        o = oper_new("open", 2, arg_def, V_INT_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_OPEN, o);
        o = oper_new("read", 1, arg_def, V_ERRNO, 1, resp_def);
        proto_add_oper(p, VFS_IN_READ, o);
        o = oper_new("write", 1, arg_def, V_ERRNO, 1, resp_def);
        proto_add_oper(p, VFS_IN_WRITE, o);
        o = oper_new("seek", 3, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_SEEK, o);
        o = oper_new("truncate", 5, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_TRUNCATE, o);
        o = oper_new("fstat", 1, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_FSTAT, o);
        o = oper_new("close", 1, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_CLOSE, o);
        o = oper_new("mount", 2, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_MOUNT, o);
/*      o = oper_new("unmount", 0, arg_def);
        proto_add_oper(p, VFS_IN_UNMOUNT, o);*/
        o = oper_new("sync", 1, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_SYNC, o);
        o = oper_new("mkdir", 1, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_MKDIR, o);
        o = oper_new("unlink", 0, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_UNLINK, o);
        o = oper_new("rename", 0, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_RENAME, o);
        o = oper_new("stat", 0, arg_def, V_ERRNO, 0, resp_def);
        proto_add_oper(p, VFS_IN_STAT, o);

        proto_register(SERVICE_VFS, p);
}

static void print_syntax()
{
        printf("Syntax:\n");
        printf("\ttrace [+<events>] <executable> [<arg1> [...]]\n");
        printf("or\ttrace [+<events>] -t <task_id>\n");
        printf("Events: (default is +tp)\n");
        printf("\n");
        printf("\tt ... Thread creation and termination\n");
        printf("\ts ... System calls\n");
        printf("\ti ... Low-level IPC\n");
        printf("\tp ... Protocol level\n");
        printf("\n");
        printf("Examples:\n");
        printf("\ttrace +s /app/tetris\n");
        printf("\ttrace +tsip -t 12\n");
}

static display_mask_t parse_display_mask(const char *text)
{
        display_mask_t dm = 0;
        const char *c = text;
        
        while (*c) {
                switch (*c) {
                case 't':
                        dm = dm | DM_THREAD;
                        break;
                case 's':
                        dm = dm | DM_SYSCALL;
                        break;
                case 'i':
                        dm = dm | DM_IPC;
                        break;
                case 'p':
                        dm = dm | DM_SYSTEM | DM_USER;
                        break;
                default:
                        printf("Unexpected event type '%c'.\n", *c);
                        exit(1);
                }
                
                ++c;
        }
        
        return dm;
}

static int parse_args(int argc, char *argv[])
{
        char *err_p;

        task_id = 0;

        --argc;
        ++argv;

        while (argc > 0) {
                char *arg = *argv;
                if (arg[0] == '+') {
                        display_mask = parse_display_mask(&arg[1]);
                } else if (arg[0] == '-') {
                        if (arg[1] == 't') {
                                /* Trace an already running task */
                                --argc;
                                ++argv;
                                task_id = strtol(*argv, &err_p, 10);
                                task_ldr = NULL;
                                task_wait_for = false;
                                if (*err_p) {
                                        printf("Task ID syntax error\n");
                                        print_syntax();
                                        return -1;
                                }
                        } else {
                                printf("Uknown option '%c'\n", arg[0]);
                                print_syntax();
                                return -1;
                        }
                } else {
                        break;
                }
                
                --argc;
                ++argv;
        }

        if (task_id != 0) {
                if (argc == 0)
                        return 0;
                printf("Extra arguments\n");
                print_syntax();
                return -1;
        }

        if (argc < 1) {
                printf("Missing argument\n");
                print_syntax();
                return -1;
        }

        /* Preload the specified program file. */
        printf("Spawning '%s' with arguments:\n", *argv);
        
        char **cp = argv;
        while (*cp)
                printf("'%s'\n", *cp++);
        
        task_ldr = preload_task(*argv, argv, &task_id);
        task_wait_for = true;

        return 0;
}

int main(int argc, char *argv[])
{
        int rc;
        task_exit_t texit;
        int retval;

        printf("System Call / IPC Tracer\n");
        printf("Controls: Q - Quit, P - Pause, R - Resume\n");

        display_mask = DM_THREAD | DM_SYSTEM | DM_USER;

        if (parse_args(argc, argv) < 0)
                return 1;

        main_init();

        rc = connect_task(task_id);
        if (rc < 0) {
                printf("Failed connecting to task %" PRIu64 ".\n", task_id);
                return 1;
        }

        printf("Connected to task %" PRIu64 ".\n", task_id);

        if (task_ldr != NULL)
                program_run();

        cev_fibril_start();
        trace_task(task_id);

        if (task_wait_for) {
                printf("Waiting for task to exit.\n");

                rc = task_wait(task_id, &texit, &retval);
                if (rc != EOK) {
                        printf("Failed waiting for task.\n");
                        return -1;
                }

                if (texit == TASK_EXIT_NORMAL) {
                        printf("Task exited normally, return value %d.\n",
                            retval);
                } else {
                        printf("Task exited unexpectedly.\n");
                }
        }

        return 0;
}

/** @}
 */