WebSVN – HelenOS – Diff – /branches/tracing/kernel/generic/src/udebug/udebug_ipc.c

 #include <syscall/copy.h>
 #include <udebug/udebug.h>
 #include <udebug/udebug_ipc.h>
 /**
- * Get a phone's callee task id.
- *
- * This will return the id of the task to which the phone
- * is connected.
- *
- * Interrupts must be already disabled.
- */
-static task_id_t get_callee_task_id(phone_t *phone)
-{
-    answerbox_t *box;
-    task_id_t taskid;
-    spinlock_lock(&phone->lock);
-    if (phone->state != IPC_PHONE_CONNECTED) {
-        spinlock_unlock(&phone->lock);
-        return NULL;
-    }
-    box = phone->callee;
-    spinlock_lock(&box->lock);
-    taskid = box->task->taskid;
-    spinlock_unlock(&box->lock);
-    spinlock_unlock(&phone->lock);
-    return taskid;
-}
-/**
  * Prepare a thread for a debugging operation.
+ *
  * Simply put, return thread t with t->debug_lock held,
  * but only if it verifies all conditions.
+ *
  * Specifically, verifies that thread t exists, is a userspace thread,
- * belongs to the callee of 'phone'. It also locks t->debug_lock,
+ * and belongs to the current task (TASK). It also locks t->debug_lock,
  * making sure that t->debug_active is true - that the thread is
  * in a valid debugging session.
+ *
  * Returns EOK if all went well, or an error code otherwise.
  * Interrupts must be already disabled when calling this function.
+ *
  * Note: This function sports complicated locking.
  */
-static int _thread_op_begin(phone_t *phone, thread_t *t)
+static int _thread_op_begin(thread_t *t)
+{
     int rc;
     task_id_t taskid;
-    int task_match;
-    DEADLOCK_PROBE_INIT(p_tasklock);
-    taskid = get_callee_task_id(phone);
+    taskid = TASK->taskid;
-    /* Need to lock down the thread and than it's owner task */
+    /* Must lock threads_lock to ensure continued existence of the thread */
-grab_locks:
     spinlock_lock(&threads_lock);
     if (!thread_exists(t)) {
         spinlock_unlock(&threads_lock);
         return ENOENT;
+    }
     spinlock_lock(&t->debug_lock);
     spinlock_lock(&t->lock);
-    if (!spinlock_trylock(&t->task->lock)) {
-        spinlock_unlock(&t->lock);
-        spinlock_unlock(&t->debug_lock);
-        DEADLOCK_PROBE(p_tasklock, DEADLOCK_THRESHOLD);
-        goto grab_locks;    /* avoid deadlock */
-    }
-    /* Now verify that it's the callee */
+    /* Now verify that it's the current task */
-    task_match = (t->task->taskid == taskid);
-    spinlock_unlock(&t->task->lock);
-    if (!task_match) {
+    if (t->task != TASK) {
         /* No such thread belonging to callee */
         rc = ENOENT;
         goto error_exit;
+    }
     /* No locks left here */
     return rc;  /* Some errors occured */
+}
 static void _thread_op_end(thread_t *t)
+{
     spinlock_unlock(&t->debug_lock);
+}
-static int udebug_rp_go(call_t *call, phone_t *phone)
-{
-    thread_t *t;
-    ipl_t ipl;
-    int rc;
-    klog_printf("debug_go()");
-    t = (thread_t *)IPC_GET_ARG2(call->data);
-    ipl = interrupts_disable();
-    /* On success, this will lock t->debug_lock */
-    rc = _thread_op_begin(phone, t);
-    if (rc != EOK) {
-        interrupts_restore(ipl);
-        return rc;
-    }
-    t->debug_go_call = call;
-    t->debug_stop = false;
-    t->cur_event = 0;   /* none */
-    /*
-     * Neither t's lock nor threads_lock may be held during wakeup
-     */
-    waitq_wakeup(&t->go_wq, WAKEUP_FIRST);
-    _thread_op_end(t);
-    interrupts_restore(ipl);
-    return 0; /* no backsend */
-}
-static int udebug_rp_args_read(call_t *call, phone_t *phone)
-{
-    thread_t *t;
-    void *uspace_buffer;
-    int rc;
-    ipl_t ipl;
-    unative_t buffer[6];
-    klog_printf("debug_args_read()");
-    t = (thread_t *)IPC_GET_ARG2(call->data);
-    ipl = interrupts_disable();
-    /* On success, this will lock t->debug_lock */
-    rc = _thread_op_begin(phone, t);
-    if (rc != EOK) {
-        interrupts_restore(ipl);
-        return rc;
-    }
-    /* Additionally we need to verify that we are inside a syscall */
-    if (t->cur_event != UDEBUG_EVENT_SYSCALL) {
-        _thread_op_end(t);
-        interrupts_restore(ipl);
-        return EINVAL;
-    }
-    /* Copy to a local buffer before releasing the lock */
-    memcpy(buffer, t->syscall_args, 6 * sizeof(unative_t));
-    _thread_op_end(t);
-    interrupts_restore(ipl);
-    /* Now copy to userspace */
-    uspace_buffer = (void *)IPC_GET_ARG3(call->data);
-    rc = copy_to_uspace(uspace_buffer, buffer, 6 * sizeof(unative_t));
-    if (rc != 0) {
-        klog_printf("debug_args_read() - copy failed");
-        return rc;
-    }
-    klog_printf("debug_args_read() done");
-    return 1; /* actually need becksend with retval 0 */
-}
-static int udebug_rp_regs_read(call_t *call, phone_t *phone)
-{
-    thread_t *t;
-    void *uspace_buffer;
-    unative_t to_copy;
-    int rc;
-    istate_t *state;
-    istate_t state_copy;
-    ipl_t ipl;
-    klog_printf("debug_regs_read()");
-    t = (thread_t *) IPC_GET_ARG2(call->data);
-    ipl = interrupts_disable();
-    /* On success, this will lock t->debug_lock */
-    rc = _thread_op_begin(phone, t);
-    if (rc != EOK) {
-        interrupts_restore(ipl);
-        return rc;
-    }
-    state = t->uspace_state;
-    if (state == NULL) {
-        _thread_op_end(t);
-        interrupts_restore(ipl);
-        klog_printf("debug_regs_read() - istate not available");
-        return EBUSY;
-    }
-    /* Copy to a local buffer so that we can release the lock */
-    memcpy(&state_copy, state, sizeof(state_copy));
-    _thread_op_end(t);
-    interrupts_restore(ipl);
-    uspace_buffer = (void *)IPC_GET_ARG3(call->data);
-    to_copy = IPC_GET_ARG4(call->data);
-    if (to_copy > sizeof(istate_t)) to_copy = sizeof(istate_t);
-    rc = copy_to_uspace(uspace_buffer, &state_copy, to_copy);
-    if (rc != 0) {
-        klog_printf("debug_regs_read() - copy failed");
-        return rc;
-    }
-    IPC_SET_ARG1(call->data, to_copy);
-    IPC_SET_ARG2(call->data, sizeof(istate_t));
-    klog_printf("debug_regs_read() done");
-    return 1; /* actually need becksend with retval 0 */
-}
 static int udebug_rp_regs_write(call_t *call, phone_t *phone)
+{
-    thread_t *t;
     void *uspace_data;
     unative_t to_copy;
     int rc;
-    istate_t *state;
+    void *buffer;
-    istate_t data_copy;
-    ipl_t ipl;
     klog_printf("debug_regs_write()");
-    /* First copy to a local buffer */
     uspace_data = (void *)IPC_GET_ARG3(call->data);
     to_copy = IPC_GET_ARG4(call->data);
     if (to_copy > sizeof(istate_t)) to_copy = sizeof(istate_t);
+    buffer = malloc(to_copy, 0); // ???
-    rc = copy_from_uspace(&data_copy, uspace_data, to_copy);
+    rc = copy_from_uspace(buffer, uspace_data, to_copy);
     if (rc != 0) {
         klog_printf("debug_regs_write() - copy failed");
         return rc;
+    }
-    /* Now try to change the thread's uspace_state */
-    ipl = interrupts_disable();
-    t = (thread_t *) IPC_GET_ARG2(call->data);
-    /* On success, this will lock t->debug_lock */
-    rc = _thread_op_begin(phone, t);
-    if (rc != EOK) {
-        interrupts_restore(ipl);
-        return rc;
-    }
-    state = t->uspace_state;
-    if (state == NULL) {
-        _thread_op_end(t);
-        interrupts_restore(ipl);
-        klog_printf("debug_regs_write() - istate not available");
-        return EBUSY;
-    }
-    memcpy(t->uspace_state, &data_copy, sizeof(t->uspace_state));
-    _thread_op_end(t);
-    interrupts_restore(ipl);
-    /* Set answer values */
+    call->buffer = buffer;
-    IPC_SET_ARG1(call->data, to_copy);
-    IPC_SET_ARG2(call->data, sizeof(istate_t));
-    klog_printf("debug_regs_write() done");
+    klog_printf(" - done");
-    return 1; /* actually need becksend with retval 0 */
+    return 0; /* No backsend */
+}
 static int udebug_rp_mem_write(call_t *call, phone_t *phone)
+{
     void *uspace_data;
 int udebug_request_preprocess(call_t *call, phone_t *phone)
+{
     int rc;
     switch (IPC_GET_ARG1(call->data)) {
-    case UDEBUG_M_GO:
-        rc = udebug_rp_go(call, phone);
-        return rc;
-    case UDEBUG_M_ARGS_READ:
-        rc = udebug_rp_args_read(call, phone);
-        return rc;
-    case UDEBUG_M_REGS_READ:
-        rc = udebug_rp_regs_read(call, phone);
-        return rc;
     case UDEBUG_M_REGS_WRITE:
         rc = udebug_rp_regs_write(call, phone);
         return rc;
     case UDEBUG_M_MEM_WRITE:
         rc = udebug_rp_mem_write(call, phone);
     IPC_SET_RETVAL(call->data, 0);
     ipc_answer(&TASK->kernel_box, call);
+}
+static void udebug_receive_go(call_t *call)
+{
+    thread_t *t;
+    ipl_t ipl;
+    int rc;
+    klog_printf("debug_go()");
+    t = (thread_t *)IPC_GET_ARG2(call->data);
+    ipl = interrupts_disable();
+    /* On success, this will lock t->debug_lock */
+    rc = _thread_op_begin(t);
+    if (rc != EOK) {
+        interrupts_restore(ipl);
+        IPC_SET_RETVAL(call->data, rc);
+        ipc_answer(&TASK->kernel_box, call);
+        return;
+    }
+    t->debug_go_call = call;
+    t->debug_stop = false;
+    t->cur_event = 0;   /* none */
+    /*
+     * Neither t's lock nor threads_lock may be held during wakeup
+     */
+    waitq_wakeup(&t->go_wq, WAKEUP_FIRST);
+    _thread_op_end(t);
+    interrupts_restore(ipl);
+    /* No reply */
+}
 static void udebug_receive_thread_read(call_t *call)
+{
     thread_t *t;
     link_t *cur;
     unative_t uspace_addr;
     call->buffer = (void *)buffer;
     ipc_answer(&TASK->kernel_box, call);
+}
+static void udebug_receive_args_read(call_t *call)
+{
+    thread_t *t;
+    unative_t uspace_addr;
+    int rc;
+    ipl_t ipl;
+    unative_t *buffer;
+    klog_printf("debug_args_read()");
+    t = (thread_t *)IPC_GET_ARG2(call->data);
+    ipl = interrupts_disable();
+    /* On success, this will lock t->debug_lock */
+    rc = _thread_op_begin(t);
+    if (rc != EOK) {
+        interrupts_restore(ipl);
+        IPC_SET_RETVAL(call->data, rc);
+        ipc_answer(&TASK->kernel_box, call);
+        return;
+    }
+    /* Additionally we need to verify that we are inside a syscall */
+    if (t->cur_event != UDEBUG_EVENT_SYSCALL) {
+        _thread_op_end(t);
+        interrupts_restore(ipl);
+        IPC_SET_RETVAL(call->data, EINVAL);
+        ipc_answer(&TASK->kernel_box, call);
+        return;
+    }
+    /* Copy to a local buffer before releasing the lock */
+    buffer = malloc(6 * sizeof(unative_t), 0); // ???
+    memcpy(buffer, t->syscall_args, 6 * sizeof(unative_t));
+    _thread_op_end(t);
+    interrupts_restore(ipl);
+    /*
+     * Make use of call->buffer to transfer data to caller's userspace
+     */
+    uspace_addr = IPC_GET_ARG3(call->data);
+    IPC_SET_RETVAL(call->data, 0);
+    /* ARG1=dest, ARG2=size as in IPC_M_DATA_READ so that
+       same code in process_answer() can be used
+       (no way to distinguish method in answer) */
+    IPC_SET_ARG1(call->data, uspace_addr);
+    IPC_SET_ARG2(call->data, 6 * sizeof(unative_t));
+    call->buffer = (void *)buffer;
+    ipc_answer(&TASK->kernel_box, call);
+}
+static void udebug_receive_regs_read(call_t *call)
+{
+    thread_t *t;
+    unative_t uspace_addr;
+    unative_t to_copy;
+    unative_t buf_size;
+    unative_t total_bytes;
+    istate_t *state;
+    void *buffer;
+    int rc;
+    ipl_t ipl;
+    klog_printf("debug_regs_read()");
+    t = (thread_t *) IPC_GET_ARG2(call->data);
+    ipl = interrupts_disable();
+    /* On success, this will lock t->debug_lock */
+    rc = _thread_op_begin(t);
+    if (rc != EOK) {
+        interrupts_restore(ipl);
+        IPC_SET_RETVAL(call->data, rc);
+        ipc_answer(&TASK->kernel_box, call);
+        return;
+    }
+    state = t->uspace_state;
+    if (state == NULL) {
+        _thread_op_end(t);
+        interrupts_restore(ipl);
+        klog_printf("debug_regs_read() - istate not available");
+        IPC_SET_RETVAL(call->data, EBUSY);
+        ipc_answer(&TASK->kernel_box, call);
+        return;
+    }
+    /* Copy to an allocated buffer */
+    buffer = malloc(sizeof(istate_t), 0); // ???
+    memcpy(buffer, state, sizeof(istate_t));
+    _thread_op_end(t);
+    interrupts_restore(ipl);
+    /*
+     * Make use of call->buffer to transfer data to caller's userspace
+     */
+    uspace_addr = IPC_GET_ARG3(call->data);
+    buf_size = IPC_GET_ARG4(call->data);
+    total_bytes = sizeof(istate_t);
+    if (buf_size > total_bytes)
+        to_copy = total_bytes;
+    else
+        to_copy = buf_size;
+    IPC_SET_RETVAL(call->data, 0);
+    /* ARG1=dest, ARG2=size as in IPC_M_DATA_READ so that
+       same code in process_answer() can be used
+       (no way to distinguish method in answer) */
+    IPC_SET_ARG1(call->data, uspace_addr);
+    IPC_SET_ARG2(call->data, to_copy);
+    IPC_SET_ARG3(call->data, total_bytes);
+    call->buffer = (void *)buffer;
+    ipc_answer(&TASK->kernel_box, call);
+}
+static void udebug_receive_regs_write(call_t *call)
+{
+    thread_t *t;
+    void *uspace_data;
+    unative_t to_copy;
+    int rc;
+    istate_t *state;
+    ipl_t ipl;
+    klog_printf("debug_regs_write()");
+    uspace_data = (void *)IPC_GET_ARG3(call->data);
+    to_copy = IPC_GET_ARG4(call->data);
+    /* Try to change the thread's uspace_state */
+    ipl = interrupts_disable();
+    t = (thread_t *) IPC_GET_ARG2(call->data);
+    /* On success, this will lock t->debug_lock */
+    rc = _thread_op_begin(t);
+    if (rc != EOK) {
+        interrupts_restore(ipl);
+        IPC_SET_RETVAL(call->data, rc);
+        ipc_answer(&TASK->kernel_box, call);
+        return;
+    }
+    state = t->uspace_state;
+    if (state == NULL) {
+        _thread_op_end(t);
+        interrupts_restore(ipl);
+        klog_printf("debug_regs_write() - istate not available");
+        IPC_SET_RETVAL(call->data, EBUSY);
+        ipc_answer(&TASK->kernel_box, call);
+        return;
+    }
+    memcpy(t->uspace_state, call->buffer, sizeof(t->uspace_state));
+    _thread_op_end(t);
+    interrupts_restore(ipl);
+    /* Set answer values */
+    IPC_SET_ARG1(call->data, to_copy);
+    IPC_SET_ARG2(call->data, sizeof(istate_t));
+    IPC_SET_RETVAL(call->data, 0);
+    ipc_answer(&TASK->kernel_box, call);
+    klog_printf("debug_regs_write() done");
+}
 static void udebug_receive_mem_read(call_t *call)
+{
     unative_t uspace_dst;
     void *uspace_ptr;
     /* NOTE: this is not strictly from a syscall... but that shouldn't
      * be a problem */
     rc = copy_from_uspace(buffer, uspace_ptr, size);
     if (rc) {
         IPC_SET_RETVAL(call->data, rc);
+        ipc_answer(&TASK->kernel_box, call);
         return;
+    }
     klog_printf("first word: %u", *((unative_t *)buffer));
         udebug_receive_begin(call);
         break;
     case UDEBUG_M_END:
         udebug_receive_end(call);
         break;
+    case UDEBUG_M_GO:
+        udebug_receive_go(call);
+        break;
     case UDEBUG_M_THREAD_READ:
         udebug_receive_thread_read(call);
         break;
+    case UDEBUG_M_ARGS_READ:
+        udebug_receive_args_read(call);
+        break;
+    case UDEBUG_M_REGS_READ:
+        udebug_receive_regs_read(call);
+        break;
+    case UDEBUG_M_REGS_WRITE:
+        udebug_receive_regs_write(call);
+        break;
     case UDEBUG_M_MEM_READ:
         udebug_receive_mem_read(call);
         break;
     case UDEBUG_M_MEM_WRITE:
         udebug_receive_mem_write(call);

Subversion Repositories HelenOS

(root)/branches/tracing/kernel/generic/src/udebug/udebug_ipc.c – Rev 2885 → 2886