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

  */
 /**
  * @file
  * @brief   Udebug operations.
+ *
+ * Udebug operations on tasks and threads are implemented here. The
+ * functions defined here are called from the udebug_ipc module
+ * when servicing udebug IPC messages.
  */
-#include <print.h>
+#include <debug.h>
 #include <proc/task.h>
 #include <proc/thread.h>
 #include <arch.h>
 #include <errno.h>
 #include <syscall/copy.h>
+ *
  * In this function, holding the TASK->udebug.lock mutex prevents the
  * thread from leaving the debugging session, while relaxing from
  * the t->lock spinlock to the t->udebug.lock mutex.
+ *
+ * @param t     Pointer, need not at all be valid.
+ * @param having_go Required thread state.
+ *
  * Returns EOK if all went well, or an error code otherwise.
  */
 static int _thread_op_begin(thread_t *t, bool having_go)
+{
     task_id_t taskid;
     /* Only t->udebug.lock left */
     return EOK; /* All went well */
+}
+/** End debugging operation on a thread. */
 static void _thread_op_end(thread_t *t)
+{
     mutex_unlock(&t->udebug.lock);
+}
+/** Begin debugging the current task.
-/**
+ *
+ * Initiates a debugging session for the current task (and its threads).
+ * When the debugging session has started a reply will be sent to the
+ * UDEBUG_BEGIN call. This may happen immediately in this function if
+ * all the threads in this task are stoppable at the moment and in this
+ * case the function returns 1.
+ *
+ * Otherwise the function returns 0 and the reply will be sent as soon as
+ * all the threads become stoppable (i.e. they can be considered stopped).
+ *
+ * @param call  The BEGIN call we are servicing.
- * \return 0 (ok, but not done yet), 1 (done) or negative error code.
+ * @return  0 (OK, but not done yet), 1 (done) or negative error code.
  */
 int udebug_begin(call_t *call)
+{
     int reply;
     thread_t *t;
     link_t *cur;
-    printf("udebug_begin()\n");
+    LOG("udebug_begin()\n");
     mutex_lock(&TASK->udebug.lock);
-    printf("debugging task %llu\n", TASK->taskid);
+    LOG("debugging task %llu\n", TASK->taskid);
     if (TASK->udebug.dt_state != UDEBUG_TS_INACTIVE) {
         mutex_unlock(&TASK->udebug.lock);
-        printf("udebug_begin(): busy error\n");
+        LOG("udebug_begin(): busy error\n");
         return EBUSY;
+    }
     TASK->udebug.dt_state = UDEBUG_TS_BEGINNING;
         mutex_unlock(&t->udebug.lock);
+    }
     mutex_unlock(&TASK->udebug.lock);
-    printf("udebug_begin() done (%s)\n",
+    LOG("udebug_begin() done (%s)\n",
         reply ? "reply" : "stoppability wait");
     return reply;
+}
+/** Finish debugging the current task.
+ *
+ * Closes the debugging session for the current task.
+ * @return Zero on success or negative error code.
+ */
 int udebug_end(void)
+{
     int rc;
-    printf("udebug_end()\n");
+    LOG("udebug_end()\n");
     mutex_lock(&TASK->udebug.lock);
-    printf("task %llu\n", TASK->taskid);
+    LOG("task %" PRIu64 "\n", TASK->taskid);
     rc = udebug_task_cleanup(TASK);
     mutex_unlock(&TASK->udebug.lock);
     return rc;
+}
+/** Set the event mask.
+ *
+ * Sets the event mask that determines which events are enabled.
+ *
+ * @param mask  Or combination of events that should be enabled.
+ * @return  Zero on success or negative error code.
+ */
 int udebug_set_evmask(udebug_evmask_t mask)
+{
-    printf("udebug_set_mask()\n");
+    LOG("udebug_set_mask()\n");
-    printf("debugging task %llu\n", TASK->taskid);
     mutex_lock(&TASK->udebug.lock);
     if (TASK->udebug.dt_state != UDEBUG_TS_ACTIVE) {
         mutex_unlock(&TASK->udebug.lock);
-        printf("udebug_set_mask(): not active debuging session\n");
+        LOG("udebug_set_mask(): not active debuging session\n");
         return EINVAL;
+    }
     TASK->udebug.evmask = mask;
     mutex_unlock(&TASK->udebug.lock);
     return 0;
+}
+/** Give thread GO.
+ *
+ * Upon recieving a go message, the thread is given GO. Having GO
+ * means the thread is allowed to execute userspace code (until
+ * a debugging event or STOP occurs, at which point the thread loses GO.
+ *
+ * @param t The thread to operate on (unlocked and need not be valid).
+ * @param call  The GO call that we are servicing.
+ */
 int udebug_go(thread_t *t, call_t *call)
+{
     int rc;
-//  printf("udebug_go()\n");
     /* On success, this will lock t->udebug.lock */
     rc = _thread_op_begin(t, false);
     if (rc != EOK) {
         return rc;
+    }
     _thread_op_end(t);
     return 0;
+}
+/** Stop a thread (i.e. take its GO away)
+ *
+ * Generates a STOP event as soon as the thread becomes stoppable (i.e.
+ * can be considered stopped).
+ *
+ * @param t The thread to operate on (unlocked and need not be valid).
+ * @param call  The GO call that we are servicing.
+ */
 int udebug_stop(thread_t *t, call_t *call)
+{
     int rc;
-    printf("udebug_stop()\n");
+    LOG("udebug_stop()\n");
     mutex_lock(&TASK->udebug.lock);
     /*
      * On success, this will lock t->udebug.lock. Note that this makes sure
      * the thread is not stopped.
+    }
     /*
      * Answer GO call
      */
-    printf("udebug_stop - answering go call\n");
+    LOG("udebug_stop - answering go call\n");
     /* Make sure nobody takes this call away from us */
     call = t->udebug.go_call;
     t->udebug.go_call = NULL;
     IPC_SET_RETVAL(call->data, 0);
     IPC_SET_ARG1(call->data, UDEBUG_EVENT_STOP);
-    printf("udebug_stop/ipc_answer\n");
+    LOG("udebug_stop/ipc_answer\n");
     THREAD->udebug.cur_event = UDEBUG_EVENT_STOP;
     _thread_op_end(t);
     ipc_answer(&TASK->answerbox, call);
     mutex_unlock(&TASK->udebug.lock);
-    printf("udebog_stop/done\n");
+    LOG("udebog_stop/done\n");
     return 0;
+}
+/** Read the list of userspace threads in the current task.
+ *
+ * The list takes the form of a sequence of thread hashes (i.e. the pointers
+ * to thread structures). A buffer of size @a buf_size is allocated and
+ * a pointer to it written to @a buffer. The sequence of hashes is written
+ * into this buffer.
+ *
+ * If the sequence is longer than @a buf_size bytes, only as much hashes
+ * as can fit are copied. The number of thread hashes copied is stored
+ * in @a n.
+ *
+ * The rationale for having @a buf_size is that this function is only
+ * used for servicing the THREAD_READ message, which always specifies
+ * a maximum size for the userspace buffer.
+ *
+ * @param buffer    The buffer for storing thread hashes.
+ * @param buf_size  Buffer size in bytes.
+ * @param n     The actual number of hashes copied will be stored here.
+ */
 int udebug_thread_read(void **buffer, size_t buf_size, size_t *n)
+{
     thread_t *t;
     link_t *cur;
     unative_t tid;
     ipl_t ipl;
     unative_t *id_buffer;
     int flags;
     size_t max_ids;
-    printf("udebug_thread_read()\n");
+    LOG("udebug_thread_read()\n");
     /* Allocate a buffer to hold thread IDs */
     id_buffer = malloc(buf_size, 0);
     mutex_lock(&TASK->udebug.lock);
     *n = copied_ids * sizeof(unative_t);
     return 0;
+}
+/** Read the arguments of a system call.
+ *
+ * The arguments of the system call being being executed are copied
+ * to an allocated buffer and a pointer to it is written to @a buffer.
+ * The size of the buffer is exactly such that it can hold the maximum number
+ * of system-call arguments.
+ *
+ * Unless the thread is currently blocked in a SYSCALL_B or SYSCALL_E event,
+ * this function will fail with an EINVAL error code.
+ *
+ * @param buffer    The buffer for storing thread hashes.
+ */
 int udebug_args_read(thread_t *t, void **buffer)
+{
     int rc;
     unative_t *arg_buffer;
-//  printf("udebug_args_read()\n");
     /* Prepare a buffer to hold the arguments */
     arg_buffer = malloc(6 * sizeof(unative_t), 0);
     /* On success, this will lock t->udebug.lock */
     rc = _thread_op_begin(t, false);
     _thread_op_end(t);
     return 0;
+}
+/** Read the memory of the debugged task.
+ *
+ * Reads @a n bytes from the address space of the debugged task, starting
+ * from @a uspace_addr. The bytes are copied into an allocated buffer
+ * and a pointer to it is written into @a buffer.
+ *
+ * @param uspace_addr   Address from where to start reading.
+ * @param n     Number of bytes to read.
+ * @param buffer    For storing a pointer to the allocated buffer.
+ */
 int udebug_mem_read(unative_t uspace_addr, size_t n, void **buffer)
+{
     void *data_buffer;
     int rc;
         return EBUSY;
+    }
     data_buffer = malloc(n, 0);
-//  printf("udebug_mem_read: src=%u, size=%u\n", uspace_addr, n);
     /* NOTE: this is not strictly from a syscall... but that shouldn't
      * be a problem */
     rc = copy_from_uspace(data_buffer, (void *)uspace_addr, n);
     mutex_unlock(&TASK->udebug.lock);

Subversion Repositories HelenOS

(root)/branches/tracing/kernel/generic/src/udebug/udebug_ops.c – Rev 3424 → 3471