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

 /*
  * 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 generic
  * @{
  */
 /**
  * @file
  * @brief   Udebug.
  */
 #include <synch/waitq.h>
 #include <console/klog.h>
 #include <udebug/udebug.h>
 #include <errno.h>
 #include <arch.h>
 void udebug_stoppable_begin(void)
+{
     int nsc;
-    call_t *db_call;
+    call_t *db_call, *go_call;
     ipl_t ipl;
     ipl = interrupts_disable();
     spinlock_lock(&TASK->lock);
     nsc = --TASK->not_stoppable_count;
     db_call = TASK->debug_begin_call;
     if (TASK->dt_state == UDEBUG_TS_BEGINNING) {
         klog_printf("udebug_stoppable_begin");
         klog_printf(" - nsc := %d", nsc);
+    }
     if (TASK->dt_state == UDEBUG_TS_BEGINNING && nsc == 0) {
+        /*
+         * This was the last non-stoppable thread. Reply to
+         * DEBUG_BEGIN call.
+         */
+        /* Lock order OK, THREAD->debug_lock is after TASK->lock */
+        spinlock_lock(&THREAD->debug_lock);
+        THREAD->debug_stoppable = true;
+        spinlock_unlock(&THREAD->debug_lock);
         TASK->dt_state = UDEBUG_TS_ACTIVE;
         TASK->debug_begin_call = NULL;
         spinlock_unlock(&TASK->lock);
         interrupts_restore(ipl);
         IPC_SET_RETVAL(db_call->data, 0);
         klog_printf("udebug_stoppable_begin/ipc_answer");
         ipc_answer(&TASK->answerbox, db_call);
+    } else if (TASK->dt_state == UDEBUG_TS_ACTIVE) {
+        /*
+         * Active debugging session
+         */
+        /* Lock order OK, THREAD->debug_lock is after TASK->lock */
+        spinlock_lock(&THREAD->debug_lock);
+        THREAD->debug_stoppable = true;
+        if (THREAD->debug_stop) {
+            /*
+             * Thread was requested to stop - answer go call
+             */
+            /* Make sure nobody takes this call away from us */
+            go_call = THREAD->debug_go_call;
+            THREAD->debug_go_call = NULL;
+            IPC_SET_RETVAL(go_call->data, 0);
+            IPC_SET_ARG1(go_call->data, UDEBUG_EVENT_STOP);
+            THREAD->cur_event = UDEBUG_EVENT_STOP;
+            spinlock_unlock(&THREAD->debug_lock);
+                ipc_answer(&TASK->answerbox, go_call);
+                spinlock_unlock(&TASK->lock);
+            interrupts_restore(ipl);
+        } else {
+            /*
+             * No stop request - nothing happens.
+             */
+            spinlock_unlock(&THREAD->debug_lock);
+                spinlock_unlock(&TASK->lock);
+            interrupts_restore(ipl);
+        }
     } else {
+        /*
+         * All other cases - nothing special happens.
+         */
+        /* Lock order OK, THREAD->debug_lock is after TASK->lock */
+        spinlock_lock(&THREAD->debug_lock);
+        THREAD->debug_stoppable = true;
+        spinlock_unlock(&THREAD->debug_lock);
             spinlock_unlock(&TASK->lock);
         interrupts_restore(ipl);
+    }
+}
 void udebug_stoppable_end(void)
+{
     ipl_t ipl;
 restart:
     ipl = interrupts_disable();
     spinlock_lock(&TASK->lock);
+    /* Lock order OK, THREAD->debug_lock is after TASK->lock */
+    spinlock_lock(&THREAD->debug_lock);
+    if (TASK->dt_state == UDEBUG_TS_ACTIVE) {
+        klog_printf("udebug_stoppable_end");
+        klog_printf("debug_stop=%d", THREAD->debug_stop);
+    }
     if ((TASK->dt_state == UDEBUG_TS_BEGINNING ||
         TASK->dt_state == UDEBUG_TS_ACTIVE) &&
         THREAD->debug_stop == true) {
         TASK->debug_begin_call = NULL;
+        spinlock_unlock(&THREAD->debug_lock);
         spinlock_unlock(&TASK->lock);
         interrupts_restore(ipl);
         klog_printf("udebug_stoppable_end: waitq_sleep");
         waitq_sleep(&THREAD->go_wq);
         goto restart;
         /* must try again - have to lose stoppability atomically */
     } else {
         ++TASK->not_stoppable_count;
+        THREAD->debug_stoppable = false;
+        spinlock_unlock(&THREAD->debug_lock);
         spinlock_unlock(&TASK->lock);
         interrupts_restore(ipl);
+    }
+}
 void udebug_syscall_event(unative_t a1, unative_t a2, unative_t a3,
     unative_t a4, unative_t a5, unative_t a6, unative_t id, unative_t rc)
+{
     call_t *call;
     ipl_t ipl;
     ipl = interrupts_disable();
     spinlock_lock(&THREAD->debug_lock);
     /* Must only generate events when in debugging session and have go */
     if (THREAD->debug_active != true ||
         THREAD->debug_stop == true) {
         spinlock_unlock(&THREAD->debug_lock);
         interrupts_restore(ipl);
         return;
+    }
     klog_printf("udebug_syscall_event");
     call = THREAD->debug_go_call;
     IPC_SET_RETVAL(call->data, 0);
     IPC_SET_ARG1(call->data, UDEBUG_EVENT_SYSCALL);
     IPC_SET_ARG2(call->data, id);
     IPC_SET_ARG3(call->data, rc);
     klog_printf("udebug_syscall_event/ipc_answer");
     THREAD->syscall_args[0] = a1;
     THREAD->syscall_args[1] = a2;
     THREAD->syscall_args[2] = a3;
     THREAD->syscall_args[3] = a4;
     THREAD->syscall_args[4] = a5;
     THREAD->syscall_args[5] = a6;
     /*
      * Make sure debug_stop is true when going to sleep
      * in case we get woken up by DEBUG_END. (At which
      * point it must be back to the initial true value).
      */
     THREAD->debug_stop = true;
     THREAD->cur_event = UDEBUG_EVENT_SYSCALL;
     spinlock_unlock(&THREAD->debug_lock);
     spinlock_lock(&TASK->lock);
     ipc_answer(&TASK->answerbox, THREAD->debug_go_call);
     spinlock_unlock(&TASK->lock);
     interrupts_restore(ipl);
     waitq_sleep(&THREAD->go_wq);
+}
 void udebug_new_thread_event(struct thread *t)
+{
     call_t *call;
     ipl_t ipl;
     ipl = interrupts_disable();
     spinlock_lock(&THREAD->debug_lock);
     klog_printf("udebug_new_thread_event");
     klog_printf("- check state");
     /* Must only generate events when in debugging session */
     if (THREAD->debug_active != true) {
         klog_printf("- debug_active: %s, debug_stop: %s",
             THREAD->debug_active ? "yes(+)" : "no(-)",
             THREAD->debug_stop ? "yes(-)" : "no(+)");
         spinlock_unlock(&THREAD->debug_lock);
         interrupts_restore(ipl);
         return;
+    }
     klog_printf("- trigger event");
     call = THREAD->debug_go_call;
     IPC_SET_RETVAL(call->data, 0);
     IPC_SET_ARG1(call->data, UDEBUG_EVENT_NEW_THREAD);
     IPC_SET_ARG2(call->data, (unative_t)t);
     /*
      * Make sure debug_stop is true when going to sleep
      * in case we get woken up by DEBUG_END. (At which
      * point it must be back to the initial true value).
      */
     THREAD->debug_stop = true;
     THREAD->cur_event = UDEBUG_EVENT_NEW_THREAD;
     spinlock_unlock(&THREAD->debug_lock);
     spinlock_lock(&TASK->lock);
     ipc_answer(&TASK->answerbox, THREAD->debug_go_call);
     spinlock_unlock(&TASK->lock);
     interrupts_restore(ipl);
     klog_printf("- sleep");
     waitq_sleep(&THREAD->go_wq);
+}
 /**
  * Terminate task debugging session.
+ *
  * \param ta Must be already locked and interrupts must be disabled.
  * \return Zero on success or negative error code.
  */
 int udebug_task_cleanup(struct task *ta)
+{
     thread_t *t;
     link_t *cur;
     int flags;
     klog_printf("udebug_task_cleanup()");
     klog_printf("task %llu", ta->taskid);
     if (ta->dt_state == UDEBUG_TS_BEGINNING &&
         ta->dt_state != UDEBUG_TS_ACTIVE) {
         klog_printf("udebug_task_cleanup(): task not being debugged");
         return EINVAL;
+    }
     /* Finish debugging of all userspace threads */
     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
         t = list_get_instance(cur, thread_t, th_link);
         spinlock_lock(&t->debug_lock);
         spinlock_lock(&t->lock);
         flags = t->flags;
         spinlock_unlock(&t->lock);
         /* Only process userspace threads */
         if ((flags & THREAD_FLAG_USPACE) != 0) {
             /* Prevent any further debug activity in thread */
             t->debug_active = false;
             t->cur_event = 0;   /* none */
             /* Still has go? */
             if (t->debug_stop == false) {
                 /*
                 * Yes, so clear go. As debug_active == false,
                  * this doesn't affect anything.
                  */
                 t->debug_stop = true;
                 /* Answer GO call */
                 klog_printf("answer GO call with EVENT_FINISHED");
                 IPC_SET_RETVAL(t->debug_go_call->data, 0);
                 IPC_SET_ARG1(t->debug_go_call->data, UDEBUG_EVENT_FINISHED);
                 ipc_answer(&ta->answerbox, t->debug_go_call);
             } else {
                 /*
                  * Debug_stop is already at initial value.
                  * Yet this means the thread needs waking up.
                  */
                 /*
                  * t's lock must not be held when calling
                  * waitq_wakeup.
                  */
                 waitq_wakeup(&t->go_wq, WAKEUP_FIRST);
+            }
+        }
         spinlock_unlock(&t->debug_lock);
+    }
     ta->dt_state = UDEBUG_TS_INACTIVE;
     ta->debugger = NULL;
     return 0;
+}
 /** @}
  */

Subversion Repositories HelenOS

(root)/branches/tracing/kernel/generic/src/udebug/udebug.c @ 2849 – Rev 2894 → 2898