| 0,0 → 1,502 |
|---|
| /* |
| * 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. |
| * |
| * Functions in this file are executed directly in each thread, which |
| * may or may not be the subject of debugging. The udebug_stoppable_begin/end() |
| * functions are also executed in the clock interrupt handler. To avoid |
| * deadlock, functions in this file are protected from the interrupt |
| * by locking the recursive lock THREAD->udebug.int_lock (just an atomic |
| * variable). This prevents udebug_stoppable_begin/end() from being |
| * executed in the interrupt handler (they are skipped). |
| * |
| * Functions in udebug_ops.c and udebug_ipc.c execute in different threads, |
| * so they needn't be protected from the (preemptible) interrupt-initiated |
| * code. |
| */ |
| |
| #include <synch/waitq.h> |
| #include <debug.h> |
| #include <udebug/udebug.h> |
| #include <errno.h> |
| #include <arch.h> |
| |
| static inline void udebug_int_lock(void) |
| { |
| atomic_inc(&THREAD->udebug.int_lock); |
| } |
| |
| static inline void udebug_int_unlock(void) |
| { |
| atomic_dec(&THREAD->udebug.int_lock); |
| } |
| |
| void udebug_task_init(udebug_task_t *ut) |
| { |
| mutex_initialize(&ut->lock, MUTEX_PASSIVE); |
| ut->dt_state = UDEBUG_TS_INACTIVE; |
| ut->begin_call = NULL; |
| ut->not_stoppable_count = 0; |
| ut->evmask = 0; |
| } |
| |
| void udebug_thread_initialize(udebug_thread_t *ut) |
| { |
| mutex_initialize(&ut->lock, MUTEX_PASSIVE); |
| waitq_initialize(&ut->go_wq); |
| |
| /* |
| * At the beginning the thread is stoppable, so int_lock be set, too. |
| */ |
| atomic_set(&ut->int_lock, 1); |
| |
| ut->go_call = NULL; |
| ut->stop = true; |
| ut->stoppable = true; |
| ut->debug_active = false; |
| ut->cur_event = 0; /* none */ |
| } |
| |
| static void udebug_wait_for_go(waitq_t *wq) |
| { |
| int rc; |
| ipl_t ipl; |
| |
| ipl = waitq_sleep_prepare(wq); |
| |
| wq->missed_wakeups = 0; /* Enforce blocking. */ |
| rc = waitq_sleep_timeout_unsafe(wq, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE); |
| |
| waitq_sleep_finish(wq, rc, ipl); |
| } |
| |
| /** Do a preliminary check that a debugging session is in progress. |
| * |
| * This only requires the THREAD->udebug.lock mutex (and not |
| * TASK->udebug.lock mutex). For an undebugged task, this will |
| * never block (while there could be collisions by different threads |
| * on the TASK mutex), thus improving SMP perormance for undebugged tasks. |
| */ |
| static bool udebug_thread_precheck(void) |
| { |
| bool res; |
| |
| mutex_lock(&THREAD->udebug.lock); |
| res = THREAD->udebug.debug_active; |
| mutex_unlock(&THREAD->udebug.lock); |
| |
| return res; |
| } |
| |
| void udebug_stoppable_begin(void) |
| { |
| int nsc; |
| call_t *db_call, *go_call; |
| |
| ASSERT(THREAD); |
| ASSERT(TASK); |
| |
| udebug_int_lock(); |
| |
| /* Early check for undebugged tasks */ |
| if (!udebug_thread_precheck()) { |
| udebug_int_unlock(); |
| return; |
| } |
| |
| mutex_lock(&TASK->udebug.lock); |
| |
| nsc = --TASK->udebug.not_stoppable_count; |
| |
| /* Lock order OK, THREAD->udebug.lock is after TASK->udebug.lock */ |
| mutex_lock(&THREAD->udebug.lock); |
| ASSERT(THREAD->udebug.stoppable == false); |
| THREAD->udebug.stoppable = true; |
| |
| if (TASK->udebug.dt_state == UDEBUG_TS_BEGINNING && nsc == 0) { |
| /* |
| * This was the last non-stoppable thread. Reply to |
| * DEBUG_BEGIN call. |
| */ |
| |
| db_call = TASK->udebug.begin_call; |
| ASSERT(db_call); |
| |
| TASK->udebug.dt_state = UDEBUG_TS_ACTIVE; |
| TASK->udebug.begin_call = NULL; |
| |
| IPC_SET_RETVAL(db_call->data, 0); |
| ipc_answer(&TASK->answerbox, db_call); |
| |
| } else if (TASK->udebug.dt_state == UDEBUG_TS_ACTIVE) { |
| /* |
| * Active debugging session |
| */ |
| |
| if (THREAD->udebug.debug_active && THREAD->udebug.stop) { |
| /* |
| * Thread was requested to stop - answer go call |
| */ |
| |
| /* Make sure nobody takes this call away from us */ |
| go_call = THREAD->udebug.go_call; |
| THREAD->udebug.go_call = NULL; |
| ASSERT(go_call); |
| |
| IPC_SET_RETVAL(go_call->data, 0); |
| IPC_SET_ARG1(go_call->data, UDEBUG_EVENT_STOP); |
| |
| THREAD->udebug.cur_event = UDEBUG_EVENT_STOP; |
| |
| ipc_answer(&TASK->answerbox, go_call); |
| } |
| } |
| |
| mutex_unlock(&THREAD->udebug.lock); |
| mutex_unlock(&TASK->udebug.lock); |
| } |
| |
| void udebug_stoppable_end(void) |
| { |
| /* Early check for undebugged tasks */ |
| if (!udebug_thread_precheck()) { |
| udebug_int_unlock(); |
| return; |
| } |
| |
| restart: |
| mutex_lock(&TASK->udebug.lock); |
| mutex_lock(&THREAD->udebug.lock); |
| |
| if (THREAD->udebug.debug_active && |
| THREAD->udebug.stop == true) { |
| TASK->udebug.begin_call = NULL; |
| mutex_unlock(&THREAD->udebug.lock); |
| mutex_unlock(&TASK->udebug.lock); |
| |
| udebug_wait_for_go(&THREAD->udebug.go_wq); |
| |
| goto restart; |
| /* must try again - have to lose stoppability atomically */ |
| } else { |
| ++TASK->udebug.not_stoppable_count; |
| ASSERT(THREAD->udebug.stoppable == true); |
| THREAD->udebug.stoppable = false; |
| |
| mutex_unlock(&THREAD->udebug.lock); |
| mutex_unlock(&TASK->udebug.lock); |
| } |
| |
| udebug_int_unlock(); |
| } |
| |
| /** Upon being scheduled to run, check if the current thread should stop. |
| * |
| * This function is called from clock(). Preemption is enabled. |
| * interrupts are disabled, but since this is called after |
| * being scheduled-in, we can enable them, if we're careful enough |
| * not to allow arbitrary recursion or deadlock with the thread context. |
| */ |
| void udebug_before_thread_runs(void) |
| { |
| ipl_t ipl; |
| |
| return; |
| ASSERT(!PREEMPTION_DISABLED); |
| |
| /* |
| * Prevent agains re-entering, such as when preempted inside this |
| * function. |
| */ |
| if (atomic_get(&THREAD->udebug.int_lock) != 0) |
| return; |
| |
| udebug_int_lock(); |
| |
| ipl = interrupts_enable(); |
| |
| /* Now we're free to do whatever we need (lock mutexes, sleep, etc.) */ |
| |
| /* Check if we're supposed to stop */ |
| udebug_stoppable_begin(); |
| udebug_stoppable_end(); |
| |
| interrupts_restore(ipl); |
| |
| udebug_int_unlock(); |
| } |
| |
| 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, |
| bool end_variant) |
| { |
| call_t *call; |
| udebug_event_t etype; |
| |
| etype = end_variant ? UDEBUG_EVENT_SYSCALL_E : UDEBUG_EVENT_SYSCALL_B; |
| |
| udebug_int_lock(); |
| |
| /* Early check for undebugged tasks */ |
| if (!udebug_thread_precheck()) { |
| udebug_int_unlock(); |
| return; |
| } |
| |
| mutex_lock(&TASK->udebug.lock); |
| mutex_lock(&THREAD->udebug.lock); |
| |
| /* Must only generate events when in debugging session and have go */ |
| if (THREAD->udebug.debug_active != true || |
| THREAD->udebug.stop == true || |
| (TASK->udebug.evmask & UDEBUG_EVMASK(etype)) == 0) { |
| mutex_unlock(&THREAD->udebug.lock); |
| mutex_unlock(&TASK->udebug.lock); |
| return; |
| } |
| |
| //printf("udebug_syscall_event\n"); |
| call = THREAD->udebug.go_call; |
| THREAD->udebug.go_call = NULL; |
| |
| IPC_SET_RETVAL(call->data, 0); |
| IPC_SET_ARG1(call->data, etype); |
| IPC_SET_ARG2(call->data, id); |
| IPC_SET_ARG3(call->data, rc); |
| //printf("udebug_syscall_event/ipc_answer\n"); |
| |
| THREAD->udebug.syscall_args[0] = a1; |
| THREAD->udebug.syscall_args[1] = a2; |
| THREAD->udebug.syscall_args[2] = a3; |
| THREAD->udebug.syscall_args[3] = a4; |
| THREAD->udebug.syscall_args[4] = a5; |
| THREAD->udebug.syscall_args[5] = a6; |
| |
| /* |
| * Make sure udebug.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->udebug.stop = true; |
| THREAD->udebug.cur_event = etype; |
| |
| ipc_answer(&TASK->answerbox, call); |
| |
| mutex_unlock(&THREAD->udebug.lock); |
| mutex_unlock(&TASK->udebug.lock); |
| |
| udebug_wait_for_go(&THREAD->udebug.go_wq); |
| |
| udebug_int_unlock(); |
| } |
| |
| void udebug_thread_b_event(struct thread *t) |
| { |
| call_t *call; |
| |
| udebug_int_lock(); |
| |
| mutex_lock(&TASK->udebug.lock); |
| mutex_lock(&THREAD->udebug.lock); |
| |
| LOG("udebug_thread_b_event\n"); |
| LOG("- check state\n"); |
| |
| /* Must only generate events when in debugging session */ |
| if (THREAD->udebug.debug_active != true) { |
| LOG("- debug_active: %s, udebug.stop: %s\n", |
| THREAD->udebug.debug_active ? "yes(+)" : "no(-)", |
| THREAD->udebug.stop ? "yes(-)" : "no(+)"); |
| mutex_unlock(&THREAD->udebug.lock); |
| mutex_unlock(&TASK->udebug.lock); |
| return; |
| } |
| |
| LOG("- trigger event\n"); |
| |
| call = THREAD->udebug.go_call; |
| THREAD->udebug.go_call = NULL; |
| IPC_SET_RETVAL(call->data, 0); |
| IPC_SET_ARG1(call->data, UDEBUG_EVENT_THREAD_B); |
| IPC_SET_ARG2(call->data, (unative_t)t); |
| |
| /* |
| * Make sure udebug.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->udebug.stop = true; |
| THREAD->udebug.cur_event = UDEBUG_EVENT_THREAD_B; |
| |
| ipc_answer(&TASK->answerbox, call); |
| |
| mutex_unlock(&THREAD->udebug.lock); |
| mutex_unlock(&TASK->udebug.lock); |
| |
| LOG("- sleep\n"); |
| udebug_wait_for_go(&THREAD->udebug.go_wq); |
| |
| udebug_int_unlock(); |
| } |
| |
| void udebug_thread_e_event(void) |
| { |
| call_t *call; |
| |
| udebug_int_lock(); |
| |
| mutex_lock(&TASK->udebug.lock); |
| mutex_lock(&THREAD->udebug.lock); |
| |
| LOG("udebug_thread_e_event\n"); |
| LOG("- check state\n"); |
| |
| /* Must only generate events when in debugging session */ |
| if (THREAD->udebug.debug_active != true) { |
| /* printf("- debug_active: %s, udebug.stop: %s\n", |
| THREAD->udebug.debug_active ? "yes(+)" : "no(-)", |
| THREAD->udebug.stop ? "yes(-)" : "no(+)");*/ |
| mutex_unlock(&THREAD->udebug.lock); |
| mutex_unlock(&TASK->udebug.lock); |
| return; |
| } |
| |
| LOG("- trigger event\n"); |
| |
| call = THREAD->udebug.go_call; |
| THREAD->udebug.go_call = NULL; |
| IPC_SET_RETVAL(call->data, 0); |
| IPC_SET_ARG1(call->data, UDEBUG_EVENT_THREAD_E); |
| |
| /* Prevent any further debug activity in thread */ |
| THREAD->udebug.debug_active = false; |
| THREAD->udebug.cur_event = 0; /* none */ |
| THREAD->udebug.stop = true; /* set to initial value */ |
| |
| ipc_answer(&TASK->answerbox, call); |
| |
| mutex_unlock(&THREAD->udebug.lock); |
| mutex_unlock(&TASK->udebug.lock); |
| |
| /* Leave int_lock enabled */ |
| /* This event does not sleep - debugging has finished in this thread */ |
| } |
| |
| /** |
| * Terminate task debugging session. |
| * |
| * \param ta->udebug.lock must be already locked. |
| * \return Zero on success or negative error code. |
| */ |
| int udebug_task_cleanup(struct task *ta) |
| { |
| thread_t *t; |
| link_t *cur; |
| int flags; |
| ipl_t ipl; |
| |
| LOG("udebug_task_cleanup()\n"); |
| LOG("task %" PRIu64 "\n", ta->taskid); |
| |
| udebug_int_lock(); |
| |
| if (ta->udebug.dt_state != UDEBUG_TS_BEGINNING && |
| ta->udebug.dt_state != UDEBUG_TS_ACTIVE) { |
| LOG("udebug_task_cleanup(): task not being debugged\n"); |
| 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); |
| |
| mutex_lock(&t->udebug.lock); |
| |
| ipl = interrupts_disable(); |
| spinlock_lock(&t->lock); |
| |
| flags = t->flags; |
| |
| spinlock_unlock(&t->lock); |
| interrupts_restore(ipl); |
| |
| /* Only process userspace threads */ |
| if ((flags & THREAD_FLAG_USPACE) != 0) { |
| /* Prevent any further debug activity in thread */ |
| t->udebug.debug_active = false; |
| t->udebug.cur_event = 0; /* none */ |
| |
| /* Still has go? */ |
| if (t->udebug.stop == false) { |
| /* |
| * Yes, so clear go. As debug_active == false, |
| * this doesn't affect anything. |
| */ |
| t->udebug.stop = true; |
| |
| /* Answer GO call */ |
| LOG("answer GO call with EVENT_FINISHED\n"); |
| IPC_SET_RETVAL(t->udebug.go_call->data, 0); |
| IPC_SET_ARG1(t->udebug.go_call->data, UDEBUG_EVENT_FINISHED); |
| |
| ipc_answer(&ta->answerbox, t->udebug.go_call); |
| t->udebug.go_call = NULL; |
| } 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->udebug.go_wq, WAKEUP_FIRST); |
| } |
| } |
| mutex_unlock(&t->udebug.lock); |
| } |
| |
| ta->udebug.dt_state = UDEBUG_TS_INACTIVE; |
| ta->udebug.debugger = NULL; |
| |
| udebug_int_unlock(); |
| |
| return 0; |
| } |
| |
| |
| /** @} |
| */ |