/*
* 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_task_init(udebug_task_t *ut)
{
ut->dt_state = UDEBUG_TS_INACTIVE;
ut->begin_call = NULL;
ut->not_stoppable_count = 0;
ut->evmask = 0;
}
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);
}
void udebug_stoppable_begin(void)
{
int nsc;
call_t *db_call, *go_call;
ipl_t ipl;
ASSERT(THREAD);
ASSERT(TASK);
ipl = interrupts_disable();
spinlock_lock(&TASK->lock);
nsc = --TASK->udebug.not_stoppable_count;
if (TASK->udebug.dt_state == UDEBUG_TS_BEGINNING) {
klog_printf("udebug_stoppable_begin");
klog_printf(" - nsc := %d", nsc);
}
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);
/* 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->udebug.dt_state = UDEBUG_TS_ACTIVE;
TASK->udebug.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->udebug.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_active && 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;
ASSERT(go_call);
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->udebug.dt_state == UDEBUG_TS_ACTIVE) {
//klog_printf("udebug_stoppable_end");
//klog_printf("debug_stop=%d", THREAD->debug_stop);
}
if (THREAD->debug_active &&
THREAD->debug_stop == true) {
TASK->udebug.begin_call = NULL;
spinlock_unlock(&THREAD->debug_lock);
spinlock_unlock(&TASK->lock);
interrupts_restore(ipl);
udebug_wait_for_go(&THREAD->go_wq);
goto restart;
/* must try again - have to lose stoppability atomically */
} else {
++TASK->udebug.not_stoppable_count;
THREAD->debug_stoppable = false;
spinlock_unlock(&THREAD->debug_lock);
spinlock_unlock(&TASK->lock);
interrupts_restore(ipl);
}
}
/** 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.
*/
void udebug_before_thread_runs(void)
{
ipl_t ipl;
/* This will happen if we get preempted inside this function. */
if (THREAD->debug_in_before_thread_runs)
return;
THREAD->debug_in_before_thread_runs = true;
ipl = interrupts_enable();
/* Now we're free to do whatever we need (lock mutexes, etc.) */
/* Check if we're supposed to stop */
udebug_stoppable_begin();
udebug_stoppable_end();
interrupts_restore(ipl);
THREAD->debug_in_before_thread_runs = false;
}
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;
ipl_t ipl;
udebug_event_t etype;
etype = end_variant ? UDEBUG_EVENT_SYSCALL_E : UDEBUG_EVENT_SYSCALL_B;
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 ||
(TASK->udebug.evmask & UDEBUG_EVMASK(etype)) == 0) {
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, etype);
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 = etype;
spinlock_unlock(&THREAD->debug_lock);
spinlock_lock(&TASK->lock);
ipc_answer(&TASK->answerbox, THREAD->debug_go_call);
spinlock_unlock(&TASK->lock);
interrupts_restore(ipl);
udebug_wait_for_go(&THREAD->go_wq);
}
void udebug_thread_b_event(struct thread *t)
{
call_t *call;
ipl_t ipl;
ipl = interrupts_disable();
spinlock_lock(&THREAD->debug_lock);
klog_printf("udebug_thread_b_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_THREAD_B);
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_THREAD_B;
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");
udebug_wait_for_go(&THREAD->go_wq);
}
void udebug_thread_e_event(void)
{
call_t *call;
ipl_t ipl;
ipl = interrupts_disable();
spinlock_lock(&THREAD->debug_lock);
klog_printf("udebug_thread_e_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_THREAD_E);
/* Prevent any further debug activity in thread */
THREAD->debug_active = false;
THREAD->cur_event = 0; /* none */
THREAD->debug_stop = true; /* set to initial value */
spinlock_unlock(&THREAD->debug_lock);
spinlock_lock(&TASK->lock);
ipc_answer(&TASK->answerbox, THREAD->debug_go_call);
spinlock_unlock(&TASK->lock);
interrupts_restore(ipl);
/* This event does not sleep - debugging has finished in this thread */
}
static void breakpoint_trap_event(uintptr_t addr, udebug_event_t etype)
{
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 ||
(TASK->udebug.evmask & UDEBUG_EVMASK(etype)) == 0) {
spinlock_unlock(&THREAD->debug_lock);
interrupts_restore(ipl);
return;
}
klog_printf("udebug_breakpoint/trap_event");
call = THREAD->debug_go_call;
IPC_SET_RETVAL(call->data, 0);
IPC_SET_ARG1(call->data, etype);
IPC_SET_ARG2(call->data, addr);
/*
* 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 = etype;
spinlock_unlock(&THREAD->debug_lock);
klog_printf("- send answer");
spinlock_lock(&TASK->lock);
ipc_answer(&TASK->answerbox, THREAD->debug_go_call);
spinlock_unlock(&TASK->lock);
interrupts_restore(ipl);
udebug_wait_for_go(&THREAD->go_wq);
}
void udebug_breakpoint_event(uintptr_t addr)
{
breakpoint_trap_event(addr, UDEBUG_EVENT_BREAKPOINT);
}
void udebug_trap_event(uintptr_t addr)
{
breakpoint_trap_event(addr, UDEBUG_EVENT_TRAP);
}
/**
* 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->udebug.dt_state == UDEBUG_TS_BEGINNING &&
ta->udebug.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->udebug.dt_state = UDEBUG_TS_INACTIVE;
ta->udebug.debugger = NULL;
return 0;
}
/** @}
*/