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 <print.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); |
|
printf("udebug_thread_b_event\n"); |
printf("- 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; |
} |
|
printf("- 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); |
|
printf("- 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); |
|
// printf("udebug_thread_e_event\n"); |
// printf("- 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; |
} |
|
// printf("- 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; |
|
printf("udebug_task_cleanup()\n"); |
printf("task %llu\n", ta->taskid); |
|
udebug_int_lock(); |
|
if (ta->udebug.dt_state != UDEBUG_TS_BEGINNING && |
ta->udebug.dt_state != UDEBUG_TS_ACTIVE) { |
printf("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 */ |
printf("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; |
} |
|
|
/** @} |
*/ |