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/branches/dd/kernel/generic/src/udebug/udebug.c
0,0 → 1,504
/*
* 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 hooks and data structure management.
*
* Udebug is an interface that makes userspace debuggers possible.
*/
#include <synch/waitq.h>
#include <debug.h>
#include <udebug/udebug.h>
#include <errno.h>
#include <print.h>
#include <arch.h>
 
 
/** Initialize udebug part of task structure.
*
* Called as part of task structure initialization.
* @param ut Pointer to the structure to initialize.
*/
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;
}
 
/** Initialize udebug part of thread structure.
*
* Called as part of thread structure initialization.
* @param ut Pointer to the structure to initialize.
*/
void udebug_thread_initialize(udebug_thread_t *ut)
{
mutex_initialize(&ut->lock, MUTEX_PASSIVE);
waitq_initialize(&ut->go_wq);
 
ut->go_call = NULL;
ut->uspace_state = NULL;
ut->go = false;
ut->stoppable = true;
ut->active = false;
ut->cur_event = 0; /* none */
}
 
/** Wait for a GO message.
*
* When a debugging event occurs in a thread or the thread is stopped,
* this function is called to block the thread until a GO message
* is received.
*
* @param wq The wait queue used by the thread to wait for GO messages.
*/
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.
*
* @return True if the thread was in a debugging session when the function
* checked, false otherwise.
*/
static bool udebug_thread_precheck(void)
{
bool res;
 
mutex_lock(&THREAD->udebug.lock);
res = THREAD->udebug.active;
mutex_unlock(&THREAD->udebug.lock);
 
return res;
}
 
/** Start of stoppable section.
*
* A stoppable section is a section of code where if the thread can be stoped. In other words,
* if a STOP operation is issued, the thread is guaranteed not to execute
* any userspace instructions until the thread is resumed.
*
* Having stoppable sections is better than having stopping points, since
* a thread can be stopped even when it is blocked indefinitely in a system
* call (whereas it would not reach any stopping point).
*/
void udebug_stoppable_begin(void)
{
int nsc;
call_t *db_call, *go_call;
 
ASSERT(THREAD);
ASSERT(TASK);
 
/* Early check for undebugged tasks */
if (!udebug_thread_precheck()) {
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.active == true &&
THREAD->udebug.go == false) {
/*
* 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);
}
 
/** End of a stoppable section.
*
* This is the point where the thread will block if it is stopped.
* (As, by definition, a stopped thread must not leave its stoppable section).
*/
void udebug_stoppable_end(void)
{
/* Early check for undebugged tasks */
if (!udebug_thread_precheck()) {
return;
}
 
restart:
mutex_lock(&TASK->udebug.lock);
mutex_lock(&THREAD->udebug.lock);
 
if (THREAD->udebug.active && THREAD->udebug.go == false) {
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);
}
}
 
/** Upon being scheduled to run, check if the current thread should stop.
*
* This function is called from clock().
*/
void udebug_before_thread_runs(void)
{
/* Check if we're supposed to stop */
udebug_stoppable_begin();
udebug_stoppable_end();
}
 
/** Syscall event hook.
*
* Must be called before and after servicing a system call. This generates
* a SYSCALL_B or SYSCALL_E event, depending on the value of @a end_variant.
*/
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;
 
/* Early check for undebugged tasks */
if (!udebug_thread_precheck()) {
return;
}
 
mutex_lock(&TASK->udebug.lock);
mutex_lock(&THREAD->udebug.lock);
 
/* Must only generate events when in debugging session and is go. */
if (THREAD->udebug.active != true || THREAD->udebug.go == false ||
(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.go is false 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.go = false;
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);
}
 
/** Thread-creation event hook combined with attaching the thread.
*
* Must be called when a new userspace thread is created in the debugged
* task. Generates a THREAD_B event. Also attaches the thread @a t
* to the task @a ta.
*
* This is necessary to avoid a race condition where the BEGIN and THREAD_READ
* requests would be handled inbetween attaching the thread and checking it
* for being in a debugging session to send the THREAD_B event. We could then
* either miss threads or get some threads both in the thread list
* and get a THREAD_B event for them.
*
* @param t Structure of the thread being created. Not locked, as the
* thread is not executing yet.
* @param ta Task to which the thread should be attached.
*/
void udebug_thread_b_event_attach(struct thread *t, struct task *ta)
{
call_t *call;
 
mutex_lock(&TASK->udebug.lock);
mutex_lock(&THREAD->udebug.lock);
 
thread_attach(t, ta);
 
LOG("udebug_thread_b_event\n");
LOG("- check state\n");
 
/* Must only generate events when in debugging session */
if (THREAD->udebug.active != true) {
LOG("- udebug.active: %s, udebug.go: %s\n",
THREAD->udebug.active ? "yes(+)" : "no(-)",
THREAD->udebug.go ? "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.go is false 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.go = false;
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);
}
 
/** Thread-termination event hook.
*
* Must be called when the current thread is terminating.
* Generates a THREAD_E event.
*/
void udebug_thread_e_event(void)
{
call_t *call;
 
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.active != true) {
/* printf("- udebug.active: %s, udebug.go: %s\n",
THREAD->udebug.active ? "yes(+)" : "no(-)",
THREAD->udebug.go ? "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.active = false;
THREAD->udebug.cur_event = 0; /* none */
THREAD->udebug.go = false; /* set to initial value */
 
ipc_answer(&TASK->answerbox, call);
 
mutex_unlock(&THREAD->udebug.lock);
mutex_unlock(&TASK->udebug.lock);
 
/*
* This event does not sleep - debugging has finished
* in this thread.
*/
}
 
/**
* Terminate task debugging session.
*
* Gracefully terminates the debugging session for a task. If the debugger
* is still waiting for events on some threads, it will receive a
* FINISHED event for each of them.
*
* @param ta Task structure. 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);
 
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.active = false;
t->udebug.cur_event = 0; /* none */
 
/* Is the thread still go? */
if (t->udebug.go == true) {
/*
* Yes, so clear go. As active == false,
* this doesn't affect anything.
*/
t->udebug.go = false;
 
/* 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;
 
return 0;
}
 
 
/** @}
*/
/branches/dd/kernel/generic/src/udebug/udebug_ops.c
0,0 → 1,524
/*
* 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 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 <debug.h>
#include <proc/task.h>
#include <proc/thread.h>
#include <arch.h>
#include <errno.h>
#include <print.h>
#include <syscall/copy.h>
#include <ipc/ipc.h>
#include <udebug/udebug.h>
#include <udebug/udebug_ops.h>
 
/**
* Prepare a thread for a debugging operation.
*
* Simply put, return thread t with t->udebug.lock held,
* but only if it verifies all conditions.
*
* Specifically, verifies that thread t exists, is a userspace thread,
* and belongs to the current task (TASK). Verifies, that the thread
* is (or is not) go according to being_go (typically false).
* It also locks t->udebug.lock, making sure that t->udebug.active
* is true - that the thread is in a valid debugging session.
*
* With this verified and the t->udebug.lock mutex held, it is ensured
* that the thread cannot leave the debugging session, let alone cease
* to exist.
*
* 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 being_go Required thread state.
*
* Returns EOK if all went well, or an error code otherwise.
*/
static int _thread_op_begin(thread_t *t, bool being_go)
{
task_id_t taskid;
ipl_t ipl;
 
taskid = TASK->taskid;
 
mutex_lock(&TASK->udebug.lock);
 
/* thread_exists() must be called with threads_lock held */
ipl = interrupts_disable();
spinlock_lock(&threads_lock);
 
if (!thread_exists(t)) {
spinlock_unlock(&threads_lock);
interrupts_restore(ipl);
mutex_unlock(&TASK->udebug.lock);
return ENOENT;
}
 
/* t->lock is enough to ensure the thread's existence */
spinlock_lock(&t->lock);
spinlock_unlock(&threads_lock);
 
/* Verify that 't' is a userspace thread. */
if ((t->flags & THREAD_FLAG_USPACE) == 0) {
/* It's not, deny its existence */
spinlock_unlock(&t->lock);
interrupts_restore(ipl);
mutex_unlock(&TASK->udebug.lock);
return ENOENT;
}
 
/* Verify debugging state. */
if (t->udebug.active != true) {
/* Not in debugging session or undesired GO state */
spinlock_unlock(&t->lock);
interrupts_restore(ipl);
mutex_unlock(&TASK->udebug.lock);
return ENOENT;
}
 
/*
* Since the thread has active == true, TASK->udebug.lock
* is enough to ensure its existence and that active remains
* true.
*/
spinlock_unlock(&t->lock);
interrupts_restore(ipl);
 
/* Only mutex TASK->udebug.lock left. */
/* Now verify that the thread belongs to the current task. */
if (t->task != TASK) {
/* No such thread belonging this task*/
mutex_unlock(&TASK->udebug.lock);
return ENOENT;
}
 
/*
* Now we need to grab the thread's debug lock for synchronization
* of the threads stoppability/stop state.
*/
mutex_lock(&t->udebug.lock);
 
/* The big task mutex is no longer needed. */
mutex_unlock(&TASK->udebug.lock);
 
if (t->udebug.go != being_go) {
/* Not in debugging session or undesired GO state. */
mutex_unlock(&t->udebug.lock);
return EINVAL;
}
 
/* 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.
*/
int udebug_begin(call_t *call)
{
int reply;
 
thread_t *t;
link_t *cur;
 
LOG("udebug_begin()\n");
 
mutex_lock(&TASK->udebug.lock);
LOG("debugging task %llu\n", TASK->taskid);
 
if (TASK->udebug.dt_state != UDEBUG_TS_INACTIVE) {
mutex_unlock(&TASK->udebug.lock);
LOG("udebug_begin(): busy error\n");
 
return EBUSY;
}
 
TASK->udebug.dt_state = UDEBUG_TS_BEGINNING;
TASK->udebug.begin_call = call;
TASK->udebug.debugger = call->sender;
 
if (TASK->udebug.not_stoppable_count == 0) {
TASK->udebug.dt_state = UDEBUG_TS_ACTIVE;
TASK->udebug.begin_call = NULL;
reply = 1; /* immediate reply */
} else {
reply = 0; /* no reply */
}
/* Set udebug.active on all of the task's userspace threads. */
 
for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
t = list_get_instance(cur, thread_t, th_link);
 
mutex_lock(&t->udebug.lock);
if ((t->flags & THREAD_FLAG_USPACE) != 0)
t->udebug.active = true;
mutex_unlock(&t->udebug.lock);
}
 
mutex_unlock(&TASK->udebug.lock);
 
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;
 
LOG("udebug_end()\n");
 
mutex_lock(&TASK->udebug.lock);
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)
{
LOG("udebug_set_mask()\n");
 
mutex_lock(&TASK->udebug.lock);
 
if (TASK->udebug.dt_state != UDEBUG_TS_ACTIVE) {
mutex_unlock(&TASK->udebug.lock);
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. Being 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;
 
/* On success, this will lock t->udebug.lock. */
rc = _thread_op_begin(t, false);
if (rc != EOK) {
return rc;
}
 
t->udebug.go_call = call;
t->udebug.go = true;
t->udebug.cur_event = 0; /* none */
 
/*
* Neither t's lock nor threads_lock may be held during wakeup.
*/
waitq_wakeup(&t->udebug.go_wq, WAKEUP_FIRST);
 
_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;
 
LOG("udebug_stop()\n");
 
/*
* On success, this will lock t->udebug.lock. Note that this makes sure
* the thread is not stopped.
*/
rc = _thread_op_begin(t, true);
if (rc != EOK) {
return rc;
}
 
/* Take GO away from the thread. */
t->udebug.go = false;
 
if (t->udebug.stoppable != true) {
/* Answer will be sent when the thread becomes stoppable. */
_thread_op_end(t);
return 0;
}
 
/*
* Answer GO call.
*/
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);
LOG("udebug_stop/ipc_answer\n");
 
THREAD->udebug.cur_event = UDEBUG_EVENT_STOP;
 
_thread_op_end(t);
 
mutex_lock(&TASK->udebug.lock);
ipc_answer(&TASK->answerbox, call);
mutex_unlock(&TASK->udebug.lock);
 
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;
unsigned copied_ids;
ipl_t ipl;
unative_t *id_buffer;
int flags;
size_t max_ids;
 
LOG("udebug_thread_read()\n");
 
/* Allocate a buffer to hold thread IDs */
id_buffer = malloc(buf_size, 0);
 
mutex_lock(&TASK->udebug.lock);
 
/* Verify task state */
if (TASK->udebug.dt_state != UDEBUG_TS_ACTIVE) {
mutex_unlock(&TASK->udebug.lock);
return EINVAL;
}
 
ipl = interrupts_disable();
spinlock_lock(&TASK->lock);
/* Copy down the thread IDs */
 
max_ids = buf_size / sizeof(unative_t);
copied_ids = 0;
 
/* FIXME: make sure the thread isn't past debug shutdown... */
for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
/* Do not write past end of buffer */
if (copied_ids >= max_ids) break;
 
t = list_get_instance(cur, thread_t, th_link);
 
spinlock_lock(&t->lock);
flags = t->flags;
spinlock_unlock(&t->lock);
 
/* Not interested in kernel threads. */
if ((flags & THREAD_FLAG_USPACE) != 0) {
/* Using thread struct pointer as identification hash */
tid = (unative_t) t;
id_buffer[copied_ids++] = tid;
}
}
 
spinlock_unlock(&TASK->lock);
interrupts_restore(ipl);
 
mutex_unlock(&TASK->udebug.lock);
 
*buffer = id_buffer;
*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;
 
/* 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);
if (rc != EOK) {
return rc;
}
 
/* Additionally we need to verify that we are inside a syscall. */
if (t->udebug.cur_event != UDEBUG_EVENT_SYSCALL_B &&
t->udebug.cur_event != UDEBUG_EVENT_SYSCALL_E) {
_thread_op_end(t);
return EINVAL;
}
 
/* Copy to a local buffer before releasing the lock. */
memcpy(arg_buffer, t->udebug.syscall_args, 6 * sizeof(unative_t));
 
_thread_op_end(t);
 
*buffer = arg_buffer;
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;
 
/* Verify task state */
mutex_lock(&TASK->udebug.lock);
 
if (TASK->udebug.dt_state != UDEBUG_TS_ACTIVE) {
mutex_unlock(&TASK->udebug.lock);
return EBUSY;
}
 
data_buffer = malloc(n, 0);
 
/* 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);
 
if (rc != 0) return rc;
 
*buffer = data_buffer;
return 0;
}
 
/** @}
*/
/branches/dd/kernel/generic/src/udebug/udebug_ipc.c
0,0 → 1,343
/*
* 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 IPC message handling.
*
* This module handles udebug IPC messages and calls the appropriate
* functions from the udebug_ops module which implement them.
*/
#include <proc/task.h>
#include <proc/thread.h>
#include <arch.h>
#include <errno.h>
#include <ipc/ipc.h>
#include <syscall/copy.h>
#include <udebug/udebug.h>
#include <udebug/udebug_ops.h>
#include <udebug/udebug_ipc.h>
 
int udebug_request_preprocess(call_t *call, phone_t *phone)
{
switch (IPC_GET_ARG1(call->data)) {
/* future UDEBUG_M_REGS_WRITE, UDEBUG_M_MEM_WRITE: */
default:
break;
}
 
return 0;
}
 
/** Process a BEGIN call.
*
* Initiates a debugging session for the current task. The reply
* to this call may or may not be sent before this function returns.
*
* @param call The call structure.
*/
static void udebug_receive_begin(call_t *call)
{
int rc;
 
rc = udebug_begin(call);
if (rc < 0) {
IPC_SET_RETVAL(call->data, rc);
ipc_answer(&TASK->kb.box, call);
return;
}
 
/*
* If the initialization of the debugging session has finished,
* send a reply.
*/
if (rc != 0) {
IPC_SET_RETVAL(call->data, 0);
ipc_answer(&TASK->kb.box, call);
}
}
 
/** Process an END call.
*
* Terminates the debugging session for the current task.
* @param call The call structure.
*/
static void udebug_receive_end(call_t *call)
{
int rc;
 
rc = udebug_end();
 
IPC_SET_RETVAL(call->data, rc);
ipc_answer(&TASK->kb.box, call);
}
 
/** Process a SET_EVMASK call.
*
* Sets an event mask for the current debugging session.
* @param call The call structure.
*/
static void udebug_receive_set_evmask(call_t *call)
{
int rc;
udebug_evmask_t mask;
 
mask = IPC_GET_ARG2(call->data);
rc = udebug_set_evmask(mask);
 
IPC_SET_RETVAL(call->data, rc);
ipc_answer(&TASK->kb.box, call);
}
 
 
/** Process a GO call.
*
* Resumes execution of the specified thread.
* @param call The call structure.
*/
static void udebug_receive_go(call_t *call)
{
thread_t *t;
int rc;
 
t = (thread_t *)IPC_GET_ARG2(call->data);
 
rc = udebug_go(t, call);
if (rc < 0) {
IPC_SET_RETVAL(call->data, rc);
ipc_answer(&TASK->kb.box, call);
return;
}
}
 
/** Process a STOP call.
*
* Suspends execution of the specified thread.
* @param call The call structure.
*/
static void udebug_receive_stop(call_t *call)
{
thread_t *t;
int rc;
 
t = (thread_t *)IPC_GET_ARG2(call->data);
 
rc = udebug_stop(t, call);
IPC_SET_RETVAL(call->data, rc);
ipc_answer(&TASK->kb.box, call);
}
 
/** Process a THREAD_READ call.
*
* Reads the list of hashes of the (userspace) threads in the current task.
* @param call The call structure.
*/
static void udebug_receive_thread_read(call_t *call)
{
unative_t uspace_addr;
unative_t to_copy;
unsigned total_bytes;
unsigned buf_size;
void *buffer;
size_t n;
int rc;
 
uspace_addr = IPC_GET_ARG2(call->data); /* Destination address */
buf_size = IPC_GET_ARG3(call->data); /* Dest. buffer size */
 
/*
* Read thread list. Variable n will be filled with actual number
* of threads times thread-id size.
*/
rc = udebug_thread_read(&buffer, buf_size, &n);
if (rc < 0) {
IPC_SET_RETVAL(call->data, rc);
ipc_answer(&TASK->kb.box, call);
return;
}
 
total_bytes = n;
 
/* Copy MAX(buf_size, total_bytes) bytes */
 
if (buf_size > total_bytes)
to_copy = total_bytes;
else
to_copy = buf_size;
 
/*
* Make use of call->buffer to transfer data to caller's userspace
*/
 
IPC_SET_RETVAL(call->data, 0);
/* ARG1=dest, ARG2=size as in IPC_M_DATA_READ so that
same code in process_answer() can be used
(no way to distinguish method in answer) */
IPC_SET_ARG1(call->data, uspace_addr);
IPC_SET_ARG2(call->data, to_copy);
 
IPC_SET_ARG3(call->data, total_bytes);
call->buffer = buffer;
 
ipc_answer(&TASK->kb.box, call);
}
 
/** Process an ARGS_READ call.
*
* Reads the argument of a current syscall event (SYSCALL_B or SYSCALL_E).
* @param call The call structure.
*/
static void udebug_receive_args_read(call_t *call)
{
thread_t *t;
unative_t uspace_addr;
int rc;
void *buffer;
 
t = (thread_t *)IPC_GET_ARG2(call->data);
 
rc = udebug_args_read(t, &buffer);
if (rc != EOK) {
IPC_SET_RETVAL(call->data, rc);
ipc_answer(&TASK->kb.box, call);
return;
}
 
/*
* Make use of call->buffer to transfer data to caller's userspace
*/
 
uspace_addr = IPC_GET_ARG3(call->data);
 
IPC_SET_RETVAL(call->data, 0);
/* ARG1=dest, ARG2=size as in IPC_M_DATA_READ so that
same code in process_answer() can be used
(no way to distinguish method in answer) */
IPC_SET_ARG1(call->data, uspace_addr);
IPC_SET_ARG2(call->data, 6 * sizeof(unative_t));
call->buffer = buffer;
 
ipc_answer(&TASK->kb.box, call);
}
 
/** Process an MEM_READ call.
*
* Reads memory of the current (debugged) task.
* @param call The call structure.
*/
static void udebug_receive_mem_read(call_t *call)
{
unative_t uspace_dst;
unative_t uspace_src;
unsigned size;
void *buffer;
int rc;
 
uspace_dst = IPC_GET_ARG2(call->data);
uspace_src = IPC_GET_ARG3(call->data);
size = IPC_GET_ARG4(call->data);
 
rc = udebug_mem_read(uspace_src, size, &buffer);
if (rc < 0) {
IPC_SET_RETVAL(call->data, rc);
ipc_answer(&TASK->kb.box, call);
return;
}
 
IPC_SET_RETVAL(call->data, 0);
/* ARG1=dest, ARG2=size as in IPC_M_DATA_READ so that
same code in process_answer() can be used
(no way to distinguish method in answer) */
IPC_SET_ARG1(call->data, uspace_dst);
IPC_SET_ARG2(call->data, size);
call->buffer = buffer;
 
ipc_answer(&TASK->kb.box, call);
}
 
/** Handle a debug call received on the kernel answerbox.
*
* This is called by the kbox servicing thread. Verifies that the sender
* is indeed the debugger and calls the appropriate processing function.
*/
void udebug_call_receive(call_t *call)
{
int debug_method;
 
debug_method = IPC_GET_ARG1(call->data);
 
if (debug_method != UDEBUG_M_BEGIN) {
/*
* Verify that the sender is this task's debugger.
* Note that this is the only thread that could change
* TASK->debugger. Therefore no locking is necessary
* and the sender can be safely considered valid until
* control exits this function.
*/
if (TASK->udebug.debugger != call->sender) {
IPC_SET_RETVAL(call->data, EINVAL);
ipc_answer(&TASK->kb.box, call);
return;
}
}
 
switch (debug_method) {
case UDEBUG_M_BEGIN:
udebug_receive_begin(call);
break;
case UDEBUG_M_END:
udebug_receive_end(call);
break;
case UDEBUG_M_SET_EVMASK:
udebug_receive_set_evmask(call);
break;
case UDEBUG_M_GO:
udebug_receive_go(call);
break;
case UDEBUG_M_STOP:
udebug_receive_stop(call);
break;
case UDEBUG_M_THREAD_READ:
udebug_receive_thread_read(call);
break;
case UDEBUG_M_ARGS_READ:
udebug_receive_args_read(call);
break;
case UDEBUG_M_MEM_READ:
udebug_receive_mem_read(call);
break;
}
}
 
/** @}
*/