WebSVN – HelenOS – Diff – /trunk/kernel/generic/src/udebug/udebug_ops.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 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 <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
 * has (or hasn't) go according to having_go (typically false).
 * It also locks t->udebug.lock, making sure that t->udebug.debug_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 having_go Required thread state.
 *
 * Returns EOK if all went well, or an error code otherwise.
 */
static int _thread_op_begin(thread_t *t, bool having_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.debug_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 debug_active == true, TASK->udebug.lock
     * is enough to ensure its existence and that debug_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.stop != having_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.debug_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.debug_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. Having 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.stop = false;
    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");
    mutex_lock(&TASK->udebug.lock);
 
    /*
     * 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.stop = true;
 
    if (!t->udebug.stoppable) {
        /* 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);
 
    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;
}
 
/** @}
 */
 

Rev 3441	Rev 3457
1	/*	1	/*
2	* Copyright (c) 2008 Jiri Svoboda	2	* Copyright (c) 2008 Jiri Svoboda
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup generic	29	/** @addtogroup generic
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file	34	* @file
35	* @brief Udebug operations.	35	* @brief Udebug operations.
-		36	*
-		37	* Udebug operations on tasks and threads are implemented here. The
-		38	* functions defined here are called from the udebug_ipc module
-		39	* when servicing udebug IPC messages.
36	*/	40	*/
37		41
38	#include <debug.h>	42	#include <debug.h>
39	#include <proc/task.h>	43	#include <proc/task.h>
40	#include <proc/thread.h>	44	#include <proc/thread.h>
41	#include <arch.h>	45	#include <arch.h>
42	#include <errno.h>	46	#include <errno.h>
43	#include <syscall/copy.h>	47	#include <syscall/copy.h>
44	#include <ipc/ipc.h>	48	#include <ipc/ipc.h>
45	#include <udebug/udebug.h>	49	#include <udebug/udebug.h>
46	#include <udebug/udebug_ops.h>	50	#include <udebug/udebug_ops.h>
47		51
48	/**	52	/**
49	* Prepare a thread for a debugging operation.	53	* Prepare a thread for a debugging operation.
50	*	54	*
51	* Simply put, return thread t with t->udebug.lock held,	55	* Simply put, return thread t with t->udebug.lock held,
52	* but only if it verifies all conditions.	56	* but only if it verifies all conditions.
53	*	57	*
54	* Specifically, verifies that thread t exists, is a userspace thread,	58	* Specifically, verifies that thread t exists, is a userspace thread,
55	* and belongs to the current task (TASK). Verifies, that the thread	59	* and belongs to the current task (TASK). Verifies, that the thread
56	* has (or hasn't) go according to having_go (typically false).	60	* has (or hasn't) go according to having_go (typically false).
57	* It also locks t->udebug.lock, making sure that t->udebug.debug_active	61	* It also locks t->udebug.lock, making sure that t->udebug.debug_active
58	* is true - that the thread is in a valid debugging session.	62	* is true - that the thread is in a valid debugging session.
59	*	63	*
60	* With this verified and the t->udebug.lock mutex held, it is ensured	64	* With this verified and the t->udebug.lock mutex held, it is ensured
61	* that the thread cannot leave the debugging session, let alone cease	65	* that the thread cannot leave the debugging session, let alone cease
62	* to exist.	66	* to exist.
63	*	67	*
64	* In this function, holding the TASK->udebug.lock mutex prevents the	68	* In this function, holding the TASK->udebug.lock mutex prevents the
65	* thread from leaving the debugging session, while relaxing from	69	* thread from leaving the debugging session, while relaxing from
66	* the t->lock spinlock to the t->udebug.lock mutex.	70	* the t->lock spinlock to the t->udebug.lock mutex.
67	*	71	*
-		72	* @param t Pointer, need not at all be valid.
-		73	* @param having_go Required thread state.
-		74	*
68	* Returns EOK if all went well, or an error code otherwise.	75	* Returns EOK if all went well, or an error code otherwise.
69	*/	76	*/
70	static int _thread_op_begin(thread_t *t, bool having_go)	77	static int _thread_op_begin(thread_t *t, bool having_go)
71	{	78	{
72	task_id_t taskid;	79	task_id_t taskid;
73	ipl_t ipl;	80	ipl_t ipl;
74		81
75	taskid = TASK->taskid;	82	taskid = TASK->taskid;
76		83
77	mutex_lock(&TASK->udebug.lock);	84	mutex_lock(&TASK->udebug.lock);
78		85
79	/* thread_exists() must be called with threads_lock held */	86	/* thread_exists() must be called with threads_lock held */
80	ipl = interrupts_disable();	87	ipl = interrupts_disable();
81	spinlock_lock(&threads_lock);	88	spinlock_lock(&threads_lock);
82		89
83	if (!thread_exists(t)) {	90	if (!thread_exists(t)) {
84	spinlock_unlock(&threads_lock);	91	spinlock_unlock(&threads_lock);
85	interrupts_restore(ipl);	92	interrupts_restore(ipl);
86	mutex_unlock(&TASK->udebug.lock);	93	mutex_unlock(&TASK->udebug.lock);
87	return ENOENT;	94	return ENOENT;
88	}	95	}
89		96
90	/* t->lock is enough to ensure the thread's existence */	97	/* t->lock is enough to ensure the thread's existence */
91	spinlock_lock(&t->lock);	98	spinlock_lock(&t->lock);
92	spinlock_unlock(&threads_lock);	99	spinlock_unlock(&threads_lock);
93		100
94	/* Verify that 't' is a userspace thread */	101	/* Verify that 't' is a userspace thread */
95	if ((t->flags & THREAD_FLAG_USPACE) == 0) {	102	if ((t->flags & THREAD_FLAG_USPACE) == 0) {
96	/* It's not, deny its existence */	103	/* It's not, deny its existence */
97	spinlock_unlock(&t->lock);	104	spinlock_unlock(&t->lock);
98	interrupts_restore(ipl);	105	interrupts_restore(ipl);
99	mutex_unlock(&TASK->udebug.lock);	106	mutex_unlock(&TASK->udebug.lock);
100	return ENOENT;	107	return ENOENT;
101	}	108	}
102		109
103	/* Verify debugging state */	110	/* Verify debugging state */
104	if (t->udebug.debug_active != true) {	111	if (t->udebug.debug_active != true) {
105	/* Not in debugging session or undesired GO state */	112	/* Not in debugging session or undesired GO state */
106	spinlock_unlock(&t->lock);	113	spinlock_unlock(&t->lock);
107	interrupts_restore(ipl);	114	interrupts_restore(ipl);
108	mutex_unlock(&TASK->udebug.lock);	115	mutex_unlock(&TASK->udebug.lock);
109	return ENOENT;	116	return ENOENT;
110	}	117	}
111		118
112	/*	119	/*
113	* Since the thread has debug_active == true, TASK->udebug.lock	120	* Since the thread has debug_active == true, TASK->udebug.lock
114	* is enough to ensure its existence and that debug_active remains	121	* is enough to ensure its existence and that debug_active remains
115	* true.	122	* true.
116	*/	123	*/
117	spinlock_unlock(&t->lock);	124	spinlock_unlock(&t->lock);
118	interrupts_restore(ipl);	125	interrupts_restore(ipl);
119		126
120	/* Only mutex TASK->udebug.lock left */	127	/* Only mutex TASK->udebug.lock left */
121		128
122	/* Now verify that the thread belongs to the current task */	129	/* Now verify that the thread belongs to the current task */
123	if (t->task != TASK) {	130	if (t->task != TASK) {
124	/* No such thread belonging this task*/	131	/* No such thread belonging this task*/
125	mutex_unlock(&TASK->udebug.lock);	132	mutex_unlock(&TASK->udebug.lock);
126	return ENOENT;	133	return ENOENT;
127	}	134	}
128		135
129	/*	136	/*
130	* Now we need to grab the thread's debug lock for synchronization	137	* Now we need to grab the thread's debug lock for synchronization
131	* of the threads stoppability/stop state.	138	* of the threads stoppability/stop state.
132	*/	139	*/
133	mutex_lock(&t->udebug.lock);	140	mutex_lock(&t->udebug.lock);
134		141
135	/* The big task mutex is no longer needed */	142	/* The big task mutex is no longer needed */
136	mutex_unlock(&TASK->udebug.lock);	143	mutex_unlock(&TASK->udebug.lock);
137		144
138	if (!t->udebug.stop != having_go) {	145	if (!t->udebug.stop != having_go) {
139	/* Not in debugging session or undesired GO state */	146	/* Not in debugging session or undesired GO state */
140	mutex_unlock(&t->udebug.lock);	147	mutex_unlock(&t->udebug.lock);
141	return EINVAL;	148	return EINVAL;
142	}	149	}
143		150
144	/* Only t->udebug.lock left */	151	/* Only t->udebug.lock left */
145		152
146	return EOK; /* All went well */	153	return EOK; /* All went well */
147	}	154	}
148		155
149		-
-		156	/** End debugging operation on a thread. */
150	static void _thread_op_end(thread_t *t)	157	static void _thread_op_end(thread_t *t)
151	{	158	{
152	mutex_unlock(&t->udebug.lock);	159	mutex_unlock(&t->udebug.lock);
153	}	160	}
154		161
-		162	/** Begin debugging the current task.
155	/**	163	*
-		164	* Initiates a debugging session for the current task (and its threads).
-		165	* When the debugging session has started a reply will be sent to the
-		166	* UDEBUG_BEGIN call. This may happen immediately in this function if
-		167	* all the threads in this task are stoppable at the moment and in this
-		168	* case the function returns 1.
-		169	*
-		170	* Otherwise the function returns 0 and the reply will be sent as soon as
-		171	* all the threads become stoppable (i.e. they can be considered stopped).
-		172	*
-		173	* @param call The BEGIN call we are servicing.
156	* \return 0 (ok, but not done yet), 1 (done) or negative error code.	174	* @return 0 (OK, but not done yet), 1 (done) or negative error code.
157	*/	175	*/
158	int udebug_begin(call_t *call)	176	int udebug_begin(call_t *call)
159	{	177	{
160	int reply;	178	int reply;
161		179
162	thread_t *t;	180	thread_t *t;
163	link_t *cur;	181	link_t *cur;
164		182
165	LOG("udebug_begin()\n");	183	LOG("udebug_begin()\n");
166		184
167	mutex_lock(&TASK->udebug.lock);	185	mutex_lock(&TASK->udebug.lock);
168	LOG("debugging task %llu\n", TASK->taskid);	186	LOG("debugging task %llu\n", TASK->taskid);
169		187
170	if (TASK->udebug.dt_state != UDEBUG_TS_INACTIVE) {	188	if (TASK->udebug.dt_state != UDEBUG_TS_INACTIVE) {
171	mutex_unlock(&TASK->udebug.lock);	189	mutex_unlock(&TASK->udebug.lock);
172	LOG("udebug_begin(): busy error\n");	190	LOG("udebug_begin(): busy error\n");
173		191
174	return EBUSY;	192	return EBUSY;
175	}	193	}
176		194
177	TASK->udebug.dt_state = UDEBUG_TS_BEGINNING;	195	TASK->udebug.dt_state = UDEBUG_TS_BEGINNING;
178	TASK->udebug.begin_call = call;	196	TASK->udebug.begin_call = call;
179	TASK->udebug.debugger = call->sender;	197	TASK->udebug.debugger = call->sender;
180		198
181	if (TASK->udebug.not_stoppable_count == 0) {	199	if (TASK->udebug.not_stoppable_count == 0) {
182	TASK->udebug.dt_state = UDEBUG_TS_ACTIVE;	200	TASK->udebug.dt_state = UDEBUG_TS_ACTIVE;
183	TASK->udebug.begin_call = NULL;	201	TASK->udebug.begin_call = NULL;
184	reply = 1; /* immediate reply */	202	reply = 1; /* immediate reply */
185	} else {	203	} else {
186	reply = 0; /* no reply */	204	reply = 0; /* no reply */
187	}	205	}
188		206
189	/* Set udebug.debug_active on all of the task's userspace threads */	207	/* Set udebug.debug_active on all of the task's userspace threads */
190		208
191	for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {	209	for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
192	t = list_get_instance(cur, thread_t, th_link);	210	t = list_get_instance(cur, thread_t, th_link);
193		211
194	mutex_lock(&t->udebug.lock);	212	mutex_lock(&t->udebug.lock);
195	if ((t->flags & THREAD_FLAG_USPACE) != 0)	213	if ((t->flags & THREAD_FLAG_USPACE) != 0)
196	t->udebug.debug_active = true;	214	t->udebug.debug_active = true;
197	mutex_unlock(&t->udebug.lock);	215	mutex_unlock(&t->udebug.lock);
198	}	216	}
199		217
200	mutex_unlock(&TASK->udebug.lock);	218	mutex_unlock(&TASK->udebug.lock);
201		219
202	LOG("udebug_begin() done (%s)\n",	220	LOG("udebug_begin() done (%s)\n",
203	reply ? "reply" : "stoppability wait");	221	reply ? "reply" : "stoppability wait");
204		222
205	return reply;	223	return reply;
206	}	224	}
207		225
-		226	/** Finish debugging the current task.
-		227	*
-		228	* Closes the debugging session for the current task.
-		229	* @return Zero on success or negative error code.
-		230	*/
208	int udebug_end(void)	231	int udebug_end(void)
209	{	232	{
210	int rc;	233	int rc;
211		234
212	LOG("udebug_end()\n");	235	LOG("udebug_end()\n");
213		236
214	mutex_lock(&TASK->udebug.lock);	237	mutex_lock(&TASK->udebug.lock);
215	LOG("task %" PRIu64 "\n", TASK->taskid);	238	LOG("task %" PRIu64 "\n", TASK->taskid);
216		239
217	rc = udebug_task_cleanup(TASK);	240	rc = udebug_task_cleanup(TASK);
218		241
219	mutex_unlock(&TASK->udebug.lock);	242	mutex_unlock(&TASK->udebug.lock);
220		243
221	return rc;	244	return rc;
222	}	245	}
223		246
-		247	/** Set the event mask.
-		248	*
-		249	* Sets the event mask that determines which events are enabled.
-		250	*
-		251	* @param mask Or combination of events that should be enabled.
-		252	* @return Zero on success or negative error code.
-		253	*/
224	int udebug_set_evmask(udebug_evmask_t mask)	254	int udebug_set_evmask(udebug_evmask_t mask)
225	{	255	{
226	LOG("udebug_set_mask()\n");	256	LOG("udebug_set_mask()\n");
227		257
228	mutex_lock(&TASK->udebug.lock);	258	mutex_lock(&TASK->udebug.lock);
229		259
230	if (TASK->udebug.dt_state != UDEBUG_TS_ACTIVE) {	260	if (TASK->udebug.dt_state != UDEBUG_TS_ACTIVE) {
231	mutex_unlock(&TASK->udebug.lock);	261	mutex_unlock(&TASK->udebug.lock);
232	LOG("udebug_set_mask(): not active debuging session\n");	262	LOG("udebug_set_mask(): not active debuging session\n");
233		263
234	return EINVAL;	264	return EINVAL;
235	}	265	}
236		266
237	TASK->udebug.evmask = mask;	267	TASK->udebug.evmask = mask;
238		268
239	mutex_unlock(&TASK->udebug.lock);	269	mutex_unlock(&TASK->udebug.lock);
240		270
241	return 0;	271	return 0;
242	}	272	}
243		273
-		274	/** Give thread GO.
-		275	*
-		276	* Upon recieving a go message, the thread is given GO. Having GO
-		277	* means the thread is allowed to execute userspace code (until
-		278	* a debugging event or STOP occurs, at which point the thread loses GO.
244		279	*
-		280	* @param t The thread to operate on (unlocked and need not be valid).
-		281	* @param call The GO call that we are servicing.
-		282	*/
245	int udebug_go(thread_t t, call_t call)	283	int udebug_go(thread_t t, call_t call)
246	{	284	{
247	int rc;	285	int rc;
248		286
249	/* On success, this will lock t->udebug.lock */	287	/* On success, this will lock t->udebug.lock */
250	rc = _thread_op_begin(t, false);	288	rc = _thread_op_begin(t, false);
251	if (rc != EOK) {	289	if (rc != EOK) {
252	return rc;	290	return rc;
253	}	291	}
254		292
255	t->udebug.go_call = call;	293	t->udebug.go_call = call;
256	t->udebug.stop = false;	294	t->udebug.stop = false;
257	t->udebug.cur_event = 0; /* none */	295	t->udebug.cur_event = 0; /* none */
258		296
259	/*	297	/*
260	* Neither t's lock nor threads_lock may be held during wakeup	298	* Neither t's lock nor threads_lock may be held during wakeup
261	*/	299	*/
262	waitq_wakeup(&t->udebug.go_wq, WAKEUP_FIRST);	300	waitq_wakeup(&t->udebug.go_wq, WAKEUP_FIRST);
263		301
264	_thread_op_end(t);	302	_thread_op_end(t);
265		303
266	return 0;	304	return 0;
267	}	305	}
268		306
-		307	/** Stop a thread (i.e. take its GO away)
-		308	*
-		309	* Generates a STOP event as soon as the thread becomes stoppable (i.e.
-		310	* can be considered stopped).
-		311	*
-		312	* @param t The thread to operate on (unlocked and need not be valid).
-		313	* @param call The GO call that we are servicing.
-		314	*/
269	int udebug_stop(thread_t t, call_t call)	315	int udebug_stop(thread_t t, call_t call)
270	{	316	{
271	int rc;	317	int rc;
272		318
273	LOG("udebug_stop()\n");	319	LOG("udebug_stop()\n");
274	mutex_lock(&TASK->udebug.lock);	320	mutex_lock(&TASK->udebug.lock);
275		321
276	/*	322	/*
277	* On success, this will lock t->udebug.lock. Note that this makes sure	323	* On success, this will lock t->udebug.lock. Note that this makes sure
278	* the thread is not stopped.	324	* the thread is not stopped.
279	*/	325	*/
280	rc = _thread_op_begin(t, true);	326	rc = _thread_op_begin(t, true);
281	if (rc != EOK) {	327	if (rc != EOK) {
282	return rc;	328	return rc;
283	}	329	}
284		330
285	/* Take GO away from the thread */	331	/* Take GO away from the thread */
286	t->udebug.stop = true;	332	t->udebug.stop = true;
287		333
288	if (!t->udebug.stoppable) {	334	if (!t->udebug.stoppable) {
289	/* Answer will be sent when the thread becomes stoppable */	335	/* Answer will be sent when the thread becomes stoppable */
290	_thread_op_end(t);	336	_thread_op_end(t);
291	return 0;	337	return 0;
292	}	338	}
293		339
294	/*	340	/*
295	* Answer GO call	341	* Answer GO call
296	*/	342	*/
297	LOG("udebug_stop - answering go call\n");	343	LOG("udebug_stop - answering go call\n");
298		344
299	/* Make sure nobody takes this call away from us */	345	/* Make sure nobody takes this call away from us */
300	call = t->udebug.go_call;	346	call = t->udebug.go_call;
301	t->udebug.go_call = NULL;	347	t->udebug.go_call = NULL;
302		348
303	IPC_SET_RETVAL(call->data, 0);	349	IPC_SET_RETVAL(call->data, 0);
304	IPC_SET_ARG1(call->data, UDEBUG_EVENT_STOP);	350	IPC_SET_ARG1(call->data, UDEBUG_EVENT_STOP);
305	LOG("udebug_stop/ipc_answer\n");	351	LOG("udebug_stop/ipc_answer\n");
306		352
307	THREAD->udebug.cur_event = UDEBUG_EVENT_STOP;	353	THREAD->udebug.cur_event = UDEBUG_EVENT_STOP;
308		354
309	_thread_op_end(t);	355	_thread_op_end(t);
310		356
311	ipc_answer(&TASK->answerbox, call);	357	ipc_answer(&TASK->answerbox, call);
312	mutex_unlock(&TASK->udebug.lock);	358	mutex_unlock(&TASK->udebug.lock);
313		359
314	LOG("udebog_stop/done\n");	360	LOG("udebog_stop/done\n");
315	return 0;	361	return 0;
316	}	362	}
317		363
-		364	/** Read the list of userspace threads in the current task.
-		365	*
-		366	* The list takes the form of a sequence of thread hashes (i.e. the pointers
-		367	* to thread structures). A buffer of size @a buf_size is allocated and
-		368	* a pointer to it written to @a buffer. The sequence of hashes is written
-		369	* into this buffer.
-		370	*
-		371	* If the sequence is longer than @a buf_size bytes, only as much hashes
-		372	* as can fit are copied. The number of thread hashes copied is stored
-		373	* in @a n.
-		374	*
-		375	* The rationale for having @a buf_size is that this function is only
-		376	* used for servicing the THREAD_READ message, which always specifies
-		377	* a maximum size for the userspace buffer.
-		378	*
-		379	* @param buffer The buffer for storing thread hashes.
-		380	* @param buf_size Buffer size in bytes.
-		381	* @param n The actual number of hashes copied will be stored here.
-		382	*/
318	int udebug_thread_read(void *buffer, size_t buf_size, size_t n)	383	int udebug_thread_read(void *buffer, size_t buf_size, size_t n)
319	{	384	{
320	thread_t *t;	385	thread_t *t;
321	link_t *cur;	386	link_t *cur;
322	unative_t tid;	387	unative_t tid;
323	unsigned copied_ids;	388	unsigned copied_ids;
324	ipl_t ipl;	389	ipl_t ipl;
325	unative_t *id_buffer;	390	unative_t *id_buffer;
326	int flags;	391	int flags;
327	size_t max_ids;	392	size_t max_ids;
328		393
329	LOG("udebug_thread_read()\n");	394	LOG("udebug_thread_read()\n");
330		395
331	/* Allocate a buffer to hold thread IDs */	396	/* Allocate a buffer to hold thread IDs */
332	id_buffer = malloc(buf_size, 0);	397	id_buffer = malloc(buf_size, 0);
333		398
334	mutex_lock(&TASK->udebug.lock);	399	mutex_lock(&TASK->udebug.lock);
335		400
336	/* Verify task state */	401	/* Verify task state */
337	if (TASK->udebug.dt_state != UDEBUG_TS_ACTIVE) {	402	if (TASK->udebug.dt_state != UDEBUG_TS_ACTIVE) {
338	mutex_unlock(&TASK->udebug.lock);	403	mutex_unlock(&TASK->udebug.lock);
339	return EINVAL;	404	return EINVAL;
340	}	405	}
341		406
342	ipl = interrupts_disable();	407	ipl = interrupts_disable();
343	spinlock_lock(&TASK->lock);	408	spinlock_lock(&TASK->lock);
344	/* Copy down the thread IDs */	409	/* Copy down the thread IDs */
345		410
346	max_ids = buf_size / sizeof(unative_t);	411	max_ids = buf_size / sizeof(unative_t);
347	copied_ids = 0;	412	copied_ids = 0;
348		413
349	/* FIXME: make sure the thread isn't past debug shutdown... */	414	/* FIXME: make sure the thread isn't past debug shutdown... */
350	for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {	415	for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
351	/* Do not write past end of buffer */	416	/* Do not write past end of buffer */
352	if (copied_ids >= max_ids) break;	417	if (copied_ids >= max_ids) break;
353		418
354	t = list_get_instance(cur, thread_t, th_link);	419	t = list_get_instance(cur, thread_t, th_link);
355		420
356	spinlock_lock(&t->lock);	421	spinlock_lock(&t->lock);
357	flags = t->flags;	422	flags = t->flags;
358	spinlock_unlock(&t->lock);	423	spinlock_unlock(&t->lock);
359		424
360	/* Not interested in kernel threads */	425	/* Not interested in kernel threads */
361	if ((flags & THREAD_FLAG_USPACE) != 0) {	426	if ((flags & THREAD_FLAG_USPACE) != 0) {
362	/* Using thread struct pointer as identification hash */	427	/* Using thread struct pointer as identification hash */
363	tid = (unative_t) t;	428	tid = (unative_t) t;
364	id_buffer[copied_ids++] = tid;	429	id_buffer[copied_ids++] = tid;
365	}	430	}
366	}	431	}
367		432
368	spinlock_unlock(&TASK->lock);	433	spinlock_unlock(&TASK->lock);
369	interrupts_restore(ipl);	434	interrupts_restore(ipl);
370		435
371	mutex_unlock(&TASK->udebug.lock);	436	mutex_unlock(&TASK->udebug.lock);
372		437
373	*buffer = id_buffer;	438	*buffer = id_buffer;
374	n = copied_ids sizeof(unative_t);	439	n = copied_ids sizeof(unative_t);
375		440
376	return 0;	441	return 0;
377	}	442	}
378		443
-		444	/** Read the arguments of a system call.
-		445	*
-		446	* The arguments of the system call being being executed are copied
-		447	* to an allocated buffer and a pointer to it is written to @a buffer.
-		448	* The size of the buffer is exactly such that it can hold the maximum number
-		449	* of system-call arguments.
-		450	*
-		451	* Unless the thread is currently blocked in a SYSCALL_B or SYSCALL_E event,
-		452	* this function will fail with an EINVAL error code.
-		453	*
-		454	* @param buffer The buffer for storing thread hashes.
-		455	*/
379	int udebug_args_read(thread_t t, void *buffer)	456	int udebug_args_read(thread_t t, void *buffer)
380	{	457	{
381	int rc;	458	int rc;
382	unative_t *arg_buffer;	459	unative_t *arg_buffer;
383		460
384	/* Prepare a buffer to hold the arguments */	461	/* Prepare a buffer to hold the arguments */
385	arg_buffer = malloc(6 * sizeof(unative_t), 0);	462	arg_buffer = malloc(6 * sizeof(unative_t), 0);
386		463
387	/* On success, this will lock t->udebug.lock */	464	/* On success, this will lock t->udebug.lock */
388	rc = _thread_op_begin(t, false);	465	rc = _thread_op_begin(t, false);
389	if (rc != EOK) {	466	if (rc != EOK) {
390	return rc;	467	return rc;
391	}	468	}
392		469
393	/* Additionally we need to verify that we are inside a syscall */	470	/* Additionally we need to verify that we are inside a syscall */
394	if (t->udebug.cur_event != UDEBUG_EVENT_SYSCALL_B &&	471	if (t->udebug.cur_event != UDEBUG_EVENT_SYSCALL_B &&
395	t->udebug.cur_event != UDEBUG_EVENT_SYSCALL_E) {	472	t->udebug.cur_event != UDEBUG_EVENT_SYSCALL_E) {
396	_thread_op_end(t);	473	_thread_op_end(t);
397	return EINVAL;	474	return EINVAL;
398	}	475	}
399		476
400	/* Copy to a local buffer before releasing the lock */	477	/* Copy to a local buffer before releasing the lock */
401	memcpy(arg_buffer, t->udebug.syscall_args, 6 * sizeof(unative_t));	478	memcpy(arg_buffer, t->udebug.syscall_args, 6 * sizeof(unative_t));
402		479
403	_thread_op_end(t);	480	_thread_op_end(t);
404		481
405	*buffer = arg_buffer;	482	*buffer = arg_buffer;
406	return 0;	483	return 0;
407	}	484	}
408		485
-		486	/** Read the memory of the debugged task.
-		487	*
-		488	* Reads @a n bytes from the address space of the debugged task, starting
-		489	* from @a uspace_addr. The bytes are copied into an allocated buffer
-		490	* and a pointer to it is written into @a buffer.
-		491	*
-		492	* @param uspace_addr Address from where to start reading.
-		493	* @param n Number of bytes to read.
-		494	* @param buffer For storing a pointer to the allocated buffer.
-		495	*/
409	int udebug_mem_read(unative_t uspace_addr, size_t n, void **buffer)	496	int udebug_mem_read(unative_t uspace_addr, size_t n, void **buffer)
410	{	497	{
411	void *data_buffer;	498	void *data_buffer;
412	int rc;	499	int rc;

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(root)/trunk/kernel/generic/src/udebug/udebug_ops.c – Rev 3441 → 3457