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/*

 * 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 <arch/asm.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;

    }

}

/** @}

 */