hwthread.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <helper/time_support.h>
#include <jtag/jtag.h>
#include "target/target.h"
#include "target/register.h"
#include <target/smp.h>
#include "rtos.h"
#include "helper/log.h"
#include "helper/types.h"
#include "server/gdb_server.h"
 
static bool hwthread_detect_rtos(struct target *target);
static int hwthread_create(struct target *target);
static int hwthread_update_threads(struct rtos *rtos);
static int hwthread_get_thread_reg_value(struct rtos *rtos, int64_t thread_id,
        uint32_t reg_num, uint32_t *size, uint8_t **value);
static int hwthread_get_thread_reg_list(struct rtos *rtos, int64_t thread_id,
        struct rtos_reg **reg_list, int *num_regs);
static int hwthread_get_symbol_list_to_lookup(struct symbol_table_elem *symbol_list[]);
static int hwthread_smp_init(struct target *target);
static int hwthread_set_reg(struct rtos *rtos, uint32_t reg_num, uint8_t *reg_value);
static int hwthread_read_buffer(struct rtos *rtos, target_addr_t address,
        uint32_t size, uint8_t *buffer);
static int hwthread_write_buffer(struct rtos *rtos, target_addr_t address,
        uint32_t size, const uint8_t *buffer);
static bool hwthread_needs_fake_step(struct target *target, int64_t thread_id);
 
#define HW_THREAD_NAME_STR_SIZE (32)
 
static inline threadid_t threadid_from_target(const struct target *target)
{
    if (!target->smp)
        return 1;
 
    threadid_t threadid = 1;
    struct target_list *head;
    foreach_smp_target(head, target->smp_targets) {
        if (target == head->target)
            return threadid;
        ++threadid;
    }
    assert(0 && "Target is not found in it's own SMP group!");
    return -1;
}
 
const struct rtos_type hwthread_rtos = {
    .name = "hwthread",
    .detect_rtos = hwthread_detect_rtos,
    .create = hwthread_create,
    .update_threads = hwthread_update_threads,
    .get_thread_reg_list = hwthread_get_thread_reg_list,
    .get_thread_reg_value = hwthread_get_thread_reg_value,
    .get_symbol_list_to_lookup = hwthread_get_symbol_list_to_lookup,
    .smp_init = hwthread_smp_init,
    .set_reg = hwthread_set_reg,
    .read_buffer = hwthread_read_buffer,
    .write_buffer = hwthread_write_buffer,
    .needs_fake_step = hwthread_needs_fake_step
};
 
struct hwthread_params {
    int dummy_param;
};
 
static int hwthread_fill_thread(struct rtos *rtos, struct target *curr, int thread_num, threadid_t tid)
{
    char tmp_str[HW_THREAD_NAME_STR_SIZE];
 
    memset(tmp_str, 0, HW_THREAD_NAME_STR_SIZE);
 
    /* thread-id is the index of this core inside the SMP group plus 1 */
    rtos->thread_details[thread_num].threadid = tid;
    /* create the thread name */
    rtos->thread_details[thread_num].exists = true;
    rtos->thread_details[thread_num].thread_name_str = strdup(target_name(curr));
    snprintf(tmp_str, HW_THREAD_NAME_STR_SIZE-1, "state: %s", debug_reason_name(curr));
    rtos->thread_details[thread_num].extra_info_str = strdup(tmp_str);
 
    return ERROR_OK;
}
 
static int hwthread_update_threads(struct rtos *rtos)
{
    int threads_found = 0;
    int thread_list_size = 0;
    struct target_list *head;
    struct target *target;
    int64_t current_thread = 0;
    int64_t current_threadid = rtos->current_threadid; /* thread selected by GDB */
    enum target_debug_reason current_reason = DBG_REASON_UNDEFINED;
 
    if (!rtos)
        return -1;
 
    target = rtos->target;
 
    /* wipe out previous thread details if any */
    rtos_free_threadlist(rtos);
 
    /* determine the number of "threads" */
    if (target->smp) {
        foreach_smp_target(head, target->smp_targets) {
            struct target *curr = head->target;
 
            if (!target_was_examined(curr) ||
                    curr->state == TARGET_UNAVAILABLE)
                continue;
 
            ++thread_list_size;
        }
    } else
        thread_list_size = 1;
 
    /* restore the threadid which is currently selected by GDB
     * because rtos_free_threadlist() wipes out it
     * (GDB thread id is 1-based indexing) */
    if (current_threadid <= thread_list_size)
        rtos->current_threadid = current_threadid;
    else
        LOG_TARGET_WARNING(target, "SMP node change, disconnect GDB from core/thread %" PRId64,
                current_threadid);
 
    /* create space for new thread details */
    rtos->thread_details = malloc(sizeof(struct thread_detail) * thread_list_size);
 
    if (target->smp) {
        /* loop over all threads */
        foreach_smp_target(head, target->smp_targets) {
            struct target *curr = head->target;
 
            if (!target_was_examined(curr) ||
                    curr->state == TARGET_UNAVAILABLE)
                continue;
 
            threadid_t tid = threadid_from_target(curr);
            hwthread_fill_thread(rtos, curr, threads_found, tid);
 
            /* find an interesting thread to set as current */
            switch (current_reason) {
            case DBG_REASON_UNDEFINED:
                current_reason = curr->debug_reason;
                current_thread = tid;
                break;
            case DBG_REASON_SINGLESTEP:
                /* single-step can only be overridden by itself */
                if (curr->debug_reason == DBG_REASON_SINGLESTEP) {
                    if (tid == rtos->current_threadid)
                        current_thread = tid;
                }
                break;
            case DBG_REASON_BREAKPOINT:
                /* single-step overrides breakpoint */
                if (curr->debug_reason == DBG_REASON_SINGLESTEP) {
                    current_reason = curr->debug_reason;
                    current_thread = tid;
                } else if (curr->debug_reason == DBG_REASON_BREAKPOINT) {
                    /* multiple breakpoints, prefer gdbs' threadid */
                    if (tid == rtos->current_threadid)
                        current_thread = tid;
                }
                break;
            case DBG_REASON_WATCHPOINT:
                /* breakpoint and single-step override watchpoint */
                if (curr->debug_reason == DBG_REASON_SINGLESTEP ||
                        curr->debug_reason == DBG_REASON_BREAKPOINT) {
                    current_reason = curr->debug_reason;
                    current_thread = tid;
                }
                break;
            case DBG_REASON_DBGRQ:
                /* all other reasons override debug-request */
                if (curr->debug_reason == DBG_REASON_SINGLESTEP ||
                        curr->debug_reason == DBG_REASON_WATCHPOINT ||
                        curr->debug_reason == DBG_REASON_BREAKPOINT) {
                    current_reason = curr->debug_reason;
                    current_thread = tid;
                } else if (curr->debug_reason == DBG_REASON_DBGRQ) {
                    if (tid == rtos->current_threadid)
                        current_thread = tid;
                }
 
                break;
 
            default:
                break;
            }
 
            threads_found++;
        }
    } else {
        current_thread = 1;
        hwthread_fill_thread(rtos, target, threads_found, current_thread);
        threads_found++;
    }
 
    rtos->thread_count = threads_found;
 
    /* we found an interesting thread, set it as current */
    if (current_thread != 0)
        rtos->current_thread = current_thread;
    else if (rtos->current_threadid != 0)
        rtos->current_thread = rtos->current_threadid;
    else
        rtos->current_thread = threadid_from_target(target);
 
    LOG_TARGET_DEBUG(target, "current_thread=%" PRId64 ", threads_found=%d",
                     rtos->current_thread, threads_found);
    return 0;
}
 
static int hwthread_smp_init(struct target *target)
{
    return hwthread_update_threads(target->rtos);
}
 
static struct target *hwthread_find_thread(struct target *target, threadid_t thread_id)
{
    /* Find the thread with that thread_id (index in SMP group plus 1)*/
    if (!(target && target->smp))
        return target;
    struct target_list *head;
    threadid_t tid = 1;
    foreach_smp_target(head, target->smp_targets) {
        if (thread_id == tid)
            return head->target;
        ++tid;
    }
    return NULL;
}
 
static int hwthread_get_thread_reg_list(struct rtos *rtos, int64_t thread_id,
        struct rtos_reg **rtos_reg_list, int *rtos_reg_list_size)
{
    if (!rtos)
        return ERROR_FAIL;
 
    struct target *target = rtos->target;
 
    struct target *curr = hwthread_find_thread(target, thread_id);
    if (!curr)
        return ERROR_FAIL;
 
    if (!target_was_examined(curr))
        return ERROR_FAIL;
 
    int reg_list_size;
    struct reg **reg_list;
    int retval = target_get_gdb_reg_list(curr, &reg_list, &reg_list_size,
            REG_CLASS_GENERAL);
    if (retval != ERROR_OK)
        return retval;
 
    int j = 0;
    for (int i = 0; i < reg_list_size; i++) {
        if (!reg_list[i] || !reg_list[i]->exist || reg_list[i]->hidden)
            continue;
        j++;
    }
    *rtos_reg_list_size = j;
    *rtos_reg_list = calloc(*rtos_reg_list_size, sizeof(struct rtos_reg));
    if (!*rtos_reg_list) {
        free(reg_list);
        return ERROR_FAIL;
    }
 
    j = 0;
    for (int i = 0; i < reg_list_size; i++) {
        if (!reg_list[i] || !reg_list[i]->exist || reg_list[i]->hidden)
            continue;
        if (!reg_list[i]->valid) {
            retval = reg_list[i]->type->get(reg_list[i]);
            if (retval != ERROR_OK) {
                LOG_TARGET_ERROR(curr, "Couldn't get register %s",
                    reg_list[i]->name);
                free(reg_list);
                free(*rtos_reg_list);
                return retval;
            }
        }
        (*rtos_reg_list)[j].number = reg_list[i]->number;
        (*rtos_reg_list)[j].size = reg_list[i]->size;
        memcpy((*rtos_reg_list)[j].value, reg_list[i]->value,
                DIV_ROUND_UP(reg_list[i]->size, 8));
        j++;
    }
    free(reg_list);
 
    return ERROR_OK;
}
 
static int hwthread_get_thread_reg_value(struct rtos *rtos, int64_t thread_id,
        uint32_t reg_num, uint32_t *size, uint8_t **value)
{
    if (!rtos)
        return ERROR_FAIL;
 
    struct target *target = rtos->target;
 
    struct target *curr = hwthread_find_thread(target, thread_id);
    if (!curr) {
        LOG_TARGET_ERROR(target, "Couldn't find RTOS thread for id %" PRId64,
            thread_id);
        return ERROR_FAIL;
    }
 
    if (!target_was_examined(curr)) {
        LOG_TARGET_ERROR(curr, "Target hasn't been examined yet.");
        return ERROR_FAIL;
    }
 
    struct reg *reg = register_get_by_number(curr->reg_cache, reg_num, true);
    if (!reg) {
        LOG_TARGET_ERROR(curr, "Couldn't find register %" PRIu32 " in thread %" PRId64,
            reg_num, thread_id);
        return ERROR_FAIL;
    }
 
    if (reg->type->get(reg) != ERROR_OK)
        return ERROR_FAIL;
 
    *size = reg->size;
    unsigned int bytes = DIV_ROUND_UP(reg->size, 8);
    *value = malloc(bytes);
    if (!*value) {
        LOG_ERROR("Failed to allocate memory for %d-bit register.", reg->size);
        return ERROR_FAIL;
    }
    memcpy(*value, reg->value, bytes);
 
    return ERROR_OK;
}
 
static int hwthread_set_reg(struct rtos *rtos, uint32_t reg_num, uint8_t *reg_value)
{
    if (!rtos)
        return ERROR_FAIL;
 
    struct target *target = rtos->target;
 
    struct target *curr = hwthread_find_thread(target, rtos->current_thread);
    if (!curr)
        return ERROR_FAIL;
 
    struct reg *reg = register_get_by_number(curr->reg_cache, reg_num, true);
    if (!reg)
        return ERROR_FAIL;
 
    return reg->type->set(reg, reg_value);
}
 
static int hwthread_get_symbol_list_to_lookup(struct symbol_table_elem *symbol_list[])
{
    /* return an empty list, we don't have any symbols to look up */
    *symbol_list = calloc(1, sizeof(struct symbol_table_elem));
    (*symbol_list)[0].symbol_name = NULL;
    return 0;
}
 
static int hwthread_target_for_threadid(struct connection *connection, int64_t thread_id, struct target **p_target)
{
    struct target *target = get_target_from_connection(connection);
 
    struct target *curr = hwthread_find_thread(target, thread_id);
    if (!curr)
        return ERROR_FAIL;
 
    *p_target = curr;
 
    return ERROR_OK;
}
 
static bool hwthread_detect_rtos(struct target *target)
{
    /* always return 0, avoid auto-detection */
    return false;
}
 
static int hwthread_thread_packet(struct connection *connection, const char *packet, int packet_size)
{
    if (packet[0] == 'H' && packet[1] == 'g') {
        int64_t current_threadid;
        sscanf(packet, "Hg%16" SCNx64, &current_threadid);
 
        struct target *target = get_target_from_connection(connection);
 
        if (current_threadid > 0) {
            struct target *curr = NULL;
            if (hwthread_target_for_threadid(connection, current_threadid, &curr) != ERROR_OK) {
                LOG_TARGET_ERROR(target, "hwthread: cannot find thread id %" PRId64,
                    current_threadid);
                gdb_put_packet(connection, "E01", 3);
                return ERROR_FAIL;
            }
            target->rtos->current_thread = current_threadid;
        } else if (current_threadid == 0 || current_threadid == -1) {
            target->rtos->current_thread = threadid_from_target(target);
        }
 
        target->rtos->current_threadid = current_threadid;
 
        gdb_put_packet(connection, "OK", 2);
        return ERROR_OK;
    }
 
    return rtos_thread_packet(connection, packet, packet_size);
}
 
static int hwthread_create(struct target *target)
{
    LOG_TARGET_INFO(target, "Hardware thread awareness created");
 
    target->rtos->rtos_specific_params = NULL;
    target->rtos->current_thread = 0;
    target->rtos->thread_details = NULL;
    target->rtos->gdb_target_for_threadid = hwthread_target_for_threadid;
    target->rtos->gdb_thread_packet = hwthread_thread_packet;
    return ERROR_OK;
}
 
static int hwthread_read_buffer(struct rtos *rtos, target_addr_t address,
        uint32_t size, uint8_t *buffer)
{
    if (!rtos)
        return ERROR_FAIL;
 
    struct target *target = rtos->target;
 
    struct target *curr = hwthread_find_thread(target, rtos->current_thread);
    if (!curr)
        return ERROR_FAIL;
 
    return target_read_buffer(curr, address, size, buffer);
}
 
static int hwthread_write_buffer(struct rtos *rtos, target_addr_t address,
        uint32_t size, const uint8_t *buffer)
{
    if (!rtos)
        return ERROR_FAIL;
 
    struct target *target = rtos->target;
 
    struct target *curr = hwthread_find_thread(target, rtos->current_thread);
    if (!curr)
        return ERROR_FAIL;
 
    return target_write_buffer(curr, address, size, buffer);
}
 
bool hwthread_needs_fake_step(struct target *target, int64_t thread_id)
{
    return false;
}