linux.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2011 by STEricsson                                      *
 *   Heythem Bouhaja heythem.bouhaja@stericsson.com   : creation           *
 *   Michel JAOUEN michel.jaouen@stericsson.com : adaptation to rtos       *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <helper/time_support.h>
#include <jtag/jtag.h>
#include "target/target.h"
#include "target/target_type.h"
#include "helper/log.h"
#include "helper/types.h"
#include "rtos.h"
#include "rtos_standard_stackings.h"
#include <target/register.h>
#include <target/smp.h>
#include "server/gdb_server.h"
 
#define LINUX_USER_KERNEL_BORDER 0xc0000000
#include "linux_header.h"
#define PHYS
#define MAX_THREADS 200
/*  specific task  */
struct linux_os {
    const char *name;
    uint32_t init_task_addr;
    int thread_count;
    int threadid_count;
    int preupdtate_threadid_count;
    int nr_cpus;
    int threads_lookup;
    int threads_needs_update;
    struct current_thread *current_threads;
    struct threads *thread_list;
    /*  virt2phys parameter */
    uint32_t phys_mask;
    uint32_t phys_base;
};
 
struct current_thread {
    int64_t threadid;
    int32_t core_id;
#ifdef PID_CHECK
    uint32_t pid;
#endif
    uint32_t TS;
    struct current_thread *next;
};
 
struct threads {
    char name[17];
    uint32_t base_addr; /*  address to read magic */
    uint32_t state;     /*  magic value : filled only at creation */
    uint32_t pid;       /* linux pid : id for identifying a thread */
    uint32_t oncpu;     /* content cpu number in current thread */
    uint32_t asid;      /*  filled only at creation  */
    int64_t threadid;
    int status;     /* dead = 1 alive = 2 current = 3 alive and current */
    /*  value that should not change during the live of a thread ? */
    uint32_t thread_info_addr;  /*  contain latest thread_info_addr computed */
    /*  retrieve from thread_info */
    struct cpu_context *context;
    struct threads *next;
};
 
struct cpu_context {
    uint32_t R4;
    uint32_t R5;
    uint32_t R6;
    uint32_t R7;
    uint32_t R8;
    uint32_t R9;
    uint32_t IP;
    uint32_t FP;
    uint32_t SP;
    uint32_t PC;
    uint32_t preempt_count;
};
static struct cpu_context *cpu_context_read(struct target *target, uint32_t base_addr,
                     uint32_t *info_addr);
static int insert_into_threadlist(struct target *target, struct threads *t);
 
static int linux_os_create(struct target *target);
 
static int linux_os_dummy_update(struct rtos *rtos)
{
    /*  update is done only when thread request come
     *  too many thread to do it on each stop */
    return 0;
}
 
static int linux_compute_virt2phys(struct target *target, target_addr_t address)
{
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    target_addr_t pa = 0;
    int retval = target->type->virt2phys(target, address, &pa);
    if (retval != ERROR_OK) {
        LOG_ERROR("Cannot compute linux virt2phys translation");
        /*  fixes default address  */
        linux_os->phys_base = 0;
        return ERROR_FAIL;
    }
 
    linux_os->init_task_addr = address;
    address = address & linux_os->phys_mask;
    linux_os->phys_base = pa - address;
    return ERROR_OK;
}
 
static int linux_read_memory(struct target *target,
    uint32_t address, uint32_t size, uint32_t count,
    uint8_t *buffer)
{
#ifdef PHYS
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    uint32_t pa = (address & linux_os->phys_mask) + linux_os->phys_base;
#endif
    if (address < 0xc0000000) {
        LOG_ERROR("linux awareness : address in user space");
        return ERROR_FAIL;
    }
#ifdef PHYS
    target_read_phys_memory(target, pa, size, count, buffer);
#endif
    target_read_memory(target, address, size, count, buffer);
    return ERROR_OK;
}
 
static int fill_buffer(struct target *target, uint32_t addr, uint8_t *buffer)
{
 
    if ((addr & 0xfffffffc) != addr)
        LOG_INFO("unaligned address %" PRIx32 "!!", addr);
 
    int retval = linux_read_memory(target, addr, 4, 1, buffer);
    return retval;
 
}
 
static int linux_os_thread_reg_list(struct rtos *rtos,
    int64_t thread_id, struct rtos_reg **reg_list, int *num_regs)
{
    struct target *target = rtos->target;
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    struct current_thread *tmp = linux_os->current_threads;
    struct current_thread *next;
    int found = 0;
    int retval;
    /*  check if a current thread is requested  */
    next = tmp;
 
    do {
        if (next->threadid == thread_id)
            found = 1;
        else
            next = next->next;
    } while ((found == 0) && (next != tmp) && (next));
 
    if (found == 0) {
        LOG_ERROR("could not find thread: %" PRIx64, thread_id);
        return ERROR_FAIL;
    }
 
    /*  search target to perform the access  */
    struct reg **gdb_reg_list;
    struct target_list *head;
    found = 0;
    foreach_smp_target(head, target->smp_targets) {
        if (head->target->coreid == next->core_id) {
            target = head->target;
            found = 1;
            break;
        }
    }
 
    if (found == 0) {
        LOG_ERROR
        (
            "current thread %" PRIx64 ": no target to perform access of core id %" PRIx32,
            thread_id,
            next->core_id);
        return ERROR_FAIL;
    }
 
    /*LOG_INFO("thread %lx current on core %x",thread_id, target->coreid);*/
    retval = target_get_gdb_reg_list(target, &gdb_reg_list, num_regs, REG_CLASS_GENERAL);
    if (retval != ERROR_OK)
        return retval;
 
    *reg_list = calloc(*num_regs, sizeof(struct rtos_reg));
 
    for (int i = 0; i < *num_regs; ++i) {
        if (!gdb_reg_list[i]->valid)
            gdb_reg_list[i]->type->get(gdb_reg_list[i]);
 
        (*reg_list)[i].number = gdb_reg_list[i]->number;
        (*reg_list)[i].size = gdb_reg_list[i]->size;
 
        buf_cpy(gdb_reg_list[i]->value, (*reg_list)[i].value, (*reg_list)[i].size);
    }
 
    return ERROR_OK;
}
 
static bool linux_os_detect(struct target *target)
{
    LOG_INFO("should no be called");
    return false;
}
 
static int linux_os_smp_init(struct target *target);
static int linux_os_clean(struct target *target);
#define INIT_TASK 0
static const char * const linux_symbol_list[] = {
    "init_task",
    NULL
};
 
static int linux_get_symbol_list_to_lookup(struct symbol_table_elem *symbol_list[])
{
    unsigned int i;
    *symbol_list = (struct symbol_table_elem *)
        calloc(ARRAY_SIZE(linux_symbol_list), sizeof(struct symbol_table_elem));
 
    for (i = 0; i < ARRAY_SIZE(linux_symbol_list); i++)
        (*symbol_list)[i].symbol_name = linux_symbol_list[i];
 
    return 0;
}
 
static char *linux_ps_command(struct target *target);
 
const struct rtos_type linux_rtos = {
    .name = "linux",
    .detect_rtos = linux_os_detect,
    .create = linux_os_create,
    .smp_init = linux_os_smp_init,
    .update_threads = linux_os_dummy_update,
    .get_thread_reg_list = linux_os_thread_reg_list,
    .get_symbol_list_to_lookup = linux_get_symbol_list_to_lookup,
    .clean = linux_os_clean,
    .ps_command = linux_ps_command,
};
 
static int linux_thread_packet(struct connection *connection, char const *packet,
        int packet_size);
static void linux_identify_current_threads(struct target *target);
 
#ifdef PID_CHECK
int fill_task_pid(struct target *target, struct threads *t)
{
    uint32_t pid_addr = t->base_addr + PID;
    uint8_t buffer[4];
    int retval = fill_buffer(target, pid_addr, buffer);
 
    if (retval == ERROR_OK) {
        uint32_t val = target_buffer_get_u32(target, buffer);
        t->pid = val;
    } else
        LOG_ERROR("fill_task_pid: unable to read memory");
 
    return retval;
}
#endif
 
static int fill_task(struct target *target, struct threads *t)
{
    int retval;
    uint32_t pid_addr = t->base_addr + PID;
    uint32_t mem_addr = t->base_addr + MEM;
    uint32_t on_cpu = t->base_addr + ONCPU;
    uint8_t *buffer = calloc(1, 4);
    retval = fill_buffer(target, t->base_addr, buffer);
 
    if (retval == ERROR_OK) {
        uint32_t val = target_buffer_get_u32(target, buffer);
        t->state = val;
    } else
        LOG_ERROR("fill_task: unable to read memory");
 
    retval = fill_buffer(target, pid_addr, buffer);
 
    if (retval == ERROR_OK) {
        uint32_t val = target_buffer_get_u32(target, buffer);
        t->pid = val;
    } else
        LOG_ERROR("fill task: unable to read memory");
 
    retval = fill_buffer(target, on_cpu, buffer);
 
    if (retval == ERROR_OK) {
        uint32_t val = target_buffer_get_u32(target, buffer);
        t->oncpu = val;
    } else
        LOG_ERROR("fill task: unable to read memory");
 
    retval = fill_buffer(target, mem_addr, buffer);
 
    if (retval == ERROR_OK) {
        uint32_t val = target_buffer_get_u32(target, buffer);
 
        if (val != 0) {
            uint32_t asid_addr = val + MM_CTX;
            retval = fill_buffer(target, asid_addr, buffer);
 
            if (retval == ERROR_OK) {
                val = target_buffer_get_u32(target, buffer);
                t->asid = val;
            } else
                LOG_ERROR
                    ("fill task: unable to read memory -- ASID");
        } else
            t->asid = 0;
    } else
        LOG_ERROR("fill task: unable to read memory");
 
    free(buffer);
 
    return retval;
}
 
static int get_name(struct target *target, struct threads *t)
{
    int retval;
    uint32_t full_name[4];
    uint32_t comm = t->base_addr + COMM;
    int i;
 
    for (i = 0; i < 17; i++)
        t->name[i] = 0;
 
    retval = linux_read_memory(target, comm, 4, 4, (uint8_t *) full_name);
 
    if (retval != ERROR_OK) {
        LOG_ERROR("get_name: unable to read memory\n");
        return ERROR_FAIL;
    }
 
    uint32_t raw_name = target_buffer_get_u32(target,
            (const uint8_t *)
            &full_name[0]);
    t->name[3] = raw_name >> 24;
    t->name[2] = raw_name >> 16;
    t->name[1] = raw_name >> 8;
    t->name[0] = raw_name;
    raw_name =
        target_buffer_get_u32(target, (const uint8_t *)&full_name[1]);
    t->name[7] = raw_name >> 24;
    t->name[6] = raw_name >> 16;
    t->name[5] = raw_name >> 8;
    t->name[4] = raw_name;
    raw_name =
        target_buffer_get_u32(target, (const uint8_t *)&full_name[2]);
    t->name[11] = raw_name >> 24;
    t->name[10] = raw_name >> 16;
    t->name[9] = raw_name >> 8;
    t->name[8] = raw_name;
    raw_name =
        target_buffer_get_u32(target, (const uint8_t *)&full_name[3]);
    t->name[15] = raw_name >> 24;
    t->name[14] = raw_name >> 16;
    t->name[13] = raw_name >> 8;
    t->name[12] = raw_name;
    return ERROR_OK;
 
}
 
static int get_current(struct target *target, int create)
{
    struct target_list *head;
    uint8_t *buf;
    uint32_t val;
    uint32_t ti_addr;
    uint8_t *buffer = calloc(1, 4);
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    struct current_thread *ctt = linux_os->current_threads;
 
    /*  invalid current threads content */
    while (ctt) {
        ctt->threadid = -1;
        ctt->TS = 0xdeadbeef;
        ctt = ctt->next;
    }
 
    foreach_smp_target(head, target->smp_targets) {
        struct reg **reg_list;
        int reg_list_size;
        int retval;
 
        if (target_get_gdb_reg_list(head->target, &reg_list,
                &reg_list_size, REG_CLASS_GENERAL) != ERROR_OK) {
            free(buffer);
            return ERROR_TARGET_FAILURE;
        }
 
        if (!reg_list[13]->valid)
            reg_list[13]->type->get(reg_list[13]);
 
        buf = reg_list[13]->value;
        val = target_buffer_get_u32(target, buf);
        ti_addr = (val & 0xffffe000);
        uint32_t ts_addr = ti_addr + 0xc;
        retval = fill_buffer(target, ts_addr, buffer);
 
        if (retval == ERROR_OK) {
            uint32_t TS = target_buffer_get_u32(target, buffer);
            uint32_t cpu, on_cpu = TS + ONCPU;
            retval = fill_buffer(target, on_cpu, buffer);
 
            if (retval == ERROR_OK) {
                /*uint32_t cpu = target_buffer_get_u32(target, buffer);*/
                struct current_thread *ct =
                    linux_os->current_threads;
                cpu = head->target->coreid;
 
                while ((ct) && (ct->core_id != (int32_t) cpu))
                    ct = ct->next;
 
                if ((ct) && (ct->TS == 0xdeadbeef))
                    ct->TS = TS;
                else
                    LOG_ERROR
                        ("error in linux current thread update");
 
                if (create && ct) {
                    struct threads *t;
                    t = calloc(1, sizeof(struct threads));
                    t->base_addr = ct->TS;
                    fill_task(target, t);
                    get_name(target, t);
                    t->oncpu = cpu;
                    insert_into_threadlist(target, t);
                    t->status = 3;
                    t->thread_info_addr = 0xdeadbeef;
                    ct->threadid = t->threadid;
                    linux_os->thread_count++;
#ifdef PID_CHECK
                    ct->pid = t->pid;
#endif
                    /*LOG_INFO("Creation of current thread %s",t->name);*/
                }
            }
        }
 
        free(reg_list);
    }
 
    free(buffer);
 
    return ERROR_OK;
}
 
static struct cpu_context *cpu_context_read(struct target *target, uint32_t base_addr,
    uint32_t *thread_info_addr_old)
{
    struct cpu_context *context = calloc(1, sizeof(struct cpu_context));
    uint32_t preempt_count_addr = 0;
    uint32_t registers[10];
    uint8_t *buffer = calloc(1, 4);
    uint32_t stack = base_addr + QAT;
    uint32_t thread_info_addr = 0;
    uint32_t thread_info_addr_update = 0;
    int retval = ERROR_FAIL;
    context->R4 = 0xdeadbeef;
    context->R5 = 0xdeadbeef;
    context->R6 = 0xdeadbeef;
    context->R7 = 0xdeadbeef;
    context->R8 = 0xdeadbeef;
    context->R9 = 0xdeadbeef;
    context->IP = 0xdeadbeef;
    context->FP = 0xdeadbeef;
    context->SP = 0xdeadbeef;
    context->PC = 0xdeadbeef;
retry:
 
    if (*thread_info_addr_old == 0xdeadbeef) {
        retval = fill_buffer(target, stack, buffer);
 
        if (retval == ERROR_OK)
            thread_info_addr = target_buffer_get_u32(target, buffer);
        else
            LOG_ERROR("cpu_context: unable to read memory");
 
        thread_info_addr_update = thread_info_addr;
    } else
        thread_info_addr = *thread_info_addr_old;
 
    preempt_count_addr = thread_info_addr + PREEMPT;
    retval = fill_buffer(target, preempt_count_addr, buffer);
 
    if (retval == ERROR_OK)
        context->preempt_count = target_buffer_get_u32(target, buffer);
    else {
        if (*thread_info_addr_old != 0xdeadbeef) {
            LOG_ERROR
                ("cpu_context: cannot read at thread_info_addr");
 
            if (*thread_info_addr_old < LINUX_USER_KERNEL_BORDER)
                LOG_INFO
                    ("cpu_context : thread_info_addr in userspace!!!");
 
            *thread_info_addr_old = 0xdeadbeef;
            goto retry;
        }
 
        LOG_ERROR("cpu_context: unable to read memory");
    }
 
    thread_info_addr += CPU_CONT;
 
    retval = linux_read_memory(target, thread_info_addr, 4, 10,
            (uint8_t *) registers);
 
    if (retval != ERROR_OK) {
        free(buffer);
        LOG_ERROR("cpu_context: unable to read memory\n");
        return context;
    }
 
    context->R4 =
        target_buffer_get_u32(target, (const uint8_t *)&registers[0]);
    context->R5 =
        target_buffer_get_u32(target, (const uint8_t *)&registers[1]);
    context->R6 =
        target_buffer_get_u32(target, (const uint8_t *)&registers[2]);
    context->R7 =
        target_buffer_get_u32(target, (const uint8_t *)&registers[3]);
    context->R8 =
        target_buffer_get_u32(target, (const uint8_t *)&registers[4]);
    context->R9 =
        target_buffer_get_u32(target, (const uint8_t *)&registers[5]);
    context->IP =
        target_buffer_get_u32(target, (const uint8_t *)&registers[6]);
    context->FP =
        target_buffer_get_u32(target, (const uint8_t *)&registers[7]);
    context->SP =
        target_buffer_get_u32(target, (const uint8_t *)&registers[8]);
    context->PC =
        target_buffer_get_u32(target, (const uint8_t *)&registers[9]);
 
    if (*thread_info_addr_old == 0xdeadbeef)
        *thread_info_addr_old = thread_info_addr_update;
 
    free(buffer);
 
    return context;
}
 
static uint32_t next_task(struct target *target, struct threads *t)
{
    uint8_t *buffer = calloc(1, 4);
    uint32_t next_addr = t->base_addr + NEXT;
    int retval = fill_buffer(target, next_addr, buffer);
 
    if (retval == ERROR_OK) {
        uint32_t val = target_buffer_get_u32(target, buffer);
        val = val - NEXT;
        free(buffer);
        return val;
    } else
        LOG_ERROR("next task: unable to read memory");
 
    free(buffer);
 
    return 0;
}
 
static struct current_thread *add_current_thread(struct current_thread *currents,
    struct current_thread *ct)
{
    ct->next = NULL;
 
    if (!currents) {
        currents = ct;
        return currents;
    } else {
        struct current_thread *temp = currents;
 
        while (temp->next)
            temp = temp->next;
 
        temp->next = ct;
        return currents;
    }
}
 
static struct threads *liste_del_task(struct threads *task_list, struct threads **t,
    struct threads *prev)
{
    LOG_INFO("del task %" PRId64, (*t)->threadid);
    if (prev)
        prev->next = (*t)->next;
    else
        task_list = (*t)->next;
 
    /*  free content of threads */
    free((*t)->context);
 
    free(*t);
    *t = prev ? prev : task_list;
    return task_list;
}
 
static struct threads *liste_add_task(struct threads *task_list, struct threads *t,
    struct threads **last)
{
    t->next = NULL;
 
    if (!*last) {
        if (!task_list) {
            task_list = t;
            return task_list;
        } else {
            struct threads *temp = task_list;
 
            while (temp->next)
                temp = temp->next;
 
            temp->next = t;
            *last = t;
            return task_list;
        }
    } else {
        (*last)->next = t;
        *last = t;
        return task_list;
    }
}
 
#ifdef PID_CHECK
static int current_pid(struct linux_os *linux_os, uint32_t pid)
#else
static int current_base_addr(struct linux_os *linux_os, uint32_t base_addr)
#endif
{
    struct current_thread *ct = linux_os->current_threads;
#ifdef PID_CHECK
 
    while ((ct) && (ct->pid != pid))
#else
    while ((ct) && (ct->TS != base_addr))
#endif
        ct = ct->next;
#ifdef PID_CHECK
    if ((ct) && (ct->pid == pid))
#else
    if ((ct) && (ct->TS == base_addr))
#endif
        return 1;
 
    return 0;
}
 
static int linux_get_tasks(struct target *target, int context)
{
    int loop = 0;
    int retval = 0;
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    linux_os->thread_list = NULL;
    linux_os->thread_count = 0;
 
    if (linux_os->init_task_addr == 0xdeadbeef) {
        LOG_INFO("no init symbol\n");
        return ERROR_FAIL;
    }
 
    int64_t start = timeval_ms();
 
    struct threads *t = calloc(1, sizeof(struct threads));
    struct threads *last = NULL;
    t->base_addr = linux_os->init_task_addr;
    /* retrieve the thread id , currently running in the different smp core */
    get_current(target, 1);
 
    while (((t->base_addr != linux_os->init_task_addr) &&
        (t->base_addr != 0)) || (loop == 0)) {
        loop++;
        fill_task(target, t);
        retval = get_name(target, t);
 
        if (loop > MAX_THREADS) {
            free(t);
            LOG_INFO("more than %d threads !!", MAX_THREADS);
            return ERROR_FAIL;
        }
 
        if (retval != ERROR_OK) {
            free(t);
            return ERROR_FAIL;
        }
 
        /*  check that this thread is not one the current threads already
         *  created */
        uint32_t base_addr;
#ifdef PID_CHECK
 
        if (!current_pid(linux_os, t->pid)) {
#else
        if (!current_base_addr(linux_os, t->base_addr)) {
#endif
            t->threadid = linux_os->threadid_count;
            t->status = 1;
            linux_os->threadid_count++;
 
            linux_os->thread_list =
                liste_add_task(linux_os->thread_list, t, &last);
            /* no interest to fill the context if it is a current thread. */
            linux_os->thread_count++;
            t->thread_info_addr = 0xdeadbeef;
 
            if (context)
                t->context =
                    cpu_context_read(target, t->base_addr,
                        &t->thread_info_addr);
            base_addr = next_task(target, t);
        } else {
            /*LOG_INFO("thread %s is a current thread already created",t->name); */
            base_addr = next_task(target, t);
            free(t);
        }
 
        t = calloc(1, sizeof(struct threads));
        t->base_addr = base_addr;
    }
 
    linux_os->threads_lookup = 1;
    linux_os->threads_needs_update = 0;
    linux_os->preupdtate_threadid_count = linux_os->threadid_count - 1;
    /*  check that all current threads have been identified  */
 
    LOG_INFO("complete time %" PRId64 ", thread mean %" PRId64 "\n",
        (timeval_ms() - start),
        (timeval_ms() - start) / linux_os->threadid_count);
 
    LOG_INFO("threadid count %d", linux_os->threadid_count);
    free(t);
 
    return ERROR_OK;
}
 
static int clean_threadlist(struct target *target)
{
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    struct threads *old, *temp = linux_os->thread_list;
 
    while (temp) {
        old = temp;
 
        free(temp->context);
 
        temp = temp->next;
        free(old);
    }
 
    return ERROR_OK;
}
 
static int linux_os_clean(struct target *target)
{
    struct linux_os *os_linux = (struct linux_os *)
        target->rtos->rtos_specific_params;
    clean_threadlist(target);
    os_linux->init_task_addr = 0xdeadbeef;
    os_linux->name = "linux";
    os_linux->thread_list = NULL;
    os_linux->thread_count = 0;
    os_linux->nr_cpus = 0;
    os_linux->threads_lookup = 0;
    os_linux->threads_needs_update = 0;
    os_linux->threadid_count = 1;
    return ERROR_OK;
}
 
static int insert_into_threadlist(struct target *target, struct threads *t)
{
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    struct threads *temp = linux_os->thread_list;
    t->threadid = linux_os->threadid_count;
    linux_os->threadid_count++;
    t->status = 1;
    t->next = NULL;
 
    if (!temp)
        linux_os->thread_list = t;
    else {
        while (temp->next)
            temp = temp->next;
 
        t->next = NULL;
        temp->next = t;
    }
 
    return ERROR_OK;
}
 
static void linux_identify_current_threads(struct target *target)
{
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    struct threads *thread_list = linux_os->thread_list;
    struct current_thread *ct = linux_os->current_threads;
    struct threads *t = NULL;
 
    while ((ct)) {
        if (ct->threadid == -1) {
 
            /*  un-identified thread */
            int found = 0;
            t = calloc(1, sizeof(struct threads));
            t->base_addr = ct->TS;
#ifdef PID_CHECK
 
            if (fill_task_pid(target, t) != ERROR_OK) {
error_handling:
                free(t);
                LOG_ERROR
                    ("linux identify_current_threads: unable to read pid");
                return;
            }
#endif
 
            /* search in the list of threads if pid
               already present */
            while ((thread_list) && (found == 0)) {
#ifdef PID_CHECK
                if (thread_list->pid == t->pid) {
#else
                if (thread_list->base_addr == t->base_addr) {
#endif
                    free(t);
                    t = thread_list;
                    found = 1;
                }
                thread_list = thread_list->next;
            }
 
            if (!found) {
                /*  it is a new thread */
                if (fill_task(target, t) != ERROR_OK)
                    goto error_handling;
 
                get_name(target, t);
                insert_into_threadlist(target, t);
                t->thread_info_addr = 0xdeadbeef;
            }
 
            t->status = 3;
            ct->threadid = t->threadid;
#ifdef PID_CHECK
            ct->pid = t->pid;
#endif
            linux_os->thread_count++;
#if 0
            if (found == 0)
                LOG_INFO("current thread core %x identified %s",
                    ct->core_id, t->name);
            else
                LOG_INFO("current thread core %x, reused %s",
                    ct->core_id, t->name);
#endif
        }
#if 0
        else {
            struct threads tmp;
            tmp.base_addr = ct->TS;
            get_name(target, &tmp);
            LOG_INFO("current thread core %x , already identified %s !!!",
                ct->core_id, tmp.name);
        }
#endif
        ct = ct->next;
    }
 
    return;
#ifndef PID_CHECK
error_handling:
    free(t);
    LOG_ERROR("unable to read pid");
    return;
 
#endif
}
 
static int linux_task_update(struct target *target, int context)
{
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    struct threads *thread_list = linux_os->thread_list;
    int retval;
    int loop = 0;
    linux_os->thread_count = 0;
 
    /*thread_list = thread_list->next; skip init_task*/
    while (thread_list) {
        thread_list->status = 0;    /*setting all tasks to dead state*/
 
        free(thread_list->context);
        thread_list->context = NULL;
 
        thread_list = thread_list->next;
    }
 
    int found = 0;
 
    if (linux_os->init_task_addr == 0xdeadbeef) {
        LOG_INFO("no init symbol\n");
        return ERROR_FAIL;
    }
    int64_t start = timeval_ms();
    struct threads *t = calloc(1, sizeof(struct threads));
    uint32_t previous = 0xdeadbeef;
    t->base_addr = linux_os->init_task_addr;
    retval = get_current(target, 0);
    /*check that all current threads have been identified  */
    linux_identify_current_threads(target);
 
    while (((t->base_addr != linux_os->init_task_addr) &&
        (t->base_addr != previous)) || (loop == 0)) {
        /*  for avoiding any permanent loop for any reason possibly due to
         *  target */
        loop++;
        previous = t->base_addr;
        /*  read only pid */
#ifdef PID_CHECK
        retval = fill_task_pid(target, t);
#endif
 
        if (retval != ERROR_OK) {
            free(t);
            return ERROR_FAIL;
        }
 
        thread_list = linux_os->thread_list;
 
        while (thread_list) {
#ifdef PID_CHECK
            if (t->pid == thread_list->pid) {
#else
            if (t->base_addr == thread_list->base_addr) {
#endif
                if (!thread_list->status) {
#ifdef PID_CHECK
                    if (t->base_addr != thread_list->base_addr)
                        LOG_INFO("thread base_addr has changed !!");
#endif
                    /*  this is not a current thread  */
                    thread_list->base_addr = t->base_addr;
                    thread_list->status = 1;
 
                    /*  we don 't update this field any more */
 
                    /*thread_list->state = t->state;
                    thread_list->oncpu = t->oncpu;
                    thread_list->asid = t->asid;
                    */
                    if (context)
                        thread_list->context =
                            cpu_context_read(target,
                                thread_list->base_addr,
                                &thread_list->thread_info_addr);
                } else {
                    /*  it is a current thread no need to read context */
                }
 
                linux_os->thread_count++;
                found = 1;
                break;
            } else {
                found = 0;
                thread_list = thread_list->next;
            }
        }
 
        if (found == 0) {
            uint32_t base_addr;
            fill_task(target, t);
            get_name(target, t);
            retval = insert_into_threadlist(target, t);
            t->thread_info_addr = 0xdeadbeef;
 
            if (context)
                t->context =
                    cpu_context_read(target, t->base_addr,
                        &t->thread_info_addr);
 
            base_addr = next_task(target, t);
            t = calloc(1, sizeof(struct threads));
            t->base_addr = base_addr;
            linux_os->thread_count++;
        } else
            t->base_addr = next_task(target, t);
    }
 
    LOG_INFO("update thread done %" PRId64 ", mean%" PRId64 "\n",
        (timeval_ms() - start), (timeval_ms() - start) / loop);
    free(t);
    linux_os->threads_needs_update = 0;
    return ERROR_OK;
}
 
static int linux_gdb_thread_packet(struct target *target,
    struct connection *connection, char const *packet,
    int packet_size)
{
    int retval;
    struct linux_os *linux_os =
        (struct linux_os *)target->rtos->rtos_specific_params;
 
    if (linux_os->init_task_addr == 0xdeadbeef) {
        /* it has not been initialized */
        LOG_INFO("received thread request without init task address");
        gdb_put_packet(connection, "l", 1);
        return ERROR_OK;
    }
 
    retval = linux_get_tasks(target, 1);
 
    if (retval != ERROR_OK)
        return ERROR_TARGET_FAILURE;
 
    char *out_str = calloc(MAX_THREADS * 17 + 10, 1);
    if (!out_str) {
        LOG_ERROR("Out of memory");
        return ERROR_FAIL;
    }
    char *tmp_str = out_str;
    tmp_str += sprintf(tmp_str, "m");
    struct threads *temp = linux_os->thread_list;
 
    while (temp) {
        tmp_str += sprintf(tmp_str, "%016" PRIx64, temp->threadid);
        temp = temp->next;
        if (temp)
            tmp_str += sprintf(tmp_str, ",");
    }
 
    gdb_put_packet(connection, out_str, strlen(out_str));
    free(out_str);
    return ERROR_OK;
}
 
static int linux_gdb_thread_update(struct target *target,
    struct connection *connection, char const *packet,
    int packet_size)
{
    int found = 0;
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    struct threads *temp = linux_os->thread_list;
 
    while (temp) {
        if (temp->threadid == linux_os->preupdtate_threadid_count + 1) {
            /*LOG_INFO("FOUND");*/
            found = 1;
            break;
        } else
            temp = temp->next;
    }
 
    if (found == 1) {
        /*LOG_INFO("INTO GDB THREAD UPDATE FOUNDING START TASK");*/
        char *out_strr = calloc(MAX_THREADS * 17 + 10, 1);
        char *tmp_strr = out_strr;
        tmp_strr += sprintf(tmp_strr, "m");
        /*LOG_INFO("CHAR MALLOC & M DONE");*/
        tmp_strr += sprintf(tmp_strr, "%016" PRIx64, temp->threadid);
 
        temp = temp->next;
 
        while (temp) {
            /*LOG_INFO("INTO GDB THREAD UPDATE WHILE");*/
            tmp_strr += sprintf(tmp_strr, ",");
            tmp_strr +=
                sprintf(tmp_strr, "%016" PRIx64, temp->threadid);
            temp = temp->next;
        }
 
        /*tmp_str[0] = 0;*/
        gdb_put_packet(connection, out_strr, strlen(out_strr));
        linux_os->preupdtate_threadid_count =
            linux_os->threadid_count - 1;
        free(out_strr);
    } else
        gdb_put_packet(connection, "l", 1);
 
    return ERROR_OK;
}
 
static int linux_thread_extra_info(struct target *target,
    struct connection *connection, char const *packet,
    int packet_size)
{
    int64_t threadid = 0;
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    sscanf(packet, "qThreadExtraInfo,%" SCNx64, &threadid);
    /*LOG_INFO("lookup extra info for thread %" SCNx64, threadid);*/
    struct threads *temp = linux_os->thread_list;
 
    while (temp) {
        if (temp->threadid == threadid) {
            char *tmp_str = alloc_printf("%cPID: %" PRIu32 ", Name: %s",
                    temp->status == 3 ? '*' : ' ',
                    temp->pid, temp->name);
            if (!tmp_str) {
                LOG_ERROR("Out of memory");
                return ERROR_FAIL;
            }
            char *hex_str = calloc(1, strlen(tmp_str) * 2 + 1);
            size_t pkt_len = hexify(hex_str, (const uint8_t *)tmp_str,
                strlen(tmp_str), strlen(tmp_str) * 2 + 1);
            gdb_put_packet(connection, hex_str, pkt_len);
            free(hex_str);
            free(tmp_str);
            return ERROR_OK;
        }
 
        temp = temp->next;
    }
 
    LOG_INFO("thread not found");
    return ERROR_OK;
}
 
static int linux_gdb_t_packet(struct connection *connection,
    struct target *target, char const *packet, int packet_size)
{
    int64_t threadid;
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    int retval = ERROR_OK;
    sscanf(packet, "T%" SCNx64, &threadid);
 
    if (linux_os->threads_needs_update == 0) {
        struct threads *temp = linux_os->thread_list;
        struct threads *prev = NULL;
 
        while (temp) {
            if (temp->threadid == threadid) {
                if (temp->status != 0) {
                    gdb_put_packet(connection, "OK", 2);
                    return ERROR_OK;
                } else {
                    /* delete item in the list   */
                    linux_os->thread_list =
                        liste_del_task(linux_os->thread_list,
                            &temp, prev);
                    linux_os->thread_count--;
                    gdb_put_packet(connection, "E01", 3);
                    return ERROR_OK;
                }
            }
 
            /*  for deletion  */
            prev = temp;
            temp = temp->next;
        }
 
        LOG_INFO("gdb requested status on non existing thread");
        gdb_put_packet(connection, "E01", 3);
        return ERROR_OK;
 
    } else {
        retval = linux_task_update(target, 1);
        struct threads *temp = linux_os->thread_list;
 
        while (temp) {
            if (temp->threadid == threadid) {
                if (temp->status == 1) {
                    gdb_put_packet(connection, "OK", 2);
                    return ERROR_OK;
                } else {
                    gdb_put_packet(connection, "E01", 3);
                    return ERROR_OK;
                }
            }
 
            temp = temp->next;
        }
    }
 
    return retval;
}
 
static int linux_gdb_h_packet(struct connection *connection,
    struct target *target, char const *packet, int packet_size)
{
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    struct current_thread *ct = linux_os->current_threads;
 
    /* select to display the current thread of the selected target */
    while ((ct) && (ct->core_id != target->coreid))
        ct = ct->next;
 
    int64_t current_gdb_thread_rq;
 
    if (linux_os->threads_lookup == 1) {
        if ((ct) && (ct->threadid == -1)) {
            ct = linux_os->current_threads;
 
            while ((ct) && (ct->threadid == -1))
                ct = ct->next;
        }
 
        if (!ct) {
            /*  no current thread can be identified
             *  any way with smp  */
            LOG_INFO("no current thread identified");
            /* attempt to display the name of the 2 threads identified with
             * get_current */
            struct threads t;
            ct = linux_os->current_threads;
 
            while ((ct) && (ct->threadid == -1)) {
                t.base_addr = ct->TS;
                get_name(target, &t);
                LOG_INFO("name of unidentified thread %s",
                    t.name);
                ct = ct->next;
            }
 
            gdb_put_packet(connection, "OK", 2);
            return ERROR_OK;
        }
 
        if (packet[1] == 'g') {
            sscanf(packet, "Hg%16" SCNx64, &current_gdb_thread_rq);
 
            if (current_gdb_thread_rq == 0) {
                target->rtos->current_threadid = ct->threadid;
                gdb_put_packet(connection, "OK", 2);
            } else {
                target->rtos->current_threadid =
                    current_gdb_thread_rq;
                gdb_put_packet(connection, "OK", 2);
            }
        } else if (packet[1] == 'c') {
            sscanf(packet, "Hc%16" SCNx64, &current_gdb_thread_rq);
 
            if ((current_gdb_thread_rq == 0) ||
                    (current_gdb_thread_rq == ct->threadid)) {
                target->rtos->current_threadid = ct->threadid;
                gdb_put_packet(connection, "OK", 2);
            } else
                gdb_put_packet(connection, "E01", 3);
        }
    } else
        gdb_put_packet(connection, "OK", 2);
 
    return ERROR_OK;
}
 
static int linux_thread_packet(struct connection *connection, char const *packet,
    int packet_size)
{
    int retval = ERROR_OK;
    struct current_thread *ct;
    struct target *target = get_target_from_connection(connection);
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
 
    switch (packet[0]) {
    case 'T':       /* Is thread alive?*/
        linux_gdb_t_packet(connection, target, packet, packet_size);
        break;
 
    case 'H':       /* Set current thread */
        /*  ( 'c' for step and continue, 'g' for all other operations )*/
        /*LOG_INFO(" H packet received '%s'", packet);*/
        linux_gdb_h_packet(connection, target, packet, packet_size);
        break;
 
    case 'q':
        if (!strncmp(packet, "qSymbol", 7)) {
            if (rtos_qsymbol(connection, packet, packet_size) == 1) {
                linux_compute_virt2phys(target,
                        target->rtos->symbols[INIT_TASK].address);
            }
        } else if (!strncmp(packet, "qfThreadInfo", 12)) {
            if (!linux_os->thread_list) {
                retval = linux_gdb_thread_packet(target,
                        connection,
                        packet,
                        packet_size);
            } else {
                retval = linux_gdb_thread_update(target,
                        connection,
                        packet,
                        packet_size);
            }
        } else if (!strncmp(packet, "qsThreadInfo", 12)) {
            gdb_put_packet(connection, "l", 1);
        } else if (!strncmp(packet, "qThreadExtraInfo,", 17)) {
            linux_thread_extra_info(target, connection, packet,
                    packet_size);
        } else {
            retval = GDB_THREAD_PACKET_NOT_CONSUMED;
        }
        break;
 
    case 'Q':
        /* previously response was : thread not found
         * gdb_put_packet(connection, "E01", 3); */
        retval = GDB_THREAD_PACKET_NOT_CONSUMED;
        break;
 
    case 'c':
    case 's':
        if (linux_os->threads_lookup == 1) {
            ct = linux_os->current_threads;
 
            while ((ct) && (ct->core_id) != target->coreid)
                ct = ct->next;
 
            if ((ct) && (ct->threadid == -1)) {
                ct = linux_os->current_threads;
 
                while ((ct) && (ct->threadid == -1))
                    ct = ct->next;
            }
 
            if ((ct) && (ct->threadid !=
                     target->rtos->current_threadid)
            && (target->rtos->current_threadid != -1))
                LOG_WARNING("WARNING! current GDB thread do not match "
                        "current thread running. "
                        "Switch thread in GDB to threadid %d",
                        (int)ct->threadid);
 
            LOG_INFO("threads_needs_update = 1");
            linux_os->threads_needs_update = 1;
        }
        break;
    }
 
    return retval;
}
 
static int linux_os_smp_init(struct target *target)
{
    struct target_list *head;
    /* keep only target->rtos */
    struct rtos *rtos = target->rtos;
    struct linux_os *os_linux =
        (struct linux_os *)rtos->rtos_specific_params;
    struct current_thread *ct;
 
    foreach_smp_target(head, target->smp_targets) {
        if (head->target->rtos != rtos) {
            struct linux_os *smp_os_linux =
                (struct linux_os *)head->target->rtos->rtos_specific_params;
            /*  remap smp target on rtos  */
            free(head->target->rtos);
            head->target->rtos = rtos;
            /*  reuse allocated ct */
            ct = smp_os_linux->current_threads;
            ct->threadid = -1;
            ct->TS = 0xdeadbeef;
            ct->core_id = head->target->coreid;
            os_linux->current_threads =
                add_current_thread(os_linux->current_threads, ct);
            os_linux->nr_cpus++;
            free(smp_os_linux);
        }
    }
 
    return ERROR_OK;
}
 
static int linux_os_create(struct target *target)
{
    struct linux_os *os_linux = calloc(1, sizeof(struct linux_os));
    struct current_thread *ct = calloc(1, sizeof(struct current_thread));
    LOG_INFO("linux os creation\n");
    os_linux->init_task_addr = 0xdeadbeef;
    os_linux->name = "linux";
    os_linux->thread_list = NULL;
    os_linux->thread_count = 0;
    target->rtos->current_threadid = -1;
    os_linux->nr_cpus = 1;
    os_linux->threads_lookup = 0;
    os_linux->threads_needs_update = 0;
    os_linux->threadid_count = 1;
    os_linux->current_threads = NULL;
    target->rtos->rtos_specific_params = os_linux;
    ct->core_id = target->coreid;
    ct->threadid = -1;
    ct->TS = 0xdeadbeef;
    os_linux->current_threads =
        add_current_thread(os_linux->current_threads, ct);
    /*  overload rtos thread default handler */
    target->rtos->gdb_thread_packet = linux_thread_packet;
    /*  initialize a default virt 2 phys translation */
    os_linux->phys_mask = ~0xc0000000;
    os_linux->phys_base = 0x0;
    return ERROR_OK;
}
 
static char *linux_ps_command(struct target *target)
{
    struct linux_os *linux_os = (struct linux_os *)
        target->rtos->rtos_specific_params;
    int retval = ERROR_OK;
    char *display;
 
    if (linux_os->threads_lookup == 0)
        retval = linux_get_tasks(target, 1);
    else {
        if (linux_os->threads_needs_update != 0)
            retval = linux_task_update(target, 0);
    }
 
    if (retval == ERROR_OK) {
        struct threads *temp = linux_os->thread_list;
        char *tmp;
        LOG_INFO("allocation for %d threads line",
            linux_os->thread_count);
        display = calloc((linux_os->thread_count + 2) * 80, 1);
 
        if (!display)
            goto error;
 
        tmp = display;
        tmp += sprintf(tmp, "PID\t\tCPU\t\tASID\t\tNAME\n");
        tmp += sprintf(tmp, "---\t\t---\t\t----\t\t----\n");
 
        while (temp) {
            if (temp->status) {
                if (temp->context)
                    tmp +=
                        sprintf(tmp,
                            "%" PRIu32 "\t\t%" PRIu32 "\t\t%" PRIx32 "\t\t%s\n",
                            temp->pid, temp->oncpu,
                            temp->asid, temp->name);
                else
                    tmp +=
                        sprintf(tmp,
                            "%" PRIu32 "\t\t%" PRIu32 "\t\t%" PRIx32 "\t\t%s\n",
                            temp->pid, temp->oncpu,
                            temp->asid, temp->name);
            }
 
            temp = temp->next;
        }
 
        return display;
    }
 
error:
    display = calloc(40, 1);
    sprintf(display, "linux_ps_command failed\n");
    return display;
}