Ejemplos de is_stack_addr en C++ (Cpp)

Ejemplo n.º 1

Archivo: trts_util.cpp Proyecto: daveti/linux-sgx

bool is_valid_sp(uintptr_t sp)
{
    return ( !(sp & (sizeof(uintptr_t) - 1))   // sp is expected to be 4/8 bytes aligned
           && is_stack_addr((void*)sp, 0) );   // sp points to the top/bottom of stack are accepted
}

Ejemplo n.º 2

Archivo: trts_veh.cpp Proyecto: axelexic/linux-sgx

extern "C" sgx_status_t trts_handle_exception(void *tcs)
{
    thread_data_t *thread_data = get_thread_data();
    ssa_gpr_t *ssa_gpr = NULL;
    sgx_exception_info_t *info = NULL;
    uintptr_t sp, *new_sp = NULL;
    size_t size = 0;

    if (tcs == NULL) goto default_handler;
    
    if(get_enclave_state() != ENCLAVE_INIT_DONE)
    {
        goto default_handler;
    }
    
    // check if the exception is raised from 2nd phrase
    if(thread_data->exception_flag == -1) {
        goto default_handler;
    }
 
    if ((TD2TCS(thread_data) != tcs) 
            || (((thread_data->first_ssa_gpr)&(~0xfff)) - SE_PAGE_SIZE) != (uintptr_t)tcs) {
        goto default_handler;
    }

    // no need to check the result of ssa_gpr because thread_data is always trusted
    ssa_gpr = reinterpret_cast<ssa_gpr_t *>(thread_data->first_ssa_gpr);
    
    sp = ssa_gpr->REG(sp);
    if(!is_stack_addr((void*)sp, 0))  // check stack overrun only, alignment will be checked after exception handled
    {
        g_enclave_state = ENCLAVE_CRASHED;
        return SGX_ERROR_STACK_OVERRUN;
    }

    size = 0;
#ifdef SE_GNU64
    size += 128; // x86_64 requires a 128-bytes red zone, which begins directly
                 // after the return addr and includes func's arguments
#endif

    // decrease the stack to give space for info
    size += sizeof(sgx_exception_info_t);
    sp -= size;
    sp = sp & ~0xF;

    // check the decreased sp to make sure it is in the trusted stack range
    if(!is_stack_addr((void *)sp, size))
    {
        g_enclave_state = ENCLAVE_CRASHED;
        return SGX_ERROR_STACK_OVERRUN;
    }

    if(ssa_gpr->exit_info.valid != 1)
    {   // exception handlers are not allowed to call in a non-exception state
        goto default_handler;
    }
    
    info = (sgx_exception_info_t *)sp;
    
    // No need to check the stack as it have already been checked by assembly code

    // initialize the info with SSA[0]
    info->exception_vector = (sgx_exception_vector_t)ssa_gpr->exit_info.vector;
    info->exception_type = (sgx_exception_type_t)ssa_gpr->exit_info.exit_type;

    info->cpu_context.REG(ax) = ssa_gpr->REG(ax);
    info->cpu_context.REG(cx) = ssa_gpr->REG(cx);
    info->cpu_context.REG(dx) = ssa_gpr->REG(dx);
    info->cpu_context.REG(bx) = ssa_gpr->REG(bx);
    info->cpu_context.REG(sp) = ssa_gpr->REG(sp);
    info->cpu_context.REG(bp) = ssa_gpr->REG(bp);
    info->cpu_context.REG(si) = ssa_gpr->REG(si);
    info->cpu_context.REG(di) = ssa_gpr->REG(di);
    info->cpu_context.REG(flags) = ssa_gpr->REG(flags);
    info->cpu_context.REG(ip) = ssa_gpr->REG(ip);
#ifdef SE_64
    info->cpu_context.r8  = ssa_gpr->r8;
    info->cpu_context.r9  = ssa_gpr->r9;
    info->cpu_context.r10 = ssa_gpr->r10;
    info->cpu_context.r11 = ssa_gpr->r11;
    info->cpu_context.r12 = ssa_gpr->r12;
    info->cpu_context.r13 = ssa_gpr->r13;
    info->cpu_context.r14 = ssa_gpr->r14;
    info->cpu_context.r15 = ssa_gpr->r15;
#endif

    // decrease the stack to save the SSA[0]->ip
    size = sizeof(uintptr_t);
    new_sp = (uintptr_t *)(sp - size);
    if(!is_stack_addr(new_sp, size))
    {
        g_enclave_state = ENCLAVE_CRASHED;
        return SGX_ERROR_STACK_OVERRUN;
    }
    ssa_gpr->REG(ip) = (size_t)internal_handle_exception; // prepare the ip for 2nd phrase handling
    ssa_gpr->REG(sp) = (size_t)new_sp;      // new stack for internal_handle_exception
    ssa_gpr->REG(ax) = (size_t)info;        // 1st parameter (info) for LINUX32
    ssa_gpr->REG(di) = (size_t)info;        // 1st parameter (info) for LINUX64, LINUX32 also uses it while restoring the context
    *new_sp = info->cpu_context.REG(ip);    // for debugger to get call trace
    
    //mark valid to 0 to prevent eenter again
    ssa_gpr->exit_info.valid = 0;

    return SGX_SUCCESS;
 
default_handler:
    g_enclave_state = ENCLAVE_CRASHED;
    return SGX_ERROR_ENCLAVE_CRASHED;
}