• [原创]ATF-FUZZ

ATF Fuzzing

FVP环境搭建

FVP下载

https://developer.arm.com/Tools%20and%20Software/Fixed%20Virtual%20Platforms

image-20240422164011956

推荐直接下载：

Armv-A Base RevC AEM FVP (x86 Linux)

Armv-A Base RevC AEM FVP (AArch64 Linux, beta)

下载完成后解压的到Base_RevC_AEMvA_pkg

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sudo apt install xterm
tar -xzvf FVP_Base_RevC-2xAEMvA_11.25_15_Linux64.tgz
# Base_RevC_AEMvA_pkg

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注意对应的binary文件在AEMv8R_base_pkg/models/Linux64_GCC-9.3目录下

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FVP的快捷的两种启动方法：1. ARM Develop Studio可视化启动 2.command line启动。本教程主要使用command line方式启动。

BL33构建

BL33作为None-security world镜像，一般情况下为uboot，当然也可以直接跳转到kernel。

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export CROSS_COMPILE=/data/toolchains/SYS_PUBLIC_TOOLS/.toolchain/gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu-linux-5.10/bin/aarch64-none-linux-gnu-
git clone https://github.com/u-boot/u-boot.git
cd u-boot
make vexpress_aemv8a_semi_defconfig
make -j 9

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ATF构建

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cd /data/Project/arm-trusted-firmware-lts-v2.8.4/
export CROSS_COMPILE=/data/toolchains/SYS_PUBLIC_TOOLS/.toolchain/gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu-linux-5.10/bin/aarch64-none-linux-gnu-
 
// 调试编译
make PLAT=fvp BL33=/data/Project/u-boot/u-boot.bin DEBUG=1 all fip
// 正常编译
make PLAT=fvp BL33=/data/Project/u-boot/u-boot.bin all fip

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ATF运行

AEMv8 Base FVP

使用FVP_Base_RevC-2xAEMv8A运行

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cd /data/Project/arm-trusted-firmware-lts-v2.8.4/build/fvp/debug/
export DISPLAY=:0

运行命令：

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/data/Project/Base_RevC_AEMvA_pkg/models/Linux64_GCC-9.3/FVP_Base_RevC-2xAEMvA \
-C pctl.startup=0.0.0.0                                     \
-C bp.secure_memory=1                                       \
-C bp.tzc_400.diagnostics=1                                 \
-C cluster0.NUM_CORES=4                                     \
-C cluster1.NUM_CORES=4                                     \
-C cache_state_modelled=1                                   \
-C bp.secureflashloader.fname="./bl1.bin"      \
-C bp.flashloader0.fname="./fip.bin"
 
# 如果需要运行到rootfs请添加下方参数，
--data cluster0.cpu0="<path-to>/<kernel-binary>"@0x80080000 \
--data cluster0.cpu0="<path-to>/<ramdisk>"@0x84000000

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TF-A Tests构建并运行

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export CROSS_COMPILE=/data/toolchains/SYS_PUBLIC_TOOLS/.toolchain/gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu-linux-5.10/bin/aarch64-none-linux-gnu-
git clone https://review.trustedfirmware.orgTF-A/tf-a-tests.git
cd tf-a-tests
make PLAT=fvp tftf

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重编译ATF，指定bl33.bin为tftf.bin

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cd /data/Project/arm-trusted-firmware-lts-v2.8.4/
export CROSS_COMPILE=/data/toolchains/SYS_PUBLIC_TOOLS/.toolchain/gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu-linux-5.10/bin/aarch64-none-linux-gnu-
make PLAT=fvp BL33=/data/Project/tf-a-tests/build/fvp/release/tftf.bin all fip

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重新使用FVP运行，成功引导进入tftf中

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运行完成后会输出测试结果并提示退出

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SMC Fuzz

推荐阅读：https://www.trustedfirmware.org/docs/Directed_Radomized_SMC_Presentation.pdf

默认配置运行

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export CROSS_COMPILE=/data/toolchains/SYS_PUBLIC_TOOLS/.toolchain/gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu-linux-5.10/bin/aarch64-none-linux-gnu-
make PLAT=fvp SMC_FUZZING=1 SMC_FUZZ_DTS=/data/Project/tf-a-tests/smc_fuzz/dts/top.dts TESTS=smcfuzzing tftf

注意这里的SMC_FUZZ_DTS是可以自定义的，这里使用了官方提供的top.dts

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/*
 * Copyright (c) 2023, Arm Limited. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
 
/*
 * Top level device tree file to bias the SMC calls.  T
 * he biases are arbitrary and can be any value.
 * They are only significant when weighted against the
 * other biases.  30 was chosen arbitrarily.
 */
 
/dts-v1/;
 
/ {
 
    sdei {
        bias = <30>;
        sdei_version {
            bias = <30>;
            functionname = "sdei_version_funcid";
        };
        sdei_pe_unmask {
            bias = <30>;
            functionname = "sdei_pe_unmask_funcid";
        };
        sdei_pe_mask {
            bias = <30>;
            functionname = "sdei_pe_mask_funcid";
        };
        sdei_event_status {
            bias = <30>;
            functionname = "sdei_event_status_funcid";
        };
        sdei_event_signal {
            bias = <30>;
            functionname = "sdei_event_signal_funcid";
        };
        sdei_private_reset {
            bias = <30>;
            functionname = "sdei_private_reset_funcid";
        };
        sdei_shared_reset {
            bias = <30>;
            functionname = "sdei_shared_reset_funcid";
        };
    };
    tsp {
        bias = <30>;
        tsp_add_op {
            bias = <30>;
            functionname = "tsp_add_op_funcid";
        };
        tsp_sub_op {
            bias = <30>;
            functionname = "tsp_sub_op_funcid";
        };
        tsp_mul_op {
            bias = <30>;
            functionname = "tsp_mul_op_funcid";
        };
        tsp_div_op {
            bias = <30>;
            functionname = "tsp_div_op_funcid";
        };
    };
};

image-20240423103107010

重编译ATF，并替换tftf.bin

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cd /data/Project/arm-trusted-firmware-lts-v2.8.4/
export CROSS_COMPILE=/data/toolchains/SYS_PUBLIC_TOOLS/.toolchain/gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu-linux-5.10/bin/aarch64-none-linux-gnu-
make PLAT=fvp BL33=/data/Project/tf-a-tests/build/fvp/release/tftf.bin all fip

image-20240423102154343

再次运行

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cd /data/Project/arm-trusted-firmware-lts-v2.8.4/build/fvp/release/
/data/Project/Base_RevC_AEMvA_pkg/models/Linux64_GCC-9.3/FVP_Base_RevC-2xAEMvA \
-C pctl.startup=0.0.0.0                                     \
-C bp.secure_memory=1                                       \
-C bp.tzc_400.diagnostics=1                                 \
-C cluster0.NUM_CORES=4                                     \
-C cluster1.NUM_CORES=4                                     \
-C cache_state_modelled=1                                   \
-C bp.secureflashloader.fname="./bl1.bin"      \
-C bp.flashloader0.fname="./fip.bin"

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扩展SMC fuzz

先来通过目录结构确定需要扩展的文件1. Dts 2. fuzz helper

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  1. 首先创建test_fuzz_helper.h ，引用上述头文件(tftf框架), 并且定义与dts中function_name对应的常量funcid。最后在底部申明使用到的函数入口run_test_fuzz和具体的handler函数tftf_test_smc
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//
// Created by ios on 24-4-23.
//
 
#include <fuzz_helper.h>
#include <power_management.h>
#include <sdei.h>
#include <test_helpers.h>
#include <tftf_lib.h>
#include <timer.h>
 
#ifndef test_funcid
#define test_funcid 0
#endif
 
void tftf_test_smc(uint64_t tsp_id, char *funcstr);
void run_test_fuzz(int funcid);
  1. 完善具体的test_fuzz_helper.c,具体功能为打印固定的字符串ios-test 并输出测试信息。
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#include <fuzz_names.h>
#include <test_fuzz_helper.h>
 
void tftf_test_smc(uint64_t tsp_id, char *funcstr)
{
    printf("current str: %s, this is test smc fuzz handler!\n", funcstr);
}
 
/*
 * TSP function called from fuzzer
 */
void run_test_fuzz(int funcid)
{
    tftf_test_smc(funcid, "ios-test");
}

  1. 创建对应的test.dts ，主要定义了两个功能test_add和test_mov，并且对应的函数均为test_funcid。

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    /*
     * Copyright (c) 2023, Arm Limited. All rights reserved.
     *
     * SPDX-License-Identifier: BSD-3-Clause
     */
     
     
    /*
     * Top level device tree file to bias the SMC calls.  T
     * he biases are arbitrary and can be any value.
     * They are only significant when weighted against the
     * other biases.  30 was chosen arbitrarily.
     */
     
    /dts-v1/;
     
    / {
        test {
            bias = <30>;
            test_add {
                bias = <30>;
                functionname = "test_funcid";
            };
            test_mov {
                bias = <30>;
                functionname = "test_funcid";
            };
        };
    };

  2. 将run_test_fuzz添加到runtestfunction_helpers.c中

    image-20240423163625289

  3. 将tftf/tests/tests-smcfuzzing.mk 中的编译依赖中添加test_fuzz_helper.c

    image-20240423163901129

  4. 调整运行的次数和并发数，tftf/tests/tests-smcfuzzing.mk

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  5. 编译仅包含smcfuzz的tftf

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export CROSS_COMPILE=/data/toolchains/SYS_PUBLIC_TOOLS/.toolchain/gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu-linux-5.10/bin/aarch64-none-linux-gnu-
make PLAT=fvp SMC_FUZZING=1 SMC_FUZZ_DTS=/data/Project/tf-a-tests/smc_fuzz/dts/test.dts TESTS=smcfuzzing tftf
  1. 打包tftf到fip.bin中
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cd /data/Project/arm-trusted-firmware-lts-v2.8.4/
export CROSS_COMPILE=/data/toolchains/SYS_PUBLIC_TOOLS/.toolchain/gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu-linux-5.10/bin/aarch64-none-linux-gnu-
make PLAT=fvp BL33=/data/Project/tf-a-tests/build/fvp/release/tftf.bin all fip
  1. 运行smc_fuzz
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cd /data/Project/arm-trusted-firmware-lts-v2.8.4/build/fvp/release/
/data/Project/Base_RevC_AEMvA_pkg/models/Linux64_GCC-9.3/FVP_Base_RevC-2xAEMvA \
-C pctl.startup=0.0.0.0                                     \
-C bp.secure_memory=1                                       \
-C bp.tzc_400.diagnostics=1                                 \
-C cluster0.NUM_CORES=4                                     \
-C cluster1.NUM_CORES=4                                     \
-C cache_state_modelled=1                                   \
-C bp.secureflashloader.fname="./bl1.bin"      \
-C bp.flashloader0.fname="./fip.bin"

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ATF BL1 FUZZ

场景描述

对BL1、BL2、BL31、BL32阶段的代码实现功能测试。此阶段代码多数为厂商定制。

功能描述

  1. 针对函数功能FUZZ
  2. 支持模拟器部分阶段FUZZ（BL1、BL2、BL31、BL32）

功能实现

待补充

效果展示

image-20240428094155981

补充

本教程主要提供了ATF官方的FUZZ教程。BL1 demo-fuzz目前没有想到更好的解决方式，希望能一起讨论分析。