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Feature/ksym backtrace - #11768

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liulangrenaaa wants to merge 3 commits into
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liulangrenaaa:feature/ksym-backtrace
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Feature/ksym backtrace#11768
liulangrenaaa wants to merge 3 commits into
RT-Thread:masterfrom
liulangrenaaa:feature/ksym-backtrace

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@liulangrenaaa

@liulangrenaaa liulangrenaaa commented Aug 28, 2026 •
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拉取/合并请求描述：(PR description)

为什么提交这份PR (why to submit this PR)

当前 RT-Thread 通用 backtrace 主要输出原始 PC 地址，并提示用户使用
addr2line 进行解析。在 exception、assert、panic 等现场，通常没有
完整 ELF/DWARF 环境，定位函数名称不够方便。

本 PR 增加一个可选的内核函数符号表，使 backtrace 可以直接输出函数名、
函数内偏移和函数大小，例如：

0x60043e90 <ksym_test_level3+0xc/0x14>
0x60043e7c <ksym_test_level2+0xc/0x14>
0x60043e68 <ksym_test_level1+0xc/0x14>

该功能默认关闭，不影响未启用配置的 ROM 和原有 backtrace 行为。

本 PR 包含三个 commit：

  1. kernel: add optional ksym table

    • 增加通用 kernel symbol table 和 rt_ksym_lookup() API
    • 增加 GCC/ELF 符号生成器及 SCons 多阶段构建流程

  2. kernel: symbolize backtraces

    • 将公共 backtrace 输出接入 kernel symbol resolver
    • 保留原始 PC，并在解析失败时回退为地址输出

  3. libcpu: add Cortex-A ksym backtrace

    • 将 Cortex-A backtrace 接入公共格式化输出
    • 增加 ARM32 和 AArch64 的静态函数回溯测试

你的解决方案是什么 (what is your solution)

新增 RT_USING_KSYMS 配置项，默认值为 n。

在 native SCons GCC/ELF 构建中，构建流程会从预链接 ELF 中提取函数符号，
生成紧凑的只读 kernel symbol table，然后重新链接最终 ELF：

objects
-> rtthread.pre1.elf
-> generate ksym table
-> rtthread.pre2.elf
-> generate final ksym table
-> rtthread.elf
-> verify final symbol addresses

符号表包含：

  • global function
  • local/static function
  • weak function
  • symbol start address
  • symbol name
  • symbol size

运行时使用无锁二分查找，不使用 heap、mutex 或动态内存。符号表使用相对地址、
name offset 和共享字符串表，以减少存储开销。

地址解析规则：

  • 支持 duplicate-address aliases
  • 使用下一个不同地址的 symbol 计算函数范围
  • 支持最后一个 symbol 和 zero-sized symbol
  • 32-bit ARM 仅清除 Thumb bit
  • AArch64 和 RISC-V 不进行 Thumb address normalization
  • 未找到 symbol 时保留原始 PC 并回退为地址输出
  • RT_USING_KSYMS=n 时保留原有 addr2line 使用方式

该版本第一阶段仅支持 GCC/ELF/native SCons 构建。其他工具链和
--target=makefile 等生成项目在启用 RT_USING_KSYMS 时会直接报错。

请提供验证的bsp和config (provide the config and bsp)

  • BSP:

    • bsp/qemu-vexpress-a9
    • bsp/qemu-virt64-aarch64
    • bsp/qemu-virt64-riscv：完成 KSYMS 构建和 ELF 验证测试

  • .config:

    CONFIG_RT_USING_KSYMS=y
    CONFIG_RT_USING_UTEST=y
    CONFIG_RT_UTEST_KSYMS=y

    其中：

    CONFIG_RT_USING_KSYMS=n

    为默认配置，不启用时保持原有行为。

  • action:

    https://github.com/liulangrenaaa/rt-thread/actions/workflows/manual_dist.yml

    PR branch:

    feature/ksym-backtrace

测试结果

  1. Python generator tests

    python3 -m unittest tools.testcases.test_gen_ksym

    ......

    Ran 6 tests in 0.001s

    OK

    另外通过：

    python3 -m py_compile
    tools/gen_ksym.py
    tools/ksym.py
    tools/testcases/test_gen_ksym.py

  2. ARM32 qemu-vexpress-a9

    • GCC/ELF 三阶段链接通过
    • gen_ksym.py --verify 通过
    • build/ksym/ 中间文件生成正常
    • QEMU 启动正常
    • core.ksym 测试通过
    • 静态函数 backtrace 解析正常

    实际输出：

    0x60043e90 <ksym_test_level3+0xc/0x14>
    0x60043e7c <ksym_test_level2+0xc/0x14>
    0x60043e68 <ksym_test_level1+0xc/0x14>

    [ PASSED ] testcase (core.ksym)
    [ PASSED ] 1 tests.

  3. AArch64 qemu-virt64-aarch64

    • GCC/ELF 三阶段链接通过
    • 使用 --exec-path 指定工具链目录
    • 工具链目录不在宿主系统 PATH 中
    • generator 和 final verify 均能正确继承 SCons 环境
    • QEMU 启动正常
    • core.ksym 测试通过
    • AArch64 未进行错误的 Thumb bit normalization

    实际输出：

    0x40099a44 <ksym_test_level3+0x8/0x18>

    [ PASSED ] testcase (core.ksym)

  4. RISC-V64 qemu-virt64-riscv

    • 三阶段 KSYMS 构建通过
    • gen_ksym.py --verify 通过
    • 符号 resolver 可以正确输出函数名称：

    0x802430e6 <_query+0x9a/0x178>

    后续失败发生在现有 RISC-V frame-pointer unwind 路径中。
    unwind 访问非法 frame 地址 0x10，随后触发嵌套异常。
    该问题发生在 symbol lookup 之后，与 rt_ksym_lookup() 和 KSYMS
    表生成无关。

  5. --exec-path 验证

    使用以下方式完成 AArch64 构建：

    scons --pyconfig-silent
    --exec-path=/opt/rtthread-aarch64-none-elf/bin

    scons -j2
    --exec-path=/opt/rtthread-aarch64-none-elf/bin

    构建过程确认：

    LINK build/ksym/rtthread.pre1.elf
    CC build/ksym/rtthread.pre1.o
    LINK build/ksym/rtthread.pre2.elf
    CC build/ksym/rtthread.final.o
    LINK rtthread.elf
    verify_final(["rtthread.elf"], ...)

  6. 代码检查

    • git diff --check 通过
    • Python generator tests 通过
    • Python syntax check 通过
    • 三个 commit 保持独立职责
    • 生成的中间文件均位于 build/ksym/
    • RT_USING_KSYMS 默认关闭

action : xxx

当前拉取/合并请求的状态 Intent for your PR

必须选择一项 Choose one (Mandatory):

  • 本拉取/合并请求是一个草稿版本 This PR is for a code-review and is intended to get feedback
  • 本拉取/合并请求是一个成熟版本 This PR is mature, and ready to be integrated into the repo

代码质量 Code Quality：

我在这个拉取/合并请求中已经考虑了 As part of this pull request, I've considered the following:

  • 已经仔细查看过代码改动的对比 Already check the difference between PR and old code
  • 代码风格正确，包括缩进空格，命名及其他风格 Style guide is adhered to, including spacing, naming and other styles
  • 没有垃圾代码，代码尽量精简，不包含#if 0代码，不包含已经被注释了的代码 All redundant code is removed and cleaned up
  • 所有变更均有原因及合理的，并且不会影响到其他软件组件代码或BSP All modifications are justified and not affect other components or BSP
  • 对难懂代码均提供对应的注释 I've commented appropriately where code is tricky
  • 代码是高质量的 Code in this PR is of high quality
  • 已经使用clang-format 源码格式化工具确保格式符合RT-Thread代码规范 This PR has been formatted with clang-format and complies with RT-Thread code specification
  • 如果是新增bsp, 已经添加ci检查到.github/ALL_BSP_COMPILE.json 详细请参考链接BSP自查

@liulangrenaaa
kernel: add optional ksym table
be19256 
Add optional symbol lookup for native SCons GCC/ELF builds.

The generated table includes local, global, and weak functions in a
compact relative-address format with a shared string table and
per-symbol sizes.

Use a lock-free binary search, preserve raw addresses, and canonicalize
Thumb addresses only for 32-bit ARM. Verify generated addresses after
the multi-pass link.

Keep artifacts under build/ksym and pass the toolchain environment to
the generators. The option remains disabled by default because the
embedded function names and entries consume read-only memory.
@liulangrenaaa
kernel: symbolize backtraces
9bff3b5 
Use the kernel symbol resolver from the common backtrace printers
when RT_USING_KSYMS is enabled.

Keep the raw program counter in every line and fall back to the
address-only format when no symbol is found. Retain the existing
addr2line guidance when the option is disabled.
@liulangrenaaa
libcpu: add Cortex-A ksym backtrace
3a46112 
Route Cortex-A unwind frames through the common formatted printer
when kernel symbols are enabled.

Disable the legacy Cortex-A function-name path in that mode to avoid
duplicate output while retaining the existing unwind behavior. Add
static-function lookup and backtrace coverage for ARM32 and AArch64.
@github-actions

github-actions Bot commented Aug 28, 2026

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👋 感谢您对 RT-Thread 的贡献！Thank you for your contribution to RT-Thread!

为确保代码符合 RT-Thread 的编码规范，请在你的仓库中执行以下步骤运行代码格式化工作流（如果格式化CI运行失败）。
To ensure your code complies with RT-Thread's coding style, please run the code formatting workflow by following the steps below (If the formatting of CI fails to run).

🛠 操作步骤 | Steps

  1. 前往 Actions 页面 | Go to the Actions page
    点击进入工作流 → | Click to open workflow →

  2. 点击 Run workflow | Click Run workflow

  • Use workflow from 保持默认分支（通常为 master）
    Keep the default branch (usually master) in Use workflow from
  • 在 branch 输入框填写 PR 分支 feature/ksym-backtrace
    Enter PR branch feature/ksym-backtrace in the branch field
  • 设置需排除的文件/目录（目录请以"/"结尾）
    Set files/directories to exclude (directories should end with "/")
  1. 等待工作流完成 | Wait for the workflow to complete
    格式化后的代码将作为独立提交推送至你的分支。
    The formatting changes will be pushed to your branch as a separate commit.

完成后，提交将自动更新至 feature/ksym-backtrace 分支，关联的 Pull Request 也会同步更新。
Once completed, commits will be pushed to the feature/ksym-backtrace branch automatically, and the related Pull Request will be updated.

如有问题欢迎联系我们，再次感谢您的贡献！💐
If you have any questions, feel free to reach out. Thanks again for your contribution!

@github-actions github-actions Bot added Kernel PR has src relate code tools libcpu labels Aug 28, 2026
@github-actions

github-actions Bot commented Aug 28, 2026

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📌 Code Review Assignment

🏷️ Tag: kernel

Reviewers: @GorrayLi @ReviewSun @hamburger-os @lianux-mm @wdfk-prog @xu18838022837

Changed Files (Click to expand)
  • src/Kconfig
  • src/kservice.c
  • src/ksym.c
  • src/utest/Kconfig
  • src/utest/SConscript
  • src/utest/ksym_tc.c

📊 Current Review Status (Last Updated: 2026-08-29 02:52 CST)

📝 Review Instructions

  1. 维护者可以通过单击此处来刷新审查状态: 🔄 刷新状态
    Maintainers can refresh the review status by clicking here: 🔄 Refresh Status

  2. 确认审核通过后评论 LGTM/lgtm
    Comment LGTM/lgtm after confirming approval

  3. PR合并前需至少一位维护者确认
    PR must be confirmed by at least one maintainer before merging

ℹ️ 刷新CI状态操作需要具备仓库写入权限。
ℹ️ Refresh CI status operation requires repository Write permission.

@github-actions

github-actions Bot commented Aug 28, 2026

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MemBrowse Memory Report

nordic-nrf51822

  • FLASH: .text +4 B (+0.0%, 52,012 B / 262,144 B, total: 20% used)

raspberry-pico-rp2040

  • FLASH: .text +8 B (+0.0%, 114,112 B / 2,097,152 B, total: 5% used)

simulator

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