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components: libc: fix pointer-to-integer cast warnings and address tr… #10019

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merged 1 commit into from
Feb 22, 2025

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…uncation

[Problem Description]

  1. When enabling RT_USING_MODULE=y, compilation warnings occur: dlelf.c:386:27: warning: cast from pointer to integer of different size dlelf.c:398:25: warning: cast from pointer to integer of different size dlelf.c:408:24: warning: cast from pointer to integer of different size

  2. On RV64 architectures (e.g. Sophgo SG2042 with RISC-V Sv39 and 40-bit physical addressing), dlsym may fail when accessing addresses beyond 32-bit range.

[Root Cause]
In dlmodule_load_relocated_object() and dlmodule_symbol_find(), pointer is cast to rt_uint32_t which truncates:
| rt_ubase_t rodata_addr = (rt_uint32_t)ptr;
This causes:

  • Warnings on 64-bit systems (pointer width > 32-bit)
  • Actual address truncation on RV64 when physical address exceeds 32-bit

[Solution]
Replace rt_uint32_t with architecture-adaptive rt_ubase_t: | rt_ubase_t rodata_addr = (rt_ubase_t)ptr;
The rt_ubase_t is defined in include/rttypes.h as: | #ifdef ARCH_CPU_64BIT
| typedef rt_uint64_t rt_ubase_t;
| #else
| typedef rt_uint32_t rt_ubase_t;
| #endif
This ensures correct width casting for both 32/64-bit architectures.

拉取/合并请求描述:(PR description)

[

为什么提交这份PR (why to submit this PR)

你的解决方案是什么 (what is your solution)

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

  • BSP:
  • .config:
  • action:

]

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formatting 等源码格式化工具确保格式符合RT-Thread代码规范 This PR complies with RT-Thread code specification
  • 如果是新增bsp, 已经添加ci检查到.github/workflows/bsp_buildings.yml 详细请参考链接BSP自查

…uncation

[Problem Description]
1. When enabling RT_USING_MODULE=y, compilation warnings occur:
   dlelf.c:386:27: warning: cast from pointer to integer of different size
   dlelf.c:398:25: warning: cast from pointer to integer of different size
   dlelf.c:408:24: warning: cast from pointer to integer of different size

2. On RV64 architectures (e.g. Sophgo SG2042 with RISC-V Sv39 and 40-bit physical addressing),
   dlsym may fail when accessing addresses beyond 32-bit range.

[Root Cause]
In dlmodule_load_relocated_object() and dlmodule_symbol_find(),
pointer is cast to rt_uint32_t which truncates:
| rt_ubase_t rodata_addr = (rt_uint32_t)ptr;
This causes:
- Warnings on 64-bit systems (pointer width > 32-bit)
- Actual address truncation on RV64 when physical address exceeds 32-bit

[Solution]
Replace rt_uint32_t with architecture-adaptive rt_ubase_t:
| rt_ubase_t rodata_addr = (rt_ubase_t)ptr;
The rt_ubase_t is defined in include/rttypes.h as:
| #ifdef ARCH_CPU_64BIT
|   typedef rt_uint64_t rt_ubase_t;
| #else
|   typedef rt_uint32_t rt_ubase_t;
| #endif
This ensures correct width casting for both 32/64-bit architectures.

Signed-off-by: Liu Gui <kenneth.liu@sophgo.com>
@BernardXiong BernardXiong added the +1 Agree +1 label Feb 22, 2025
@mysterywolf mysterywolf merged commit 4940bb1 into RT-Thread:master Feb 22, 2025
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3 participants