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

Signed-off-by: Liu Gui <kenneth.liu@sophgo.com>
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KennethLiu61 authored and mysterywolf committed Feb 22, 2025
1 parent aa3328f commit 4940bb1
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Showing 3 changed files with 9 additions and 9 deletions.
10 changes: 5 additions & 5 deletions components/libc/posix/libdl/dlelf.c
Original file line number Diff line number Diff line change
Expand Up @@ -383,9 +383,9 @@ rt_err_t dlmodule_load_relocated_object(struct rt_dlmodule* module, void *module
rt_memcpy(ptr,
(rt_uint8_t *)elf_module + shdr[index].sh_offset,
shdr[index].sh_size);
rodata_addr = (rt_uint32_t)ptr;
rodata_addr = (rt_ubase_t)ptr;
LOG_D("load rodata 0x%x, size %d, rodata 0x%x", ptr,
shdr[index].sh_size, *(rt_uint32_t *)data_addr);
shdr[index].sh_size, *(rt_ubase_t *)rodata_addr);
ptr += shdr[index].sh_size;
}

Expand All @@ -395,17 +395,17 @@ rt_err_t dlmodule_load_relocated_object(struct rt_dlmodule* module, void *module
rt_memcpy(ptr,
(rt_uint8_t *)elf_module + shdr[index].sh_offset,
shdr[index].sh_size);
data_addr = (rt_uint32_t)ptr;
data_addr = (rt_ubase_t)ptr;
LOG_D("load data 0x%x, size %d, data 0x%x", ptr,
shdr[index].sh_size, *(rt_uint32_t *)data_addr);
shdr[index].sh_size, *(rt_ubase_t *)data_addr);
ptr += shdr[index].sh_size;
}

/* load bss section */
if (IS_NOPROG(shdr[index]) && IS_AW(shdr[index]))
{
rt_memset(ptr, 0, shdr[index].sh_size);
bss_addr = (rt_uint32_t)ptr;
bss_addr = (rt_ubase_t)ptr;
LOG_D("load bss 0x%x, size %d", ptr, shdr[index].sh_size);
}
}
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6 changes: 3 additions & 3 deletions components/libc/posix/libdl/dlmodule.c
Original file line number Diff line number Diff line change
Expand Up @@ -837,18 +837,18 @@ void dlmodule_exit(int ret_code)
* @brief search for a symbol by its name in the kernel symbol table.
*
* @param sym_str the symbol name string.
* @return rt_uint32_t On success, it returns the address of the symbol.
* @return rt_ubase_t On success, it returns the address of the symbol.
* Otherwise, it returns 0 (indicating the symbol was not found).
*/
rt_uint32_t dlmodule_symbol_find(const char *sym_str)
rt_ubase_t dlmodule_symbol_find(const char *sym_str)
{
/* find in kernel symbol table */
struct rt_module_symtab *index;

for (index = _rt_module_symtab_begin; index != _rt_module_symtab_end; index ++)
{
if (rt_strcmp(index->name, sym_str) == 0)
return (rt_uint32_t)index->addr;
return (rt_ubase_t)index->addr;
}

return 0;
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2 changes: 1 addition & 1 deletion components/libc/posix/libdl/dlmodule.h
Original file line number Diff line number Diff line change
Expand Up @@ -82,6 +82,6 @@ void dlmodule_exit(int ret_code);

struct rt_dlmodule *dlmodule_find(const char *name);

rt_uint32_t dlmodule_symbol_find(const char *sym_str);
rt_ubase_t dlmodule_symbol_find(const char *sym_str);

#endif

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