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preload symbol names for each loaded, non library module

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This commit is contained in:
Kasper
2025-03-21 00:32:22 +02:00
parent 5bcff694f7
commit 7ecb0b7936
4 changed files with 72 additions and 61 deletions
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41
src/symbols.c
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@@ -22,9 +22,6 @@ add_ptr_offset_if_invalid(uptr p, uptr offset,
/**
* Gathers and populates symbols, given a dynamic module info
*
* Will clear and free the given SymbolInfo struct. Allocates enough memory to
* hold found symbols.
*/
HiloadResult hi_create_symbol_info(SymbolInfos *symbols,
struct sc_array_memreg *const regions,
@@ -35,6 +32,10 @@ HiloadResult hi_create_symbol_info(SymbolInfos *symbols,
hi_free_symbol_info(symbols);
for (int i = 0; i < info->dlpi_phnum; i++) {
const ElfW(Phdr) *phdr = &info->dlpi_phdr[i];
}
for (int i = 0; i < info->dlpi_phnum; i++) {
const ElfW(Phdr) *phdr = &info->dlpi_phdr[i];
@@ -55,13 +56,12 @@ HiloadResult hi_create_symbol_info(SymbolInfos *symbols,
const ElfW(Dyn) *dyn = (const ElfW(Dyn) *)(info->dlpi_addr + phdr->p_vaddr);
const char *strtab = NULL;
const ElfW(Sym) *symtab = NULL;
size_t symtab_size = 0;
size_t strtab_size = 0;
uptr off = info->dlpi_addr;
// Parse the dynamic table. Add offset if address is not in executable memory.
// NOTE: Haven't found a better way to differentiate with items that have
// relative address, and items that don't.
// Parse the dynamic table. Add offset if address is not in executable
// memory. NOTE: Haven't found a better way to differentiate with items that
// have relative address, and items that don't.
for (; dyn->d_tag != DT_NULL; dyn++) {
if (dyn->d_tag == DT_STRTAB) {
@@ -76,34 +76,43 @@ HiloadResult hi_create_symbol_info(SymbolInfos *symbols,
uptr p = dyn->d_un.d_ptr;
p = add_ptr_offset_if_invalid(p, off, regions);
symtab = (const ElfW(Sym) *)(p);
} else if (dyn->d_tag == DT_SYMENT) {
symtab_size = dyn->d_un.d_val;
}
}
// Ensure we found the symbol and string tables
if (!strtab || !symtab || strtab_size == 0 || symtab_size == 0) {
if (!strtab || !symtab || strtab_size == 0) {
sc_log_error("Failed to find symbol or string table in %s\n",
info->dlpi_name);
info->dlpi_name);
return HILOAD_FAIL;
}
// Iterate over the symbol table
for (const ElfW(Sym) *sym = symtab;
(const char *)sym < (const char *)symtab + symtab_size; sym++) {
// We assume the dynsym and dynstr are linked
const char *strptr = strtab;
for (const ElfW(Sym) *sym = symtab;; sym++) {
// escape if we'd hit the end of string table
strptr = strtab + sym->st_name;
if (strptr + strlen(strptr) + 1 >= strtab + strtab_size)
break;
if (ELF64_ST_TYPE(sym->st_info) == STT_FUNC ||
ELF64_ST_TYPE(sym->st_info) == STT_OBJECT) {
const char *name = strdup(&strtab[sym->st_name]);
const char *name = strdup(strtab + sym->st_name);
void *address = (void *)(info->dlpi_addr + sym->st_value);
// Store the symbol information in the arrays
// Store the symbol information in the arrays
sc_array_add(&symbols->names, name);
sc_array_add(&symbols->addresses, address);
sc_log_debug("%s: %p\n", name, address);
}
}
}
sc_log_debug("Symbols for %s gathered...\n", info->dlpi_name);
return HILOAD_OK;
}