Field name fixed in elt_symbol.read_data()

src/pelfy/__init__.py

@@ -33,6 +33,8 @@ class elf_symbol():
 
         name: Name of the symbol
 
+        section: section where the symbol data is placed
+
         index: Absolut index in the symbol table
 
         info: Type of the symbol
@@ -55,6 +57,8 @@ class elf_symbol():
         else:
             self.name = ''
 
+        self.section: elf_section | None = self.file.sections[self['st_shndx']] if self['st_shndx'] < len(self.file.sections) else None
+
         self.index = index
 
         self.info, self.description = fdat.st_info_values[fields['st_info'] & 0x0F]
@@ -68,7 +72,11 @@ class elf_symbol():
         Returns:
             Symbol data
         """
-        offset = self.file.sections[self['st_shndx']]['sh_offset'] + self['st_value']
+        assert self.section, 'This symbol is not associated to a data section'
+        if self.section.type == 'SHT_NOBITS':
+            return b'\x00' * self['st_size']
+        else:
+            offset = self.section['sh_offset'] + self['st_value']
             return self.file.read_bytes(offset, self['st_size'])
 
     def read_data_hex(self) -> str:
@@ -76,7 +84,7 @@ class elf_symbol():
 
     def get_relocations(self) -> 'relocation_list':
         """List all relocations that are pointing to this symbol.
-        The symbol must be of type SHT_PROGBITS (program code). Therefore
+        The symbol section must be of type SHT_PROGBITS (program code). Therefore
         this function lists typically all relocations that will be
         applied to the function represented by the symbol.
 
@@ -84,10 +92,9 @@ class elf_symbol():
             List of relocations
         """
         ret: list[elf_relocation] = list()
-        section = self.file.sections[self.fields['st_shndx']]
+        assert self.section and self.section.type == 'SHT_PROGBITS'
-        assert section.type == 'SHT_PROGBITS'
         for reloc in self.file.get_relocations():
-            if reloc.target_section == section:
+            if reloc.target_section == self.section:
                 offset = reloc['r_offset'] - self['st_value']
                 if 0 <= offset < self['st_size']:
                     ret.append(reloc)
@@ -105,7 +112,7 @@ class elf_symbol():
                f'name              {self.name}\n' +\
                f'stb               {self.stb} ({self.stb_description})\n' +\
                f'info              {self.info} ({self.description})\n' +\
-               '\n'.join(f'{k:18} {v:4}' for k, v in self.fields.items()) + '\n'
+               '\n'.join(f"{k:18} {v:4} {fdat.symbol_fields[k]}" for k, v in self.fields.items()) + '\n'
 
 
 class elf_section():
@@ -156,8 +163,19 @@ class elf_section():
         Returns:
             Data of the section
         """
+        if self.type == 'SHT_NOBITS':
+            return b'\x00' * self['sh_size']
+        else:
             return self.file.read_bytes(self['sh_offset'], self['sh_size'])
 
+    def get_symbols(self) -> 'symbol_list':
+        """Lists all ELF symbols associated with this section
+
+        Returns:
+            Symbol list
+        """
+        return symbol_list(self.file._list_symbols(self.index))
+
     def get_data_hex(self) -> str:
         data = self.file.read_bytes(self['sh_offset'], self['sh_size'])
         return ' '.join(f'{d:02X}' for d in data)
@@ -320,9 +338,9 @@ class symbol_list(elf_list[elf_symbol]):
     """A class for representing a list of ELF symbols
     """
     def _compact_table(self) -> tuple[list[str], list[list[int | str]], list[str]]:
-        columns = ['index', 'name', 'info', 'size', 'stb', 'description']
+        columns = ['index', 'name', 'info', 'size', 'stb', 'section', 'description']
         data: list[list[str | int]] = [[item.index, item.name, item.info, item.fields['st_size'],
-                                       item.stb, item.description] for item in self]
+                                       item.stb, item.section.name if item.section else '', item.description] for item in self]
         return columns, data, ['index', 'size']
 
 
@@ -369,14 +387,15 @@ class elf_file:
         string_table_section: The string table section (first section with
             the name .strtab)
     """
-    def __init__(self, data: bytes):
+    def __init__(self, data: bytes | bytearray):
+        assert isinstance(data, (bytes, bytearray)), 'Binary ELF data must be provided as bytes or bytearray.'
         self._data = data
 
         # Defaults required for function _read_int_from_elf_field
         self.bit_width = 32
         self.byteorder: Literal['little', 'big'] = 'little'
 
-        assert self._read_bytes_from_elf_field('e_ident[EI_MAG]') == bytes([0x7F, 0x45, 0x4c, 0x46]), 'Not an ELF file'
+        assert self._read_bytes_from_elf_field('e_ident[EI_MAG]') == b'\x7fELF', 'Not an ELF file'
 
         self.bit_width = {1: 32, 2: 64}[self._read_int_from_elf_field('e_ident[EI_CLASS]')]
 
@@ -414,7 +433,7 @@ class elf_file:
             offs = self.fields['e_shoff'] + i * self.fields['e_shentsize']
             yield {fn: self._read_from_sh_field(offs, fn) for fn in fdat.section_header.keys()}
 
-    def _list_symbols(self) -> Generator[elf_symbol, None, None]:
+    def _list_symbols(self, section_index: int | None = None) -> Generator[elf_symbol, None, None]:
         if self.symbol_table_section:
             offs = self.symbol_table_section['sh_offset']
 
@@ -434,6 +453,7 @@ class elf_file:
                     ret['st_value'] = self.read_int(i + 8, 8)
                     ret['st_size'] = self.read_int(i + 16, 8)
 
+                if section_index is None or section_index == ret['st_shndx']:
                     yield elf_symbol(self, ret, j)
 
     def get_relocations(self, reloc_section: elf_section | str | list[str] | None = None) -> relocation_list:

src/pelfy/fields_data.py

@@ -271,7 +271,7 @@ section_header = {
     },
     "sh_size": {
         "32": "0x14", "64": "0x20", "size32": "4", "size64": "8", "field_name": "sh_size",
-        "description": "Size in bytes of the section in the file image. May be 0."
+        "description": "Size in bytes of the section in memory or 0. May be equal to size in file."
     },
     "sh_link": {
         "32": "0x18", "64": "0x28", "size32": "4", "size64": "4", "field_name": "sh_link",
@@ -316,16 +316,25 @@ section_header_types_ex = {0x60000000: 'OS-specific',
                            0x70000000: 'Processor-specific',
                            0x80000000: 'Application-specific'}
 
+symbol_fields = {
+    "st_name": "Index into the string table for the symbol's name",
+    "st_info": "Encodes the symbol's type and its binding attribute",
+    "st_other": "Defines symbol visibility within and outside the object file",
+    "st_shndx": "Specifies which section this symbol is associated with",
+    "st_value": "Holds the symbol's address or offset, depending on context",
+    "st_size": "Specifies the size of the symbol (e.g., function length or variable size)"
+}
+
 st_info_values = {
-    0: ("STT_NOTYPE", "Symbol type is unspecified"),
+    0: ("STT_NOTYPE", "Type is unspecified"),
-    1: ("STT_OBJECT", "Symbol is a data object"),
+    1: ("STT_OBJECT", "Data object"),
-    2: ("STT_FUNC", "Symbol is a code object"),
+    2: ("STT_FUNC", "Code object"),
-    3: ("STT_SECTION", "Symbol associated with a section"),
+    3: ("STT_SECTION", "Section associated"),
-    4: ("STT_FILE", "Symbol's name is file name"),
+    4: ("STT_FILE", "File name"),
-    5: ("STT_COMMON", "Symbol is a common data object"),
+    5: ("STT_COMMON", "Common data object"),
-    6: ("STT_TLS", "Symbol is thread-local data object"),
+    6: ("STT_TLS", "Thread-local data object"),
     7: ("STT_NUM", "Number of defined types"),
-    10: ("STT_GNU_IFUNC", "Symbol is indirect code object")
+    10: ("STT_GNU_IFUNC", "Indirect code object")
 }
 
 stb_values = {