Update for elflint problems

tccgen.c:
- When __FUNCTION__ is used and no code is generated use symbol len = 0.

tccelf.c:
- If library is present in verneed it should be in DT_NEEDED.
- @plt symbols should have size 0
- set _GLOBAL_OFFSET_TABLE_ st_size correct
- Remove version symbol if new value present

reported by elflint:

__FUNCTION__ problem:
  section [19] '.symtab': symbol 2134 (L.195) does not fit completely in referenced section [14] '.data.ro'
DT_NEEDED problem:
  section [26] '.gnu.version_r': entry 2 references unknown dependency
@plt symbols should have size 0:
  section [22] '.symtab': symbol 36557 (r_core_config_init@plt) does not fit completely in referenced section [14] '.plt'
_GLOBAL_OFFSET_TABLE_ size:
  section [44] '.symtab': _GLOBAL_OFFSET_TABLE_ symbol size 4 does not match .got section size 736
Remove version symbol:
  section [25] '.gnu.version': symbol 86: version index 3 is for requested version
  This happened for example with bounds checking symbol malloc
This commit is contained in:
herman ten brugge 2022-05-17 07:34:10 +02:00
parent a4f9e3cf4c
commit 4c82b00342
2 changed files with 31 additions and 4 deletions

View file

@ -547,7 +547,7 @@ LIBTCCAPI void tcc_list_symbols(TCCState *s, void *ctx,
static void
version_add (TCCState *s1)
{
int i;
int i, j;
ElfW(Sym) *sym;
ElfW(Verneed) *vn = NULL;
Section *symtab;
@ -593,6 +593,14 @@ version_add (TCCState *s1)
ElfW(Vernaux) *vna = 0;
if (sv->out_index < 1)
continue;
/* If present in verneed it should be in DT_NEEDED */
for (j = 0; j < s1->nb_loaded_dlls; j++) {
DLLReference *dllref = s1->loaded_dlls[j];
if (!strcmp(sv->lib, dllref->name)) {
dllref->level = 0;
break;
}
}
vnofs = section_add(verneed_section, sizeof(*vn), 1);
vn = (ElfW(Verneed)*)(verneed_section->data + vnofs);
vn->vn_version = 1;
@ -1137,7 +1145,7 @@ static struct sym_attr * put_got_entry(TCCState *s1, int dyn_reloc_type,
len = sizeof plt_name - 5;
memcpy(plt_name, name, len);
strcpy(plt_name + len, "@plt");
attr->plt_sym = put_elf_sym(s1->symtab, attr->plt_offset, sym->st_size,
attr->plt_sym = put_elf_sym(s1->symtab, attr->plt_offset, 0,
ELFW(ST_INFO)(STB_GLOBAL, STT_FUNC), 0, s1->plt->sh_num, plt_name);
} else {
attr->got_offset = got_offset;
@ -2526,6 +2534,14 @@ static Section *create_bsd_note_section(TCCState *s1,
}
#endif
static void elf_patch_global_offset_size(TCCState *s1, Section *s)
{
int sym_index;
if ((sym_index = find_elf_sym(s, "_GLOBAL_OFFSET_TABLE_")))
((ElfW(Sym) *)s->data)[sym_index].st_size = s1->got->data_offset;
}
/* Output an elf, coff or binary file */
/* XXX: suppress unneeded sections */
static int elf_output_file(TCCState *s1, const char *filename)
@ -2589,7 +2605,8 @@ static int elf_output_file(TCCState *s1, const char *filename)
dynamic->link = dynstr;
dynamic->sh_entsize = sizeof(ElfW(Dyn));
build_got(s1);
if (!s1->got)
build_got(s1);
if (file_type == TCC_OUTPUT_EXE) {
bind_exe_dynsyms(s1);
@ -2602,6 +2619,8 @@ static int elf_output_file(TCCState *s1, const char *filename)
}
}
build_got_entries(s1);
elf_patch_global_offset_size(s1, symtab_section);
elf_patch_global_offset_size(s1, s1->dynsym);
version_add (s1);
}
@ -3065,6 +3084,14 @@ ST_FUNC int tcc_load_object_file(TCCState *s1,
sym->st_info, sym->st_other,
sym->st_shndx, name);
old_to_new_syms[i] = sym_index;
#ifndef ELF_OBJ_ONLY
/* Remove version symbol if new value present */
sym_index = find_elf_sym(s1->dynsymtab_section, name);
if (sym_index && sym_index < nb_sym_to_version &&
sym->st_shndx != SHN_UNDEF &&
ELFW(ST_BIND)(sym->st_info) != STB_LOCAL)
sym_to_version[sym_index] = -1;
#endif
}
/* third pass to patch relocation entries */

View file

@ -5328,7 +5328,7 @@ ST_FUNC void unary(void)
type.t |= VT_ARRAY;
type.ref->c = len;
sec = rodata_section;
vpush_ref(&type, sec, sec->data_offset, len);
vpush_ref(&type, sec, sec->data_offset, NODATA_WANTED ? 0 : len);
if (!NODATA_WANTED)
memcpy(section_ptr_add(sec, len), funcname, len);
next();