- Remove an extra section.len member in favour of section.sh_size

- Align .altinstructions section creation with the kernel's by creating
 them with entry size of 0
 
 - Fix objtool to convert a reloc symbol to a section offset and not to
 not warn about not knowing how
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmFirC4ACgkQEsHwGGHe
 VUqkNg/8Dc8CUTz950A0aGmqrTvy4JWlbh+vHMF3o45oEA7JI34awSAGR2I6USTf
 Z9EQCjaSf/i6IddZKJBqO8ajBXcOfZi6w6lsAtN2mKK4zgx5JLEP7PKTBjaCBWZC
 8+nTKhCd1ZBsh5ndjntO7ippMZYpiMzneMtHn84qtCarMxX6HEkm1zjB7f6y1S5v
 C3I1V0EdxNfyJQIFiOoGVpMZTmPLp9akvJAe5tUElAsMJ+fQgvlc2jgCRX3JeXUr
 buaZRgAONbIhnxC9xgCt7s7nn0ICgp5r6P5aA8QAzfDBPbeL/g2ZggozTufYECxM
 KE2FVPibwejKpUEtUyBNjA+yz46Ce89xryoTKN8uwTKcDQIheo0mE03eWtbObZW1
 vDPFyGAEl6a3g7WOotL5tDYUEHtGPKSmXrz8UL8F+E4nEKtlNySZspkrOx+aJSg7
 fHbbc4L1GllDaC8spF8hH1EDYva2QZyc1xt9rFdEAOBluwX0unVo250+Ue5D6DE8
 aOQtv/RJgkPxlk8UEyPzP1HHQ/VXQ07F8jRRgkuQbEsvY3mxAvt+BcG+ZtLF0FKk
 e7jO3I3wCHclS4EnP/4kY/Diy9A9htqr30vJayiy2+G80hbFYoE7nuiLU75rukWp
 fQcsHGv8UjkOO9qkNecDn0znc2sqhgxF+3RyaEfNaeEsVmsUASE=
 =0JCB
 -----END PGP SIGNATURE-----

Merge tag 'objtool_urgent_for_v5.15_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool fixes from Borislav Petkov:

 - Remove an extra section.len member in favour of section.sh_size

 - Align .altinstructions section creation with the kernel's by creating
   them with entry size of 0

 - Fix objtool to convert a reloc symbol to a section offset and not to
   not warn about not knowing how

* tag 'objtool_urgent_for_v5.15_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Remove redundant 'len' field from struct section
  objtool: Make .altinstructions section entry size consistent
  objtool: Remove reloc symbol type checks in get_alt_entry()
This commit is contained in:
Linus Torvalds 2021-10-10 10:05:39 -07:00
commit 75cd9b0152
6 changed files with 25 additions and 50 deletions

View File

@ -684,7 +684,7 @@ static int elf_add_alternative(struct elf *elf,
sec = find_section_by_name(elf, ".altinstructions");
if (!sec) {
sec = elf_create_section(elf, ".altinstructions",
SHF_ALLOC, size, 0);
SHF_ALLOC, 0, 0);
if (!sec) {
WARN_ELF("elf_create_section");

View File

@ -292,7 +292,7 @@ static int decode_instructions(struct objtool_file *file)
!strcmp(sec->name, ".entry.text"))
sec->noinstr = true;
for (offset = 0; offset < sec->len; offset += insn->len) {
for (offset = 0; offset < sec->sh.sh_size; offset += insn->len) {
insn = malloc(sizeof(*insn));
if (!insn) {
WARN("malloc failed");
@ -307,7 +307,7 @@ static int decode_instructions(struct objtool_file *file)
insn->offset = offset;
ret = arch_decode_instruction(file->elf, sec, offset,
sec->len - offset,
sec->sh.sh_size - offset,
&insn->len, &insn->type,
&insn->immediate,
&insn->stack_ops);
@ -349,9 +349,9 @@ static struct instruction *find_last_insn(struct objtool_file *file,
{
struct instruction *insn = NULL;
unsigned int offset;
unsigned int end = (sec->len > 10) ? sec->len - 10 : 0;
unsigned int end = (sec->sh.sh_size > 10) ? sec->sh.sh_size - 10 : 0;
for (offset = sec->len - 1; offset >= end && !insn; offset--)
for (offset = sec->sh.sh_size - 1; offset >= end && !insn; offset--)
insn = find_insn(file, sec, offset);
return insn;
@ -389,7 +389,7 @@ static int add_dead_ends(struct objtool_file *file)
insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (insn)
insn = list_prev_entry(insn, list);
else if (reloc->addend == reloc->sym->sec->len) {
else if (reloc->addend == reloc->sym->sec->sh.sh_size) {
insn = find_last_insn(file, reloc->sym->sec);
if (!insn) {
WARN("can't find unreachable insn at %s+0x%x",
@ -424,7 +424,7 @@ reachable:
insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (insn)
insn = list_prev_entry(insn, list);
else if (reloc->addend == reloc->sym->sec->len) {
else if (reloc->addend == reloc->sym->sec->sh.sh_size) {
insn = find_last_insn(file, reloc->sym->sec);
if (!insn) {
WARN("can't find reachable insn at %s+0x%x",
@ -1561,14 +1561,14 @@ static int read_unwind_hints(struct objtool_file *file)
return -1;
}
if (sec->len % sizeof(struct unwind_hint)) {
if (sec->sh.sh_size % sizeof(struct unwind_hint)) {
WARN("struct unwind_hint size mismatch");
return -1;
}
file->hints = true;
for (i = 0; i < sec->len / sizeof(struct unwind_hint); i++) {
for (i = 0; i < sec->sh.sh_size / sizeof(struct unwind_hint); i++) {
hint = (struct unwind_hint *)sec->data->d_buf + i;
reloc = find_reloc_by_dest(file->elf, sec, i * sizeof(*hint));

View File

@ -286,10 +286,9 @@ static int read_sections(struct elf *elf)
return -1;
}
}
sec->len = sec->sh.sh_size;
if (sec->sh.sh_flags & SHF_EXECINSTR)
elf->text_size += sec->len;
elf->text_size += sec->sh.sh_size;
list_add_tail(&sec->list, &elf->sections);
elf_hash_add(section, &sec->hash, sec->idx);
@ -734,8 +733,8 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str)
data->d_size = strlen(str) + 1;
data->d_align = 1;
len = strtab->len;
strtab->len += data->d_size;
len = strtab->sh.sh_size;
strtab->sh.sh_size += data->d_size;
strtab->changed = true;
return len;
@ -790,9 +789,9 @@ struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name)
data->d_align = 1;
data->d_type = ELF_T_SYM;
sym->idx = symtab->len / sizeof(sym->sym);
sym->idx = symtab->sh.sh_size / sizeof(sym->sym);
symtab->len += data->d_size;
symtab->sh.sh_size += data->d_size;
symtab->changed = true;
symtab_shndx = find_section_by_name(elf, ".symtab_shndx");
@ -814,7 +813,7 @@ struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name)
data->d_align = 4;
data->d_type = ELF_T_WORD;
symtab_shndx->len += 4;
symtab_shndx->sh.sh_size += 4;
symtab_shndx->changed = true;
}
@ -855,7 +854,6 @@ struct section *elf_create_section(struct elf *elf, const char *name,
}
sec->idx = elf_ndxscn(s);
sec->len = size;
sec->changed = true;
sec->data = elf_newdata(s);

View File

@ -38,7 +38,6 @@ struct section {
Elf_Data *data;
char *name;
int idx;
unsigned int len;
bool changed, text, rodata, noinstr;
};

View File

@ -204,7 +204,7 @@ int orc_create(struct objtool_file *file)
/* Add a section terminator */
if (!empty) {
orc_list_add(&orc_list, &null, sec, sec->len);
orc_list_add(&orc_list, &null, sec, sec->sh.sh_size);
nr++;
}
}

View File

@ -58,22 +58,11 @@ void __weak arch_handle_alternative(unsigned short feature, struct special_alt *
{
}
static bool reloc2sec_off(struct reloc *reloc, struct section **sec, unsigned long *off)
static void reloc_to_sec_off(struct reloc *reloc, struct section **sec,
unsigned long *off)
{
switch (reloc->sym->type) {
case STT_FUNC:
*sec = reloc->sym->sec;
*off = reloc->sym->offset + reloc->addend;
return true;
case STT_SECTION:
*sec = reloc->sym->sec;
*off = reloc->addend;
return true;
default:
return false;
}
*sec = reloc->sym->sec;
*off = reloc->sym->offset + reloc->addend;
}
static int get_alt_entry(struct elf *elf, struct special_entry *entry,
@ -109,13 +98,8 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
WARN_FUNC("can't find orig reloc", sec, offset + entry->orig);
return -1;
}
if (!reloc2sec_off(orig_reloc, &alt->orig_sec, &alt->orig_off)) {
WARN_FUNC("don't know how to handle reloc symbol type %d: %s",
sec, offset + entry->orig,
orig_reloc->sym->type,
orig_reloc->sym->name);
return -1;
}
reloc_to_sec_off(orig_reloc, &alt->orig_sec, &alt->orig_off);
if (!entry->group || alt->new_len) {
new_reloc = find_reloc_by_dest(elf, sec, offset + entry->new);
@ -133,13 +117,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
if (arch_is_retpoline(new_reloc->sym))
return 1;
if (!reloc2sec_off(new_reloc, &alt->new_sec, &alt->new_off)) {
WARN_FUNC("don't know how to handle reloc symbol type %d: %s",
sec, offset + entry->new,
new_reloc->sym->type,
new_reloc->sym->name);
return -1;
}
reloc_to_sec_off(new_reloc, &alt->new_sec, &alt->new_off);
/* _ASM_EXTABLE_EX hack */
if (alt->new_off >= 0x7ffffff0)
@ -181,13 +159,13 @@ int special_get_alts(struct elf *elf, struct list_head *alts)
if (!sec)
continue;
if (sec->len % entry->size != 0) {
if (sec->sh.sh_size % entry->size != 0) {
WARN("%s size not a multiple of %d",
sec->name, entry->size);
return -1;
}
nr_entries = sec->len / entry->size;
nr_entries = sec->sh.sh_size / entry->size;
for (idx = 0; idx < nr_entries; idx++) {
alt = malloc(sizeof(*alt));