Merge tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - KLP support updates and fixes (Song Liu)

 - KLP-build script updates and fixes (Joe Lawrence)

 - Support Clang RAX DRAP sequence, to address clang false positive
   (Josh Poimboeuf)

 - Reorder ORC register numbering to match regular x86 register
   numbering (Josh Poimboeuf)

 - Misc cleanups (Wentong Tian, Song Liu)

* tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool/x86: Reorder ORC register numbering
  objtool: Support Clang RAX DRAP sequence
  livepatch/klp-build: report patch validation fuzz
  livepatch/klp-build: add terminal color output
  livepatch/klp-build: provide friendlier error messages
  livepatch/klp-build: improve short-circuit validation
  livepatch/klp-build: fix shellcheck complaints
  livepatch/klp-build: add Makefile with check target
  livepatch/klp-build: add grep-override function
  livepatch/klp-build: switch to GNU patch and recountdiff
  livepatch/klp-build: support patches that add/remove files
  objtool/klp: Correlate locals to globals
  objtool/klp: Match symbols based on demangled_name for global variables
  objtool/klp: Remove .llvm suffix in demangle_name()
  objtool/klp: Also demangle global objects
  objtool/klp: Use sym->demangled_name for symbol_name hash
  objtool/klp: Remove trailing '_' in demangle_name()
  objtool/klp: Remove redundant strcmp() in correlate_symbols()
  objtool: Use section/symbol type helpers
This commit is contained in:
Linus Torvalds
2026-04-14 13:00:04 -07:00
12 changed files with 337 additions and 126 deletions

View File

@@ -875,14 +875,20 @@ int arch_decode_hint_reg(u8 sp_reg, int *base)
case ORC_REG_UNDEFINED:
*base = CFI_UNDEFINED;
break;
case ORC_REG_AX:
*base = CFI_AX;
break;
case ORC_REG_DX:
*base = CFI_DX;
break;
case ORC_REG_SP:
*base = CFI_SP;
break;
case ORC_REG_BP:
*base = CFI_BP;
break;
case ORC_REG_SP_INDIRECT:
*base = CFI_SP_INDIRECT;
case ORC_REG_DI:
*base = CFI_DI;
break;
case ORC_REG_R10:
*base = CFI_R10;
@@ -890,11 +896,11 @@ int arch_decode_hint_reg(u8 sp_reg, int *base)
case ORC_REG_R13:
*base = CFI_R13;
break;
case ORC_REG_DI:
*base = CFI_DI;
case ORC_REG_SP_INDIRECT:
*base = CFI_SP_INDIRECT;
break;
case ORC_REG_DX:
*base = CFI_DX;
case ORC_REG_BP_INDIRECT:
*base = CFI_BP_INDIRECT;
break;
default:
return -1;

View File

@@ -46,17 +46,20 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
orc->signal = cfi->signal;
switch (cfi->cfa.base) {
case CFI_AX:
orc->sp_reg = ORC_REG_AX;
break;
case CFI_DX:
orc->sp_reg = ORC_REG_DX;
break;
case CFI_SP:
orc->sp_reg = ORC_REG_SP;
break;
case CFI_SP_INDIRECT:
orc->sp_reg = ORC_REG_SP_INDIRECT;
break;
case CFI_BP:
orc->sp_reg = ORC_REG_BP;
break;
case CFI_BP_INDIRECT:
orc->sp_reg = ORC_REG_BP_INDIRECT;
case CFI_DI:
orc->sp_reg = ORC_REG_DI;
break;
case CFI_R10:
orc->sp_reg = ORC_REG_R10;
@@ -64,11 +67,11 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
case CFI_R13:
orc->sp_reg = ORC_REG_R13;
break;
case CFI_DI:
orc->sp_reg = ORC_REG_DI;
case CFI_SP_INDIRECT:
orc->sp_reg = ORC_REG_SP_INDIRECT;
break;
case CFI_DX:
orc->sp_reg = ORC_REG_DX;
case CFI_BP_INDIRECT:
orc->sp_reg = ORC_REG_BP_INDIRECT;
break;
default:
ERROR_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
@@ -122,22 +125,24 @@ static const char *reg_name(unsigned int reg)
switch (reg) {
case ORC_REG_PREV_SP:
return "prevsp";
case ORC_REG_AX:
return "ax";
case ORC_REG_DX:
return "dx";
case ORC_REG_DI:
return "di";
case ORC_REG_BP:
return "bp";
case ORC_REG_SP:
return "sp";
case ORC_REG_DI:
return "di";
case ORC_REG_R10:
return "r10";
case ORC_REG_R13:
return "r13";
case ORC_REG_BP_INDIRECT:
return "bp(ind)";
case ORC_REG_SP_INDIRECT:
return "sp(ind)";
case ORC_REG_BP_INDIRECT:
return "bp(ind)";
default:
return "?";
}

View File

@@ -4306,8 +4306,8 @@ static int validate_retpoline(struct objtool_file *file)
list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
struct symbol *sym = insn->sym;
if (sym && (sym->type == STT_NOTYPE ||
sym->type == STT_FUNC) && !sym->nocfi) {
if (sym && (is_notype_sym(sym) ||
is_func_sym(sym)) && !sym->nocfi) {
struct instruction *prev =
prev_insn_same_sym(file, insn);

View File

@@ -264,7 +264,7 @@ static void disas_print_addr_reloc(bfd_vma addr, struct disassemble_info *dinfo)
* If the relocation symbol is a section name (for example ".bss")
* then we try to further resolve the name.
*/
if (reloc->sym->type == STT_SECTION) {
if (is_sec_sym(reloc->sym)) {
str = offstr(reloc->sym->sec, reloc->sym->offset + offset);
DINFO_FPRINTF(dinfo, bfd_vma_fmt, addr, str);
free(str);
@@ -580,7 +580,7 @@ static size_t disas_insn_common(struct disas_context *dctx,
*/
dinfo->buffer = insn->sec->data->d_buf;
dinfo->buffer_vma = 0;
dinfo->buffer_length = insn->sec->sh.sh_size;
dinfo->buffer_length = sec_size(insn->sec);
return disasm(insn->offset, &dctx->info);
}
@@ -1231,7 +1231,7 @@ void disas_funcs(struct disas_context *dctx)
for_each_sec(dctx->file->elf, sec) {
if (!(sec->sh.sh_flags & SHF_EXECINSTR))
if (!is_text_sec(sec))
continue;
sec_for_each_sym(sec, sym) {

View File

@@ -25,11 +25,18 @@
#include <objtool/elf.h>
#include <objtool/warn.h>
static ssize_t demangled_name_len(const char *name);
static inline u32 str_hash(const char *str)
{
return jhash(str, strlen(str), 0);
}
static inline u32 str_hash_demangled(const char *str)
{
return jhash(str, demangled_name_len(str), 0);
}
#define __elf_table(name) (elf->name##_hash)
#define __elf_bits(name) (elf->name##_bits)
@@ -293,7 +300,7 @@ static struct symbol *find_local_symbol_by_file_and_name(const struct elf *elf,
{
struct symbol *sym;
elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash(name)) {
elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash_demangled(name)) {
if (sym->bind == STB_LOCAL && sym->file == file &&
!strcmp(sym->name, name)) {
return sym;
@@ -307,7 +314,7 @@ struct symbol *find_global_symbol_by_name(const struct elf *elf, const char *nam
{
struct symbol *sym;
elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash(name)) {
elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash_demangled(name)) {
if (!strcmp(sym->name, name) && !is_local_sym(sym))
return sym;
}
@@ -315,6 +322,19 @@ struct symbol *find_global_symbol_by_name(const struct elf *elf, const char *nam
return NULL;
}
void iterate_global_symbol_by_demangled_name(const struct elf *elf,
const char *demangled_name,
void (*process)(struct symbol *sym, void *data),
void *data)
{
struct symbol *sym;
elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash(demangled_name)) {
if (!strcmp(sym->demangled_name, demangled_name) && !is_local_sym(sym))
process(sym, data);
}
}
struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
unsigned long offset, unsigned int len)
{
@@ -440,34 +460,67 @@ static int read_sections(struct elf *elf)
return 0;
}
/*
* Returns desired length of the demangled name.
* If name doesn't need demangling, return strlen(name).
*/
static ssize_t demangled_name_len(const char *name)
{
ssize_t idx;
const char *p;
p = strstr(name, ".llvm.");
if (p)
return p - name;
if (!strstarts(name, "__UNIQUE_ID_") && !strchr(name, '.'))
return strlen(name);
for (idx = strlen(name) - 1; idx >= 0; idx--) {
char c = name[idx];
if (!isdigit(c) && c != '.' && c != '_')
break;
}
if (idx <= 0)
return strlen(name);
return idx + 1;
}
/*
* Remove number suffix of a symbol.
*
* Specifically, remove trailing numbers for "__UNIQUE_ID_" symbols and
* symbols with '.'.
*
* With CONFIG_LTO_CLANG_THIN, it is possible to have nested __UNIQUE_ID_,
* such as
*
* __UNIQUE_ID_addressable___UNIQUE_ID_pci_invalid_bar_694_695
*
* to remove both trailing numbers, also remove trailing '_'.
*
* For symbols with llvm suffix, i.e., foo.llvm.<hash>, remove the
* .llvm.<hash> part.
*/
static const char *demangle_name(struct symbol *sym)
{
char *str;
if (!is_local_sym(sym))
return sym->name;
ssize_t len;
if (!is_func_sym(sym) && !is_object_sym(sym))
return sym->name;
if (!strstarts(sym->name, "__UNIQUE_ID_") && !strchr(sym->name, '.'))
len = demangled_name_len(sym->name);
if (len == strlen(sym->name))
return sym->name;
str = strdup(sym->name);
str = strndup(sym->name, len);
if (!str) {
ERROR_GLIBC("strdup");
return NULL;
}
for (int i = strlen(str) - 1; i >= 0; i--) {
char c = str[i];
if (!isdigit(c) && c != '.') {
str[i + 1] = '\0';
break;
}
}
return str;
}
@@ -503,9 +556,13 @@ static int elf_add_symbol(struct elf *elf, struct symbol *sym)
entry = &sym->sec->symbol_list;
list_add(&sym->list, entry);
sym->demangled_name = demangle_name(sym);
if (!sym->demangled_name)
return -1;
list_add_tail(&sym->global_list, &elf->symbols);
elf_hash_add(symbol, &sym->hash, sym->idx);
elf_hash_add(symbol_name, &sym->name_hash, str_hash(sym->name));
elf_hash_add(symbol_name, &sym->name_hash, str_hash(sym->demangled_name));
if (is_func_sym(sym) &&
(strstarts(sym->name, "__pfx_") ||
@@ -529,10 +586,6 @@ static int elf_add_symbol(struct elf *elf, struct symbol *sym)
sym->pfunc = sym->cfunc = sym;
sym->demangled_name = demangle_name(sym);
if (!sym->demangled_name)
return -1;
return 0;
}
@@ -613,7 +666,7 @@ static int read_symbols(struct elf *elf)
if (elf_add_symbol(elf, sym))
return -1;
if (sym->type == STT_FILE)
if (is_file_sym(sym))
file = sym;
else if (sym->bind == STB_LOCAL)
sym->file = file;
@@ -1318,7 +1371,7 @@ unsigned int elf_add_string(struct elf *elf, struct section *strtab, const char
return -1;
}
offset = ALIGN(strtab->sh.sh_size, strtab->sh.sh_addralign);
offset = ALIGN(sec_size(strtab), strtab->sh.sh_addralign);
if (!elf_add_data(elf, strtab, str, strlen(str) + 1))
return -1;
@@ -1360,7 +1413,7 @@ void *elf_add_data(struct elf *elf, struct section *sec, const void *data, size_
sec->data->d_size = size;
sec->data->d_align = sec->sh.sh_addralign;
offset = ALIGN(sec->sh.sh_size, sec->sh.sh_addralign);
offset = ALIGN(sec_size(sec), sec->sh.sh_addralign);
sec->sh.sh_size = offset + size;
mark_sec_changed(elf, sec, true);

View File

@@ -186,6 +186,9 @@ struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
struct symbol *find_symbol_by_name(const struct elf *elf, const char *name);
struct symbol *find_global_symbol_by_name(const struct elf *elf, const char *name);
void iterate_global_symbol_by_demangled_name(const struct elf *elf, const char *demangled_name,
void (*process)(struct symbol *sym, void *data),
void *data);
struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset);
int find_symbol_hole_containing(const struct section *sec, unsigned long offset);
struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);

View File

@@ -272,7 +272,7 @@ static bool is_uncorrelated_static_local(struct symbol *sym)
*/
static bool is_clang_tmp_label(struct symbol *sym)
{
return sym->type == STT_NOTYPE &&
return is_notype_sym(sym) &&
is_text_sec(sym->sec) &&
strstarts(sym->name, ".Ltmp") &&
isdigit(sym->name[5]);
@@ -356,6 +356,46 @@ static bool dont_correlate(struct symbol *sym)
strstarts(sym->name, "__initcall__");
}
struct process_demangled_name_data {
struct symbol *ret;
int count;
};
static void process_demangled_name(struct symbol *sym, void *d)
{
struct process_demangled_name_data *data = d;
if (sym->twin)
return;
data->count++;
data->ret = sym;
}
/*
* When there is no full name match, try match demangled_name. This would
* match original foo.llvm.123 to patched foo.llvm.456.
*
* Note that, in very rare cases, it is possible to have multiple
* foo.llvm.<hash> in the same kernel. When this happens, report error and
* fail the diff.
*/
static int find_global_symbol_by_demangled_name(struct elf *elf, struct symbol *sym,
struct symbol **out_sym)
{
struct process_demangled_name_data data = {};
iterate_global_symbol_by_demangled_name(elf, sym->demangled_name,
process_demangled_name,
&data);
if (data.count > 1) {
ERROR("Multiple (%d) correlation candidates for %s", data.count, sym->name);
return -1;
}
*out_sym = data.ret;
return 0;
}
/*
* For each symbol in the original kernel, find its corresponding "twin" in the
* patched kernel.
@@ -454,13 +494,60 @@ static int correlate_symbols(struct elfs *e)
continue;
sym2 = find_global_symbol_by_name(e->patched, sym1->name);
if (sym2 && !sym2->twin && !strcmp(sym1->name, sym2->name)) {
if (sym2 && !sym2->twin) {
sym1->twin = sym2;
sym2->twin = sym1;
}
}
/*
* Correlate globals with demangled_name.
* A separate loop is needed because we want to finish all the
* full name correlations first.
*/
for_each_sym(e->orig, sym1) {
if (sym1->bind == STB_LOCAL || sym1->twin)
continue;
if (find_global_symbol_by_demangled_name(e->patched, sym1, &sym2))
return -1;
if (sym2 && !sym2->twin) {
sym1->twin = sym2;
sym2->twin = sym1;
}
}
/* Correlate original locals with patched globals */
for_each_sym(e->orig, sym1) {
if (sym1->twin || dont_correlate(sym1) || !is_local_sym(sym1))
continue;
sym2 = find_global_symbol_by_name(e->patched, sym1->name);
if (!sym2 && find_global_symbol_by_demangled_name(e->patched, sym1, &sym2))
return -1;
if (sym2 && !sym2->twin) {
sym1->twin = sym2;
sym2->twin = sym1;
}
}
/* Correlate original globals with patched locals */
for_each_sym(e->patched, sym2) {
if (sym2->twin || dont_correlate(sym2) || !is_local_sym(sym2))
continue;
sym1 = find_global_symbol_by_name(e->orig, sym2->name);
if (!sym1 && find_global_symbol_by_demangled_name(e->orig, sym2, &sym1))
return -1;
if (sym1 && !sym1->twin) {
sym2->twin = sym1;
sym1->twin = sym2;
}
}
for_each_sym(e->orig, sym1) {
if (sym1->twin || dont_correlate(sym1))
continue;
@@ -481,7 +568,7 @@ static unsigned long find_sympos(struct elf *elf, struct symbol *sym)
if (sym->bind != STB_LOCAL)
return 0;
if (vmlinux && sym->type == STT_FUNC) {
if (vmlinux && is_func_sym(sym)) {
/*
* HACK: Unfortunately, symbol ordering can differ between
* vmlinux.o and vmlinux due to the linker script emitting
@@ -1047,8 +1134,8 @@ static int clone_reloc_klp(struct elfs *e, struct reloc *patched_reloc,
sec->name, offset, patched_sym->name, \
addend >= 0 ? "+" : "-", labs(addend), \
sym_type(patched_sym), \
patched_sym->type == STT_SECTION ? "" : " ", \
patched_sym->type == STT_SECTION ? "" : sym_bind(patched_sym), \
is_sec_sym(patched_sym) ? "" : " ", \
is_sec_sym(patched_sym) ? "" : sym_bind(patched_sym), \
is_undef_sym(patched_sym) ? " UNDEF" : "", \
export ? " EXPORTED" : "", \
klp ? " KLP" : "")