diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-04-14 13:00:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-04-14 13:00:04 -0700 |
| commit | 4b2bdc22210e39a02b3dc984cb8eb6b3293a56a7 (patch) | |
| tree | b49b693d6eb7165e7f3781fe9063f7612be118bd /tools/objtool/klp-diff.c | |
| parent | 7393febcb1b2082c0484952729cbebfe4dc508d5 (diff) | |
| parent | 1735858caa4bbb8b923860c0833d463b5d9c5f79 (diff) | |
| download | lwn-4b2bdc22210e39a02b3dc984cb8eb6b3293a56a7.tar.gz lwn-4b2bdc22210e39a02b3dc984cb8eb6b3293a56a7.zip | |
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
Diffstat (limited to 'tools/objtool/klp-diff.c')
| -rw-r--r-- | tools/objtool/klp-diff.c | 97 |
1 files changed, 92 insertions, 5 deletions
diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c index c2c4e4968bc2..0b0d1503851f 100644 --- a/tools/objtool/klp-diff.c +++ b/tools/objtool/klp-diff.c @@ -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) { + 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 && !strcmp(sym1->name, sym2->name)) { + 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" : "") |
