diff options
Diffstat (limited to 'tools/objtool/check.c')
| -rw-r--r-- | tools/objtool/check.c | 106 |
1 files changed, 94 insertions, 12 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index d14f20ef1db1..9004fbc06769 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -217,6 +217,7 @@ static bool is_rust_noreturn(const struct symbol *func) * these come from the Rust standard library). */ return str_ends_with(func->name, "_4core5sliceSp15copy_from_slice17len_mismatch_fail") || + str_ends_with(func->name, "_4core6option13expect_failed") || str_ends_with(func->name, "_4core6option13unwrap_failed") || str_ends_with(func->name, "_4core6result13unwrap_failed") || str_ends_with(func->name, "_4core9panicking5panic") || @@ -2392,6 +2393,8 @@ static int __annotate_ifc(struct objtool_file *file, int type, struct instructio static int __annotate_late(struct objtool_file *file, int type, struct instruction *insn) { + struct symbol *sym; + switch (type) { case ANNOTYPE_NOENDBR: /* early */ @@ -2433,6 +2436,15 @@ static int __annotate_late(struct objtool_file *file, int type, struct instructi insn->dead_end = false; break; + case ANNOTYPE_NOCFI: + sym = insn->sym; + if (!sym) { + ERROR_INSN(insn, "dodgy NOCFI annotation"); + return -1; + } + insn->sym->nocfi = 1; + break; + default: ERROR_INSN(insn, "Unknown annotation type: %d", type); return -1; @@ -2453,16 +2465,6 @@ static bool is_profiling_func(const char *name) if (!strncmp(name, "__sanitizer_cov_", 16)) return true; - /* - * Some compilers currently do not remove __tsan_func_entry/exit nor - * __tsan_atomic_signal_fence (used for barrier instrumentation) with - * the __no_sanitize_thread attribute, remove them. Once the kernel's - * minimum Clang version is 14.0, this can be removed. - */ - if (!strncmp(name, "__tsan_func_", 12) || - !strcmp(name, "__tsan_atomic_signal_fence")) - return true; - return false; } @@ -3514,8 +3516,11 @@ static bool skip_alt_group(struct instruction *insn) { struct instruction *alt_insn = insn->alts ? insn->alts->insn : NULL; + if (!insn->alt_group) + return false; + /* ANNOTATE_IGNORE_ALTERNATIVE */ - if (insn->alt_group && insn->alt_group->ignore) + if (insn->alt_group->ignore) return true; /* @@ -3564,7 +3569,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, if (func && insn_func(insn) && func != insn_func(insn)->pfunc) { /* Ignore KCFI type preambles, which always fall through */ if (!strncmp(func->name, "__cfi_", 6) || - !strncmp(func->name, "__pfx_", 6)) + !strncmp(func->name, "__pfx_", 6) || + !strncmp(func->name, "__pi___cfi_", 11) || + !strncmp(func->name, "__pi___pfx_", 11)) return 0; if (file->ignore_unreachables) @@ -4002,6 +4009,37 @@ static int validate_retpoline(struct objtool_file *file) warnings++; } + if (!opts.cfi) + return warnings; + + /* + * kCFI call sites look like: + * + * movl $(-0x12345678), %r10d + * addl -4(%r11), %r10d + * jz 1f + * ud2 + * 1: cs call __x86_indirect_thunk_r11 + * + * Verify all indirect calls are kCFI adorned by checking for the + * UD2. Notably, doing __nocfi calls to regular (cfi) functions is + * broken. + */ + 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) { + struct instruction *prev = + prev_insn_same_sym(file, insn); + + if (!prev || prev->type != INSN_BUG) { + WARN_INSN(insn, "no-cfi indirect call!"); + warnings++; + } + } + } + return warnings; } @@ -4644,6 +4682,47 @@ static void disas_warned_funcs(struct objtool_file *file) disas_funcs(funcs); } +__weak bool arch_absolute_reloc(struct elf *elf, struct reloc *reloc) +{ + unsigned int type = reloc_type(reloc); + size_t sz = elf_addr_size(elf); + + return (sz == 8) ? (type == R_ABS64) : (type == R_ABS32); +} + +static int check_abs_references(struct objtool_file *file) +{ + struct section *sec; + struct reloc *reloc; + int ret = 0; + + for_each_sec(file, sec) { + /* absolute references in non-loadable sections are fine */ + if (!(sec->sh.sh_flags & SHF_ALLOC)) + continue; + + /* section must have an associated .rela section */ + if (!sec->rsec) + continue; + + /* + * Special case for compiler generated metadata that is not + * consumed until after boot. + */ + if (!strcmp(sec->name, "__patchable_function_entries")) + continue; + + for_each_reloc(sec->rsec, reloc) { + if (arch_absolute_reloc(file->elf, reloc)) { + WARN("section %s has absolute relocation at offset 0x%llx", + sec->name, (unsigned long long)reloc_offset(reloc)); + ret++; + } + } + } + return ret; +} + struct insn_chunk { void *addr; struct insn_chunk *next; @@ -4777,6 +4856,9 @@ int check(struct objtool_file *file) goto out; } + if (opts.noabs) + warnings += check_abs_references(file); + if (opts.orc && nr_insns) { ret = orc_create(file); if (ret) |