diff options
Diffstat (limited to 'tools/objtool/check.c')
| -rw-r--r-- | tools/objtool/check.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index a72059fcbc83..a5770570b106 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -2392,6 +2392,8 @@ 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 +2435,15 @@ 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; @@ -3994,6 +4005,37 @@ 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; } |