diff options
Diffstat (limited to 'tools/objtool/check.c')
| -rw-r--r-- | tools/objtool/check.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index abf97159bf1e..87e528c2840c 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -257,6 +257,9 @@ static int decode_instructions(struct objtool_file *file) strncmp(sec->name, ".discard.", 9)) sec->text = true; + if (!strcmp(sec->name, ".noinstr.text")) + sec->noinstr = true; + for (offset = 0; offset < sec->len; offset += insn->len) { insn = malloc(sizeof(*insn)); if (!insn) { @@ -1340,6 +1343,53 @@ static int read_retpoline_hints(struct objtool_file *file) return 0; } +static int read_instr_hints(struct objtool_file *file) +{ + struct section *sec; + struct instruction *insn; + struct rela *rela; + + sec = find_section_by_name(file->elf, ".rela.discard.instr_end"); + if (!sec) + return 0; + + list_for_each_entry(rela, &sec->rela_list, list) { + if (rela->sym->type != STT_SECTION) { + WARN("unexpected relocation symbol type in %s", sec->name); + return -1; + } + + insn = find_insn(file, rela->sym->sec, rela->addend); + if (!insn) { + WARN("bad .discard.instr_end entry"); + return -1; + } + + insn->instr--; + } + + sec = find_section_by_name(file->elf, ".rela.discard.instr_begin"); + if (!sec) + return 0; + + list_for_each_entry(rela, &sec->rela_list, list) { + if (rela->sym->type != STT_SECTION) { + WARN("unexpected relocation symbol type in %s", sec->name); + return -1; + } + + insn = find_insn(file, rela->sym->sec, rela->addend); + if (!insn) { + WARN("bad .discard.instr_begin entry"); + return -1; + } + + insn->instr++; + } + + return 0; +} + static void mark_rodata(struct objtool_file *file) { struct section *sec; @@ -1411,6 +1461,10 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret; + ret = read_instr_hints(file); + if (ret) + return ret; + return 0; } @@ -2007,6 +2061,13 @@ static inline const char *call_dest_name(struct instruction *insn) static int validate_call(struct instruction *insn, struct insn_state *state) { + if (state->noinstr && state->instr <= 0 && + (!insn->call_dest || insn->call_dest->sec != insn->sec)) { + WARN_FUNC("call to %s() leaves .noinstr.text section", + insn->sec, insn->offset, call_dest_name(insn)); + return 1; + } + if (state->uaccess && !func_uaccess_safe(insn->call_dest)) { WARN_FUNC("call to %s() with UACCESS enabled", insn->sec, insn->offset, call_dest_name(insn)); @@ -2035,6 +2096,12 @@ static int validate_sibling_call(struct instruction *insn, struct insn_state *st static int validate_return(struct symbol *func, struct instruction *insn, struct insn_state *state) { + if (state->noinstr && state->instr > 0) { + WARN_FUNC("return with instrumentation enabled", + insn->sec, insn->offset); + return 1; + } + if (state->uaccess && !func_uaccess_safe(func)) { WARN_FUNC("return with UACCESS enabled", insn->sec, insn->offset); @@ -2115,6 +2182,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, return 0; } + if (state.noinstr) + state.instr += insn->instr; + if (insn->hint) state.cfi = insn->cfi; else @@ -2422,6 +2492,14 @@ static int validate_section(struct objtool_file *file, struct section *sec) struct insn_state state; int ret, warnings = 0; + /* + * We need the full vmlinux for noinstr validation, otherwise we can + * not correctly determine insn->call_dest->sec (external symbols do + * not have a section). + */ + if (vmlinux) + state.noinstr = sec->noinstr; + list_for_each_entry(func, &sec->symbol_list, list) { if (func->type != STT_FUNC) continue; @@ -2456,6 +2534,17 @@ static int validate_section(struct objtool_file *file, struct section *sec) return warnings; } +static int validate_vmlinux_functions(struct objtool_file *file) +{ + struct section *sec; + + sec = find_section_by_name(file->elf, ".noinstr.text"); + if (!sec) + return 0; + + return validate_section(file, sec); +} + static int validate_functions(struct objtool_file *file) { struct section *sec; @@ -2513,6 +2602,15 @@ int check(const char *_objname, bool orc) if (list_empty(&file.insn_list)) goto out; + if (vmlinux && !validate_dup) { + ret = validate_vmlinux_functions(&file); + if (ret < 0) + goto out; + + warnings += ret; + goto out; + } + if (retpoline) { ret = validate_retpoline(&file); if (ret < 0) |