diff options
Diffstat (limited to 'tools/objtool')
-rw-r--r-- | tools/objtool/arch/loongarch/decode.c | 33 | ||||
-rw-r--r-- | tools/objtool/arch/loongarch/special.c | 23 | ||||
-rw-r--r-- | tools/objtool/arch/x86/decode.c | 45 | ||||
-rw-r--r-- | tools/objtool/arch/x86/special.c | 2 | ||||
-rw-r--r-- | tools/objtool/builtin-check.c | 2 | ||||
-rw-r--r-- | tools/objtool/check.c | 170 | ||||
-rw-r--r-- | tools/objtool/elf.c | 38 | ||||
-rw-r--r-- | tools/objtool/include/objtool/arch.h | 4 | ||||
-rw-r--r-- | tools/objtool/include/objtool/builtin.h | 1 | ||||
-rw-r--r-- | tools/objtool/include/objtool/elf.h | 2 | ||||
-rw-r--r-- | tools/objtool/noreturns.h | 2 |
11 files changed, 284 insertions, 38 deletions
diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c index b6fdc68053cc..2e555c4060c5 100644 --- a/tools/objtool/arch/loongarch/decode.c +++ b/tools/objtool/arch/loongarch/decode.c @@ -278,6 +278,25 @@ static bool decode_insn_reg2i16_fomat(union loongarch_instruction inst, return true; } +static bool decode_insn_reg3_fomat(union loongarch_instruction inst, + struct instruction *insn) +{ + switch (inst.reg3_format.opcode) { + case amswapw_op: + if (inst.reg3_format.rd == LOONGARCH_GPR_ZERO && + inst.reg3_format.rk == LOONGARCH_GPR_RA && + inst.reg3_format.rj == LOONGARCH_GPR_ZERO) { + /* amswap.w $zero, $ra, $zero */ + insn->type = INSN_BUG; + } + break; + default: + return false; + } + + return true; +} + int arch_decode_instruction(struct objtool_file *file, const struct section *sec, unsigned long offset, unsigned int maxlen, struct instruction *insn) @@ -309,11 +328,19 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec return 0; if (decode_insn_reg2i16_fomat(inst, insn)) return 0; + if (decode_insn_reg3_fomat(inst, insn)) + return 0; - if (inst.word == 0) + if (inst.word == 0) { + /* andi $zero, $zero, 0x0 */ insn->type = INSN_NOP; - else if (inst.reg0i15_format.opcode == break_op) { - /* break */ + } else if (inst.reg0i15_format.opcode == break_op && + inst.reg0i15_format.immediate == 0x0) { + /* break 0x0 */ + insn->type = INSN_TRAP; + } else if (inst.reg0i15_format.opcode == break_op && + inst.reg0i15_format.immediate == 0x1) { + /* break 0x1 */ insn->type = INSN_BUG; } else if (inst.reg2_format.opcode == ertn_op) { /* ertn */ diff --git a/tools/objtool/arch/loongarch/special.c b/tools/objtool/arch/loongarch/special.c index e39f86d97002..a80b75f7b061 100644 --- a/tools/objtool/arch/loongarch/special.c +++ b/tools/objtool/arch/loongarch/special.c @@ -27,6 +27,7 @@ static void get_rodata_table_size_by_table_annotate(struct objtool_file *file, struct table_info *next_table; unsigned long tmp_insn_offset; unsigned long tmp_rodata_offset; + bool is_valid_list = false; rsec = find_section_by_name(file->elf, ".rela.discard.tablejump_annotate"); if (!rsec) @@ -35,6 +36,12 @@ static void get_rodata_table_size_by_table_annotate(struct objtool_file *file, INIT_LIST_HEAD(&table_list); for_each_reloc(rsec, reloc) { + if (reloc->sym->sec->rodata) + continue; + + if (strcmp(insn->sec->name, reloc->sym->sec->name)) + continue; + orig_table = malloc(sizeof(struct table_info)); if (!orig_table) { WARN("malloc failed"); @@ -49,6 +56,22 @@ static void get_rodata_table_size_by_table_annotate(struct objtool_file *file, if (reloc_idx(reloc) + 1 == sec_num_entries(rsec)) break; + + if (strcmp(insn->sec->name, (reloc + 1)->sym->sec->name)) { + list_for_each_entry(orig_table, &table_list, jump_info) { + if (orig_table->insn_offset == insn->offset) { + is_valid_list = true; + break; + } + } + + if (!is_valid_list) { + list_del_init(&table_list); + continue; + } + + break; + } } list_for_each_entry(orig_table, &table_list, jump_info) { diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 33d861c04ebd..0ad5cc70ecbe 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -189,6 +189,15 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec op2 = ins.opcode.bytes[1]; op3 = ins.opcode.bytes[2]; + /* + * XXX hack, decoder is buggered and thinks 0xea is 7 bytes long. + */ + if (op1 == 0xea) { + insn->len = 1; + insn->type = INSN_BUG; + return 0; + } + if (ins.rex_prefix.nbytes) { rex = ins.rex_prefix.bytes[0]; rex_w = X86_REX_W(rex) >> 3; @@ -522,7 +531,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec case INAT_PFX_REPNE: if (modrm == 0xca) /* eretu/erets */ - insn->type = INSN_CONTEXT_SWITCH; + insn->type = INSN_SYSRET; break; default: if (modrm == 0xca) @@ -535,11 +544,15 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec insn->type = INSN_JUMP_CONDITIONAL; - } else if (op2 == 0x05 || op2 == 0x07 || op2 == 0x34 || - op2 == 0x35) { + } else if (op2 == 0x05 || op2 == 0x34) { - /* sysenter, sysret */ - insn->type = INSN_CONTEXT_SWITCH; + /* syscall, sysenter */ + insn->type = INSN_SYSCALL; + + } else if (op2 == 0x07 || op2 == 0x35) { + + /* sysret, sysexit */ + insn->type = INSN_SYSRET; } else if (op2 == 0x0b || op2 == 0xb9) { @@ -676,7 +689,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec case 0xca: /* retf */ case 0xcb: /* retf */ - insn->type = INSN_CONTEXT_SWITCH; + insn->type = INSN_SYSRET; break; case 0xe0: /* loopne */ @@ -721,7 +734,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec } else if (modrm_reg == 5) { /* jmpf */ - insn->type = INSN_CONTEXT_SWITCH; + insn->type = INSN_SYSRET; } else if (modrm_reg == 6) { @@ -838,12 +851,14 @@ int arch_decode_hint_reg(u8 sp_reg, int *base) bool arch_is_retpoline(struct symbol *sym) { - return !strncmp(sym->name, "__x86_indirect_", 15); + return !strncmp(sym->name, "__x86_indirect_", 15) || + !strncmp(sym->name, "__pi___x86_indirect_", 20); } bool arch_is_rethunk(struct symbol *sym) { - return !strcmp(sym->name, "__x86_return_thunk"); + return !strcmp(sym->name, "__x86_return_thunk") || + !strcmp(sym->name, "__pi___x86_return_thunk"); } bool arch_is_embedded_insn(struct symbol *sym) @@ -865,3 +880,15 @@ unsigned int arch_reloc_size(struct reloc *reloc) return 8; } } + +bool arch_absolute_reloc(struct elf *elf, struct reloc *reloc) +{ + switch (reloc_type(reloc)) { + case R_X86_64_32: + case R_X86_64_32S: + case R_X86_64_64: + return true; + default: + return false; + } +} diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c index 403e587676f1..06ca4a2659a4 100644 --- a/tools/objtool/arch/x86/special.c +++ b/tools/objtool/arch/x86/special.c @@ -126,7 +126,7 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, * indicates a rare GCC quirk/bug which can leave dead * code behind. */ - if (reloc_type(text_reloc) == R_X86_64_PC32) { + if (!file->ignore_unreachables && reloc_type(text_reloc) == R_X86_64_PC32) { WARN_INSN(insn, "ignoring unreachables due to jump table quirk"); file->ignore_unreachables = true; } diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 80239843e9f0..0f6b197cfcb0 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -87,6 +87,7 @@ static const struct option check_options[] = { OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"), OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"), OPT_BOOLEAN(0 , "cfi", &opts.cfi, "annotate kernel control flow integrity (kCFI) function preambles"), + OPT_BOOLEAN(0 , "noabs", &opts.noabs, "reject absolute references in allocatable sections"), OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump), OPT_GROUP("Options:"), @@ -162,6 +163,7 @@ static bool opts_valid(void) opts.hack_noinstr || opts.ibt || opts.mcount || + opts.noabs || opts.noinstr || opts.orc || opts.retpoline || diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 4a1f6c3169b3..a5770570b106 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -224,11 +224,15 @@ static bool is_rust_noreturn(const struct symbol *func) str_ends_with(func->name, "_4core9panicking14panic_explicit") || str_ends_with(func->name, "_4core9panicking14panic_nounwind") || str_ends_with(func->name, "_4core9panicking18panic_bounds_check") || + str_ends_with(func->name, "_4core9panicking18panic_nounwind_fmt") || str_ends_with(func->name, "_4core9panicking19assert_failed_inner") || + str_ends_with(func->name, "_4core9panicking30panic_null_pointer_dereference") || str_ends_with(func->name, "_4core9panicking36panic_misaligned_pointer_dereference") || + str_ends_with(func->name, "_7___rustc17rust_begin_unwind") || strstr(func->name, "_4core9panicking13assert_failed") || strstr(func->name, "_4core9panicking11panic_const24panic_const_") || - (strstr(func->name, "_4core5slice5index24slice_") && + (strstr(func->name, "_4core5slice5index") && + strstr(func->name, "slice_") && str_ends_with(func->name, "_fail")); } @@ -1189,8 +1193,8 @@ static const char *uaccess_safe_builtin[] = { "__ubsan_handle_type_mismatch_v1", "__ubsan_handle_shift_out_of_bounds", "__ubsan_handle_load_invalid_value", - /* STACKLEAK */ - "stackleak_track_stack", + /* KSTACK_ERASE */ + "__sanitizer_cov_stack_depth", /* TRACE_BRANCH_PROFILING */ "ftrace_likely_update", /* STACKPROTECTOR */ @@ -2315,6 +2319,7 @@ static int read_annotate(struct objtool_file *file, for_each_reloc(sec->rsec, reloc) { type = *(u32 *)(sec->data->d_buf + (reloc_idx(reloc) * sec->sh.sh_entsize) + 4); + type = bswap_if_needed(file->elf, type); offset = reloc->sym->offset + reloc_addend(reloc); insn = find_insn(file, reloc->sym->sec, offset); @@ -2387,6 +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 */ @@ -2428,6 +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; @@ -2448,16 +2464,6 @@ 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; } @@ -3505,6 +3511,34 @@ next_orig: return next_insn_same_sec(file, alt_group->orig_group->last_insn); } +static bool skip_alt_group(struct instruction *insn) +{ + struct instruction *alt_insn = insn->alts ? insn->alts->insn : NULL; + + /* ANNOTATE_IGNORE_ALTERNATIVE */ + if (insn->alt_group && insn->alt_group->ignore) + return true; + + /* + * For NOP patched with CLAC/STAC, only follow the latter to avoid + * impossible code paths combining patched CLAC with unpatched STAC + * or vice versa. + * + * ANNOTATE_IGNORE_ALTERNATIVE could have been used here, but Linus + * requested not to do that to avoid hurting .s file readability + * around CLAC/STAC alternative sites. + */ + + if (!alt_insn) + return false; + + /* Don't override ASM_{CLAC,STAC}_UNSAFE */ + if (alt_insn->alt_group && alt_insn->alt_group->ignore) + return false; + + return alt_insn->type == INSN_CLAC || alt_insn->type == INSN_STAC; +} + /* * Follow the branch starting at the given instruction, and recursively follow * any other branches (jumps). Meanwhile, track the frame pointer state at @@ -3531,7 +3565,9 @@ 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) @@ -3625,7 +3661,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, } } - if (insn->alt_group && insn->alt_group->ignore) + if (skip_alt_group(insn)) return 0; if (handle_insn_ops(insn, next_insn, &state)) @@ -3684,14 +3720,20 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, break; - case INSN_CONTEXT_SWITCH: - if (func) { - if (!next_insn || !next_insn->hint) { - WARN_INSN(insn, "unsupported instruction in callable function"); - return 1; - } - break; + case INSN_SYSCALL: + if (func && (!next_insn || !next_insn->hint)) { + WARN_INSN(insn, "unsupported instruction in callable function"); + return 1; + } + + break; + + case INSN_SYSRET: + if (func && (!next_insn || !next_insn->hint)) { + WARN_INSN(insn, "unsupported instruction in callable function"); + return 1; } + return 0; case INSN_STAC: @@ -3886,6 +3928,12 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) WARN_INSN(insn, "RET before UNTRAIN"); return 1; + case INSN_SYSCALL: + break; + + case INSN_SYSRET: + return 0; + case INSN_NOP: if (insn->retpoline_safe) return 0; @@ -3895,6 +3943,9 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) break; } + if (insn->dead_end) + return 0; + if (!next) { WARN_INSN(insn, "teh end!"); return 1; @@ -3954,6 +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; } @@ -4596,6 +4678,47 @@ 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%lx", + sec->name, reloc_offset(reloc)); + ret++; + } + } + } + return ret; +} + struct insn_chunk { void *addr; struct insn_chunk *next; @@ -4729,6 +4852,9 @@ 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) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 727a3a4fd9d7..ca5d77db692a 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -572,6 +572,34 @@ err: return -1; } +static int mark_group_syms(struct elf *elf) +{ + struct section *symtab, *sec; + struct symbol *sym; + + symtab = find_section_by_name(elf, ".symtab"); + if (!symtab) { + ERROR("no .symtab"); + return -1; + } + + list_for_each_entry(sec, &elf->sections, list) { + if (sec->sh.sh_type == SHT_GROUP && + sec->sh.sh_link == symtab->idx) { + sym = find_symbol_by_index(elf, sec->sh.sh_info); + if (!sym) { + ERROR("%s: can't find SHT_GROUP signature symbol", + sec->name); + return -1; + } + + sym->group_sec = sec; + } + } + + return 0; +} + /* * @sym's idx has changed. Update the relocs which reference it. */ @@ -745,7 +773,7 @@ __elf_create_symbol(struct elf *elf, struct symbol *sym) /* * Move the first global symbol, as per sh_info, into a new, higher - * symbol index. This fees up a spot for a new local symbol. + * symbol index. This frees up a spot for a new local symbol. */ first_non_local = symtab->sh.sh_info; old = find_symbol_by_index(elf, first_non_local); @@ -763,6 +791,11 @@ __elf_create_symbol(struct elf *elf, struct symbol *sym) if (elf_update_sym_relocs(elf, old)) return NULL; + if (old->group_sec) { + old->group_sec->sh.sh_info = new_idx; + mark_sec_changed(elf, old->group_sec, true); + } + new_idx = first_non_local; } @@ -1035,6 +1068,9 @@ struct elf *elf_open_read(const char *name, int flags) if (read_symbols(elf)) goto err; + if (mark_group_syms(elf)) + goto err; + if (read_relocs(elf)) goto err; diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h index 089a1acc48a8..be33c7b43180 100644 --- a/tools/objtool/include/objtool/arch.h +++ b/tools/objtool/include/objtool/arch.h @@ -19,7 +19,8 @@ enum insn_type { INSN_CALL, INSN_CALL_DYNAMIC, INSN_RETURN, - INSN_CONTEXT_SWITCH, + INSN_SYSCALL, + INSN_SYSRET, INSN_BUG, INSN_NOP, INSN_STAC, @@ -96,6 +97,7 @@ bool arch_is_embedded_insn(struct symbol *sym); int arch_rewrite_retpolines(struct objtool_file *file); bool arch_pc_relative_reloc(struct reloc *reloc); +bool arch_absolute_reloc(struct elf *elf, struct reloc *reloc); unsigned int arch_reloc_size(struct reloc *reloc); unsigned long arch_jump_table_sym_offset(struct reloc *reloc, struct reloc *table); diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index 6b08666fa69d..ab22673862e1 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/objtool/builtin.h @@ -26,6 +26,7 @@ struct opts { bool uaccess; int prefix; bool cfi; + bool noabs; /* options: */ bool backtrace; diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index c7c4e87ebe88..df8434d3b744 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -70,8 +70,10 @@ struct symbol { u8 local_label : 1; u8 frame_pointer : 1; u8 ignore : 1; + u8 nocfi : 1; struct list_head pv_target; struct reloc *relocs; + struct section *group_sec; }; struct reloc { diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h index eacfe3b0a8d1..802895fae3ca 100644 --- a/tools/objtool/noreturns.h +++ b/tools/objtool/noreturns.h @@ -38,13 +38,13 @@ NORETURN(mpt_halt_firmware) NORETURN(mwait_play_dead) NORETURN(nmi_panic_self_stop) NORETURN(panic) +NORETURN(vpanic) NORETURN(panic_smp_self_stop) NORETURN(rest_init) NORETURN(rewind_stack_and_make_dead) NORETURN(rust_begin_unwind) NORETURN(rust_helper_BUG) NORETURN(sev_es_terminate) -NORETURN(snp_abort) NORETURN(start_kernel) NORETURN(stop_this_cpu) NORETURN(usercopy_abort) |