diff options
Diffstat (limited to 'tools/objtool/check.c')
| -rw-r--r-- | tools/objtool/check.c | 3423 |
1 files changed, 1963 insertions, 1460 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 4b7c8b33069e..3f7999317f4d 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3,36 +3,40 @@ * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com> */ +#define _GNU_SOURCE /* memmem() */ +#include <fnmatch.h> #include <string.h> #include <stdlib.h> #include <inttypes.h> #include <sys/mman.h> -#include <arch/elf.h> #include <objtool/builtin.h> #include <objtool/cfi.h> #include <objtool/arch.h> +#include <objtool/disas.h> #include <objtool/check.h> #include <objtool/special.h> +#include <objtool/trace.h> #include <objtool/warn.h> -#include <objtool/endianness.h> +#include <objtool/checksum.h> +#include <objtool/util.h> -#include <linux/objtool.h> +#include <linux/objtool_types.h> #include <linux/hashtable.h> #include <linux/kernel.h> #include <linux/static_call_types.h> - -struct alternative { - struct list_head list; - struct instruction *insn; - bool skip_orig; -}; +#include <linux/string.h> static unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache; static struct cfi_init_state initial_func_cfi; static struct cfi_state init_cfi; static struct cfi_state func_cfi; +static struct cfi_state force_undefined_cfi; + +struct disas_context *objtool_disas_ctx; + +size_t sym_name_max_len; struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset) @@ -47,27 +51,29 @@ struct instruction *find_insn(struct objtool_file *file, return NULL; } -static struct instruction *next_insn_same_sec(struct objtool_file *file, - struct instruction *insn) +struct instruction *next_insn_same_sec(struct objtool_file *file, + struct instruction *insn) { - struct instruction *next = list_next_entry(insn, list); + if (insn->idx == INSN_CHUNK_MAX) + return find_insn(file, insn->sec, insn->offset + insn->len); - if (!next || &next->list == &file->insn_list || next->sec != insn->sec) + insn++; + if (!insn->len) return NULL; - return next; + return insn; } static struct instruction *next_insn_same_func(struct objtool_file *file, struct instruction *insn) { - struct instruction *next = list_next_entry(insn, list); + struct instruction *next = next_insn_same_sec(file, insn); struct symbol *func = insn_func(insn); if (!func) return NULL; - if (&next->list != &file->insn_list && insn_func(next) == func) + if (next && insn_func(next) == func) return next; /* Check if we're already in the subfunction: */ @@ -78,17 +84,35 @@ static struct instruction *next_insn_same_func(struct objtool_file *file, return find_insn(file, func->cfunc->sec, func->cfunc->offset); } +static struct instruction *prev_insn_same_sec(struct objtool_file *file, + struct instruction *insn) +{ + if (insn->idx == 0) { + if (insn->prev_len) + return find_insn(file, insn->sec, insn->offset - insn->prev_len); + return NULL; + } + + return insn - 1; +} + static struct instruction *prev_insn_same_sym(struct objtool_file *file, - struct instruction *insn) + struct instruction *insn) { - struct instruction *prev = list_prev_entry(insn, list); + struct instruction *prev = prev_insn_same_sec(file, insn); - if (&prev->list != &file->insn_list && insn_func(prev) == insn_func(insn)) + if (prev && insn_func(prev) == insn_func(insn)) return prev; return NULL; } +#define for_each_insn(file, insn) \ + for (struct section *__sec, *__fake = (struct section *)1; \ + __fake; __fake = NULL) \ + for_each_sec(file->elf, __sec) \ + sec_for_each_insn(file, __sec, insn) + #define func_for_each_insn(file, func, insn) \ for (insn = find_insn(file, func->sec, func->offset); \ insn; \ @@ -96,16 +120,13 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file, #define sym_for_each_insn(file, sym, insn) \ for (insn = find_insn(file, sym->sec, sym->offset); \ - insn && &insn->list != &file->insn_list && \ - insn->sec == sym->sec && \ - insn->offset < sym->offset + sym->len; \ - insn = list_next_entry(insn, list)) + insn && insn->offset < sym->offset + sym->len; \ + insn = next_insn_same_sec(file, insn)) #define sym_for_each_insn_continue_reverse(file, sym, insn) \ - for (insn = list_prev_entry(insn, list); \ - &insn->list != &file->insn_list && \ - insn->sec == sym->sec && insn->offset >= sym->offset; \ - insn = list_prev_entry(insn, list)) + for (insn = prev_insn_same_sec(file, insn); \ + insn && insn->offset >= sym->offset; \ + insn = prev_insn_same_sec(file, insn)) #define sec_for_each_insn_from(file, insn) \ for (; insn; insn = next_insn_same_sec(file, insn)) @@ -114,16 +135,34 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file, for (insn = next_insn_same_sec(file, insn); insn; \ insn = next_insn_same_sec(file, insn)) +static inline struct reloc *insn_jump_table(struct instruction *insn) +{ + if (insn->type == INSN_JUMP_DYNAMIC || + insn->type == INSN_CALL_DYNAMIC) + return insn->_jump_table; + + return NULL; +} + +static inline unsigned long insn_jump_table_size(struct instruction *insn) +{ + if (insn->type == INSN_JUMP_DYNAMIC || + insn->type == INSN_CALL_DYNAMIC) + return insn->_jump_table_size; + + return 0; +} + static bool is_jump_table_jump(struct instruction *insn) { struct alt_group *alt_group = insn->alt_group; - if (insn->jump_table) + if (insn_jump_table(insn)) return true; /* Retpoline alternative for a jump table? */ return alt_group && alt_group->orig_group && - alt_group->orig_group->first_insn->jump_table; + insn_jump_table(alt_group->orig_group->first_insn); } static bool is_sibling_call(struct instruction *insn) @@ -137,8 +176,46 @@ static bool is_sibling_call(struct instruction *insn) return !is_jump_table_jump(insn); } - /* add_jump_destinations() sets insn->call_dest for sibling calls. */ - return (is_static_jump(insn) && insn->call_dest); + /* add_jump_destinations() sets insn_call_dest(insn) for sibling calls. */ + return (is_static_jump(insn) && insn_call_dest(insn)); +} + +/* + * Checks if a function is a Rust "noreturn" one. + */ +static bool is_rust_noreturn(const struct symbol *func) +{ + /* + * If it does not start with "_R", then it is not a Rust symbol. + */ + if (strncmp(func->name, "_R", 2)) + return false; + + /* + * These are just heuristics -- we do not control the precise symbol + * name, due to the crate disambiguators (which depend on the compiler) + * as well as changes to the source code itself between versions (since + * 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") || + str_ends_with(func->name, "_4core9panicking9panic_fmt") || + 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, "_4core5slice5index") && + strstr(func->name, "slice_") && + str_ends_with(func->name, "_fail")); } /* @@ -157,48 +234,26 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, struct instruction *insn; bool empty = true; - /* - * Unfortunately these have to be hard coded because the noreturn - * attribute isn't provided in ELF data. Keep 'em sorted. - */ +#define NORETURN(func) __stringify(func), static const char * const global_noreturns[] = { - "__invalid_creds", - "__module_put_and_kthread_exit", - "__reiserfs_panic", - "__stack_chk_fail", - "__ubsan_handle_builtin_unreachable", - "cpu_bringup_and_idle", - "cpu_startup_entry", - "do_exit", - "do_group_exit", - "do_task_dead", - "ex_handler_msr_mce", - "fortify_panic", - "kthread_complete_and_exit", - "kthread_exit", - "kunit_try_catch_throw", - "lbug_with_loc", - "machine_real_restart", - "make_task_dead", - "panic", - "rewind_stack_and_make_dead", - "sev_es_terminate", - "snp_abort", - "stop_this_cpu", - "usercopy_abort", - "xen_start_kernel", +#include "noreturns.h" }; +#undef NORETURN if (!func) return false; - if (func->bind == STB_WEAK) - return false; + if (!is_local_sym(func)) { + if (is_rust_noreturn(func)) + return true; - if (func->bind == STB_GLOBAL) for (i = 0; i < ARRAY_SIZE(global_noreturns); i++) if (!strcmp(func->name, global_noreturns[i])) return true; + } + + if (is_weak_sym(func)) + return false; if (!func->len) return false; @@ -271,20 +326,15 @@ static void init_insn_state(struct objtool_file *file, struct insn_state *state, memset(state, 0, sizeof(*state)); init_cfi_state(&state->cfi); - /* - * 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 (opts.link && opts.noinstr && sec) + if (opts.noinstr && sec) state->noinstr = sec->noinstr; } static struct cfi_state *cfi_alloc(void) { - struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1); + struct cfi_state *cfi = calloc(1, sizeof(struct cfi_state)); if (!cfi) { - WARN("calloc failed"); + ERROR_GLIBC("calloc"); exit(1); } nr_cfi++; @@ -340,7 +390,7 @@ static void *cfi_hash_alloc(unsigned long size) PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0); if (cfi_hash == (void *)-1L) { - WARN("mmap fail cfi_hash"); + ERROR_GLIBC("mmap fail cfi_hash"); cfi_hash = NULL; } else if (opts.stats) { printf("cfi_bits: %d\n", cfi_bits); @@ -362,11 +412,13 @@ static int decode_instructions(struct objtool_file *file) struct symbol *func; unsigned long offset; struct instruction *insn; - int ret; - for_each_sec(file, sec) { + for_each_sec(file->elf, sec) { + struct instruction *insns = NULL; + u8 prev_len = 0; + u8 idx = 0; - if (!(sec->sh.sh_flags & SHF_EXECINSTR)) + if (!is_text_sec(sec)) continue; if (strcmp(sec->name, ".altinstr_replacement") && @@ -376,7 +428,8 @@ static int decode_instructions(struct objtool_file *file) if (!strcmp(sec->name, ".noinstr.text") || !strcmp(sec->name, ".entry.text") || - !strncmp(sec->name, ".text.__x86.", 12)) + !strcmp(sec->name, ".cpuidle.text") || + !strncmp(sec->name, ".text..__x86.", 13)) sec->noinstr = true; /* @@ -388,27 +441,29 @@ static int decode_instructions(struct objtool_file *file) if (!strcmp(sec->name, ".init.text") && !opts.module) sec->init = true; - for (offset = 0; offset < sec->sh.sh_size; offset += insn->len) { - insn = malloc(sizeof(*insn)); - if (!insn) { - WARN("malloc failed"); - return -1; + for (offset = 0; offset < sec_size(sec); offset += insn->len) { + if (!insns || idx == INSN_CHUNK_MAX) { + insns = calloc(INSN_CHUNK_SIZE, sizeof(*insn)); + if (!insns) { + ERROR_GLIBC("calloc"); + return -1; + } + idx = 0; + } else { + idx++; } - memset(insn, 0, sizeof(*insn)); - INIT_LIST_HEAD(&insn->alts); - INIT_LIST_HEAD(&insn->stack_ops); - INIT_LIST_HEAD(&insn->call_node); + insn = &insns[idx]; + insn->idx = idx; + INIT_LIST_HEAD(&insn->call_node); insn->sec = sec; insn->offset = offset; + insn->prev_len = prev_len; - ret = arch_decode_instruction(file, sec, offset, - sec->sh.sh_size - offset, - &insn->len, &insn->type, - &insn->immediate, - &insn->stack_ops); - if (ret) - goto err; + if (arch_decode_instruction(file, sec, offset, sec_size(sec) - offset, insn)) + return -1; + + prev_len = insn->len; /* * By default, "ud2" is a dead end unless otherwise @@ -419,35 +474,32 @@ static int decode_instructions(struct objtool_file *file) insn->dead_end = true; hash_add(file->insn_hash, &insn->hash, sec_offset_hash(sec, insn->offset)); - list_add_tail(&insn->list, &file->insn_list); nr_insns++; } - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->type != STT_NOTYPE && func->type != STT_FUNC) + sec_for_each_sym(sec, func) { + if (!is_notype_sym(func) && !is_func_sym(func)) continue; - if (func->offset == sec->sh.sh_size) { + if (func->offset == sec_size(sec)) { /* Heuristic: likely an "end" symbol */ - if (func->type == STT_NOTYPE) + if (is_notype_sym(func)) continue; - WARN("%s(): STT_FUNC at end of section", - func->name); + ERROR("%s(): STT_FUNC at end of section", func->name); return -1; } - if (func->return_thunk || func->alias != func) + if (func->embedded_insn || func->alias != func) continue; if (!find_insn(file, sec, func->offset)) { - WARN("%s(): can't find starting instruction", - func->name); + ERROR("%s(): can't find starting instruction", func->name); return -1; } sym_for_each_insn(file, func, insn) { insn->sym = func; - if (func->type == STT_FUNC && + if (is_func_sym(func) && insn->type == INSN_ENDBR && list_empty(&insn->call_node)) { if (insn->offset == func->offset) { @@ -465,10 +517,6 @@ static int decode_instructions(struct objtool_file *file) printf("nr_insns: %lu\n", nr_insns); return 0; - -err: - free(insn); - return ret; } /* @@ -478,7 +526,7 @@ static int add_pv_ops(struct objtool_file *file, const char *symname) { struct symbol *sym, *func; unsigned long off, end; - struct reloc *rel; + struct reloc *reloc; int idx; sym = find_symbol_by_name(file->elf, symname); @@ -488,19 +536,26 @@ static int add_pv_ops(struct objtool_file *file, const char *symname) off = sym->offset; end = off + sym->len; for (;;) { - rel = find_reloc_by_dest_range(file->elf, sym->sec, off, end - off); - if (!rel) + reloc = find_reloc_by_dest_range(file->elf, sym->sec, off, end - off); + if (!reloc) break; - func = rel->sym; - if (func->type == STT_SECTION) - func = find_symbol_by_offset(rel->sym->sec, rel->addend); + idx = (reloc_offset(reloc) - sym->offset) / sizeof(unsigned long); - idx = (rel->offset - sym->offset) / sizeof(unsigned long); + func = reloc->sym; + if (is_sec_sym(func)) + func = find_symbol_by_offset(reloc->sym->sec, + reloc_addend(reloc)); + if (!func) { + ERROR_FUNC(reloc->sym->sec, reloc_addend(reloc), + "can't find func at %s[%d]", symname, idx); + return -1; + } - objtool_pv_add(file, idx, func); + if (objtool_pv_add(file, idx, func)) + return -1; - off = rel->offset + 1; + off = reloc_offset(reloc) + 1; if (off > end) break; } @@ -534,114 +589,41 @@ static int init_pv_ops(struct objtool_file *file) return 0; nr = sym->len / sizeof(unsigned long); - file->pv_ops = calloc(sizeof(struct pv_state), nr); - if (!file->pv_ops) + file->pv_ops = calloc(nr, sizeof(struct pv_state)); + if (!file->pv_ops) { + ERROR_GLIBC("calloc"); return -1; + } for (idx = 0; idx < nr; idx++) INIT_LIST_HEAD(&file->pv_ops[idx].targets); - for (idx = 0; (pv_ops = pv_ops_tables[idx]); idx++) - add_pv_ops(file, pv_ops); + for (idx = 0; (pv_ops = pv_ops_tables[idx]); idx++) { + if (add_pv_ops(file, pv_ops)) + return -1; + } return 0; } -static struct instruction *find_last_insn(struct objtool_file *file, - struct section *sec) -{ - struct instruction *insn = NULL; - unsigned int offset; - unsigned int end = (sec->sh.sh_size > 10) ? sec->sh.sh_size - 10 : 0; - - for (offset = sec->sh.sh_size - 1; offset >= end && !insn; offset--) - insn = find_insn(file, sec, offset); - - return insn; -} - -/* - * Mark "ud2" instructions and manually annotated dead ends. - */ -static int add_dead_ends(struct objtool_file *file) +static bool is_livepatch_module(struct objtool_file *file) { struct section *sec; - struct reloc *reloc; - struct instruction *insn; - /* - * Check for manually annotated dead ends. - */ - sec = find_section_by_name(file->elf, ".rela.discard.unreachable"); - if (!sec) - goto reachable; - - list_for_each_entry(reloc, &sec->reloc_list, list) { - if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); - return -1; - } - insn = find_insn(file, reloc->sym->sec, reloc->addend); - if (insn) - insn = list_prev_entry(insn, list); - else if (reloc->addend == reloc->sym->sec->sh.sh_size) { - insn = find_last_insn(file, reloc->sym->sec); - if (!insn) { - WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); - return -1; - } - } else { - WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); - return -1; - } - - insn->dead_end = true; - } + if (!opts.module) + return false; -reachable: - /* - * These manually annotated reachable checks are needed for GCC 4.4, - * where the Linux unreachable() macro isn't supported. In that case - * GCC doesn't know the "ud2" is fatal, so it generates code as if it's - * not a dead end. - */ - sec = find_section_by_name(file->elf, ".rela.discard.reachable"); + sec = find_section_by_name(file->elf, ".modinfo"); if (!sec) - return 0; - - list_for_each_entry(reloc, &sec->reloc_list, list) { - if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); - return -1; - } - insn = find_insn(file, reloc->sym->sec, reloc->addend); - if (insn) - insn = list_prev_entry(insn, list); - else if (reloc->addend == reloc->sym->sec->sh.sh_size) { - insn = find_last_insn(file, reloc->sym->sec); - if (!insn) { - WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); - return -1; - } - } else { - WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); - return -1; - } - - insn->dead_end = false; - } + return false; - return 0; + return memmem(sec->data->d_buf, sec_size(sec), "\0livepatch=Y", 12); } static int create_static_call_sections(struct objtool_file *file) { - struct section *sec; struct static_call_site *site; + struct section *sec; struct instruction *insn; struct symbol *key_sym; char *key_name, *tmp; @@ -649,8 +631,14 @@ static int create_static_call_sections(struct objtool_file *file) sec = find_section_by_name(file->elf, ".static_call_sites"); if (sec) { - INIT_LIST_HEAD(&file->static_call_list); - WARN("file already has .static_call_sites section, skipping"); + /* + * Livepatch modules may have already extracted the static call + * site entries to take advantage of vmlinux static call + * privileges. + */ + if (!file->klp) + WARN("file already has .static_call_sites section, skipping"); + return 0; } @@ -661,33 +649,32 @@ static int create_static_call_sections(struct objtool_file *file) list_for_each_entry(insn, &file->static_call_list, call_node) idx++; - sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE, - sizeof(struct static_call_site), idx); + sec = elf_create_section_pair(file->elf, ".static_call_sites", + sizeof(*site), idx, idx * 2); if (!sec) return -1; + /* Allow modules to modify the low bits of static_call_site::key */ + sec->sh.sh_flags |= SHF_WRITE; + idx = 0; list_for_each_entry(insn, &file->static_call_list, call_node) { - site = (struct static_call_site *)sec->data->d_buf + idx; - memset(site, 0, sizeof(struct static_call_site)); - /* populate reloc for 'addr' */ - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(struct static_call_site), - R_X86_64_PC32, - insn->sec, insn->offset)) + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(*site), idx * 2, + insn->sec, insn->offset)) return -1; /* find key symbol */ - key_name = strdup(insn->call_dest->name); + key_name = strdup(insn_call_dest(insn)->name); if (!key_name) { - perror("strdup"); + ERROR_GLIBC("strdup"); return -1; } if (strncmp(key_name, STATIC_CALL_TRAMP_PREFIX_STR, STATIC_CALL_TRAMP_PREFIX_LEN)) { - WARN("static_call: trampoline name malformed: %s", key_name); + ERROR("static_call: trampoline name malformed: %s", key_name); return -1; } tmp = key_name + STATIC_CALL_TRAMP_PREFIX_LEN - STATIC_CALL_KEY_PREFIX_LEN; @@ -695,8 +682,8 @@ static int create_static_call_sections(struct objtool_file *file) key_sym = find_symbol_by_name(file->elf, tmp); if (!key_sym) { - if (!opts.module) { - WARN("static_call: can't find static_call_key symbol: %s", tmp); + if (!opts.module || file->klp) { + ERROR("static_call: can't find static_call_key symbol: %s", tmp); return -1; } @@ -709,15 +696,14 @@ static int create_static_call_sections(struct objtool_file *file) * trampoline address. This is fixed up in * static_call_add_module(). */ - key_sym = insn->call_dest; + key_sym = insn_call_dest(insn); } - free(key_name); /* populate reloc for 'key' */ - if (elf_add_reloc(file->elf, sec, - idx * sizeof(struct static_call_site) + 4, - R_X86_64_PC32, key_sym, - is_sibling_call(insn) * STATIC_CALL_SITE_TAIL)) + if (!elf_init_reloc_data_sym(file->elf, sec, + idx * sizeof(*site) + 4, + (idx * 2) + 1, key_sym, + is_sibling_call(insn) * STATIC_CALL_SITE_TAIL)) return -1; idx++; @@ -745,26 +731,18 @@ static int create_retpoline_sites_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".retpoline_sites", 0, - sizeof(int), idx); - if (!sec) { - WARN("elf_create_section: .retpoline_sites"); + sec = elf_create_section_pair(file->elf, ".retpoline_sites", + sizeof(int), idx, idx); + if (!sec) return -1; - } idx = 0; list_for_each_entry(insn, &file->retpoline_call_list, call_node) { - int *site = (int *)sec->data->d_buf + idx; - *site = 0; - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(int), - R_X86_64_PC32, - insn->sec, insn->offset)) { - WARN("elf_add_reloc_to_insn: .retpoline_sites"); + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(int), idx, + insn->sec, insn->offset)) return -1; - } idx++; } @@ -791,26 +769,18 @@ static int create_return_sites_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".return_sites", 0, - sizeof(int), idx); - if (!sec) { - WARN("elf_create_section: .return_sites"); + sec = elf_create_section_pair(file->elf, ".return_sites", + sizeof(int), idx, idx); + if (!sec) return -1; - } idx = 0; list_for_each_entry(insn, &file->return_thunk_list, call_node) { - int *site = (int *)sec->data->d_buf + idx; - *site = 0; - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(int), - R_X86_64_PC32, - insn->sec, insn->offset)) { - WARN("elf_add_reloc_to_insn: .return_sites"); + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(int), idx, + insn->sec, insn->offset)) return -1; - } idx++; } @@ -843,27 +813,32 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".ibt_endbr_seal", 0, - sizeof(int), idx); - if (!sec) { - WARN("elf_create_section: .ibt_endbr_seal"); + sec = elf_create_section_pair(file->elf, ".ibt_endbr_seal", + sizeof(int), idx, idx); + if (!sec) return -1; - } idx = 0; list_for_each_entry(insn, &file->endbr_list, call_node) { int *site = (int *)sec->data->d_buf + idx; + struct symbol *sym = insn->sym; *site = 0; - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(int), - R_X86_64_PC32, - insn->sec, insn->offset)) { - WARN("elf_add_reloc_to_insn: .ibt_endbr_seal"); + if (opts.module && sym && is_func_sym(sym) && + insn->offset == sym->offset && + (!strcmp(sym->name, "init_module") || + !strcmp(sym->name, "cleanup_module"))) { + ERROR("%s(): Magic init_module() function name is deprecated, use module_init(fn) instead", + sym->name); return -1; } + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(int), idx, + insn->sec, insn->offset)) + return -1; + idx++; } @@ -872,61 +847,46 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file) static int create_cfi_sections(struct objtool_file *file) { - struct section *sec, *s; + struct section *sec; struct symbol *sym; - unsigned int *loc; int idx; sec = find_section_by_name(file->elf, ".cfi_sites"); if (sec) { - INIT_LIST_HEAD(&file->call_list); WARN("file already has .cfi_sites section, skipping"); return 0; } idx = 0; - for_each_sec(file, s) { - if (!s->text) + for_each_sym(file->elf, sym) { + if (!is_func_sym(sym)) continue; - list_for_each_entry(sym, &s->symbol_list, list) { - if (sym->type != STT_FUNC) - continue; - - if (strncmp(sym->name, "__cfi_", 6)) - continue; + if (strncmp(sym->name, "__cfi_", 6)) + continue; - idx++; - } + idx++; } - sec = elf_create_section(file->elf, ".cfi_sites", 0, sizeof(unsigned int), idx); + sec = elf_create_section_pair(file->elf, ".cfi_sites", + sizeof(unsigned int), idx, idx); if (!sec) return -1; idx = 0; - for_each_sec(file, s) { - if (!s->text) + for_each_sym(file->elf, sym) { + if (!is_func_sym(sym)) continue; - list_for_each_entry(sym, &s->symbol_list, list) { - if (sym->type != STT_FUNC) - continue; - - if (strncmp(sym->name, "__cfi_", 6)) - continue; - - loc = (unsigned int *)sec->data->d_buf + idx; - memset(loc, 0, sizeof(unsigned int)); + if (strncmp(sym->name, "__cfi_", 6)) + continue; - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(unsigned int), - R_X86_64_PC32, - s, sym->offset)) - return -1; + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(unsigned int), idx, + sym->sec, sym->offset)) + return -1; - idx++; - } + idx++; } return 0; @@ -934,15 +894,20 @@ static int create_cfi_sections(struct objtool_file *file) static int create_mcount_loc_sections(struct objtool_file *file) { - int addrsize = elf_class_addrsize(file->elf); + size_t addr_size = elf_addr_size(file->elf); struct instruction *insn; struct section *sec; int idx; sec = find_section_by_name(file->elf, "__mcount_loc"); if (sec) { - INIT_LIST_HEAD(&file->mcount_loc_list); - WARN("file already has __mcount_loc section, skipping"); + /* + * Livepatch modules have already extracted their __mcount_loc + * entries to cover the !CONFIG_FTRACE_MCOUNT_USE_OBJTOOL case. + */ + if (!file->klp) + WARN("file already has __mcount_loc section, skipping"); + return 0; } @@ -953,25 +918,26 @@ static int create_mcount_loc_sections(struct objtool_file *file) list_for_each_entry(insn, &file->mcount_loc_list, call_node) idx++; - sec = elf_create_section(file->elf, "__mcount_loc", 0, addrsize, idx); + sec = elf_create_section_pair(file->elf, "__mcount_loc", addr_size, + idx, idx); if (!sec) return -1; - sec->sh.sh_addralign = addrsize; + sec->sh.sh_addralign = addr_size; idx = 0; list_for_each_entry(insn, &file->mcount_loc_list, call_node) { - void *loc; - loc = sec->data->d_buf + idx; - memset(loc, 0, addrsize); + struct reloc *reloc; - if (elf_add_reloc_to_insn(file->elf, sec, idx, - addrsize == sizeof(u64) ? R_ABS64 : R_ABS32, - insn->sec, insn->offset)) + reloc = elf_init_reloc_text_sym(file->elf, sec, idx * addr_size, idx, + insn->sec, insn->offset); + if (!reloc) return -1; - idx += addrsize; + set_reloc_type(file->elf, reloc, addr_size == 8 ? R_ABS64 : R_ABS32); + + idx++; } return 0; @@ -981,12 +947,10 @@ static int create_direct_call_sections(struct objtool_file *file) { struct instruction *insn; struct section *sec; - unsigned int *loc; int idx; sec = find_section_by_name(file->elf, ".call_sites"); if (sec) { - INIT_LIST_HEAD(&file->call_list); WARN("file already has .call_sites section, skipping"); return 0; } @@ -998,62 +962,115 @@ static int create_direct_call_sections(struct objtool_file *file) list_for_each_entry(insn, &file->call_list, call_node) idx++; - sec = elf_create_section(file->elf, ".call_sites", 0, sizeof(unsigned int), idx); + sec = elf_create_section_pair(file->elf, ".call_sites", + sizeof(unsigned int), idx, idx); if (!sec) return -1; idx = 0; list_for_each_entry(insn, &file->call_list, call_node) { - loc = (unsigned int *)sec->data->d_buf + idx; - memset(loc, 0, sizeof(unsigned int)); + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(unsigned int), idx, + insn->sec, insn->offset)) + return -1; - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(unsigned int), - R_X86_64_PC32, - insn->sec, insn->offset)) + idx++; + } + + return 0; +} + +#ifdef BUILD_KLP +static int create_sym_checksum_section(struct objtool_file *file) +{ + struct section *sec; + struct symbol *sym; + unsigned int idx = 0; + struct sym_checksum *checksum; + size_t entsize = sizeof(struct sym_checksum); + + sec = find_section_by_name(file->elf, ".discard.sym_checksum"); + if (sec) { + if (!opts.dryrun) + WARN("file already has .discard.sym_checksum section, skipping"); + + return 0; + } + + for_each_sym(file->elf, sym) + if (sym->csum.checksum) + idx++; + + if (!idx) + return 0; + + sec = elf_create_section_pair(file->elf, ".discard.sym_checksum", entsize, + idx, idx); + if (!sec) + return -1; + + idx = 0; + for_each_sym(file->elf, sym) { + if (!sym->csum.checksum) + continue; + + if (!elf_init_reloc(file->elf, sec->rsec, idx, idx * entsize, + sym, 0, R_TEXT64)) return -1; + checksum = (struct sym_checksum *)sec->data->d_buf + idx; + checksum->addr = 0; /* reloc */ + checksum->checksum = sym->csum.checksum; + + mark_sec_changed(file->elf, sec, true); + idx++; } return 0; } +#else +static int create_sym_checksum_section(struct objtool_file *file) { return -EINVAL; } +#endif /* * Warnings shouldn't be reported for ignored functions. */ -static void add_ignores(struct objtool_file *file) +static int add_ignores(struct objtool_file *file) { - struct instruction *insn; - struct section *sec; + struct section *rsec; struct symbol *func; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard"); - if (!sec) - return; + rsec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard"); + if (!rsec) + return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { switch (reloc->sym->type) { case STT_FUNC: func = reloc->sym; break; case STT_SECTION: - func = find_func_by_offset(reloc->sym->sec, reloc->addend); + func = find_func_by_offset(reloc->sym->sec, reloc_addend(reloc)); if (!func) continue; break; default: - WARN("unexpected relocation symbol type in %s: %d", sec->name, reloc->sym->type); - continue; + ERROR("unexpected relocation symbol type in %s: %d", + rsec->name, reloc->sym->type); + return -1; } - func_for_each_insn(file, func, insn) - insn->ignore = true; + func->ignore = true; + if (func->cfunc) + func->cfunc->ignore = true; } + + return 0; } /* @@ -1186,6 +1203,8 @@ static const char *uaccess_safe_builtin[] = { "__tsan_atomic64_compare_exchange_val", "__tsan_atomic_thread_fence", "__tsan_atomic_signal_fence", + "__tsan_unaligned_read16", + "__tsan_unaligned_write16", /* KCOV */ "write_comp_data", "check_kcov_mode", @@ -1201,6 +1220,8 @@ static const char *uaccess_safe_builtin[] = { "__sanitizer_cov_trace_switch", /* KMSAN */ "kmsan_copy_to_user", + "kmsan_disable_current", + "kmsan_enable_current", "kmsan_report", "kmsan_unpoison_entry_regs", "kmsan_unpoison_memory", @@ -1224,15 +1245,21 @@ static const char *uaccess_safe_builtin[] = { "__ubsan_handle_type_mismatch", "__ubsan_handle_type_mismatch_v1", "__ubsan_handle_shift_out_of_bounds", + "__ubsan_handle_load_invalid_value", + /* KSTACK_ERASE */ + "__sanitizer_cov_stack_depth", + /* TRACE_BRANCH_PROFILING */ + "ftrace_likely_update", + /* STACKPROTECTOR */ + "__stack_chk_fail", /* misc */ "csum_partial_copy_generic", "copy_mc_fragile", "copy_mc_fragile_handle_tail", "copy_mc_enhanced_fast_string", - "ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */ - "clear_user_erms", - "clear_user_rep_good", - "clear_user_original", + "rep_stos_alternative", + "rep_movs_alternative", + "__copy_user_nocache", NULL }; @@ -1254,107 +1281,80 @@ static void add_uaccess_safe(struct objtool_file *file) } /* - * FIXME: For now, just ignore any alternatives which add retpolines. This is - * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline. - * But it at least allows objtool to understand the control flow *around* the - * retpoline. + * Symbols that replace INSN_CALL_DYNAMIC, every (tail) call to such a symbol + * will be added to the .retpoline_sites section. */ -static int add_ignore_alternatives(struct objtool_file *file) -{ - struct section *sec; - struct reloc *reloc; - struct instruction *insn; - - sec = find_section_by_name(file->elf, ".rela.discard.ignore_alts"); - if (!sec) - return 0; - - list_for_each_entry(reloc, &sec->reloc_list, list) { - if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); - return -1; - } - - insn = find_insn(file, reloc->sym->sec, reloc->addend); - if (!insn) { - WARN("bad .discard.ignore_alts entry"); - return -1; - } - - insn->ignore_alts = true; - } - - return 0; -} - __weak bool arch_is_retpoline(struct symbol *sym) { return false; } +/* + * Symbols that replace INSN_RETURN, every (tail) call to such a symbol + * will be added to the .return_sites section. + */ __weak bool arch_is_rethunk(struct symbol *sym) { return false; } -#define NEGATIVE_RELOC ((void *)-1L) +/* + * Symbols that are embedded inside other instructions, because sometimes crazy + * code exists. These are mostly ignored for validation purposes. + */ +__weak bool arch_is_embedded_insn(struct symbol *sym) +{ + return false; +} static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn) { - if (insn->reloc == NEGATIVE_RELOC) + struct reloc *reloc; + + if (insn->no_reloc) return NULL; - if (!insn->reloc) { - if (!file) - return NULL; + if (!file) + return NULL; - insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); - if (!insn->reloc) { - insn->reloc = NEGATIVE_RELOC; - return NULL; - } + reloc = find_reloc_by_dest_range(file->elf, insn->sec, + insn->offset, insn->len); + if (!reloc) { + insn->no_reloc = 1; + return NULL; } - return insn->reloc; + return reloc; } static void remove_insn_ops(struct instruction *insn) { - struct stack_op *op, *tmp; + struct stack_op *op, *next; - list_for_each_entry_safe(op, tmp, &insn->stack_ops, list) { - list_del(&op->list); + for (op = insn->stack_ops; op; op = next) { + next = op->next; free(op); } + insn->stack_ops = NULL; } -static void annotate_call_site(struct objtool_file *file, +static int annotate_call_site(struct objtool_file *file, struct instruction *insn, bool sibling) { struct reloc *reloc = insn_reloc(file, insn); - struct symbol *sym = insn->call_dest; + struct symbol *sym = insn_call_dest(insn); if (!sym) sym = reloc->sym; - /* - * Alternative replacement code is just template code which is - * sometimes copied to the original instruction. For now, don't - * annotate it. (In the future we might consider annotating the - * original instruction if/when it ever makes sense to do so.) - */ - if (!strcmp(insn->sec->name, ".altinstr_replacement")) - return; - if (sym->static_call_tramp) { list_add_tail(&insn->call_node, &file->static_call_list); - return; + return 0; } if (sym->retpoline_thunk) { list_add_tail(&insn->call_node, &file->retpoline_call_list); - return; + return 0; } /* @@ -1363,15 +1363,15 @@ static void annotate_call_site(struct objtool_file *file, * noinstr text. */ if (opts.hack_noinstr && insn->sec->noinstr && sym->profiling_func) { - if (reloc) { - reloc->type = R_NONE; - elf_write_reloc(file->elf, reloc); - } + if (reloc) + set_reloc_type(file->elf, reloc, R_NONE); - elf_write_insn(file->elf, insn->sec, - insn->offset, insn->len, - sibling ? arch_ret_insn(insn->len) - : arch_nop_insn(insn->len)); + if (elf_write_insn(file->elf, insn->sec, + insn->offset, insn->len, + sibling ? arch_ret_insn(insn->len) + : arch_nop_insn(insn->len))) { + return -1; + } insn->type = sibling ? INSN_RETURN : INSN_NOP; @@ -1385,42 +1385,45 @@ static void annotate_call_site(struct objtool_file *file, insn->retpoline_safe = true; } - return; + return 0; } if (opts.mcount && sym->fentry) { if (sibling) - WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset); + WARN_INSN(insn, "tail call to __fentry__ !?!?"); if (opts.mnop) { - if (reloc) { - reloc->type = R_NONE; - elf_write_reloc(file->elf, reloc); - } + if (reloc) + set_reloc_type(file->elf, reloc, R_NONE); - elf_write_insn(file->elf, insn->sec, - insn->offset, insn->len, - arch_nop_insn(insn->len)); + if (elf_write_insn(file->elf, insn->sec, + insn->offset, insn->len, + arch_nop_insn(insn->len))) { + return -1; + } insn->type = INSN_NOP; } list_add_tail(&insn->call_node, &file->mcount_loc_list); - return; + return 0; } - if (insn->type == INSN_CALL && !insn->sec->init) + if (insn->type == INSN_CALL && !insn->sec->init && + !insn->_call_dest->embedded_insn) list_add_tail(&insn->call_node, &file->call_list); if (!sibling && dead_end_function(file, sym)) insn->dead_end = true; + + return 0; } -static void add_call_dest(struct objtool_file *file, struct instruction *insn, +static int add_call_dest(struct objtool_file *file, struct instruction *insn, struct symbol *dest, bool sibling) { - insn->call_dest = dest; + insn->_call_dest = dest; if (!dest) - return; + return 0; /* * Whatever stack impact regular CALLs have, should be undone @@ -1431,10 +1434,10 @@ static void add_call_dest(struct objtool_file *file, struct instruction *insn, */ remove_insn_ops(insn); - annotate_call_site(file, insn, sibling); + return annotate_call_site(file, insn, sibling); } -static void add_retpoline_call(struct objtool_file *file, struct instruction *insn) +static int add_retpoline_call(struct objtool_file *file, struct instruction *insn) { /* * Retpoline calls/jumps are really dynamic calls/jumps in disguise, @@ -1451,7 +1454,7 @@ static void add_retpoline_call(struct objtool_file *file, struct instruction *in insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL; break; default: - return; + return 0; } insn->retpoline_safe = true; @@ -1465,7 +1468,7 @@ static void add_retpoline_call(struct objtool_file *file, struct instruction *in */ remove_insn_ops(insn); - annotate_call_site(file, insn, false); + return annotate_call_site(file, insn, false); } static void add_return_call(struct objtool_file *file, struct instruction *insn, bool add) @@ -1482,9 +1485,14 @@ static void add_return_call(struct objtool_file *file, struct instruction *insn, } static bool is_first_func_insn(struct objtool_file *file, - struct instruction *insn, struct symbol *sym) + struct instruction *insn) { - if (insn->offset == sym->offset) + struct symbol *func = insn_func(insn); + + if (!func) + return false; + + if (insn->offset == func->offset) return true; /* Allow direct CALL/JMP past ENDBR */ @@ -1492,7 +1500,7 @@ static bool is_first_func_insn(struct objtool_file *file, struct instruction *prev = prev_insn_same_sym(file, insn); if (prev && prev->type == INSN_ENDBR && - insn->offset == sym->offset + prev->len) + insn->offset == func->offset + prev->len) return true; } @@ -1500,42 +1508,23 @@ static bool is_first_func_insn(struct objtool_file *file, } /* - * A sibling call is a tail-call to another symbol -- to differentiate from a - * recursive tail-call which is to the same symbol. - */ -static bool jump_is_sibling_call(struct objtool_file *file, - struct instruction *from, struct instruction *to) -{ - struct symbol *fs = from->sym; - struct symbol *ts = to->sym; - - /* Not a sibling call if from/to a symbol hole */ - if (!fs || !ts) - return false; - - /* Not a sibling call if not targeting the start of a symbol. */ - if (!is_first_func_insn(file, to, ts)) - return false; - - /* Disallow sibling calls into STT_NOTYPE */ - if (ts->type == STT_NOTYPE) - return false; - - /* Must not be self to be a sibling */ - return fs->pfunc != ts->pfunc; -} - -/* * Find the destination instructions for all jumps. */ static int add_jump_destinations(struct objtool_file *file) { - struct instruction *insn, *jump_dest; + struct instruction *insn; struct reloc *reloc; - struct section *dest_sec; - unsigned long dest_off; for_each_insn(file, insn) { + struct symbol *func = insn_func(insn); + struct instruction *dest_insn; + struct section *dest_sec; + struct symbol *dest_sym; + unsigned long dest_off; + + if (!is_static_jump(insn)) + continue; + if (insn->jump_dest) { /* * handle_group_alt() may have previously set @@ -1543,99 +1532,106 @@ static int add_jump_destinations(struct objtool_file *file) */ continue; } - if (!is_static_jump(insn)) - continue; reloc = insn_reloc(file, insn); if (!reloc) { dest_sec = insn->sec; dest_off = arch_jump_destination(insn); - } else if (reloc->sym->type == STT_SECTION) { - dest_sec = reloc->sym->sec; - dest_off = arch_dest_reloc_offset(reloc->addend); - } else if (reloc->sym->retpoline_thunk) { - add_retpoline_call(file, insn); - continue; - } else if (reloc->sym->return_thunk) { - add_return_call(file, insn, true); - continue; - } else if (insn_func(insn)) { - /* - * External sibling call or internal sibling call with - * STT_FUNC reloc. - */ - add_call_dest(file, insn, reloc->sym, true); - continue; - } else if (reloc->sym->sec->idx) { - dest_sec = reloc->sym->sec; - dest_off = reloc->sym->sym.st_value + - arch_dest_reloc_offset(reloc->addend); + dest_sym = dest_sec->sym; } else { - /* non-func asm code jumping to another file */ - continue; + dest_sym = reloc->sym; + if (is_undef_sym(dest_sym)) { + if (dest_sym->retpoline_thunk) { + if (add_retpoline_call(file, insn)) + return -1; + continue; + } + + if (dest_sym->return_thunk) { + add_return_call(file, insn, true); + continue; + } + + /* External symbol */ + if (func) { + /* External sibling call */ + if (add_call_dest(file, insn, dest_sym, true)) + return -1; + continue; + } + + /* Non-func asm code jumping to external symbol */ + continue; + } + + dest_sec = dest_sym->sec; + dest_off = dest_sym->offset + arch_insn_adjusted_addend(insn, reloc); } - jump_dest = find_insn(file, dest_sec, dest_off); - if (!jump_dest) { + dest_insn = find_insn(file, dest_sec, dest_off); + if (!dest_insn) { struct symbol *sym = find_symbol_by_offset(dest_sec, dest_off); /* - * This is a special case for zen_untrain_ret(). - * It jumps to __x86_return_thunk(), but objtool - * can't find the thunk's starting RET - * instruction, because the RET is also in the - * middle of another instruction. Objtool only - * knows about the outer instruction. + * retbleed_untrain_ret() jumps to + * __x86_return_thunk(), but objtool can't find + * the thunk's starting RET instruction, + * because the RET is also in the middle of + * another instruction. Objtool only knows + * about the outer instruction. */ - if (sym && sym->return_thunk) { + if (sym && sym->embedded_insn) { add_return_call(file, insn, false); continue; } - WARN_FUNC("can't find jump dest instruction at %s+0x%lx", - insn->sec, insn->offset, dest_sec->name, - dest_off); + /* + * GCOV/KCOV dead code can jump to the end of + * the function/section. + */ + if (file->ignore_unreachables && func && + dest_sec == insn->sec && + dest_off == func->offset + func->len) + continue; + + ERROR_INSN(insn, "can't find jump dest instruction at %s", + offstr(dest_sec, dest_off)); return -1; } - /* - * Cross-function jump. - */ - if (insn_func(insn) && insn_func(jump_dest) && - insn_func(insn) != insn_func(jump_dest)) { + if (!dest_sym || is_sec_sym(dest_sym)) { + dest_sym = dest_insn->sym; + if (!dest_sym) + goto set_jump_dest; + } - /* - * For GCC 8+, create parent/child links for any cold - * subfunctions. This is _mostly_ redundant with a - * similar initialization in read_symbols(). - * - * If a function has aliases, we want the *first* such - * function in the symbol table to be the subfunction's - * parent. In that case we overwrite the - * initialization done in read_symbols(). - * - * However this code can't completely replace the - * read_symbols() code because this doesn't detect the - * case where the parent function's only reference to a - * subfunction is through a jump table. - */ - if (!strstr(insn_func(insn)->name, ".cold") && - strstr(insn_func(jump_dest)->name, ".cold")) { - insn_func(insn)->cfunc = insn_func(jump_dest); - insn_func(jump_dest)->pfunc = insn_func(insn); - } + if (dest_sym->retpoline_thunk && dest_insn->offset == dest_sym->offset) { + if (add_retpoline_call(file, insn)) + return -1; + continue; } - if (jump_is_sibling_call(file, insn, jump_dest)) { - /* - * Internal sibling call without reloc or with - * STT_SECTION reloc. - */ - add_call_dest(file, insn, insn_func(jump_dest), true); + if (dest_sym->return_thunk && dest_insn->offset == dest_sym->offset) { + add_return_call(file, insn, true); continue; } - insn->jump_dest = jump_dest; + if (!insn->sym || insn->sym->pfunc == dest_sym->pfunc) + goto set_jump_dest; + + /* + * Internal cross-function jump. + */ + + if (is_first_func_insn(file, dest_insn)) { + /* Internal sibling call */ + if (add_call_dest(file, insn, dest_sym, true)) + return -1; + continue; + } + +set_jump_dest: + insn->jump_dest = dest_insn; } return 0; @@ -1663,6 +1659,7 @@ static int add_call_destinations(struct objtool_file *file) struct reloc *reloc; for_each_insn(file, insn) { + struct symbol *func = insn_func(insn); if (insn->type != INSN_CALL) continue; @@ -1671,40 +1668,42 @@ static int add_call_destinations(struct objtool_file *file) dest_off = arch_jump_destination(insn); dest = find_call_destination(insn->sec, dest_off); - add_call_dest(file, insn, dest, false); + if (add_call_dest(file, insn, dest, false)) + return -1; - if (insn->ignore) + if (func && func->ignore) continue; - if (!insn->call_dest) { - WARN_FUNC("unannotated intra-function call", insn->sec, insn->offset); + if (!insn_call_dest(insn)) { + ERROR_INSN(insn, "unannotated intra-function call"); return -1; } - if (insn_func(insn) && insn->call_dest->type != STT_FUNC) { - WARN_FUNC("unsupported call to non-function", - insn->sec, insn->offset); + if (func && !is_func_sym(insn_call_dest(insn))) { + ERROR_INSN(insn, "unsupported call to non-function"); return -1; } - } else if (reloc->sym->type == STT_SECTION) { - dest_off = arch_dest_reloc_offset(reloc->addend); + } else if (is_sec_sym(reloc->sym)) { + dest_off = arch_insn_adjusted_addend(insn, reloc); dest = find_call_destination(reloc->sym->sec, dest_off); if (!dest) { - WARN_FUNC("can't find call dest symbol at %s+0x%lx", - insn->sec, insn->offset, - reloc->sym->sec->name, - dest_off); + ERROR_INSN(insn, "can't find call dest symbol at %s+0x%lx", + reloc->sym->sec->name, dest_off); return -1; } - add_call_dest(file, insn, dest, false); + if (add_call_dest(file, insn, dest, false)) + return -1; } else if (reloc->sym->retpoline_thunk) { - add_retpoline_call(file, insn); + if (add_retpoline_call(file, insn)) + return -1; - } else - add_call_dest(file, insn, reloc->sym, false); + } else { + if (add_call_dest(file, insn, reloc->sym, false)) + return -1; + } } return 0; @@ -1719,40 +1718,55 @@ static int handle_group_alt(struct objtool_file *file, struct instruction *orig_insn, struct instruction **new_insn) { - struct instruction *last_orig_insn, *last_new_insn = NULL, *insn, *nop = NULL; + struct instruction *last_new_insn = NULL, *insn, *nop = NULL; struct alt_group *orig_alt_group, *new_alt_group; unsigned long dest_off; - - orig_alt_group = malloc(sizeof(*orig_alt_group)); + orig_alt_group = orig_insn->alt_group; if (!orig_alt_group) { - WARN("malloc failed"); - return -1; - } - orig_alt_group->cfi = calloc(special_alt->orig_len, - sizeof(struct cfi_state *)); - if (!orig_alt_group->cfi) { - WARN("calloc failed"); - return -1; - } + struct instruction *last_orig_insn = NULL; - last_orig_insn = NULL; - insn = orig_insn; - sec_for_each_insn_from(file, insn) { - if (insn->offset >= special_alt->orig_off + special_alt->orig_len) - break; + orig_alt_group = calloc(1, sizeof(*orig_alt_group)); + if (!orig_alt_group) { + ERROR_GLIBC("calloc"); + return -1; + } + orig_alt_group->cfi = calloc(special_alt->orig_len, + sizeof(struct cfi_state *)); + if (!orig_alt_group->cfi) { + ERROR_GLIBC("calloc"); + return -1; + } - insn->alt_group = orig_alt_group; - last_orig_insn = insn; - } - orig_alt_group->orig_group = NULL; - orig_alt_group->first_insn = orig_insn; - orig_alt_group->last_insn = last_orig_insn; + insn = orig_insn; + sec_for_each_insn_from(file, insn) { + if (insn->offset >= special_alt->orig_off + special_alt->orig_len) + break; + insn->alt_group = orig_alt_group; + last_orig_insn = insn; + } + orig_alt_group->orig_group = NULL; + orig_alt_group->first_insn = orig_insn; + orig_alt_group->last_insn = last_orig_insn; + orig_alt_group->nop = NULL; + orig_alt_group->ignore = orig_insn->ignore_alts; + orig_alt_group->feature = 0; + } else { + if (orig_alt_group->last_insn->offset + orig_alt_group->last_insn->len - + orig_alt_group->first_insn->offset != special_alt->orig_len) { + ERROR_INSN(orig_insn, "weirdly overlapping alternative! %ld != %d", + orig_alt_group->last_insn->offset + + orig_alt_group->last_insn->len - + orig_alt_group->first_insn->offset, + special_alt->orig_len); + return -1; + } + } - new_alt_group = malloc(sizeof(*new_alt_group)); + new_alt_group = calloc(1, sizeof(*new_alt_group)); if (!new_alt_group) { - WARN("malloc failed"); + ERROR_GLIBC("calloc"); return -1; } @@ -1764,14 +1778,12 @@ static int handle_group_alt(struct objtool_file *file, * instruction affects the stack, the instruction after it (the * nop) will propagate the new state to the shared CFI array. */ - nop = malloc(sizeof(*nop)); + nop = calloc(1, sizeof(*nop)); if (!nop) { - WARN("malloc failed"); + ERROR_GLIBC("calloc"); return -1; } memset(nop, 0, sizeof(*nop)); - INIT_LIST_HEAD(&nop->alts); - INIT_LIST_HEAD(&nop->stack_ops); nop->sec = special_alt->new_sec; nop->offset = special_alt->new_off + special_alt->new_len; @@ -1779,7 +1791,7 @@ static int handle_group_alt(struct objtool_file *file, nop->type = INSN_NOP; nop->sym = orig_insn->sym; nop->alt_group = new_alt_group; - nop->ignore = orig_insn->ignore_alts; + nop->fake = 1; } if (!special_alt->new_len) { @@ -1796,7 +1808,6 @@ static int handle_group_alt(struct objtool_file *file, last_new_insn = insn; - insn->ignore = orig_insn->ignore_alts; insn->sym = orig_insn->sym; insn->alt_group = new_alt_group; @@ -1812,8 +1823,7 @@ static int handle_group_alt(struct objtool_file *file, if (alt_reloc && arch_pc_relative_reloc(alt_reloc) && !arch_support_alt_relocation(special_alt, insn, alt_reloc)) { - WARN_FUNC("unsupported relocation in alternatives section", - insn->sec, insn->offset); + ERROR_INSN(insn, "unsupported relocation in alternatives section"); return -1; } @@ -1825,28 +1835,28 @@ static int handle_group_alt(struct objtool_file *file, dest_off = arch_jump_destination(insn); if (dest_off == special_alt->new_off + special_alt->new_len) { - insn->jump_dest = next_insn_same_sec(file, last_orig_insn); + insn->jump_dest = next_insn_same_sec(file, orig_alt_group->last_insn); if (!insn->jump_dest) { - WARN_FUNC("can't find alternative jump destination", - insn->sec, insn->offset); + ERROR_INSN(insn, "can't find alternative jump destination"); return -1; } } } if (!last_new_insn) { - WARN_FUNC("can't find last new alternative instruction", - special_alt->new_sec, special_alt->new_off); + ERROR_FUNC(special_alt->new_sec, special_alt->new_off, + "can't find last new alternative instruction"); return -1; } - if (nop) - list_add(&nop->list, &last_new_insn->list); end: new_alt_group->orig_group = orig_alt_group; new_alt_group->first_insn = *new_insn; - new_alt_group->last_insn = nop ? : last_new_insn; + new_alt_group->last_insn = last_new_insn; + new_alt_group->nop = nop; + new_alt_group->ignore = (*new_insn)->ignore_alts; new_alt_group->cfi = orig_alt_group->cfi; + new_alt_group->feature = special_alt->feature; return 0; } @@ -1863,21 +1873,22 @@ static int handle_jump_alt(struct objtool_file *file, if (orig_insn->type != INSN_JUMP_UNCONDITIONAL && orig_insn->type != INSN_NOP) { - WARN_FUNC("unsupported instruction at jump label", - orig_insn->sec, orig_insn->offset); + ERROR_INSN(orig_insn, "unsupported instruction at jump label"); return -1; } if (opts.hack_jump_label && special_alt->key_addend & 2) { struct reloc *reloc = insn_reloc(file, orig_insn); - if (reloc) { - reloc->type = R_NONE; - elf_write_reloc(file->elf, reloc); + if (reloc) + set_reloc_type(file->elf, reloc, R_NONE); + + if (elf_write_insn(file->elf, orig_insn->sec, + orig_insn->offset, orig_insn->len, + arch_nop_insn(orig_insn->len))) { + return -1; } - elf_write_insn(file->elf, orig_insn->sec, - orig_insn->offset, orig_insn->len, - arch_nop_insn(orig_insn->len)); + orig_insn->type = INSN_NOP; } @@ -1895,7 +1906,7 @@ static int handle_jump_alt(struct objtool_file *file, else file->jl_long++; - *new_insn = list_next_entry(orig_insn, list); + *new_insn = next_insn_same_sec(file, orig_insn); return 0; } @@ -1910,22 +1921,21 @@ static int add_special_section_alts(struct objtool_file *file) struct list_head special_alts; struct instruction *orig_insn, *new_insn; struct special_alt *special_alt, *tmp; + enum alternative_type alt_type; struct alternative *alt; - int ret; + struct alternative *a; - ret = special_get_alts(file->elf, &special_alts); - if (ret) - return ret; + if (special_get_alts(file->elf, &special_alts)) + return -1; list_for_each_entry_safe(special_alt, tmp, &special_alts, list) { orig_insn = find_insn(file, special_alt->orig_sec, special_alt->orig_off); if (!orig_insn) { - WARN_FUNC("special: can't find orig instruction", - special_alt->orig_sec, special_alt->orig_off); - ret = -1; - goto out; + ERROR_FUNC(special_alt->orig_sec, special_alt->orig_off, + "special: can't find orig instruction"); + return -1; } new_insn = NULL; @@ -1933,43 +1943,53 @@ static int add_special_section_alts(struct objtool_file *file) new_insn = find_insn(file, special_alt->new_sec, special_alt->new_off); if (!new_insn) { - WARN_FUNC("special: can't find new instruction", - special_alt->new_sec, - special_alt->new_off); - ret = -1; - goto out; + ERROR_FUNC(special_alt->new_sec, special_alt->new_off, + "special: can't find new instruction"); + return -1; } } if (special_alt->group) { if (!special_alt->orig_len) { - WARN_FUNC("empty alternative entry", - orig_insn->sec, orig_insn->offset); + ERROR_INSN(orig_insn, "empty alternative entry"); continue; } - ret = handle_group_alt(file, special_alt, orig_insn, - &new_insn); - if (ret) - goto out; + if (handle_group_alt(file, special_alt, orig_insn, &new_insn)) + return -1; + + alt_type = ALT_TYPE_INSTRUCTIONS; + } else if (special_alt->jump_or_nop) { - ret = handle_jump_alt(file, special_alt, orig_insn, - &new_insn); - if (ret) - goto out; + if (handle_jump_alt(file, special_alt, orig_insn, &new_insn)) + return -1; + + alt_type = ALT_TYPE_JUMP_TABLE; + } else { + alt_type = ALT_TYPE_EX_TABLE; } - alt = malloc(sizeof(*alt)); + alt = calloc(1, sizeof(*alt)); if (!alt) { - WARN("malloc failed"); - ret = -1; - goto out; + ERROR_GLIBC("calloc"); + return -1; } alt->insn = new_insn; - alt->skip_orig = special_alt->skip_orig; - orig_insn->ignore_alts |= special_alt->skip_alt; - list_add_tail(&alt->list, &orig_insn->alts); + alt->type = alt_type; + alt->next = NULL; + + /* + * Store alternatives in the same order they have been + * defined. + */ + if (!orig_insn->alts) { + orig_insn->alts = alt; + } else { + for (a = orig_insn->alts; a->next; a = a->next) + ; + a->next = alt; + } list_del(&special_alt->list); free(special_alt); @@ -1981,39 +2001,56 @@ static int add_special_section_alts(struct objtool_file *file) printf("long:\t%ld\t%ld\n", file->jl_nop_long, file->jl_long); } -out: - return ret; + return 0; } -static int add_jump_table(struct objtool_file *file, struct instruction *insn, - struct reloc *table) +__weak unsigned long arch_jump_table_sym_offset(struct reloc *reloc, struct reloc *table) { - struct reloc *reloc = table; - struct instruction *dest_insn; - struct alternative *alt; + return reloc->sym->offset + reloc_addend(reloc); +} + +static int add_jump_table(struct objtool_file *file, struct instruction *insn) +{ + unsigned long table_size = insn_jump_table_size(insn); struct symbol *pfunc = insn_func(insn)->pfunc; + struct reloc *table = insn_jump_table(insn); + struct instruction *dest_insn; unsigned int prev_offset = 0; + struct reloc *reloc = table; + struct alternative *alt; + unsigned long sym_offset; /* * Each @reloc is a switch table relocation which points to the target * instruction. */ - list_for_each_entry_from(reloc, &table->sec->reloc_list, list) { + for_each_reloc_from(table->sec, reloc) { /* Check for the end of the table: */ - if (reloc != table && reloc->jump_table_start) + if (table_size && reloc_offset(reloc) - reloc_offset(table) >= table_size) + break; + if (reloc != table && is_jump_table(reloc)) break; /* Make sure the table entries are consecutive: */ - if (prev_offset && reloc->offset != prev_offset + 8) + if (prev_offset && reloc_offset(reloc) != prev_offset + arch_reloc_size(reloc)) break; + sym_offset = arch_jump_table_sym_offset(reloc, table); + /* Detect function pointers from contiguous objects: */ - if (reloc->sym->sec == pfunc->sec && - reloc->addend == pfunc->offset) + if (reloc->sym->sec == pfunc->sec && sym_offset == pfunc->offset) break; - dest_insn = find_insn(file, reloc->sym->sec, reloc->addend); + /* + * Clang sometimes leaves dangling unused jump table entries + * which point to the end of the function. Ignore them. + */ + if (reloc->sym->sec == pfunc->sec && + sym_offset == pfunc->offset + pfunc->len) + goto next; + + dest_insn = find_insn(file, reloc->sym->sec, sym_offset); if (!dest_insn) break; @@ -2021,20 +2058,21 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, if (!insn_func(dest_insn) || insn_func(dest_insn)->pfunc != pfunc) break; - alt = malloc(sizeof(*alt)); + alt = calloc(1, sizeof(*alt)); if (!alt) { - WARN("malloc failed"); + ERROR_GLIBC("calloc"); return -1; } alt->insn = dest_insn; - list_add_tail(&alt->list, &insn->alts); - prev_offset = reloc->offset; + alt->next = insn->alts; + insn->alts = alt; +next: + prev_offset = reloc_offset(reloc); } if (!prev_offset) { - WARN_FUNC("can't find switch jump table", - insn->sec, insn->offset); + ERROR_INSN(insn, "can't find switch jump table"); return -1; } @@ -2045,12 +2083,13 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, * find_jump_table() - Given a dynamic jump, find the switch jump table * associated with it. */ -static struct reloc *find_jump_table(struct objtool_file *file, - struct symbol *func, - struct instruction *insn) +static void find_jump_table(struct objtool_file *file, struct symbol *func, + struct instruction *insn) { struct reloc *table_reloc; struct instruction *dest_insn, *orig_insn = insn; + unsigned long table_size; + unsigned long sym_offset; /* * Backward search using the @first_jump_src links, these help avoid @@ -2069,19 +2108,24 @@ static struct reloc *find_jump_table(struct objtool_file *file, insn->jump_dest && (insn->jump_dest->offset <= insn->offset || insn->jump_dest->offset > orig_insn->offset)) - break; + break; - table_reloc = arch_find_switch_table(file, insn); + table_reloc = arch_find_switch_table(file, insn, &table_size); if (!table_reloc) continue; - dest_insn = find_insn(file, table_reloc->sym->sec, table_reloc->addend); + + sym_offset = table_reloc->sym->offset + reloc_addend(table_reloc); + + dest_insn = find_insn(file, table_reloc->sym->sec, sym_offset); if (!dest_insn || !insn_func(dest_insn) || insn_func(dest_insn)->pfunc != func) continue; - return table_reloc; - } + set_jump_table(table_reloc); + orig_insn->_jump_table = table_reloc; + orig_insn->_jump_table_size = table_size; - return NULL; + break; + } } /* @@ -2092,7 +2136,6 @@ static void mark_func_jump_tables(struct objtool_file *file, struct symbol *func) { struct instruction *insn, *last = NULL; - struct reloc *reloc; func_for_each_insn(file, func, insn) { if (!last) @@ -2115,11 +2158,7 @@ static void mark_func_jump_tables(struct objtool_file *file, if (insn->type != INSN_JUMP_DYNAMIC) continue; - reloc = find_jump_table(file, func, insn); - if (reloc) { - reloc->jump_table_start = true; - insn->jump_table = reloc; - } + find_jump_table(file, func, insn); } } @@ -2127,15 +2166,13 @@ static int add_func_jump_tables(struct objtool_file *file, struct symbol *func) { struct instruction *insn; - int ret; func_for_each_insn(file, func, insn) { - if (!insn->jump_table) + if (!insn_jump_table(insn)) continue; - ret = add_jump_table(file, insn, insn->jump_table); - if (ret) - return ret; + if (add_jump_table(file, insn)) + return -1; } return 0; @@ -2148,23 +2185,18 @@ static int add_func_jump_tables(struct objtool_file *file, */ static int add_jump_table_alts(struct objtool_file *file) { - struct section *sec; struct symbol *func; - int ret; if (!file->rodata) return 0; - for_each_sec(file, sec) { - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->type != STT_FUNC) - continue; + for_each_sym(file->elf, func) { + if (!is_func_sym(func) || func->alias != func) + continue; - mark_func_jump_tables(file, func); - ret = add_func_jump_tables(file, func); - if (ret) - return ret; - } + mark_func_jump_tables(file, func); + if (add_func_jump_tables(file, func)) + return -1; } return 0; @@ -2176,51 +2208,59 @@ static void set_func_state(struct cfi_state *state) memcpy(&state->regs, &initial_func_cfi.regs, CFI_NUM_REGS * sizeof(struct cfi_reg)); state->stack_size = initial_func_cfi.cfa.offset; + state->type = UNWIND_HINT_TYPE_CALL; } static int read_unwind_hints(struct objtool_file *file) { struct cfi_state cfi = init_cfi; - struct section *sec, *relocsec; + struct section *sec; struct unwind_hint *hint; struct instruction *insn; struct reloc *reloc; + unsigned long offset; int i; sec = find_section_by_name(file->elf, ".discard.unwind_hints"); if (!sec) return 0; - relocsec = sec->reloc; - if (!relocsec) { - WARN("missing .rela.discard.unwind_hints section"); + if (!sec->rsec) { + ERROR("missing .rela.discard.unwind_hints section"); return -1; } - if (sec->sh.sh_size % sizeof(struct unwind_hint)) { - WARN("struct unwind_hint size mismatch"); + if (sec_size(sec) % sizeof(struct unwind_hint)) { + ERROR("struct unwind_hint size mismatch"); return -1; } file->hints = true; - for (i = 0; i < sec->sh.sh_size / sizeof(struct unwind_hint); i++) { + for (i = 0; i < sec_size(sec) / sizeof(struct unwind_hint); i++) { hint = (struct unwind_hint *)sec->data->d_buf + i; reloc = find_reloc_by_dest(file->elf, sec, i * sizeof(*hint)); if (!reloc) { - WARN("can't find reloc for unwind_hints[%d]", i); + ERROR("can't find reloc for unwind_hints[%d]", i); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + offset = reloc->sym->offset + reloc_addend(reloc); + + insn = find_insn(file, reloc->sym->sec, offset); if (!insn) { - WARN("can't find insn for unwind_hints[%d]", i); + ERROR("can't find insn for unwind_hints[%d]", i); return -1; } insn->hint = true; + if (hint->type == UNWIND_HINT_TYPE_UNDEFINED) { + insn->cfi = &force_undefined_cfi; + continue; + } + if (hint->type == UNWIND_HINT_TYPE_SAVE) { insn->hint = false; insn->save = true; @@ -2235,21 +2275,14 @@ static int read_unwind_hints(struct objtool_file *file) if (hint->type == UNWIND_HINT_TYPE_REGS_PARTIAL) { struct symbol *sym = find_symbol_by_offset(insn->sec, insn->offset); - if (sym && sym->bind == STB_GLOBAL) { + if (sym && is_global_sym(sym)) { if (opts.ibt && insn->type != INSN_ENDBR && !insn->noendbr) { - WARN_FUNC("UNWIND_HINT_IRET_REGS without ENDBR", - insn->sec, insn->offset); + ERROR_INSN(insn, "UNWIND_HINT_IRET_REGS without ENDBR"); + return -1; } - - insn->entry = 1; } } - if (hint->type == UNWIND_HINT_TYPE_ENTRY) { - hint->type = UNWIND_HINT_TYPE_CALL; - insn->entry = 1; - } - if (hint->type == UNWIND_HINT_TYPE_FUNC) { insn->cfi = &func_cfi; continue; @@ -2259,14 +2292,13 @@ static int read_unwind_hints(struct objtool_file *file) cfi = *(insn->cfi); if (arch_decode_hint_reg(hint->sp_reg, &cfi.cfa.base)) { - WARN_FUNC("unsupported unwind_hint sp base reg %d", - insn->sec, insn->offset, hint->sp_reg); + ERROR_INSN(insn, "unsupported unwind_hint sp base reg %d", hint->sp_reg); return -1; } cfi.cfa.offset = bswap_if_needed(file->elf, hint->sp_offset); cfi.type = hint->type; - cfi.end = hint->end; + cfi.signal = hint->signal; insn->cfi = cfi_hash_find_or_add(&cfi); } @@ -2274,159 +2306,163 @@ static int read_unwind_hints(struct objtool_file *file) return 0; } -static int read_noendbr_hints(struct objtool_file *file) +static int read_annotate(struct objtool_file *file, + int (*func)(struct objtool_file *file, int type, struct instruction *insn)) { struct section *sec; struct instruction *insn; struct reloc *reloc; + uint64_t offset; + int type; - sec = find_section_by_name(file->elf, ".rela.discard.noendbr"); + sec = find_section_by_name(file->elf, ".discard.annotate_insn"); if (!sec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { - insn = find_insn(file, reloc->sym->sec, reloc->sym->offset + reloc->addend); - if (!insn) { - WARN("bad .discard.noendbr entry"); - return -1; - } + if (!sec->rsec) + return 0; - insn->noendbr = 1; + if (sec->sh.sh_entsize != 8) { + static bool warned = false; + if (!warned && opts.verbose) { + WARN("%s: dodgy linker, sh_entsize != 8", sec->name); + warned = true; + } + sec->sh.sh_entsize = 8; } - return 0; -} - -static int read_retpoline_hints(struct objtool_file *file) -{ - struct section *sec; - struct instruction *insn; - struct reloc *reloc; - - sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe"); - if (!sec) - return 0; + if (sec_num_entries(sec) != sec_num_entries(sec->rsec)) { + ERROR("bad .discard.annotate_insn section: missing relocs"); + return -1; + } - list_for_each_entry(reloc, &sec->reloc_list, list) { - if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); - return -1; - } + for_each_reloc(sec->rsec, reloc) { + type = annotype(file->elf, sec, reloc); + offset = reloc->sym->offset + reloc_addend(reloc); + insn = find_insn(file, reloc->sym->sec, offset); - insn = find_insn(file, reloc->sym->sec, reloc->addend); if (!insn) { - WARN("bad .discard.retpoline_safe entry"); + ERROR("bad .discard.annotate_insn entry: %d of type %d", reloc_idx(reloc), type); return -1; } - if (insn->type != INSN_JUMP_DYNAMIC && - insn->type != INSN_CALL_DYNAMIC && - insn->type != INSN_RETURN && - insn->type != INSN_NOP) { - WARN_FUNC("retpoline_safe hint not an indirect jump/call/ret/nop", - insn->sec, insn->offset); + if (func(file, type, insn)) return -1; - } - - insn->retpoline_safe = true; } return 0; } -static int read_instr_hints(struct objtool_file *file) +static int __annotate_early(struct objtool_file *file, int type, struct instruction *insn) { - struct section *sec; - struct instruction *insn; - struct reloc *reloc; + switch (type) { - sec = find_section_by_name(file->elf, ".rela.discard.instr_end"); - if (!sec) - return 0; - - list_for_each_entry(reloc, &sec->reloc_list, list) { - if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); - return -1; - } + /* Must be before add_special_section_alts() */ + case ANNOTYPE_IGNORE_ALTS: + insn->ignore_alts = true; + break; - insn = find_insn(file, reloc->sym->sec, reloc->addend); - if (!insn) { - WARN("bad .discard.instr_end entry"); - return -1; - } + /* + * Must be before read_unwind_hints() since that needs insn->noendbr. + */ + case ANNOTYPE_NOENDBR: + insn->noendbr = 1; + break; - insn->instr--; + default: + break; } - sec = find_section_by_name(file->elf, ".rela.discard.instr_begin"); - if (!sec) + return 0; +} + +static int __annotate_ifc(struct objtool_file *file, int type, struct instruction *insn) +{ + unsigned long dest_off; + + if (type != ANNOTYPE_INTRA_FUNCTION_CALL) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { - if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); - return -1; - } + if (insn->type != INSN_CALL) { + ERROR_INSN(insn, "intra_function_call not a direct call"); + return -1; + } - insn = find_insn(file, reloc->sym->sec, reloc->addend); - if (!insn) { - WARN("bad .discard.instr_begin entry"); - return -1; - } + /* + * Treat intra-function CALLs as JMPs, but with a stack_op. + * See add_call_destinations(), which strips stack_ops from + * normal CALLs. + */ + insn->type = INSN_JUMP_UNCONDITIONAL; - insn->instr++; + dest_off = arch_jump_destination(insn); + insn->jump_dest = find_insn(file, insn->sec, dest_off); + if (!insn->jump_dest) { + ERROR_INSN(insn, "can't find call dest at %s+0x%lx", + insn->sec->name, dest_off); + return -1; } return 0; } -static int read_intra_function_calls(struct objtool_file *file) +static int __annotate_late(struct objtool_file *file, int type, struct instruction *insn) { - struct instruction *insn; - struct section *sec; - struct reloc *reloc; - - sec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls"); - if (!sec) - return 0; + struct symbol *sym; - list_for_each_entry(reloc, &sec->reloc_list, list) { - unsigned long dest_off; + switch (type) { + case ANNOTYPE_NOENDBR: + /* early */ + break; - if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", - sec->name); + case ANNOTYPE_RETPOLINE_SAFE: + if (insn->type != INSN_JUMP_DYNAMIC && + insn->type != INSN_CALL_DYNAMIC && + insn->type != INSN_RETURN && + insn->type != INSN_NOP) { + ERROR_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop"); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); - if (!insn) { - WARN("bad .discard.intra_function_call entry"); - return -1; - } + insn->retpoline_safe = true; + break; - if (insn->type != INSN_CALL) { - WARN_FUNC("intra_function_call not a direct call", - insn->sec, insn->offset); - return -1; - } + case ANNOTYPE_INSTR_BEGIN: + insn->instr++; + break; - /* - * Treat intra-function CALLs as JMPs, but with a stack_op. - * See add_call_destinations(), which strips stack_ops from - * normal CALLs. - */ - insn->type = INSN_JUMP_UNCONDITIONAL; + case ANNOTYPE_INSTR_END: + insn->instr--; + break; - dest_off = arch_jump_destination(insn); - insn->jump_dest = find_insn(file, insn->sec, dest_off); - if (!insn->jump_dest) { - WARN_FUNC("can't find call dest at %s+0x%lx", - insn->sec, insn->offset, - insn->sec->name, dest_off); + case ANNOTYPE_UNRET_BEGIN: + insn->unret = 1; + break; + + case ANNOTYPE_IGNORE_ALTS: + /* early */ + break; + + case ANNOTYPE_INTRA_FUNCTION_CALL: + /* ifc */ + break; + + case ANNOTYPE_REACHABLE: + 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; } return 0; @@ -2444,45 +2480,43 @@ 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; } static int classify_symbols(struct objtool_file *file) { - struct section *sec; struct symbol *func; + size_t len; - for_each_sec(file, sec) { - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->bind != STB_GLOBAL) - continue; + for_each_sym(file->elf, func) { + if (is_notype_sym(func) && strstarts(func->name, ".L")) + func->local_label = true; - if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR, - strlen(STATIC_CALL_TRAMP_PREFIX_STR))) - func->static_call_tramp = true; + if (!is_global_sym(func)) + continue; - if (arch_is_retpoline(func)) - func->retpoline_thunk = true; + if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR, + strlen(STATIC_CALL_TRAMP_PREFIX_STR))) + func->static_call_tramp = true; - if (arch_is_rethunk(func)) - func->return_thunk = true; + if (arch_is_retpoline(func)) + func->retpoline_thunk = true; - if (arch_ftrace_match(func->name)) - func->fentry = true; + if (arch_is_rethunk(func)) + func->return_thunk = true; - if (is_profiling_func(func->name)) - func->profiling_func = true; - } + if (arch_is_embedded_insn(func)) + func->embedded_insn = true; + + if (arch_ftrace_match(func->name)) + func->fentry = true; + + if (is_profiling_func(func->name)) + func->profiling_func = true; + + len = strlen(func->name); + if (len > sym_name_max_len) + sym_name_max_len = len; } return 0; @@ -2499,13 +2533,14 @@ static void mark_rodata(struct objtool_file *file) * * - .rodata: can contain GCC switch tables * - .rodata.<func>: same, if -fdata-sections is being used - * - .rodata..c_jump_table: contains C annotated jump tables + * - .data.rel.ro.c_jump_table: contains C annotated jump tables * * .rodata.str1.* sections are ignored; they don't contain jump tables. */ - for_each_sec(file, sec) { - if (!strncmp(sec->name, ".rodata", 7) && - !strstr(sec->name, ".str1.")) { + for_each_sec(file->elf, sec) { + if ((!strncmp(sec->name, ".rodata", 7) && + !strstr(sec->name, ".str1.")) || + !strncmp(sec->name, ".data.rel.ro", 12)) { sec->rodata = true; found = true; } @@ -2514,100 +2549,130 @@ static void mark_rodata(struct objtool_file *file) file->rodata = found; } +static void mark_holes(struct objtool_file *file) +{ + struct instruction *insn; + bool in_hole = false; + + if (!opts.link) + return; + + /* + * Whole archive runs might encounter dead code from weak symbols. + * This is where the linker will have dropped the weak symbol in + * favour of a regular symbol, but leaves the code in place. + */ + for_each_insn(file, insn) { + if (insn->sym || !find_symbol_hole_containing(insn->sec, insn->offset)) { + in_hole = false; + continue; + } + + /* Skip function padding and pfx code */ + if (!in_hole && insn->type == INSN_NOP) + continue; + + in_hole = true; + insn->hole = 1; + + /* + * If this hole jumps to a .cold function, mark it ignore. + */ + if (insn->jump_dest) { + struct symbol *dest_func = insn_func(insn->jump_dest); + + if (dest_func && dest_func->cold) + dest_func->ignore = true; + } + } +} + +static bool validate_branch_enabled(void) +{ + return opts.stackval || + opts.orc || + opts.uaccess || + opts.checksum; +} + static int decode_sections(struct objtool_file *file) { - int ret; + file->klp = is_livepatch_module(file); mark_rodata(file); - ret = init_pv_ops(file); - if (ret) - return ret; + if (init_pv_ops(file)) + return -1; /* * Must be before add_{jump_call}_destination. */ - ret = classify_symbols(file); - if (ret) - return ret; + if (classify_symbols(file)) + return -1; - ret = decode_instructions(file); - if (ret) - return ret; + if (decode_instructions(file)) + return -1; - add_ignores(file); - add_uaccess_safe(file); + if (add_ignores(file)) + return -1; - ret = add_ignore_alternatives(file); - if (ret) - return ret; + add_uaccess_safe(file); - /* - * Must be before read_unwind_hints() since that needs insn->noendbr. - */ - ret = read_noendbr_hints(file); - if (ret) - return ret; + if (read_annotate(file, __annotate_early)) + return -1; /* * Must be before add_jump_destinations(), which depends on 'func' * being set for alternatives, to enable proper sibling call detection. */ - if (opts.stackval || opts.orc || opts.uaccess || opts.noinstr) { - ret = add_special_section_alts(file); - if (ret) - return ret; + if (validate_branch_enabled() || opts.noinstr || opts.hack_jump_label || opts.disas) { + if (add_special_section_alts(file)) + return -1; } - ret = add_jump_destinations(file); - if (ret) - return ret; + if (add_jump_destinations(file)) + return -1; /* * Must be before add_call_destination(); it changes INSN_CALL to * INSN_JUMP. */ - ret = read_intra_function_calls(file); - if (ret) - return ret; + if (read_annotate(file, __annotate_ifc)) + return -1; - ret = add_call_destinations(file); - if (ret) - return ret; + if (add_call_destinations(file)) + return -1; + + if (add_jump_table_alts(file)) + return -1; + + if (read_unwind_hints(file)) + return -1; + + /* Must be after add_jump_destinations() */ + mark_holes(file); /* * Must be after add_call_destinations() such that it can override * dead_end_function() marks. */ - ret = add_dead_ends(file); - if (ret) - return ret; - - ret = add_jump_table_alts(file); - if (ret) - return ret; - - ret = read_unwind_hints(file); - if (ret) - return ret; - - ret = read_retpoline_hints(file); - if (ret) - return ret; - - ret = read_instr_hints(file); - if (ret) - return ret; + if (read_annotate(file, __annotate_late)) + return -1; return 0; } -static bool is_fentry_call(struct instruction *insn) +static bool is_special_call(struct instruction *insn) { - if (insn->type == INSN_CALL && - insn->call_dest && - insn->call_dest->fentry) - return true; + if (insn->type == INSN_CALL) { + struct symbol *dest = insn_call_dest(insn); + + if (!dest) + return false; + + if (dest->fentry || dest->embedded_insn) + return true; + } return false; } @@ -2757,11 +2822,15 @@ static int update_cfi_state(struct instruction *insn, struct cfi_reg *cfa = &cfi->cfa; struct cfi_reg *regs = cfi->regs; + /* ignore UNWIND_HINT_UNDEFINED regions */ + if (cfi->force_undefined) + return 0; + /* stack operations don't make sense with an undefined CFA */ if (cfa->base == CFI_UNDEFINED) { if (insn_func(insn)) { - WARN_FUNC("undefined stack state", insn->sec, insn->offset); - return -1; + WARN_INSN(insn, "undefined stack state"); + return 1; } return 0; } @@ -2902,21 +2971,27 @@ static int update_cfi_state(struct instruction *insn, break; } - if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) { - - /* lea disp(%rbp), %rsp */ - cfi->stack_size = -(op->src.offset + regs[CFI_BP].offset); + if (op->dest.reg == CFI_BP && op->src.reg == CFI_SP && + insn->sym->frame_pointer) { + /* addi.d fp,sp,imm on LoongArch */ + if (cfa->base == CFI_SP && cfa->offset == op->src.offset) { + cfa->base = CFI_BP; + cfa->offset = 0; + } break; } - if (!cfi->drap && op->src.reg == CFI_SP && - op->dest.reg == CFI_BP && cfa->base == CFI_SP && - check_reg_frame_pos(®s[CFI_BP], -cfa->offset + op->src.offset)) { - - /* lea disp(%rsp), %rbp */ - cfa->base = CFI_BP; - cfa->offset -= op->src.offset; - cfi->bp_scratch = false; + if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) { + /* addi.d sp,fp,imm on LoongArch */ + if (cfa->base == CFI_BP && cfa->offset == 0) { + if (insn->sym->frame_pointer) { + cfa->base = CFI_SP; + cfa->offset = -op->src.offset; + } + } else { + /* lea disp(%rbp), %rsp */ + cfi->stack_size = -(op->src.offset + regs[CFI_BP].offset); + } break; } @@ -2954,8 +3029,7 @@ static int update_cfi_state(struct instruction *insn, } if (op->dest.reg == cfi->cfa.base && !(next_insn && next_insn->hint)) { - WARN_FUNC("unsupported stack register modification", - insn->sec, insn->offset); + WARN_INSN(insn, "unsupported stack register modification"); return -1; } @@ -2965,8 +3039,7 @@ static int update_cfi_state(struct instruction *insn, if (op->dest.reg != CFI_SP || (cfi->drap_reg != CFI_UNDEFINED && cfa->base != CFI_SP) || (cfi->drap_reg == CFI_UNDEFINED && cfa->base != CFI_BP)) { - WARN_FUNC("unsupported stack pointer realignment", - insn->sec, insn->offset); + WARN_INSN(insn, "unsupported stack pointer realignment"); return -1; } @@ -3061,8 +3134,7 @@ static int update_cfi_state(struct instruction *insn, break; default: - WARN_FUNC("unknown stack-related instruction", - insn->sec, insn->offset); + WARN_INSN(insn, "unknown stack-related instruction"); return -1; } @@ -3151,8 +3223,7 @@ static int update_cfi_state(struct instruction *insn, case OP_DEST_MEM: if (op->src.type != OP_SRC_POP && op->src.type != OP_SRC_POPF) { - WARN_FUNC("unknown stack-related memory operation", - insn->sec, insn->offset); + WARN_INSN(insn, "unknown stack-related memory operation"); return -1; } @@ -3164,8 +3235,7 @@ static int update_cfi_state(struct instruction *insn, break; default: - WARN_FUNC("unknown stack-related instruction", - insn->sec, insn->offset); + WARN_INSN(insn, "unknown stack-related instruction"); return -1; } @@ -3201,8 +3271,10 @@ static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn alt_cfi[group_off] = insn->cfi; } else { if (cficmp(alt_cfi[group_off], insn->cfi)) { - WARN_FUNC("stack layout conflict in alternatives", - insn->sec, insn->offset); + struct alt_group *orig_group = insn->alt_group->orig_group ?: insn->alt_group; + struct instruction *orig = orig_group->first_insn; + WARN_INSN(orig, "stack layout conflict in alternatives: %s", + offstr(insn->sec, insn->offset)); return -1; } } @@ -3210,27 +3282,30 @@ static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn return 0; } -static int handle_insn_ops(struct instruction *insn, - struct instruction *next_insn, - struct insn_state *state) +static int noinline handle_insn_ops(struct instruction *insn, + struct instruction *next_insn, + struct insn_state *state) { + struct insn_state prev_state __maybe_unused = *state; struct stack_op *op; + int ret = 0; - list_for_each_entry(op, &insn->stack_ops, list) { + for (op = insn->stack_ops; op; op = op->next) { - if (update_cfi_state(insn, next_insn, &state->cfi, op)) - return 1; + ret = update_cfi_state(insn, next_insn, &state->cfi, op); + if (ret) + goto done; - if (!insn->alt_group) + if (!opts.uaccess || !insn->alt_group) continue; if (op->dest.type == OP_DEST_PUSHF) { if (!state->uaccess_stack) { state->uaccess_stack = 1; } else if (state->uaccess_stack >> 31) { - WARN_FUNC("PUSHF stack exhausted", - insn->sec, insn->offset); - return 1; + WARN_INSN(insn, "PUSHF stack exhausted"); + ret = 1; + goto done; } state->uaccess_stack <<= 1; state->uaccess_stack |= state->uaccess; @@ -3246,7 +3321,10 @@ static int handle_insn_ops(struct instruction *insn, } } - return 0; +done: + TRACE_INSN_STATE(insn, &prev_state, state); + + return ret; } static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2) @@ -3261,42 +3339,44 @@ static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2) if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) { - WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d", - insn->sec, insn->offset, + WARN_INSN(insn, "stack state mismatch: cfa1=%d%+d cfa2=%d%+d", cfi1->cfa.base, cfi1->cfa.offset, cfi2->cfa.base, cfi2->cfa.offset); + return false; - } else if (memcmp(&cfi1->regs, &cfi2->regs, sizeof(cfi1->regs))) { + } + + if (memcmp(&cfi1->regs, &cfi2->regs, sizeof(cfi1->regs))) { for (i = 0; i < CFI_NUM_REGS; i++) { - if (!memcmp(&cfi1->regs[i], &cfi2->regs[i], - sizeof(struct cfi_reg))) + + if (!memcmp(&cfi1->regs[i], &cfi2->regs[i], sizeof(struct cfi_reg))) continue; - WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d", - insn->sec, insn->offset, + WARN_INSN(insn, "stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d", i, cfi1->regs[i].base, cfi1->regs[i].offset, i, cfi2->regs[i].base, cfi2->regs[i].offset); - break; } + return false; + } - } else if (cfi1->type != cfi2->type) { + if (cfi1->type != cfi2->type) { - WARN_FUNC("stack state mismatch: type1=%d type2=%d", - insn->sec, insn->offset, cfi1->type, cfi2->type); + WARN_INSN(insn, "stack state mismatch: type1=%d type2=%d", + cfi1->type, cfi2->type); + return false; + } - } else if (cfi1->drap != cfi2->drap || + if (cfi1->drap != cfi2->drap || (cfi1->drap && cfi1->drap_reg != cfi2->drap_reg) || (cfi1->drap && cfi1->drap_offset != cfi2->drap_offset)) { - WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)", - insn->sec, insn->offset, + WARN_INSN(insn, "stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)", cfi1->drap, cfi1->drap_reg, cfi1->drap_offset, cfi2->drap, cfi2->drap_reg, cfi2->drap_offset); + return false; + } - } else - return true; - - return false; + return true; } static inline bool func_uaccess_safe(struct symbol *func) @@ -3310,15 +3390,15 @@ static inline bool func_uaccess_safe(struct symbol *func) static inline const char *call_dest_name(struct instruction *insn) { static char pvname[19]; - struct reloc *rel; + struct reloc *reloc; int idx; - if (insn->call_dest) - return insn->call_dest->name; + if (insn_call_dest(insn)) + return insn_call_dest(insn)->name; - rel = insn_reloc(NULL, insn); - if (rel && !strcmp(rel->sym->name, "pv_ops")) { - idx = (rel->addend / sizeof(void *)); + reloc = insn_reloc(NULL, insn); + if (reloc && !strcmp(reloc->sym->name, "pv_ops")) { + idx = (reloc_addend(reloc) / sizeof(void *)); snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx); return pvname; } @@ -3329,14 +3409,14 @@ static inline const char *call_dest_name(struct instruction *insn) static bool pv_call_dest(struct objtool_file *file, struct instruction *insn) { struct symbol *target; - struct reloc *rel; + struct reloc *reloc; int idx; - rel = insn_reloc(file, insn); - if (!rel || strcmp(rel->sym->name, "pv_ops")) + reloc = insn_reloc(file, insn); + if (!reloc || strcmp(reloc->sym->name, "pv_ops")) return false; - idx = (arch_dest_reloc_offset(rel->addend) / sizeof(void *)); + idx = arch_insn_adjusted_addend(insn, reloc) / sizeof(void *); if (file->pv_ops[idx].clean) return true; @@ -3375,6 +3455,12 @@ static inline bool noinstr_call_dest(struct objtool_file *file, return true; /* + * If the symbol is a static_call trampoline, we can't tell. + */ + if (func->static_call_tramp) + return true; + + /* * The __ubsan_handle_*() calls are like WARN(), they only happen when * something 'BAD' happened. At the risk of taking the machine down, * let them proceed to get the message out. @@ -3390,21 +3476,18 @@ static int validate_call(struct objtool_file *file, struct insn_state *state) { if (state->noinstr && state->instr <= 0 && - !noinstr_call_dest(file, insn, insn->call_dest)) { - WARN_FUNC("call to %s() leaves .noinstr.text section", - insn->sec, insn->offset, call_dest_name(insn)); + !noinstr_call_dest(file, insn, insn_call_dest(insn))) { + WARN_INSN(insn, "call to %s() leaves .noinstr.text section", 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)); + if (state->uaccess && !func_uaccess_safe(insn_call_dest(insn))) { + WARN_INSN(insn, "call to %s() with UACCESS enabled", call_dest_name(insn)); return 1; } if (state->df) { - WARN_FUNC("call to %s() with DF set", - insn->sec, insn->offset, call_dest_name(insn)); + WARN_INSN(insn, "call to %s() with DF set", call_dest_name(insn)); return 1; } @@ -3416,8 +3499,7 @@ static int validate_sibling_call(struct objtool_file *file, struct insn_state *state) { if (insn_func(insn) && has_modified_stack_frame(insn, state)) { - WARN_FUNC("sibling call from callable instruction with modified stack frame", - insn->sec, insn->offset); + WARN_INSN(insn, "sibling call from callable instruction with modified stack frame"); return 1; } @@ -3427,38 +3509,32 @@ static int validate_sibling_call(struct objtool_file *file, 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); + WARN_INSN(insn, "return with instrumentation enabled"); return 1; } if (state->uaccess && !func_uaccess_safe(func)) { - WARN_FUNC("return with UACCESS enabled", - insn->sec, insn->offset); + WARN_INSN(insn, "return with UACCESS enabled"); return 1; } if (!state->uaccess && func_uaccess_safe(func)) { - WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function", - insn->sec, insn->offset); + WARN_INSN(insn, "return with UACCESS disabled from a UACCESS-safe function"); return 1; } if (state->df) { - WARN_FUNC("return with DF set", - insn->sec, insn->offset); + WARN_INSN(insn, "return with DF set"); return 1; } if (func && has_modified_stack_frame(insn, state)) { - WARN_FUNC("return with modified stack frame", - insn->sec, insn->offset); + WARN_INSN(insn, "return with modified stack frame"); return 1; } if (state->cfi.bp_scratch) { - WARN_FUNC("BP used as a scratch register", - insn->sec, insn->offset); + WARN_INSN(insn, "BP used as a scratch register"); return 1; } @@ -3474,256 +3550,501 @@ static struct instruction *next_insn_to_validate(struct objtool_file *file, * Simulate the fact that alternatives are patched in-place. When the * end of a replacement alt_group is reached, redirect objtool flow to * the end of the original alt_group. + * + * insn->alts->insn -> alt_group->first_insn + * ... + * alt_group->last_insn + * [alt_group->nop] -> next(orig_group->last_insn) */ - if (alt_group && insn == alt_group->last_insn && alt_group->orig_group) - return next_insn_same_sec(file, alt_group->orig_group->last_insn); + if (alt_group) { + if (alt_group->nop) { + /* ->nop implies ->orig_group */ + if (insn == alt_group->last_insn) + return alt_group->nop; + if (insn == alt_group->nop) + goto next_orig; + } + if (insn == alt_group->last_insn && alt_group->orig_group) + goto next_orig; + } return next_insn_same_sec(file, insn); + +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; + + if (!insn->alt_group) + return false; + + /* ANNOTATE_IGNORE_ALTERNATIVE */ + if (insn->alt_group->ignore) { + TRACE_ALT(insn, "alt group ignored"); + 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; +} + +static int checksum_debug_init(struct objtool_file *file) +{ + char *dup, *s; + + if (!opts.debug_checksum) + return 0; + + dup = strdup(opts.debug_checksum); + if (!dup) { + ERROR_GLIBC("strdup"); + return -1; + } + + s = dup; + while (*s) { + struct symbol *func; + char *comma; + + comma = strchr(s, ','); + if (comma) + *comma = '\0'; + + func = find_symbol_by_name(file->elf, s); + if (!func || !is_func_sym(func)) + WARN("--debug-checksum: can't find '%s'", s); + else + func->debug_checksum = 1; + + if (!comma) + break; + + s = comma + 1; + } + + free(dup); + return 0; +} + +static void checksum_update_insn(struct objtool_file *file, struct symbol *func, + struct instruction *insn) +{ + struct reloc *reloc = insn_reloc(file, insn); + unsigned long offset; + struct symbol *sym; + + if (insn->fake) + return; + + checksum_update(func, insn, insn->sec->data->d_buf + insn->offset, insn->len); + + if (!reloc) { + struct symbol *call_dest = insn_call_dest(insn); + + if (call_dest) + checksum_update(func, insn, call_dest->demangled_name, + strlen(call_dest->demangled_name)); + return; + } + + sym = reloc->sym; + offset = arch_insn_adjusted_addend(insn, reloc); + + if (is_string_sec(sym->sec)) { + char *str; + + str = sym->sec->data->d_buf + sym->offset + offset; + checksum_update(func, insn, str, strlen(str)); + return; + } + + if (is_sec_sym(sym)) { + sym = find_symbol_containing(reloc->sym->sec, offset); + if (!sym) + return; + + offset -= sym->offset; + } + + checksum_update(func, insn, sym->demangled_name, strlen(sym->demangled_name)); + checksum_update(func, insn, &offset, sizeof(offset)); } -/* - * Follow the branch starting at the given instruction, and recursively follow - * any other branches (jumps). Meanwhile, track the frame pointer state at - * each instruction and validate all the rules described in - * tools/objtool/Documentation/objtool.txt. - */ static int validate_branch(struct objtool_file *file, struct symbol *func, - struct instruction *insn, struct insn_state state) + struct instruction *insn, struct insn_state state); +static int do_validate_branch(struct objtool_file *file, struct symbol *func, + struct instruction *insn, struct insn_state state); + +static int validate_insn(struct objtool_file *file, struct symbol *func, + struct instruction *insn, struct insn_state *statep, + struct instruction *prev_insn, struct instruction *next_insn, + bool *dead_end) { + char *alt_name __maybe_unused = NULL; struct alternative *alt; - struct instruction *next_insn, *prev_insn = NULL; - struct section *sec; u8 visited; int ret; - sec = insn->sec; - - while (1) { - next_insn = next_insn_to_validate(file, insn); - - 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)) - return 0; + /* + * Any returns before the end of this function are effectively dead + * ends, i.e. validate_branch() has reached the end of the branch. + */ + *dead_end = true; - WARN("%s() falls through to next function %s()", - func->name, insn_func(insn)->name); + visited = VISITED_BRANCH << statep->uaccess; + if (insn->visited & VISITED_BRANCH_MASK) { + if (!insn->hint && !insn_cfi_match(insn, &statep->cfi)) return 1; - } - if (func && insn->ignore) { - WARN_FUNC("BUG: why am I validating an ignored function?", - sec, insn->offset); - return 1; - } - - visited = VISITED_BRANCH << state.uaccess; - if (insn->visited & VISITED_BRANCH_MASK) { - if (!insn->hint && !insn_cfi_match(insn, &state.cfi)) - return 1; - - if (insn->visited & visited) - return 0; - } else { - nr_insns_visited++; + if (insn->visited & visited) { + TRACE_INSN(insn, "already visited"); + return 0; } + } else { + nr_insns_visited++; + } - if (state.noinstr) - state.instr += insn->instr; + if (statep->noinstr) + statep->instr += insn->instr; - if (insn->hint) { - if (insn->restore) { - struct instruction *save_insn, *i; + if (insn->hint) { + if (insn->restore) { + struct instruction *save_insn, *i; - i = insn; - save_insn = NULL; + i = insn; + save_insn = NULL; - sym_for_each_insn_continue_reverse(file, func, i) { - if (i->save) { - save_insn = i; - break; - } + sym_for_each_insn_continue_reverse(file, func, i) { + if (i->save) { + save_insn = i; + break; } + } - if (!save_insn) { - WARN_FUNC("no corresponding CFI save for CFI restore", - sec, insn->offset); - return 1; - } + if (!save_insn) { + WARN_INSN(insn, "no corresponding CFI save for CFI restore"); + return 1; + } - if (!save_insn->visited) { - WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo", - sec, insn->offset); - return 1; + if (!save_insn->visited) { + /* + * If the restore hint insn is at the + * beginning of a basic block and was + * branched to from elsewhere, and the + * save insn hasn't been visited yet, + * defer following this branch for now. + * It will be seen later via the + * straight-line path. + */ + if (!prev_insn) { + TRACE_INSN(insn, "defer restore"); + return 0; } - insn->cfi = save_insn->cfi; - nr_cfi_reused++; + WARN_INSN(insn, "objtool isn't smart enough to handle this CFI save/restore combo"); + return 1; } - state.cfi = *insn->cfi; + insn->cfi = save_insn->cfi; + nr_cfi_reused++; + } + + statep->cfi = *insn->cfi; + } else { + /* XXX track if we actually changed statep->cfi */ + + if (prev_insn && !cficmp(prev_insn->cfi, &statep->cfi)) { + insn->cfi = prev_insn->cfi; + nr_cfi_reused++; } else { - /* XXX track if we actually changed state.cfi */ + insn->cfi = cfi_hash_find_or_add(&statep->cfi); + } + } - if (prev_insn && !cficmp(prev_insn->cfi, &state.cfi)) { - insn->cfi = prev_insn->cfi; - nr_cfi_reused++; - } else { - insn->cfi = cfi_hash_find_or_add(&state.cfi); + insn->visited |= visited; + + if (propagate_alt_cfi(file, insn)) + return 1; + + if (insn->alts) { + for (alt = insn->alts; alt; alt = alt->next) { + TRACE_ALT_BEGIN(insn, alt, alt_name); + ret = validate_branch(file, func, alt->insn, *statep); + TRACE_ALT_END(insn, alt, alt_name); + if (ret) { + BT_INSN(insn, "(alt)"); + return ret; } } + TRACE_ALT_INFO_NOADDR(insn, "/ ", "DEFAULT"); + } - insn->visited |= visited; + if (skip_alt_group(insn)) + return 0; - if (propagate_alt_cfi(file, insn)) - return 1; + if (handle_insn_ops(insn, next_insn, statep)) + return 1; - if (!insn->ignore_alts && !list_empty(&insn->alts)) { - bool skip_orig = false; + switch (insn->type) { - list_for_each_entry(alt, &insn->alts, list) { - if (alt->skip_orig) - skip_orig = true; + case INSN_RETURN: + TRACE_INSN(insn, "return"); + return validate_return(func, insn, statep); - ret = validate_branch(file, func, alt->insn, state); - if (ret) { - if (opts.backtrace) - BT_FUNC("(alt)", insn); - return ret; - } - } + case INSN_CALL: + case INSN_CALL_DYNAMIC: + if (insn->type == INSN_CALL) + TRACE_INSN(insn, "call"); + else + TRACE_INSN(insn, "indirect call"); - if (skip_orig) - return 0; - } + ret = validate_call(file, insn, statep); + if (ret) + return ret; - if (handle_insn_ops(insn, next_insn, &state)) + if (opts.stackval && func && !is_special_call(insn) && + !has_valid_stack_frame(statep)) { + WARN_INSN(insn, "call without frame pointer save/setup"); return 1; + } - switch (insn->type) { - - case INSN_RETURN: - return validate_return(func, insn, &state); + break; - case INSN_CALL: - case INSN_CALL_DYNAMIC: - ret = validate_call(file, insn, &state); + case INSN_JUMP_CONDITIONAL: + case INSN_JUMP_UNCONDITIONAL: + if (is_sibling_call(insn)) { + TRACE_INSN(insn, "sibling call"); + ret = validate_sibling_call(file, insn, statep); if (ret) return ret; - if (opts.stackval && func && !is_fentry_call(insn) && - !has_valid_stack_frame(&state)) { - WARN_FUNC("call without frame pointer save/setup", - sec, insn->offset); - return 1; + } else if (insn->jump_dest) { + if (insn->type == INSN_JUMP_UNCONDITIONAL) + TRACE_INSN(insn, "unconditional jump"); + else + TRACE_INSN(insn, "jump taken"); + + ret = validate_branch(file, func, insn->jump_dest, *statep); + if (ret) { + BT_INSN(insn, "(branch)"); + return ret; } + } - if (insn->dead_end) - return 0; + if (insn->type == INSN_JUMP_UNCONDITIONAL) + return 0; - break; + TRACE_INSN(insn, "jump not taken"); + break; - case INSN_JUMP_CONDITIONAL: - case INSN_JUMP_UNCONDITIONAL: - if (is_sibling_call(insn)) { - ret = validate_sibling_call(file, insn, &state); - if (ret) - return ret; + case INSN_JUMP_DYNAMIC: + case INSN_JUMP_DYNAMIC_CONDITIONAL: + TRACE_INSN(insn, "indirect jump"); + if (is_sibling_call(insn)) { + ret = validate_sibling_call(file, insn, statep); + if (ret) + return ret; + } - } else if (insn->jump_dest) { - ret = validate_branch(file, func, - insn->jump_dest, state); - if (ret) { - if (opts.backtrace) - BT_FUNC("(branch)", insn); - return ret; - } - } + if (insn->type == INSN_JUMP_DYNAMIC) + return 0; - if (insn->type == INSN_JUMP_UNCONDITIONAL) - return 0; + break; - break; + case INSN_SYSCALL: + TRACE_INSN(insn, "syscall"); + if (func && (!next_insn || !next_insn->hint)) { + WARN_INSN(insn, "unsupported instruction in callable function"); + return 1; + } - case INSN_JUMP_DYNAMIC: - case INSN_JUMP_DYNAMIC_CONDITIONAL: - if (is_sibling_call(insn)) { - ret = validate_sibling_call(file, insn, &state); - if (ret) - return ret; - } + break; - if (insn->type == INSN_JUMP_DYNAMIC) - return 0; + case INSN_SYSRET: + TRACE_INSN(insn, "sysret"); + if (func && (!next_insn || !next_insn->hint)) { + WARN_INSN(insn, "unsupported instruction in callable function"); + return 1; + } + + return 0; + case INSN_STAC: + TRACE_INSN(insn, "stac"); + if (!opts.uaccess) break; - case INSN_CONTEXT_SWITCH: - if (func && (!next_insn || !next_insn->hint)) { - WARN_FUNC("unsupported instruction in callable function", - sec, insn->offset); - return 1; - } - return 0; + if (statep->uaccess) { + WARN_INSN(insn, "recursive UACCESS enable"); + return 1; + } - case INSN_STAC: - if (state.uaccess) { - WARN_FUNC("recursive UACCESS enable", sec, insn->offset); - return 1; - } + statep->uaccess = true; + break; - state.uaccess = true; + case INSN_CLAC: + TRACE_INSN(insn, "clac"); + if (!opts.uaccess) break; - case INSN_CLAC: - if (!state.uaccess && func) { - WARN_FUNC("redundant UACCESS disable", sec, insn->offset); - return 1; - } + if (!statep->uaccess && func) { + WARN_INSN(insn, "redundant UACCESS disable"); + return 1; + } - if (func_uaccess_safe(func) && !state.uaccess_stack) { - WARN_FUNC("UACCESS-safe disables UACCESS", sec, insn->offset); - return 1; - } + if (func_uaccess_safe(func) && !statep->uaccess_stack) { + WARN_INSN(insn, "UACCESS-safe disables UACCESS"); + return 1; + } - state.uaccess = false; - break; + statep->uaccess = false; + break; - case INSN_STD: - if (state.df) { - WARN_FUNC("recursive STD", sec, insn->offset); - return 1; - } + case INSN_STD: + TRACE_INSN(insn, "std"); + if (statep->df) { + WARN_INSN(insn, "recursive STD"); + return 1; + } - state.df = true; - break; + statep->df = true; + break; - case INSN_CLD: - if (!state.df && func) { - WARN_FUNC("redundant CLD", sec, insn->offset); - return 1; - } + case INSN_CLD: + TRACE_INSN(insn, "cld"); + if (!statep->df && func) { + WARN_INSN(insn, "redundant CLD"); + return 1; + } - state.df = false; - break; + statep->df = false; + break; - default: - break; + default: + break; + } + + if (insn->dead_end) + TRACE_INSN(insn, "dead end"); + + *dead_end = insn->dead_end; + return 0; +} + +/* + * Follow the branch starting at the given instruction, and recursively follow + * any other branches (jumps). Meanwhile, track the frame pointer state at + * each instruction and validate all the rules described in + * tools/objtool/Documentation/objtool.txt. + */ +static int do_validate_branch(struct objtool_file *file, struct symbol *func, + struct instruction *insn, struct insn_state state) +{ + struct instruction *next_insn, *prev_insn = NULL; + bool dead_end; + int ret; + + if (func && func->ignore) + return 0; + + do { + insn->trace = 0; + next_insn = next_insn_to_validate(file, insn); + + if (opts.checksum && func && insn->sec) + checksum_update_insn(file, func, insn); + + if (func && insn_func(insn) && func != insn_func(insn)->pfunc) { + /* Ignore KCFI type preambles, which always fall through */ + if (is_prefix_func(func)) + return 0; + + if (file->ignore_unreachables) + return 0; + + WARN("%s() falls through to next function %s()", + func->name, insn_func(insn)->name); + func->warned = 1; + + return 1; } - if (insn->dead_end) - return 0; + ret = validate_insn(file, func, insn, &state, prev_insn, next_insn, + &dead_end); + + if (!insn->trace) { + if (ret) + TRACE_INSN(insn, "warning (%d)", ret); + else + TRACE_INSN(insn, NULL); + } - if (!next_insn) { + if (!dead_end && !next_insn) { if (state.cfi.cfa.base == CFI_UNDEFINED) return 0; - WARN("%s: unexpected end of section", sec->name); + if (file->ignore_unreachables) + return 0; + + WARN("%s%sunexpected end of section %s", + func ? func->name : "", func ? "(): " : "", + insn->sec->name); return 1; } prev_insn = insn; insn = next_insn; + + } while (!dead_end); + + return ret; +} + +static int validate_branch(struct objtool_file *file, struct symbol *func, + struct instruction *insn, struct insn_state state) +{ + int ret; + + trace_depth_inc(); + ret = do_validate_branch(file, func, insn, state); + trace_depth_dec(); + + return ret; +} + +static int validate_unwind_hint(struct objtool_file *file, + struct instruction *insn, + struct insn_state *state) +{ + if (insn->hint && !insn->visited) { + struct symbol *func = insn_func(insn); + int ret; + + if (opts.checksum) + checksum_init(func); + + ret = validate_branch(file, func, insn, *state); + if (ret) + BT_INSN(insn, "<=== (hint)"); + return ret; } return 0; @@ -3733,7 +4054,7 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec) { struct instruction *insn; struct insn_state state; - int ret, warnings = 0; + int warnings = 0; if (!file->hints) return 0; @@ -3741,22 +4062,11 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec) init_insn_state(file, &state, sec); if (sec) { - insn = find_insn(file, sec, 0); - if (!insn) - return 0; + sec_for_each_insn(file, sec, insn) + warnings += validate_unwind_hint(file, insn, &state); } else { - insn = list_first_entry(&file->insn_list, typeof(*insn), list); - } - - while (&insn->list != &file->insn_list && (!sec || insn->sec == sec)) { - if (insn->hint && !insn->visited && !insn->ignore) { - ret = validate_branch(file, insn_func(insn), insn, state); - if (ret && opts.backtrace) - BT_FUNC("<=== (hint)", insn); - warnings += ret; - } - - insn = list_next_entry(insn, list); + for_each_insn(file, insn) + warnings += validate_unwind_hint(file, insn, &state); } return warnings; @@ -3765,40 +4075,31 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec) /* * Validate rethunk entry constraint: must untrain RET before the first RET. * - * Follow every branch (intra-function) and ensure ANNOTATE_UNRET_END comes + * Follow every branch (intra-function) and ensure VALIDATE_UNRET_END comes * before an actual RET instruction. */ -static int validate_entry(struct objtool_file *file, struct instruction *insn) +static int validate_unret(struct objtool_file *file, struct instruction *insn) { struct instruction *next, *dest; - int ret, warnings = 0; + int ret; for (;;) { next = next_insn_to_validate(file, insn); - if (insn->visited & VISITED_ENTRY) + if (insn->visited & VISITED_UNRET) return 0; - insn->visited |= VISITED_ENTRY; + insn->visited |= VISITED_UNRET; - if (!insn->ignore_alts && !list_empty(&insn->alts)) { + if (insn->alts) { struct alternative *alt; - bool skip_orig = false; - - list_for_each_entry(alt, &insn->alts, list) { - if (alt->skip_orig) - skip_orig = true; - - ret = validate_entry(file, alt->insn); + for (alt = insn->alts; alt; alt = alt->next) { + ret = validate_unret(file, alt->insn); if (ret) { - if (opts.backtrace) - BT_FUNC("(alt)", insn); + BT_INSN(insn, "(alt)"); return ret; } } - - if (skip_orig) - return 0; } switch (insn->type) { @@ -3806,23 +4107,20 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn) case INSN_CALL_DYNAMIC: case INSN_JUMP_DYNAMIC: case INSN_JUMP_DYNAMIC_CONDITIONAL: - WARN_FUNC("early indirect call", insn->sec, insn->offset); + WARN_INSN(insn, "early indirect call"); return 1; case INSN_JUMP_UNCONDITIONAL: case INSN_JUMP_CONDITIONAL: if (!is_sibling_call(insn)) { if (!insn->jump_dest) { - WARN_FUNC("unresolved jump target after linking?!?", - insn->sec, insn->offset); - return -1; + WARN_INSN(insn, "unresolved jump target after linking?!?"); + return 1; } - ret = validate_entry(file, insn->jump_dest); + ret = validate_unret(file, insn->jump_dest); if (ret) { - if (opts.backtrace) { - BT_FUNC("(branch%s)", insn, - insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : ""); - } + BT_INSN(insn, "(branch%s)", + insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : ""); return ret; } @@ -3834,18 +4132,17 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn) /* fallthrough */ case INSN_CALL: - dest = find_insn(file, insn->call_dest->sec, - insn->call_dest->offset); + dest = find_insn(file, insn_call_dest(insn)->sec, + insn_call_dest(insn)->offset); if (!dest) { WARN("Unresolved function after linking!?: %s", - insn->call_dest->name); - return -1; + insn_call_dest(insn)->name); + return 1; } - ret = validate_entry(file, dest); + ret = validate_unret(file, dest); if (ret) { - if (opts.backtrace) - BT_FUNC("(call)", insn); + BT_INSN(insn, "(call)"); return ret; } /* @@ -3855,9 +4152,15 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn) return 0; case INSN_RETURN: - WARN_FUNC("RET before UNTRAIN", insn->sec, insn->offset); + 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; @@ -3867,35 +4170,33 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn) break; } + if (insn->dead_end) + return 0; + if (!next) { - WARN_FUNC("teh end!", insn->sec, insn->offset); - return -1; + WARN_INSN(insn, "teh end!"); + return 1; } insn = next; } - return warnings; + return 0; } /* - * Validate that all branches starting at 'insn->entry' encounter UNRET_END - * before RET. + * Validate that all branches starting at VALIDATE_UNRET_BEGIN encounter + * VALIDATE_UNRET_END before RET. */ -static int validate_unret(struct objtool_file *file) +static int validate_unrets(struct objtool_file *file) { struct instruction *insn; - int ret, warnings = 0; + int warnings = 0; for_each_insn(file, insn) { - if (!insn->entry) + if (!insn->unret) continue; - ret = validate_entry(file, insn); - if (ret < 0) { - WARN_FUNC("Failed UNRET validation", insn->sec, insn->offset); - return ret; - } - warnings += ret; + warnings += validate_unret(file, insn); } return warnings; @@ -3920,41 +4221,72 @@ static int validate_retpoline(struct objtool_file *file) if (insn->type == INSN_RETURN) { if (opts.rethunk) { - WARN_FUNC("'naked' return found in RETHUNK build", - insn->sec, insn->offset); - } else - continue; - } else { - WARN_FUNC("indirect %s found in RETPOLINE build", - insn->sec, insn->offset, - insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call"); + WARN_INSN(insn, "'naked' return found in MITIGATION_RETHUNK build"); + warnings++; + } + continue; } + WARN_INSN(insn, "indirect %s found in MITIGATION_RETPOLINE build", + insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call"); 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; } static bool is_kasan_insn(struct instruction *insn) { return (insn->type == INSN_CALL && - !strcmp(insn->call_dest->name, "__asan_handle_no_return")); + !strcmp(insn_call_dest(insn)->name, "__asan_handle_no_return")); } static bool is_ubsan_insn(struct instruction *insn) { return (insn->type == INSN_CALL && - !strcmp(insn->call_dest->name, + !strcmp(insn_call_dest(insn)->name, "__ubsan_handle_builtin_unreachable")); } static bool ignore_unreachable_insn(struct objtool_file *file, struct instruction *insn) { - int i; + struct symbol *func = insn_func(insn); struct instruction *prev_insn; + int i; - if (insn->ignore || insn->type == INSN_NOP || insn->type == INSN_TRAP) + if (insn->type == INSN_NOP || insn->type == INSN_TRAP || + insn->hole || (func && func->ignore)) return true; /* @@ -3965,53 +4297,10 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio !strcmp(insn->sec->name, ".altinstr_aux")) return true; - /* - * Whole archive runs might encounter dead code from weak symbols. - * This is where the linker will have dropped the weak symbol in - * favour of a regular symbol, but leaves the code in place. - * - * In this case we'll find a piece of code (whole function) that is not - * covered by a !section symbol. Ignore them. - */ - if (opts.link && !insn_func(insn)) { - int size = find_symbol_hole_containing(insn->sec, insn->offset); - unsigned long end = insn->offset + size; - - if (!size) /* not a hole */ - return false; - - if (size < 0) /* hole until the end */ - return true; - - sec_for_each_insn_continue(file, insn) { - /* - * If we reach a visited instruction at or before the - * end of the hole, ignore the unreachable. - */ - if (insn->visited) - return true; - - if (insn->offset >= end) - break; - - /* - * If this hole jumps to a .cold function, mark it ignore too. - */ - if (insn->jump_dest && insn_func(insn->jump_dest) && - strstr(insn_func(insn->jump_dest)->name, ".cold")) { - struct instruction *dest = insn->jump_dest; - func_for_each_insn(file, insn_func(dest), dest) - dest->ignore = true; - } - } - - return false; - } - - if (!insn_func(insn)) + if (!func) return false; - if (insn_func(insn)->static_call_tramp) + if (func->static_call_tramp) return true; /* @@ -4022,8 +4311,8 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio * * It may also insert a UD2 after calling a __noreturn function. */ - prev_insn = list_prev_entry(insn, list); - if ((prev_insn->dead_end || dead_end_function(file, prev_insn->call_dest)) && + prev_insn = prev_insn_same_sec(file, insn); + if (prev_insn && prev_insn->dead_end && (insn->type == INSN_BUG || (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest && insn->jump_dest->type == INSN_BUG))) @@ -4042,7 +4331,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio if (insn->type == INSN_JUMP_UNCONDITIONAL) { if (insn->jump_dest && - insn_func(insn->jump_dest) == insn_func(insn)) { + insn_func(insn->jump_dest) == func) { insn = insn->jump_dest; continue; } @@ -4050,58 +4339,121 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio break; } - if (insn->offset + insn->len >= insn_func(insn)->offset + insn_func(insn)->len) + if (insn->offset + insn->len >= func->offset + func->len) break; - insn = list_next_entry(insn, list); + insn = next_insn_same_sec(file, insn); } return false; } -static int add_prefix_symbol(struct objtool_file *file, struct symbol *func, - struct instruction *insn) +/* + * For FineIBT or kCFI, a certain number of bytes preceding the function may be + * NOPs. Those NOPs may be rewritten at runtime and executed, so give them a + * proper function name: __pfx_<func>. + * + * The NOPs may not exist for the following cases: + * + * - compiler cloned functions (*.cold, *.part0, etc) + * - asm functions created with inline asm or without SYM_FUNC_START() + * + * Also, the function may already have a prefix from a previous objtool run + * (livepatch extracted functions, or manually running objtool multiple times). + * + * So return 0 if the NOPs are missing or the function already has a prefix + * symbol. + */ +static int create_prefix_symbol(struct objtool_file *file, struct symbol *func) { - if (!opts.prefix) + struct instruction *insn, *prev; + char name[SYM_NAME_LEN]; + struct cfi_state *cfi; + + if (!is_func_sym(func) || is_prefix_func(func) || + func->cold || func->static_call_tramp) return 0; - for (;;) { - struct instruction *prev = list_prev_entry(insn, list); - u64 offset; + if ((strlen(func->name) + sizeof("__pfx_") > SYM_NAME_LEN)) { + WARN("%s: symbol name too long, can't create __pfx_ symbol", + func->name); + return 0; + } - if (&prev->list == &file->insn_list) - break; + if (snprintf_check(name, SYM_NAME_LEN, "__pfx_%s", func->name)) + return -1; + + if (file->klp) { + struct symbol *pfx; + + pfx = find_symbol_by_offset(func->sec, func->offset - opts.prefix); + if (pfx && is_prefix_func(pfx) && !strcmp(pfx->name, name)) + return 0; + } + + insn = find_insn(file, func->sec, func->offset); + if (!insn) { + WARN("%s: can't find starting instruction", func->name); + return -1; + } + + for (prev = prev_insn_same_sec(file, insn); + prev; + prev = prev_insn_same_sec(file, prev)) { + u64 offset; if (prev->type != INSN_NOP) - break; + return 0; offset = func->offset - prev->offset; - if (offset >= opts.prefix) { - if (offset == opts.prefix) { - /* - * Since the sec->symbol_list is ordered by - * offset (see elf_add_symbol()) the added - * symbol will not be seen by the iteration in - * validate_section(). - * - * Hence the lack of list_for_each_entry_safe() - * there. - * - * The direct concequence is that prefix symbols - * don't get visited (because pointless), except - * for the logic in ignore_unreachable_insn() - * that needs the terminating insn to be visited - * otherwise it will report the hole. - * - * Hence mark the first instruction of the - * prefix symbol as visisted. - */ - prev->visited |= VISITED_BRANCH; - elf_create_prefix_symbol(file->elf, func, opts.prefix); - } - break; + + if (offset > opts.prefix) + return 0; + + if (offset < opts.prefix) + continue; + + if (!elf_create_symbol(file->elf, name, func->sec, + GELF_ST_BIND(func->sym.st_info), + GELF_ST_TYPE(func->sym.st_info), + prev->offset, opts.prefix)) + return -1; + + break; + } + + if (!prev) + return 0; + + if (!insn->cfi) { + /* + * This can happen if stack validation isn't enabled or the + * function is annotated with STACK_FRAME_NON_STANDARD. + */ + return 0; + } + + /* Propagate insn->cfi to the prefix code */ + cfi = cfi_hash_find_or_add(insn->cfi); + for (; prev != insn; prev = next_insn_same_sec(file, prev)) + prev->cfi = cfi; + + return 0; +} + +static int create_prefix_symbols(struct objtool_file *file) +{ + struct section *sec; + struct symbol *func; + + for_each_sec(file->elf, sec) { + if (!is_text_sec(sec)) + continue; + + sec_for_each_sym(sec, func) { + if (create_prefix_symbol(file, func)) + return -1; } - insn = prev; } return 0; @@ -4111,6 +4463,7 @@ static int validate_symbol(struct objtool_file *file, struct section *sec, struct symbol *sym, struct insn_state *state) { struct instruction *insn; + struct symbol *func; int ret; if (!sym->len) { @@ -4122,16 +4475,32 @@ static int validate_symbol(struct objtool_file *file, struct section *sec, return 0; insn = find_insn(file, sec, sym->offset); - if (!insn || insn->ignore || insn->visited) + if (!insn || insn->visited) return 0; - add_prefix_symbol(file, sym, insn); + if (opts.uaccess) + state->uaccess = sym->uaccess_safe; + + func = insn_func(insn); + + if (opts.checksum) + checksum_init(func); + + if (opts.trace && !fnmatch(opts.trace, sym->name, 0)) { + trace_enable(); + TRACE("%s: validation begin\n", sym->name); + } + + ret = validate_branch(file, func, insn, *state); + if (ret) + BT_INSN(insn, "<=== (sym)"); + + TRACE("%s: validation %s\n\n", sym->name, ret ? "failed" : "end"); + trace_disable(); - state->uaccess = sym->uaccess_safe; + if (opts.checksum) + checksum_finish(func); - ret = validate_branch(file, insn_func(insn), insn, *state); - if (ret && opts.backtrace) - BT_FUNC("<=== (sym)", insn); return ret; } @@ -4141,8 +4510,8 @@ static int validate_section(struct objtool_file *file, struct section *sec) struct symbol *func; int warnings = 0; - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->type != STT_FUNC) + sec_for_each_sym(sec, func) { + if (!is_func_sym(func)) continue; init_insn_state(file, &state, sec); @@ -4171,6 +4540,12 @@ static int validate_noinstr_sections(struct objtool_file *file) warnings += validate_unwind_hints(file, sec); } + sec = find_section_by_name(file->elf, ".cpuidle.text"); + if (sec) { + warnings += validate_section(file, sec); + warnings += validate_unwind_hints(file, sec); + } + return warnings; } @@ -4179,8 +4554,8 @@ static int validate_functions(struct objtool_file *file) struct section *sec; int warnings = 0; - for_each_sec(file, sec) { - if (!(sec->sh.sh_flags & SHF_EXECINSTR)) + for_each_sec(file->elf, sec) { + if (!is_text_sec(sec)) continue; warnings += validate_section(file, sec); @@ -4213,6 +4588,51 @@ static bool noendbr_range(struct objtool_file *file, struct instruction *insn) return insn->offset == sym->offset + sym->len; } +static int __validate_ibt_insn(struct objtool_file *file, struct instruction *insn, + struct instruction *dest) +{ + if (dest->type == INSN_ENDBR) { + mark_endbr_used(dest); + return 0; + } + + if (insn_func(dest) && insn_func(insn) && + insn_func(dest)->pfunc == insn_func(insn)->pfunc) { + /* + * Anything from->to self is either _THIS_IP_ or + * IRET-to-self. + * + * There is no sane way to annotate _THIS_IP_ since the + * compiler treats the relocation as a constant and is + * happy to fold in offsets, skewing any annotation we + * do, leading to vast amounts of false-positives. + * + * There's also compiler generated _THIS_IP_ through + * KCOV and such which we have no hope of annotating. + * + * As such, blanket accept self-references without + * issue. + */ + return 0; + } + + /* + * Accept anything ANNOTATE_NOENDBR. + */ + if (dest->noendbr) + return 0; + + /* + * Accept if this is the instruction after a symbol + * that is (no)endbr -- typical code-range usage. + */ + if (noendbr_range(file, dest)) + return 0; + + WARN_INSN(insn, "relocation to !ENDBR: %s", offstr(dest->sec, dest->offset)); + return 1; +} + static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn) { struct instruction *dest; @@ -4225,6 +4645,7 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn * direct/indirect branches: */ switch (insn->type) { + case INSN_CALL: case INSN_CALL_DYNAMIC: case INSN_JUMP_CONDITIONAL: @@ -4234,6 +4655,23 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn case INSN_RETURN: case INSN_NOP: return 0; + + case INSN_LEA_RIP: + if (!insn_reloc(file, insn)) { + /* local function pointer reference without reloc */ + + off = arch_jump_destination(insn); + + dest = find_insn(file, insn->sec, off); + if (!dest) { + WARN_INSN(insn, "corrupt function pointer reference"); + return 1; + } + + return __validate_ibt_insn(file, insn, dest); + } + break; + default: break; } @@ -4241,68 +4679,16 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn for (reloc = insn_reloc(file, insn); reloc; reloc = find_reloc_by_dest_range(file->elf, insn->sec, - reloc->offset + 1, - (insn->offset + insn->len) - (reloc->offset + 1))) { + reloc_offset(reloc) + 1, + (insn->offset + insn->len) - (reloc_offset(reloc) + 1))) { - /* - * static_call_update() references the trampoline, which - * doesn't have (or need) ENDBR. Skip warning in that case. - */ - if (reloc->sym->static_call_tramp) - continue; - - off = reloc->sym->offset; - if (reloc->type == R_X86_64_PC32 || reloc->type == R_X86_64_PLT32) - off += arch_dest_reloc_offset(reloc->addend); - else - off += reloc->addend; + off = reloc->sym->offset + arch_insn_adjusted_addend(insn, reloc); dest = find_insn(file, reloc->sym->sec, off); if (!dest) continue; - if (dest->type == INSN_ENDBR) { - mark_endbr_used(dest); - continue; - } - - if (insn_func(dest) && insn_func(dest) == insn_func(insn)) { - /* - * Anything from->to self is either _THIS_IP_ or - * IRET-to-self. - * - * There is no sane way to annotate _THIS_IP_ since the - * compiler treats the relocation as a constant and is - * happy to fold in offsets, skewing any annotation we - * do, leading to vast amounts of false-positives. - * - * There's also compiler generated _THIS_IP_ through - * KCOV and such which we have no hope of annotating. - * - * As such, blanket accept self-references without - * issue. - */ - continue; - } - - /* - * Accept anything ANNOTATE_NOENDBR. - */ - if (dest->noendbr) - continue; - - /* - * Accept if this is the instruction after a symbol - * that is (no)endbr -- typical code-range usage. - */ - if (noendbr_range(file, dest)) - continue; - - WARN_FUNC("relocation to !ENDBR: %s", - insn->sec, insn->offset, - offstr(dest->sec, dest->offset)); - - warnings++; + warnings += __validate_ibt_insn(file, insn, dest); } return warnings; @@ -4314,7 +4700,7 @@ static int validate_ibt_data_reloc(struct objtool_file *file, struct instruction *dest; dest = find_insn(file, reloc->sym->sec, - reloc->sym->offset + reloc->addend); + reloc->sym->offset + reloc_addend(reloc)); if (!dest) return 0; @@ -4326,9 +4712,8 @@ static int validate_ibt_data_reloc(struct objtool_file *file, if (dest->noendbr) return 0; - WARN_FUNC("data relocation to !ENDBR: %s", - reloc->sec->base, reloc->offset, - offstr(dest->sec, dest->offset)); + WARN_FUNC(reloc->sec->base, reloc_offset(reloc), + "data relocation to !ENDBR: %s", offstr(dest->sec, dest->offset)); return 1; } @@ -4348,13 +4733,13 @@ static int validate_ibt(struct objtool_file *file) for_each_insn(file, insn) warnings += validate_ibt_insn(file, insn); - for_each_sec(file, sec) { + for_each_sec(file->elf, sec) { /* Already done by validate_ibt_insn() */ - if (sec->sh.sh_flags & SHF_EXECINSTR) + if (is_text_sec(sec)) continue; - if (!sec->reloc) + if (!sec->rsec) continue; /* @@ -4366,8 +4751,8 @@ static int validate_ibt(struct objtool_file *file) !strncmp(sec->name, ".debug", 6) || !strcmp(sec->name, ".altinstructions") || !strcmp(sec->name, ".ibt_endbr_seal") || + !strcmp(sec->name, ".kcfi_traps") || !strcmp(sec->name, ".orc_unwind_ip") || - !strcmp(sec->name, ".parainstructions") || !strcmp(sec->name, ".retpoline_sites") || !strcmp(sec->name, ".smp_locks") || !strcmp(sec->name, ".static_call_sites") || @@ -4376,12 +4761,17 @@ static int validate_ibt(struct objtool_file *file) !strcmp(sec->name, "__bug_table") || !strcmp(sec->name, "__ex_table") || !strcmp(sec->name, "__jump_table") || + !strcmp(sec->name, "__klp_funcs") || !strcmp(sec->name, "__mcount_loc") || - !strcmp(sec->name, ".kcfi_traps") || - strstr(sec->name, "__patchable_function_entries")) + !strcmp(sec->name, ".llvm.call-graph-profile") || + !strcmp(sec->name, ".llvm_bb_addr_map") || + !strcmp(sec->name, "__tracepoints") || + !strcmp(sec->name, ".return_sites") || + !strcmp(sec->name, ".call_sites") || + !strcmp(sec->name, "__patchable_function_entries")) continue; - list_for_each_entry(reloc, &sec->reloc->reloc_list, list) + for_each_reloc(sec->rsec, reloc) warnings += validate_ibt_data_reloc(file, reloc); } @@ -4402,16 +4792,14 @@ static int validate_sls(struct objtool_file *file) switch (insn->type) { case INSN_RETURN: if (!next_insn || next_insn->type != INSN_TRAP) { - WARN_FUNC("missing int3 after ret", - insn->sec, insn->offset); + WARN_INSN(insn, "missing int3 after ret"); warnings++; } break; case INSN_JUMP_DYNAMIC: if (!next_insn || next_insn->type != INSN_TRAP) { - WARN_FUNC("missing int3 after indirect jump", - insn->sec, insn->offset); + WARN_INSN(insn, "missing int3 after indirect jump"); warnings++; } break; @@ -4425,7 +4813,9 @@ static int validate_sls(struct objtool_file *file) static int validate_reachable_instructions(struct objtool_file *file) { - struct instruction *insn; + struct instruction *insn, *prev_insn; + struct symbol *call_dest; + int warnings = 0; if (file->ignore_unreachables) return 0; @@ -4434,67 +4824,163 @@ static int validate_reachable_instructions(struct objtool_file *file) if (insn->visited || ignore_unreachable_insn(file, insn)) continue; - WARN_FUNC("unreachable instruction", insn->sec, insn->offset); - return 1; + prev_insn = prev_insn_same_sec(file, insn); + if (prev_insn && prev_insn->dead_end) { + call_dest = insn_call_dest(prev_insn); + if (call_dest) { + WARN_INSN(insn, "%s() missing __noreturn in .c/.h or NORETURN() in noreturns.h", + call_dest->name); + warnings++; + continue; + } + } + + WARN_INSN(insn, "unreachable instruction"); + warnings++; } - return 0; + return warnings; +} + +__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->elf, 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; +}; + +/* + * Reduce peak RSS usage by freeing insns memory before writing the ELF file, + * which can trigger more allocations for .debug_* sections whose data hasn't + * been read yet. + */ +static void free_insns(struct objtool_file *file) +{ + struct instruction *insn; + struct insn_chunk *chunks = NULL, *chunk; + + for_each_insn(file, insn) { + if (!insn->idx) { + chunk = malloc(sizeof(*chunk)); + chunk->addr = insn; + chunk->next = chunks; + chunks = chunk; + } + } + + for (chunk = chunks; chunk; chunk = chunk->next) + free(chunk->addr); +} + +const char *objtool_disas_insn(struct instruction *insn) +{ + struct disas_context *dctx = objtool_disas_ctx; + + if (!dctx) + return ""; + + disas_insn(dctx, insn); + return disas_result(dctx); } int check(struct objtool_file *file) { - int ret, warnings = 0; + struct disas_context *disas_ctx = NULL; + int ret = 0, warnings = 0; + + /* + * Create a disassembly context if we might disassemble any + * instruction or function. + */ + if (opts.verbose || opts.backtrace || opts.trace || opts.disas) { + disas_ctx = disas_context_create(file); + if (!disas_ctx) { + opts.disas = false; + opts.trace = false; + } + objtool_disas_ctx = disas_ctx; + } arch_initial_func_cfi_state(&initial_func_cfi); init_cfi_state(&init_cfi); init_cfi_state(&func_cfi); set_func_state(&func_cfi); + init_cfi_state(&force_undefined_cfi); + force_undefined_cfi.force_undefined = true; - if (!cfi_hash_alloc(1UL << (file->elf->symbol_bits - 3))) + if (!cfi_hash_alloc(1UL << (file->elf->symbol_bits - 3))) { + ret = -1; goto out; + } cfi_hash_add(&init_cfi); cfi_hash_add(&func_cfi); - ret = decode_sections(file); - if (ret < 0) + ret = checksum_debug_init(file); + if (ret) goto out; - warnings += ret; + ret = decode_sections(file); + if (ret) + goto out; - if (list_empty(&file->insn_list)) + if (!nr_insns) goto out; - if (opts.retpoline) { - ret = validate_retpoline(file); - if (ret < 0) - return ret; - warnings += ret; - } + if (opts.retpoline) + warnings += validate_retpoline(file); - if (opts.stackval || opts.orc || opts.uaccess) { - ret = validate_functions(file); - if (ret < 0) - goto out; - warnings += ret; + if (validate_branch_enabled()) { + int w = 0; - ret = validate_unwind_hints(file, NULL); - if (ret < 0) - goto out; - warnings += ret; + w += validate_functions(file); + w += validate_unwind_hints(file, NULL); + if (!w) + w += validate_reachable_instructions(file); - if (!warnings) { - ret = validate_reachable_instructions(file); - if (ret < 0) - goto out; - warnings += ret; - } + warnings += w; } else if (opts.noinstr) { - ret = validate_noinstr_sections(file); - if (ret < 0) - goto out; - warnings += ret; + warnings += validate_noinstr_sections(file); } if (opts.unret) { @@ -4502,82 +4988,77 @@ int check(struct objtool_file *file) * Must be after validate_branch() and friends, it plays * further games with insn->visited. */ - ret = validate_unret(file); - if (ret < 0) - return ret; - warnings += ret; + warnings += validate_unrets(file); } - if (opts.ibt) { - ret = validate_ibt(file); - if (ret < 0) - goto out; - warnings += ret; - } + if (opts.ibt) + warnings += validate_ibt(file); - if (opts.sls) { - ret = validate_sls(file); - if (ret < 0) - goto out; - warnings += ret; - } + if (opts.sls) + warnings += validate_sls(file); if (opts.static_call) { ret = create_static_call_sections(file); - if (ret < 0) + if (ret) goto out; - warnings += ret; } if (opts.retpoline) { ret = create_retpoline_sites_sections(file); - if (ret < 0) + if (ret) goto out; - warnings += ret; } if (opts.cfi) { ret = create_cfi_sections(file); - if (ret < 0) + if (ret) goto out; - warnings += ret; } if (opts.rethunk) { ret = create_return_sites_sections(file); - if (ret < 0) + if (ret) goto out; - warnings += ret; if (opts.hack_skylake) { ret = create_direct_call_sections(file); - if (ret < 0) + if (ret) goto out; - warnings += ret; } } if (opts.mcount) { ret = create_mcount_loc_sections(file); - if (ret < 0) + if (ret) + goto out; + } + + if (opts.prefix) { + ret = create_prefix_symbols(file); + if (ret) goto out; - warnings += ret; } if (opts.ibt) { ret = create_ibt_endbr_seal_sections(file); - if (ret < 0) + if (ret) goto out; - warnings += ret; } - if (opts.orc && !list_empty(&file->insn_list)) { - ret = orc_create(file); - if (ret < 0) + if (opts.noabs) + warnings += check_abs_references(file); + + if (opts.checksum) { + ret = create_sym_checksum_section(file); + if (ret) goto out; - warnings += ret; } + if (opts.orc && nr_insns) { + ret = orc_create(file); + if (ret) + goto out; + } if (opts.stats) { printf("nr_insns_visited: %ld\n", nr_insns_visited); @@ -4587,10 +5068,32 @@ int check(struct objtool_file *file) } out: - /* - * For now, don't fail the kernel build on fatal warnings. These - * errors are still fairly common due to the growing matrix of - * supported toolchains and their recent pace of change. - */ - return 0; + if (ret || warnings) { + if (opts.werror && warnings) + ret = 1; + + if (opts.verbose) { + if (opts.werror && warnings) + WARN("%d warning(s) upgraded to errors", warnings); + disas_warned_funcs(disas_ctx); + } + } + + if (opts.disas) + disas_funcs(disas_ctx); + + if (disas_ctx) { + disas_context_destroy(disas_ctx); + objtool_disas_ctx = NULL; + } + + free_insns(file); + + if (!ret && !warnings) + return 0; + + if (opts.backup && make_backup()) + return 1; + + return ret; } |