diff options
Diffstat (limited to 'tools/objtool/check.c')
-rw-r--r-- | tools/objtool/check.c | 236 |
1 files changed, 118 insertions, 118 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 5e5388a38e2a..9ed1a4cd00dc 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -108,6 +108,18 @@ 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 bool is_jump_table_jump(struct instruction *insn) +{ + struct alt_group *alt_group = insn->alt_group; + + if (insn->jump_table) + return true; + + /* Retpoline alternative for a jump table? */ + return alt_group && alt_group->orig_group && + alt_group->orig_group->first_insn->jump_table; +} + static bool is_sibling_call(struct instruction *insn) { /* @@ -120,7 +132,7 @@ static bool is_sibling_call(struct instruction *insn) /* An indirect jump is either a sibling call or a jump to a table. */ if (insn->type == INSN_JUMP_DYNAMIC) - return list_empty(&insn->alts); + return !is_jump_table_jump(insn); /* add_jump_destinations() sets insn->call_dest for sibling calls. */ return (is_static_jump(insn) && insn->call_dest); @@ -433,8 +445,7 @@ reachable: static int create_static_call_sections(struct objtool_file *file) { - struct section *sec, *reloc_sec; - struct reloc *reloc; + struct section *sec; struct static_call_site *site; struct instruction *insn; struct symbol *key_sym; @@ -452,7 +463,7 @@ static int create_static_call_sections(struct objtool_file *file) return 0; idx = 0; - list_for_each_entry(insn, &file->static_call_list, static_call_node) + list_for_each_entry(insn, &file->static_call_list, call_node) idx++; sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE, @@ -460,36 +471,18 @@ static int create_static_call_sections(struct objtool_file *file) if (!sec) return -1; - reloc_sec = elf_create_reloc_section(file->elf, sec, SHT_RELA); - if (!reloc_sec) - return -1; - idx = 0; - list_for_each_entry(insn, &file->static_call_list, static_call_node) { + 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' */ - reloc = malloc(sizeof(*reloc)); - - if (!reloc) { - perror("malloc"); - return -1; - } - memset(reloc, 0, sizeof(*reloc)); - - insn_to_reloc_sym_addend(insn->sec, insn->offset, reloc); - if (!reloc->sym) { - WARN_FUNC("static call tramp: missing containing symbol", - insn->sec, insn->offset); + if (elf_add_reloc_to_insn(file->elf, sec, + idx * sizeof(struct static_call_site), + R_X86_64_PC32, + insn->sec, insn->offset)) return -1; - } - - reloc->type = R_X86_64_PC32; - reloc->offset = idx * sizeof(struct static_call_site); - reloc->sec = reloc_sec; - elf_add_reloc(file->elf, reloc); /* find key symbol */ key_name = strdup(insn->call_dest->name); @@ -526,32 +519,21 @@ static int create_static_call_sections(struct objtool_file *file) free(key_name); /* populate reloc for 'key' */ - reloc = malloc(sizeof(*reloc)); - if (!reloc) { - perror("malloc"); + 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)) return -1; - } - memset(reloc, 0, sizeof(*reloc)); - reloc->sym = key_sym; - reloc->addend = is_sibling_call(insn) ? STATIC_CALL_SITE_TAIL : 0; - reloc->type = R_X86_64_PC32; - reloc->offset = idx * sizeof(struct static_call_site) + 4; - reloc->sec = reloc_sec; - elf_add_reloc(file->elf, reloc); idx++; } - if (elf_rebuild_reloc_section(file->elf, reloc_sec)) - return -1; - return 0; } static int create_mcount_loc_sections(struct objtool_file *file) { - struct section *sec, *reloc_sec; - struct reloc *reloc; + struct section *sec; unsigned long *loc; struct instruction *insn; int idx; @@ -574,49 +556,21 @@ static int create_mcount_loc_sections(struct objtool_file *file) if (!sec) return -1; - reloc_sec = elf_create_reloc_section(file->elf, sec, SHT_RELA); - if (!reloc_sec) - return -1; - idx = 0; list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node) { loc = (unsigned long *)sec->data->d_buf + idx; memset(loc, 0, sizeof(unsigned long)); - reloc = malloc(sizeof(*reloc)); - if (!reloc) { - perror("malloc"); + if (elf_add_reloc_to_insn(file->elf, sec, + idx * sizeof(unsigned long), + R_X86_64_64, + insn->sec, insn->offset)) return -1; - } - memset(reloc, 0, sizeof(*reloc)); - - if (insn->sec->sym) { - reloc->sym = insn->sec->sym; - reloc->addend = insn->offset; - } else { - reloc->sym = find_symbol_containing(insn->sec, insn->offset); - - if (!reloc->sym) { - WARN("missing symbol for insn at offset 0x%lx\n", - insn->offset); - return -1; - } - - reloc->addend = insn->offset - reloc->sym->offset; - } - - reloc->type = R_X86_64_64; - reloc->offset = idx * sizeof(unsigned long); - reloc->sec = reloc_sec; - elf_add_reloc(file->elf, reloc); idx++; } - if (elf_rebuild_reloc_section(file->elf, reloc_sec)) - return -1; - return 0; } @@ -850,6 +804,30 @@ static int add_ignore_alternatives(struct objtool_file *file) return 0; } +__weak bool arch_is_retpoline(struct symbol *sym) +{ + return false; +} + +#define NEGATIVE_RELOC ((void *)-1L) + +static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn) +{ + if (insn->reloc == NEGATIVE_RELOC) + return NULL; + + if (!insn->reloc) { + insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec, + insn->offset, insn->len); + if (!insn->reloc) { + insn->reloc = NEGATIVE_RELOC; + return NULL; + } + } + + return insn->reloc; +} + /* * Find the destination instructions for all jumps. */ @@ -864,16 +842,14 @@ static int add_jump_destinations(struct objtool_file *file) if (!is_static_jump(insn)) continue; - reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); + 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 (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) || - !strncmp(reloc->sym->name, "__x86_retpoline_", 16)) { + } else if (arch_is_retpoline(reloc->sym)) { /* * Retpoline jumps are really dynamic jumps in * disguise, so convert them accordingly. @@ -883,13 +859,16 @@ static int add_jump_destinations(struct objtool_file *file) else insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL; + list_add_tail(&insn->call_node, + &file->retpoline_call_list); + insn->retpoline_safe = true; continue; } else if (insn->func) { /* internal or external sibling call (with reloc) */ insn->call_dest = reloc->sym; if (insn->call_dest->static_call_tramp) { - list_add_tail(&insn->static_call_node, + list_add_tail(&insn->call_node, &file->static_call_list); } continue; @@ -951,7 +930,7 @@ static int add_jump_destinations(struct objtool_file *file) /* internal sibling call (without reloc) */ insn->call_dest = insn->jump_dest->func; if (insn->call_dest->static_call_tramp) { - list_add_tail(&insn->static_call_node, + list_add_tail(&insn->call_node, &file->static_call_list); } } @@ -995,8 +974,7 @@ static int add_call_destinations(struct objtool_file *file) if (insn->type != INSN_CALL) continue; - reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); + reloc = insn_reloc(file, insn); if (!reloc) { dest_off = arch_jump_destination(insn); insn->call_dest = find_call_destination(insn->sec, dest_off); @@ -1026,9 +1004,29 @@ static int add_call_destinations(struct objtool_file *file) dest_off); return -1; } + + } else if (arch_is_retpoline(reloc->sym)) { + /* + * Retpoline calls are really dynamic calls in + * disguise, so convert them accordingly. + */ + insn->type = INSN_CALL_DYNAMIC; + insn->retpoline_safe = true; + + list_add_tail(&insn->call_node, + &file->retpoline_call_list); + + remove_insn_ops(insn); + continue; + } else insn->call_dest = reloc->sym; + if (insn->call_dest && insn->call_dest->static_call_tramp) { + list_add_tail(&insn->call_node, + &file->static_call_list); + } + /* * Many compilers cannot disable KCOV with a function attribute * so they need a little help, NOP out any KCOV calls from noinstr @@ -1175,8 +1173,7 @@ static int handle_group_alt(struct objtool_file *file, * alternatives code can adjust the relative offsets * accordingly. */ - alt_reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); + alt_reloc = insn_reloc(file, insn); if (alt_reloc && !arch_support_alt_relocation(special_alt, insn, alt_reloc)) { @@ -1751,6 +1748,11 @@ static void mark_rodata(struct objtool_file *file) file->rodata = found; } +__weak int arch_rewrite_retpolines(struct objtool_file *file) +{ + return 0; +} + static int decode_sections(struct objtool_file *file) { int ret; @@ -1772,10 +1774,17 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret; + /* + * Must be before add_{jump_call}_destination. + */ ret = read_static_call_tramps(file); if (ret) return ret; + /* + * Must be before add_special_section_alts() as that depends on + * jump_dest being set. + */ ret = add_jump_destinations(file); if (ret) return ret; @@ -1784,6 +1793,10 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret; + /* + * Must be before add_call_destination(); it changes INSN_CALL to + * INSN_JUMP. + */ ret = read_intra_function_calls(file); if (ret) return ret; @@ -1808,6 +1821,15 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret; + /* + * Must be after add_special_section_alts(), since this will emit + * alternatives. Must be after add_{jump,call}_destination(), since + * those create the call insn lists. + */ + ret = arch_rewrite_retpolines(file); + if (ret) + return ret; + return 0; } @@ -1959,8 +1981,9 @@ static void restore_reg(struct cfi_state *cfi, unsigned char reg) * 41 5d pop %r13 * c3 retq */ -static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi, - struct stack_op *op) +static int update_cfi_state(struct instruction *insn, + struct instruction *next_insn, + struct cfi_state *cfi, struct stack_op *op) { struct cfi_reg *cfa = &cfi->cfa; struct cfi_reg *regs = cfi->regs; @@ -2019,7 +2042,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi, } else if (op->src.reg == CFI_BP && op->dest.reg == CFI_SP && - cfa->base == CFI_BP) { + (cfa->base == CFI_BP || cfa->base == cfi->drap_reg)) { /* * mov %rbp, %rsp @@ -2161,7 +2184,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi, break; } - if (op->dest.reg == cfi->cfa.base) { + if (op->dest.reg == cfi->cfa.base && !(next_insn && next_insn->hint)) { WARN_FUNC("unsupported stack register modification", insn->sec, insn->offset); return -1; @@ -2216,7 +2239,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi, cfa->offset = 0; cfi->drap_offset = -1; - } else if (regs[op->dest.reg].offset == -cfi->stack_size) { + } else if (cfi->stack_size == -regs[op->dest.reg].offset) { /* pop %reg */ restore_reg(cfi, op->dest.reg); @@ -2357,26 +2380,6 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi, break; - case OP_DEST_LEAVE: - if ((!cfi->drap && cfa->base != CFI_BP) || - (cfi->drap && cfa->base != cfi->drap_reg)) { - WARN_FUNC("leave instruction with modified stack frame", - insn->sec, insn->offset); - return -1; - } - - /* leave (mov %rbp, %rsp; pop %rbp) */ - - cfi->stack_size = -cfi->regs[CFI_BP].offset - 8; - restore_reg(cfi, CFI_BP); - - if (!cfi->drap) { - cfa->base = CFI_SP; - cfa->offset -= 8; - } - - break; - case OP_DEST_MEM: if (op->src.type != OP_SRC_POP && op->src.type != OP_SRC_POPF) { WARN_FUNC("unknown stack-related memory operation", @@ -2433,13 +2436,15 @@ static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn return 0; } -static int handle_insn_ops(struct instruction *insn, struct insn_state *state) +static int handle_insn_ops(struct instruction *insn, + struct instruction *next_insn, + struct insn_state *state) { struct stack_op *op; list_for_each_entry(op, &insn->stack_ops, list) { - if (update_cfi_state(insn, &state->cfi, op)) + if (update_cfi_state(insn, next_insn, &state->cfi, op)) return 1; if (!insn->alt_group) @@ -2722,7 +2727,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, return 0; } - if (handle_insn_ops(insn, &state)) + if (handle_insn_ops(insn, next_insn, &state)) return 1; switch (insn->type) { @@ -2746,11 +2751,6 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, if (dead_end_function(file, insn->call_dest)) return 0; - if (insn->type == INSN_CALL && insn->call_dest->static_call_tramp) { - list_add_tail(&insn->static_call_node, - &file->static_call_list); - } - break; case INSN_JUMP_CONDITIONAL: |