diff options
Diffstat (limited to 'tools/objtool/check.c')
| -rw-r--r-- | tools/objtool/check.c | 132 |
1 files changed, 93 insertions, 39 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index ce3c25fec2a6..fb3f251ea021 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -683,6 +683,52 @@ static int create_static_call_sections(struct objtool_file *file) return 0; } +static int create_retpoline_sites_sections(struct objtool_file *file) +{ + struct instruction *insn; + struct section *sec; + int idx; + + sec = find_section_by_name(file->elf, ".retpoline_sites"); + if (sec) { + WARN("file already has .retpoline_sites, skipping"); + return 0; + } + + idx = 0; + list_for_each_entry(insn, &file->retpoline_call_list, call_node) + idx++; + + if (!idx) + return 0; + + sec = elf_create_section(file->elf, ".retpoline_sites", 0, + sizeof(int), idx); + if (!sec) { + WARN("elf_create_section: .retpoline_sites"); + 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"); + return -1; + } + + idx++; + } + + return 0; +} + static int create_mcount_loc_sections(struct objtool_file *file) { struct section *sec; @@ -1016,6 +1062,11 @@ static void annotate_call_site(struct objtool_file *file, return; } + if (sym->retpoline_thunk) { + list_add_tail(&insn->call_node, &file->retpoline_call_list); + return; + } + /* * Many compilers cannot disable KCOV with a function attribute * so they need a little help, NOP out any KCOV calls from noinstr @@ -1075,6 +1126,39 @@ static void add_call_dest(struct objtool_file *file, struct instruction *insn, annotate_call_site(file, insn, sibling); } +static void add_retpoline_call(struct objtool_file *file, struct instruction *insn) +{ + /* + * Retpoline calls/jumps are really dynamic calls/jumps in disguise, + * so convert them accordingly. + */ + switch (insn->type) { + case INSN_CALL: + insn->type = INSN_CALL_DYNAMIC; + break; + case INSN_JUMP_UNCONDITIONAL: + insn->type = INSN_JUMP_DYNAMIC; + break; + case INSN_JUMP_CONDITIONAL: + insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL; + break; + default: + return; + } + + insn->retpoline_safe = true; + + /* + * Whatever stack impact regular CALLs have, should be undone + * by the RETURN of the called function. + * + * Annotated intra-function calls retain the stack_ops but + * are converted to JUMP, see read_intra_function_calls(). + */ + remove_insn_ops(insn); + + annotate_call_site(file, insn, false); +} /* * Find the destination instructions for all jumps. */ @@ -1097,19 +1181,7 @@ static int add_jump_destinations(struct objtool_file *file) dest_sec = reloc->sym->sec; dest_off = arch_dest_reloc_offset(reloc->addend); } else if (reloc->sym->retpoline_thunk) { - /* - * Retpoline jumps are really dynamic jumps in - * disguise, so convert them accordingly. - */ - if (insn->type == INSN_JUMP_UNCONDITIONAL) - insn->type = INSN_JUMP_DYNAMIC; - else - insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL; - - list_add_tail(&insn->call_node, - &file->retpoline_call_list); - - insn->retpoline_safe = true; + add_retpoline_call(file, insn); continue; } else if (insn->func) { /* internal or external sibling call (with reloc) */ @@ -1238,18 +1310,7 @@ static int add_call_destinations(struct objtool_file *file) add_call_dest(file, insn, dest, false); } else if (reloc->sym->retpoline_thunk) { - /* - * 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; + add_retpoline_call(file, insn); } else add_call_dest(file, insn, reloc->sym, false); @@ -1980,11 +2041,6 @@ 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; @@ -2057,15 +2113,6 @@ 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; } @@ -3468,6 +3515,13 @@ int check(struct objtool_file *file) goto out; warnings += ret; + if (retpoline) { + ret = create_retpoline_sites_sections(file); + if (ret < 0) + goto out; + warnings += ret; + } + if (mcount) { ret = create_mcount_loc_sections(file); if (ret < 0) |