diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/include/linux/objtool.h | 32 | ||||
| -rw-r--r-- | tools/objtool/arch/x86/decode.c | 34 | ||||
| -rw-r--r-- | tools/objtool/builtin-check.c | 7 | ||||
| -rw-r--r-- | tools/objtool/check.c | 400 | ||||
| -rw-r--r-- | tools/objtool/elf.c | 63 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/arch.h | 1 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/builtin.h | 3 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/check.h | 13 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/elf.h | 1 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/objtool.h | 4 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/warn.h | 2 | ||||
| -rw-r--r-- | tools/objtool/objtool.c | 1 |
12 files changed, 526 insertions, 35 deletions
diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h index aca52db2f3f3..586d35720f13 100644 --- a/tools/include/linux/objtool.h +++ b/tools/include/linux/objtool.h @@ -77,6 +77,18 @@ struct unwind_hint { #define STACK_FRAME_NON_STANDARD_FP(func) #endif +#define ANNOTATE_NOENDBR \ + "986: \n\t" \ + ".pushsection .discard.noendbr\n\t" \ + _ASM_PTR " 986b\n\t" \ + ".popsection\n\t" + +#define ASM_REACHABLE \ + "998:\n\t" \ + ".pushsection .discard.reachable\n\t" \ + ".long 998b - .\n\t" \ + ".popsection\n\t" + #else /* __ASSEMBLY__ */ /* @@ -129,6 +141,20 @@ struct unwind_hint { .popsection .endm +.macro ANNOTATE_NOENDBR +.Lhere_\@: + .pushsection .discard.noendbr + .quad .Lhere_\@ + .popsection +.endm + +.macro REACHABLE +.Lhere_\@: + .pushsection .discard.reachable + .long .Lhere_\@ - . + .popsection +.endm + #endif /* __ASSEMBLY__ */ #else /* !CONFIG_STACK_VALIDATION */ @@ -139,12 +165,18 @@ struct unwind_hint { "\n\t" #define STACK_FRAME_NON_STANDARD(func) #define STACK_FRAME_NON_STANDARD_FP(func) +#define ANNOTATE_NOENDBR +#define ASM_REACHABLE #else #define ANNOTATE_INTRA_FUNCTION_CALL .macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0 .endm .macro STACK_FRAME_NON_STANDARD func:req .endm +.macro ANNOTATE_NOENDBR +.endm +.macro REACHABLE +.endm #endif #endif /* CONFIG_STACK_VALIDATION */ diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 479e769ca324..943cb41cddf7 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -103,6 +103,18 @@ unsigned long arch_jump_destination(struct instruction *insn) #define rm_is_mem(reg) (mod_is_mem() && !is_RIP() && rm_is(reg)) #define rm_is_reg(reg) (mod_is_reg() && modrm_rm == (reg)) +static bool has_notrack_prefix(struct insn *insn) +{ + int i; + + for (i = 0; i < insn->prefixes.nbytes; i++) { + if (insn->prefixes.bytes[i] == 0x3e) + return true; + } + + return false; +} + int arch_decode_instruction(struct objtool_file *file, const struct section *sec, unsigned long offset, unsigned int maxlen, unsigned int *len, enum insn_type *type, @@ -112,7 +124,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec const struct elf *elf = file->elf; struct insn insn; int x86_64, ret; - unsigned char op1, op2, op3, + unsigned char op1, op2, op3, prefix, rex = 0, rex_b = 0, rex_r = 0, rex_w = 0, rex_x = 0, modrm = 0, modrm_mod = 0, modrm_rm = 0, modrm_reg = 0, sib = 0, /* sib_scale = 0, */ sib_index = 0, sib_base = 0; @@ -137,6 +149,8 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec if (insn.vex_prefix.nbytes) return 0; + prefix = insn.prefixes.bytes[0]; + op1 = insn.opcode.bytes[0]; op2 = insn.opcode.bytes[1]; op3 = insn.opcode.bytes[2]; @@ -492,6 +506,12 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec /* nopl/nopw */ *type = INSN_NOP; + } else if (op2 == 0x1e) { + + if (prefix == 0xf3 && (modrm == 0xfa || modrm == 0xfb)) + *type = INSN_ENDBR; + + } else if (op2 == 0x38 && op3 == 0xf8) { if (insn.prefixes.nbytes == 1 && insn.prefixes.bytes[0] == 0xf2) { @@ -636,20 +656,24 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec break; case 0xff: - if (modrm_reg == 2 || modrm_reg == 3) + if (modrm_reg == 2 || modrm_reg == 3) { *type = INSN_CALL_DYNAMIC; + if (has_notrack_prefix(&insn)) + WARN("notrack prefix found at %s:0x%lx", sec->name, offset); - else if (modrm_reg == 4) + } else if (modrm_reg == 4) { *type = INSN_JUMP_DYNAMIC; + if (has_notrack_prefix(&insn)) + WARN("notrack prefix found at %s:0x%lx", sec->name, offset); - else if (modrm_reg == 5) + } else if (modrm_reg == 5) { /* jmpf */ *type = INSN_CONTEXT_SWITCH; - else if (modrm_reg == 6) { + } else if (modrm_reg == 6) { /* push from mem */ ADD_OP(op) { diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 38070f26105b..fc6975ab8b06 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -20,7 +20,8 @@ #include <objtool/objtool.h> bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, - validate_dup, vmlinux, mcount, noinstr, backup, sls; + lto, vmlinux, mcount, noinstr, backup, sls, dryrun, + ibt; static const char * const check_usage[] = { "objtool check [<options>] file.o", @@ -40,12 +41,14 @@ const struct option check_options[] = { OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"), OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"), OPT_BOOLEAN('s', "stats", &stats, "print statistics"), - OPT_BOOLEAN('d', "duplicate", &validate_dup, "duplicate validation for vmlinux.o"), + OPT_BOOLEAN(0, "lto", <o, "whole-archive like runs"), OPT_BOOLEAN('n', "noinstr", &noinstr, "noinstr validation for vmlinux.o"), OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"), OPT_BOOLEAN('M', "mcount", &mcount, "generate __mcount_loc"), OPT_BOOLEAN('B', "backup", &backup, "create .orig files before modification"), OPT_BOOLEAN('S', "sls", &sls, "validate straight-line-speculation"), + OPT_BOOLEAN(0, "dry-run", &dryrun, "don't write the modifications"), + OPT_BOOLEAN(0, "ibt", &ibt, "validate ENDBR placement"), OPT_END(), }; diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 7c33ec67c4a9..6de5085e3e5a 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -181,6 +181,9 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "kunit_try_catch_throw", "xen_start_kernel", "cpu_bringup_and_idle", + "do_group_exit", + "stop_this_cpu", + "__invalid_creds", }; if (!func) @@ -380,6 +383,7 @@ static int decode_instructions(struct objtool_file *file) memset(insn, 0, sizeof(*insn)); INIT_LIST_HEAD(&insn->alts); INIT_LIST_HEAD(&insn->stack_ops); + INIT_LIST_HEAD(&insn->call_node); insn->sec = sec; insn->offset = offset; @@ -392,6 +396,14 @@ static int decode_instructions(struct objtool_file *file) if (ret) goto err; + /* + * By default, "ud2" is a dead end unless otherwise + * annotated, because GCC 7 inserts it for certain + * divide-by-zero cases. + */ + if (insn->type == INSN_BUG) + 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++; @@ -407,8 +419,17 @@ static int decode_instructions(struct objtool_file *file) return -1; } - sym_for_each_insn(file, func, insn) + sym_for_each_insn(file, func, insn) { insn->func = func; + if (insn->type == INSN_ENDBR && list_empty(&insn->call_node)) { + if (insn->offset == insn->func->offset) { + list_add_tail(&insn->call_node, &file->endbr_list); + file->nr_endbr++; + } else { + file->nr_endbr_int++; + } + } + } } } @@ -521,14 +542,6 @@ static int add_dead_ends(struct objtool_file *file) struct instruction *insn; /* - * By default, "ud2" is a dead end unless otherwise annotated, because - * GCC 7 inserts it for certain divide-by-zero cases. - */ - for_each_insn(file, insn) - if (insn->type == INSN_BUG) - insn->dead_end = true; - - /* * Check for manually annotated dead ends. */ sec = find_section_by_name(file->elf, ".rela.discard.unreachable"); @@ -731,6 +744,58 @@ static int create_retpoline_sites_sections(struct objtool_file *file) return 0; } +static int create_ibt_endbr_seal_sections(struct objtool_file *file) +{ + struct instruction *insn; + struct section *sec; + int idx; + + sec = find_section_by_name(file->elf, ".ibt_endbr_seal"); + if (sec) { + WARN("file already has .ibt_endbr_seal, skipping"); + return 0; + } + + idx = 0; + list_for_each_entry(insn, &file->endbr_list, call_node) + idx++; + + if (stats) { + printf("ibt: ENDBR at function start: %d\n", file->nr_endbr); + printf("ibt: ENDBR inside functions: %d\n", file->nr_endbr_int); + printf("ibt: superfluous ENDBR: %d\n", idx); + } + + 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"); + return -1; + } + + idx = 0; + list_for_each_entry(insn, &file->endbr_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: .ibt_endbr_seal"); + return -1; + } + + idx++; + } + + return 0; +} + static int create_mcount_loc_sections(struct objtool_file *file) { struct section *sec; @@ -1111,6 +1176,9 @@ static void annotate_call_site(struct objtool_file *file, list_add_tail(&insn->call_node, &file->mcount_loc_list); return; } + + if (!sibling && dead_end_function(file, sym)) + insn->dead_end = true; } static void add_call_dest(struct objtool_file *file, struct instruction *insn, @@ -1165,6 +1233,19 @@ static void add_retpoline_call(struct objtool_file *file, struct instruction *in annotate_call_site(file, insn, false); } + +static bool same_function(struct instruction *insn1, struct instruction *insn2) +{ + return insn1->func->pfunc == insn2->func->pfunc; +} + +static bool is_first_func_insn(struct instruction *insn) +{ + return insn->offset == insn->func->offset || + (insn->type == INSN_ENDBR && + insn->offset == insn->func->offset + insn->len); +} + /* * Find the destination instructions for all jumps. */ @@ -1245,8 +1326,8 @@ static int add_jump_destinations(struct objtool_file *file) insn->func->cfunc = insn->jump_dest->func; insn->jump_dest->func->pfunc = insn->func; - } else if (insn->jump_dest->func->pfunc != insn->func->pfunc && - insn->jump_dest->offset == insn->jump_dest->func->offset) { + } else if (!same_function(insn, insn->jump_dest) && + is_first_func_insn(insn->jump_dest)) { /* internal sibling call (without reloc) */ add_call_dest(file, insn, insn->jump_dest->func, true); } @@ -1836,6 +1917,16 @@ static int read_unwind_hints(struct objtool_file *file) insn->hint = true; + if (ibt && hint->type == UNWIND_HINT_TYPE_REGS_PARTIAL) { + struct symbol *sym = find_symbol_by_offset(insn->sec, insn->offset); + + if (sym && sym->bind == STB_GLOBAL && + insn->type != INSN_ENDBR && !insn->noendbr) { + WARN_FUNC("UNWIND_HINT_IRET_REGS without ENDBR", + insn->sec, insn->offset); + } + } + if (hint->type == UNWIND_HINT_TYPE_FUNC) { insn->cfi = &func_cfi; continue; @@ -1860,6 +1951,32 @@ static int read_unwind_hints(struct objtool_file *file) return 0; } +static int read_noendbr_hints(struct objtool_file *file) +{ + struct section *sec; + struct instruction *insn; + struct reloc *reloc; + + sec = find_section_by_name(file->elf, ".rela.discard.noendbr"); + 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 (insn->type == INSN_ENDBR) + WARN_FUNC("ANNOTATE_NOENDBR on ENDBR", insn->sec, insn->offset); + + insn->noendbr = 1; + } + + return 0; +} + static int read_retpoline_hints(struct objtool_file *file) { struct section *sec; @@ -2086,10 +2203,6 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret; - ret = add_dead_ends(file); - if (ret) - return ret; - add_ignores(file); add_uaccess_safe(file); @@ -2098,6 +2211,13 @@ static int decode_sections(struct objtool_file *file) return ret; /* + * Must be before read_unwind_hints() since that needs insn->noendbr. + */ + ret = read_noendbr_hints(file); + if (ret) + return ret; + + /* * Must be before add_{jump_call}_destination. */ ret = classify_symbols(file); @@ -2128,6 +2248,14 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret; + /* + * 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; @@ -3026,6 +3154,115 @@ static struct instruction *next_insn_to_validate(struct objtool_file *file, return next_insn_same_sec(file, insn); } +static struct instruction * +validate_ibt_reloc(struct objtool_file *file, struct reloc *reloc) +{ + struct instruction *dest; + struct section *sec; + unsigned long off; + + sec = reloc->sym->sec; + off = reloc->sym->offset; + + if ((reloc->sec->base->sh.sh_flags & SHF_EXECINSTR) && + (reloc->type == R_X86_64_PC32 || reloc->type == R_X86_64_PLT32)) + off += arch_dest_reloc_offset(reloc->addend); + else + off += reloc->addend; + + dest = find_insn(file, sec, off); + if (!dest) + return NULL; + + if (dest->type == INSN_ENDBR) { + if (!list_empty(&dest->call_node)) + list_del_init(&dest->call_node); + + return NULL; + } + + if (reloc->sym->static_call_tramp) + return NULL; + + return dest; +} + +static void warn_noendbr(const char *msg, struct section *sec, unsigned long offset, + struct instruction *dest) +{ + WARN_FUNC("%srelocation to !ENDBR: %s+0x%lx", sec, offset, msg, + dest->func ? dest->func->name : dest->sec->name, + dest->func ? dest->offset - dest->func->offset : dest->offset); +} + +static void validate_ibt_dest(struct objtool_file *file, struct instruction *insn, + struct instruction *dest) +{ + if (dest->func && dest->func == insn->func) { + /* + * 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; + } + + if (dest->noendbr) + return; + + warn_noendbr("", insn->sec, insn->offset, dest); +} + +static void validate_ibt_insn(struct objtool_file *file, struct instruction *insn) +{ + struct instruction *dest; + struct reloc *reloc; + + switch (insn->type) { + case INSN_CALL: + case INSN_CALL_DYNAMIC: + case INSN_JUMP_CONDITIONAL: + case INSN_JUMP_UNCONDITIONAL: + case INSN_JUMP_DYNAMIC: + case INSN_JUMP_DYNAMIC_CONDITIONAL: + case INSN_RETURN: + /* + * We're looking for code references setting up indirect code + * flow. As such, ignore direct code flow and the actual + * dynamic branches. + */ + return; + + case INSN_NOP: + /* + * handle_group_alt() will create INSN_NOP instruction that + * don't belong to any section, ignore all NOP since they won't + * carry a (useful) relocation anyway. + */ + return; + + default: + break; + } + + 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))) { + dest = validate_ibt_reloc(file, reloc); + if (dest) + validate_ibt_dest(file, insn, dest); + } +} + /* * Follow the branch starting at the given instruction, and recursively follow * any other branches (jumps). Meanwhile, track the frame pointer state at @@ -3115,9 +3352,8 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, switch (insn->type) { case INSN_RETURN: - if (next_insn && next_insn->type == INSN_TRAP) { - next_insn->ignore = true; - } else if (sls && !insn->retpoline_safe) { + if (sls && !insn->retpoline_safe && + next_insn && next_insn->type != INSN_TRAP) { WARN_FUNC("missing int3 after ret", insn->sec, insn->offset); } @@ -3136,7 +3372,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, return 1; } - if (dead_end_function(file, insn->call_dest)) + if (insn->dead_end) return 0; break; @@ -3164,9 +3400,8 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, break; case INSN_JUMP_DYNAMIC: - if (next_insn && next_insn->type == INSN_TRAP) { - next_insn->ignore = true; - } else if (sls && !insn->retpoline_safe) { + if (sls && !insn->retpoline_safe && + next_insn && next_insn->type != INSN_TRAP) { WARN_FUNC("missing int3 after indirect jump", insn->sec, insn->offset); } @@ -3237,6 +3472,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, break; } + if (ibt) + validate_ibt_insn(file, insn); + if (insn->dead_end) return 0; @@ -3337,7 +3575,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio int i; struct instruction *prev_insn; - if (insn->ignore || insn->type == INSN_NOP) + if (insn->ignore || insn->type == INSN_NOP || insn->type == INSN_TRAP) return true; /* @@ -3348,6 +3586,49 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio !strcmp(insn->sec->name, ".altinstr_aux")) return true; + /* + * Whole archive runs might encounder 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 (!insn->func && lto) { + 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->jump_dest->func && + strstr(insn->jump_dest->func->name, ".cold")) { + struct instruction *dest = insn->jump_dest; + func_for_each_insn(file, dest->func, dest) + dest->ignore = true; + } + } + + return false; + } + if (!insn->func) return false; @@ -3479,6 +3760,53 @@ static int validate_functions(struct objtool_file *file) return warnings; } +static int validate_ibt(struct objtool_file *file) +{ + struct section *sec; + struct reloc *reloc; + + for_each_sec(file, sec) { + bool is_data; + + /* already done in validate_branch() */ + if (sec->sh.sh_flags & SHF_EXECINSTR) + continue; + + if (!sec->reloc) + continue; + + if (!strncmp(sec->name, ".orc", 4)) + continue; + + if (!strncmp(sec->name, ".discard", 8)) + continue; + + if (!strncmp(sec->name, ".debug", 6)) + continue; + + if (!strcmp(sec->name, "_error_injection_whitelist")) + continue; + + if (!strcmp(sec->name, "_kprobe_blacklist")) + continue; + + is_data = strstr(sec->name, ".data") || strstr(sec->name, ".rodata"); + + list_for_each_entry(reloc, &sec->reloc->reloc_list, list) { + struct instruction *dest; + + dest = validate_ibt_reloc(file, reloc); + if (is_data && dest && !dest->noendbr) { + warn_noendbr("data ", reloc->sym->sec, + reloc->sym->offset + reloc->addend, + dest); + } + } + } + + return 0; +} + static int validate_reachable_instructions(struct objtool_file *file) { struct instruction *insn; @@ -3501,6 +3829,16 @@ int check(struct objtool_file *file) { int ret, warnings = 0; + if (lto && !(vmlinux || module)) { + fprintf(stderr, "--lto requires: --vmlinux or --module\n"); + return 1; + } + + if (ibt && !lto) { + fprintf(stderr, "--ibt requires: --lto\n"); + return 1; + } + arch_initial_func_cfi_state(&initial_func_cfi); init_cfi_state(&init_cfi); init_cfi_state(&func_cfi); @@ -3521,7 +3859,7 @@ int check(struct objtool_file *file) if (list_empty(&file->insn_list)) goto out; - if (vmlinux && !validate_dup) { + if (vmlinux && !lto) { ret = validate_vmlinux_functions(file); if (ret < 0) goto out; @@ -3547,6 +3885,13 @@ int check(struct objtool_file *file) goto out; warnings += ret; + if (ibt) { + ret = validate_ibt(file); + if (ret < 0) + goto out; + warnings += ret; + } + if (!warnings) { ret = validate_reachable_instructions(file); if (ret < 0) @@ -3573,6 +3918,13 @@ int check(struct objtool_file *file) warnings += ret; } + if (ibt) { + ret = create_ibt_endbr_seal_sections(file); + if (ret < 0) + goto out; + warnings += ret; + } + if (stats) { printf("nr_insns_visited: %ld\n", nr_insns_visited); printf("nr_cfi: %ld\n", nr_cfi); diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 4b384c907027..d7b99a737496 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -83,6 +83,31 @@ static int symbol_by_offset(const void *key, const struct rb_node *node) return 0; } +struct symbol_hole { + unsigned long key; + const struct symbol *sym; +}; + +/* + * Find !section symbol where @offset is after it. + */ +static int symbol_hole_by_offset(const void *key, const struct rb_node *node) +{ + const struct symbol *s = rb_entry(node, struct symbol, node); + struct symbol_hole *sh = (void *)key; + + if (sh->key < s->offset) + return -1; + + if (sh->key >= s->offset + s->len) { + if (s->type != STT_SECTION) + sh->sym = s; + return 1; + } + + return 0; +} + struct section *find_section_by_name(const struct elf *elf, const char *name) { struct section *sec; @@ -162,6 +187,41 @@ struct symbol *find_symbol_containing(const struct section *sec, unsigned long o return NULL; } +/* + * Returns size of hole starting at @offset. + */ +int find_symbol_hole_containing(const struct section *sec, unsigned long offset) +{ + struct symbol_hole hole = { + .key = offset, + .sym = NULL, + }; + struct rb_node *n; + struct symbol *s; + + /* + * Find the rightmost symbol for which @offset is after it. + */ + n = rb_find(&hole, &sec->symbol_tree, symbol_hole_by_offset); + + /* found a symbol that contains @offset */ + if (n) + return 0; /* not a hole */ + + /* didn't find a symbol for which @offset is after it */ + if (!hole.sym) + return 0; /* not a hole */ + + /* @offset >= sym->offset + sym->len, find symbol after it */ + n = rb_next(&hole.sym->node); + if (!n) + return -1; /* until end of address space */ + + /* hole until start of next symbol */ + s = rb_entry(n, struct symbol, node); + return s->offset - offset; +} + struct symbol *find_func_containing(struct section *sec, unsigned long offset) { struct rb_node *node; @@ -1019,6 +1079,9 @@ int elf_write(struct elf *elf) struct section *sec; Elf_Scn *s; + if (dryrun) + return 0; + /* Update changed relocation sections and section headers: */ list_for_each_entry(sec, &elf->sections, list) { if (sec->changed) { diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h index 76bae3078286..9b19cc304195 100644 --- a/tools/objtool/include/objtool/arch.h +++ b/tools/objtool/include/objtool/arch.h @@ -27,6 +27,7 @@ enum insn_type { INSN_STD, INSN_CLD, INSN_TRAP, + INSN_ENDBR, INSN_OTHER, }; diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index 89ba869ed08f..c39dbfaef6dc 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/objtool/builtin.h @@ -9,7 +9,8 @@ extern const struct option check_options[]; extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, - validate_dup, vmlinux, mcount, noinstr, backup, sls; + lto, vmlinux, mcount, noinstr, backup, sls, dryrun, + ibt; extern int cmd_parse_options(int argc, const char **argv, const char * const usage[]); diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h index 6cfff078897f..f10d7374f388 100644 --- a/tools/objtool/include/objtool/check.h +++ b/tools/objtool/include/objtool/check.h @@ -45,11 +45,18 @@ struct instruction { unsigned int len; enum insn_type type; unsigned long immediate; - bool dead_end, ignore, ignore_alts; - bool hint; - bool retpoline_safe; + + u8 dead_end : 1, + ignore : 1, + ignore_alts : 1, + hint : 1, + retpoline_safe : 1, + noendbr : 1; + /* 2 bit hole */ s8 instr; u8 visited; + /* u8 hole */ + struct alt_group *alt_group; struct symbol *call_dest; struct instruction *jump_dest; diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index d22336781401..22ba7e2b816e 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -152,6 +152,7 @@ struct symbol *find_func_by_offset(struct section *sec, unsigned long offset); struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); struct symbol *find_symbol_by_name(const struct elf *elf, const char *name); struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset); +int find_symbol_hole_containing(const struct section *sec, unsigned long offset); struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset); struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec, unsigned long offset, unsigned int len); diff --git a/tools/objtool/include/objtool/objtool.h b/tools/objtool/include/objtool/objtool.h index f99fbc6078d5..7a5c13a78f87 100644 --- a/tools/objtool/include/objtool/objtool.h +++ b/tools/objtool/include/objtool/objtool.h @@ -26,8 +26,12 @@ struct objtool_file { struct list_head retpoline_call_list; struct list_head static_call_list; struct list_head mcount_loc_list; + struct list_head endbr_list; bool ignore_unreachables, c_file, hints, rodata; + unsigned int nr_endbr; + unsigned int nr_endbr_int; + unsigned long jl_short, jl_long; unsigned long jl_nop_short, jl_nop_long; diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h index d99c4675e4a5..802cfda0a6f6 100644 --- a/tools/objtool/include/objtool/warn.h +++ b/tools/objtool/include/objtool/warn.h @@ -22,6 +22,8 @@ static inline char *offstr(struct section *sec, unsigned long offset) unsigned long name_off; func = find_func_containing(sec, offset); + if (!func) + func = find_symbol_containing(sec, offset); if (func) { name = func->name; name_off = offset - func->offset; diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c index bdf699f6552b..b09946f4e1d6 100644 --- a/tools/objtool/objtool.c +++ b/tools/objtool/objtool.c @@ -128,6 +128,7 @@ struct objtool_file *objtool_open_read(const char *_objname) INIT_LIST_HEAD(&file.retpoline_call_list); INIT_LIST_HEAD(&file.static_call_list); INIT_LIST_HEAD(&file.mcount_loc_list); + INIT_LIST_HEAD(&file.endbr_list); file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment"); file.ignore_unreachables = no_unreachable; file.hints = false; |