Messages in this thread Patch in this message | | | From | Josh Poimboeuf <> | Subject | [PATCH 1/3] objtool: Separate prefix code from stack validation code | Date | Wed, 12 Apr 2023 13:26:13 -0700 |
| |
Simplify the prefix code and make it a standalone feature.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> --- tools/objtool/check.c | 88 ++++++++++++++++++++++++------------------- 1 file changed, 50 insertions(+), 38 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 53940e2ac632..2f3136145b2e 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4120,54 +4120,61 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio return false; } -static int add_prefix_symbol(struct objtool_file *file, struct symbol *func, - struct instruction *insn) +static int add_prefix_symbol(struct objtool_file *file, struct symbol *func) { - if (!opts.prefix) - return 0; + struct instruction *insn, *prev; - for (;;) { - struct instruction *prev = prev_insn_same_sec(file, insn); - u64 offset; + insn = find_insn(file, func->sec, func->offset); + if (!insn) + return -1; - if (!prev) - break; + 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 -1; 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; - } - insn = prev; + + if (offset > opts.prefix) + return -1; + + if (offset < opts.prefix) + continue; + + elf_create_prefix_symbol(file->elf, func, opts.prefix); + break; } + if (!prev) + return -1; + return 0; } +static int add_prefix_symbols(struct objtool_file *file) +{ + struct section *sec; + struct symbol *func; + int ret, warnings = 0; + + for_each_sec(file, sec) { + if (!(sec->sh.sh_flags & SHF_EXECINSTR)) + continue; + + list_for_each_entry(func, &sec->symbol_list, list) { + if (func->type != STT_FUNC) + continue; + + add_prefix_symbol(file, func); + } + } + + return warnings; +} + static int validate_symbol(struct objtool_file *file, struct section *sec, struct symbol *sym, struct insn_state *state) { @@ -4186,8 +4193,6 @@ static int validate_symbol(struct objtool_file *file, struct section *sec, if (!insn || insn->ignore || insn->visited) return 0; - add_prefix_symbol(file, sym, insn); - state->uaccess = sym->uaccess_safe; ret = validate_branch(file, insn_func(insn), insn, *state); @@ -4744,6 +4749,13 @@ int check(struct objtool_file *file) warnings += ret; } + if (opts.prefix) { + ret = add_prefix_symbols(file); + if (ret < 0) + return ret; + warnings += ret; + } + if (opts.ibt) { ret = create_ibt_endbr_seal_sections(file); if (ret < 0) -- 2.39.2
| |