From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE776C77B6E for ; Wed, 12 Apr 2023 20:26:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229826AbjDLU01 (ORCPT ); Wed, 12 Apr 2023 16:26:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229704AbjDLU0X (ORCPT ); Wed, 12 Apr 2023 16:26:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDD1D18F for ; Wed, 12 Apr 2023 13:26:22 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7A09D638F2 for ; Wed, 12 Apr 2023 20:26:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE6F2C4339B; Wed, 12 Apr 2023 20:26:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681331181; bh=PtEZ2XxRT+V9+YOlqDPVexSNm4/7T9Gs06ZBZ6BpOSI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L2pgvMDWoT9nJBFn0Rn1R0uCBjMOfrFyChbbIZ026c93YYDLFX/PFpqjuMdA160Qs lXdXXgDUYi5AqcnMuEbsJC8wGcPeBAJp/qsArOMkw2Z254qGFRjpxKquFi7rY+Qgr9 WuqXMbWj9Nt3y6+QlOvPlT863k3mSIsK9aaXxoBNdFSQpAiwEDdPEpoetc0pITMkY1 M0ENx/C0StKxtQk2y+fK+ZT0RXg/6IGKGH6x5XOnVWk+gXWk9bzUowvqIbT1hxwIj5 Cm/VbbvLGD8McPER+7vtxBiu9IK3EFmvjgQDK9kp16QHvRQ9PJD7inpxzZZaMIRjy7 ZytnaGGKemc5A== From: Josh Poimboeuf To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Miroslav Benes Subject: [PATCH 1/3] objtool: Separate prefix code from stack validation code Date: Wed, 12 Apr 2023 13:26:13 -0700 Message-Id: X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Content-type: text/plain Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Simplify the prefix code and make it a standalone feature. Signed-off-by: Josh Poimboeuf --- 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