From patchwork Wed Jun 22 15:48:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen Zhongjin X-Patchwork-Id: 12891075 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E8764C43334 for ; Wed, 22 Jun 2022 16:00:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Q23i4Xv71Lz9HT5Ru39Jng5JIyR49ilVPomdr8nfwiE=; b=Mqw6MPlmY7Fm3I y97Q3ouIARuXrsUNtIArE4pCEGEuCncUa7YiP+kSHSOVzFztB627oUkch/+cvTejDTptprtT8xQwa L5+rmOw5TCsDGgUl5BFUJot444Uum+zXbvYP18OCA9JKyxZueUF+VKWwjICZlpB2VuRccV7c71J2k 5UT2WPnhUBGm8+zFKx9bkht3VdWqgVG1DSiwezDBEIgqPa3K+fCxThSmRob6DUkpZzL9Ta3eq0JEx Q0BR6YFjH2sK5h8aJ9r7kvcv/97koxhP/Xegc4V6RuhNcjWQXlKy3PDgddsm4uPjMyrg0dEVK99fq p27Qf/qW0gtr018ynx8g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o42lD-00BKDN-6m; Wed, 22 Jun 2022 15:59:19 +0000 Received: from szxga03-in.huawei.com ([45.249.212.189]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o42ey-00BHdr-Vn for linux-arm-kernel@lists.infradead.org; Wed, 22 Jun 2022 15:53:03 +0000 Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4LSnvD2wrwzDqqv; Wed, 22 Jun 2022 23:52:08 +0800 (CST) Received: from dggpemm500013.china.huawei.com (7.185.36.172) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 22 Jun 2022 23:52:41 +0800 Received: from ubuntu1804.huawei.com (10.67.175.36) by dggpemm500013.china.huawei.com (7.185.36.172) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 22 Jun 2022 23:52:41 +0800 From: Chen Zhongjin To: , , , , , CC: , , , , , , , , , , , , , Subject: [PATCH v5 00/33] objtool: add base support for arm64 Date: Wed, 22 Jun 2022 23:48:47 +0800 Message-ID: <20220622154920.95075-1-chenzhongjin@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.67.175.36] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpemm500013.china.huawei.com (7.185.36.172) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220622_085254_202749_D4CB36B9 X-CRM114-Status: GOOD ( 25.11 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This series enables objtool to start doing stack validation and orc generation on arm64 kernel builds. Based on Julien's previous work(1)(2), Now I have finished most of work for objtool enable on arm64. This series includes objtool part [1-13] and arm64 support part [14-33], the second part is to make objtool run correctly with no warning on arm64 so if necessary it can be taken apart as two series. ORC generation feature is implemented but not used because we don't have an unwinder_orc on arm64, now it only be used to check whether objtool has correct validation. This series depends on (https://lkml.org/lkml/2022/6/22/463) I moved some changes which work for all architectures to that series because this one becomes too big now. And it is rebased to tip/objtool/core branch. I think the series is complete enough so I removed the RFC. However now there are still (maybe only) two unsolved problems: 1. the switch optimization and dynamic jump Although this problem has been troubling us for a long time and temporarily resolved by -no-jump-table. Hopefully we have chance to fix it. I'm trying for that and it will be updated in next version. 2. alternative_cb alternative_cb in arm64 is an dynamic patch mechanism on arm64 which is similiar to alternative instruction but doesn't give instructions explicitly. It cause trouble when there is a jump instructions inside it and causes some branch that objtool can't reach. I have solved some of them by adding UNWIND_HINT one macro "mitigate_spectre_bhb_loop" can't be fixed because it is used in different assembly files. (1) https://lkml.org/lkml/2021/3/3/1135 (2) https://github.com/julien-thierry/linux.git --- v5 Changes: Compare to last RFC v4 series, this series does a lot of changes, including code rebase, refactoring and solution for several warning in last series. After refactoring and moving some patches out, the number of lines in this series decrease a thousand. Here are changes for each patch. [1] Removed unnecessary part from insn.h and insn.c to avoid extra dependencies and wired hack. So the patch to add head files also be removed. [2] Rebase Makefile, clear sync-check for insn.h/c and add arm64 elf relocation types in elf.h. Remove other callee saved registers tracking except FP and LR. Beacause in arm64 there are lots of branches store these CSRs in different order or positions, tracking them will cause some false stack state mismatch warnings. [3-6] Refactor code. Add some macros to make code more clean. For instructions load/store on stack, Simplifies the logic of moving SP and accessing data because the order of ops makes no differences. [7-8] Remove delete in record_invalid_insn because now we don't need to handle special undecoded instructions. [13] New patch to enable ORC generation. [12, 14, 17] Rebase to current branch. [19-21] Add annotations for trans_pgd-asm.S and some unreachable branches. [29] Moves kuser32.S and sigreturn32.S to rodata because they are VDSO. [31] Remove ignores for hibernate.c. [33] New patch to fix a fallthrough problem. --- v4 Changes: - fix EX_ENTRY_SIZE from 8 to 12. - modify arm64 for supporting objtool, including annotation, asm code modification, ignoring some validation, to make objtool be enable to pass arm64 builds. v3 Changes: - rebase Julien's version to mainstream and solve conflicts. - Merge dumplicate "*type = INSN_OTHER". - When meeting unrecognized instructions such as datas in .text code or 0x0 padding insns, last version used "loc->ignorable" to mark and remove them from objtool insn list. However there are two problems to do so: 1. when meeting insns can't be decoded or excluded, objtool will just stop. 2. deleting every insn can cause problems in fellow procedure. So I changed "record_invalid_insn" that we can delete one insn or just set it ignored. Now check will throw an error and going on when meeting undecodable instructions. Also, to prevent the confusion between "loc->ignorable" and "insn->ignore" I changed "ignore" to "delete". v2 Changes: - Drop gcc plugin in favor of -fno-jump-tables - miscelaneous fixes and cleanups