From patchwork Mon Mar 22 12:28:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 406146 Delivered-To: patch@linaro.org Received: by 2002:a02:8562:0:0:0:0:0 with SMTP id g89csp3538672jai; Mon, 22 Mar 2021 05:50:33 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzc44kuCphI6+gZwC/1wtnLaVuKeZjjox/91HCD1eL4FN8r88GMw7B+12nUI1eugRYRjK0/ X-Received: by 2002:a05:6402:2552:: with SMTP id l18mr25128274edb.71.1616417433530; Mon, 22 Mar 2021 05:50:33 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1616417433; cv=none; d=google.com; s=arc-20160816; b=TmyVtlH3+eAYiw31rCeQgdKmOxfZQVb+2h4viWBkdjtDNaxZFPnhgiRVe53TauloFM zoCh4yTNZ0dKZ4OEcHL2qnrkDjcJHN932QXtdUYu0GNjwt/L+fIrv63Iy3yGl4ZMFQim 1zHFdDVtvpxr4ulMDH9kyJnihQJmRXMDBhSqWxgZIocNhNeagsa8QZX6NsXv4V4LSuFX owfOHKjA1lcKTqE59elYdBusSiS1n6WQKJaQNFIv5NwC3MKDA6cc60ghvz9YEpcMsvGW PVfDTxGCwuA7+zyfq0cp1NmRfkH0e8hQqu47z3ptLzho9DW2rMCljh7mp5XtQXlof+Ym ApDw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=crdtPIDTC1i0jX7Os926RsH7oVxdejBrF2lpIE++uSM=; b=r33KndLCU2LvsNry+02KCPnozXNTW74TijoQ59xaDgprtMH+3KKYVohyHdW0XpA8eS /GKGhQVLf/68nwu/Hgdy2AHIbfTcvgtU06Yq12qFIcGTkpiiR3a2Zq9UQ/Xsy0/F3RZM H8zsN/tuvZ2iBk9D0kUZJwf6z6eoaqB+U5XOI7F6yCwoLGYQ5opcGoVcbqupvIyb9W7v M0vvZvssfeli4OgK/a2TnJkrmtdUNh/UV89Krzy2lZWUVgmv5/j/tBrS1k7GzgtwEND9 uMWkWdhuot75nORvfTY4a91E4c/fB2EvgS/RoENzudF3mxGoLVp97DeXon1Cz29M/EDT 9DBA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=YUm0g63Z; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id bx12si11199464edb.404.2021.03.22.05.50.33; Mon, 22 Mar 2021 05:50:33 -0700 (PDT) Received-SPF: pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=YUm0g63Z; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232208AbhCVMuA (ORCPT + 12 others); Mon, 22 Mar 2021 08:50:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:40960 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232835AbhCVMsR (ORCPT ); Mon, 22 Mar 2021 08:48:17 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 60791619DC; Mon, 22 Mar 2021 12:44:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1616417068; bh=csEDHaGiGz95T2hFcn+4A2Nc9jq13tmY/hcqh1IU/Pk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YUm0g63Z5u+Axd61rRB/Pbqm7CMs9YxBQNkuB4ZhnxbdhYB/u23BLrggk0c4uBP5l J2HSMYWsj8UllGqUkXjpwjF3Oyn1TVYaDBG9TQ14tFssqLmALMWoZ15QfpC/TWOjoB 8wVZPFQwVmz0uLFgCj1W+e7dA7U3sMFs0Cxk3x20= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Arnd Bergmann , Kees Cook , Mark Rutland , Nicolas Boichat Subject: [PATCH 4.19 06/43] lkdtm: dont move ctors to .rodata Date: Mon, 22 Mar 2021 13:28:20 +0100 Message-Id: <20210322121920.142955352@linuxfoundation.org> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210322121919.936671417@linuxfoundation.org> References: <20210322121919.936671417@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nicolas Boichat From: Mark Rutland commit 3f618ab3323407ee4c6a6734a37eb6e9663ebfb9 upstream. When building with KASAN and LKDTM, clang may implictly generate an asan.module_ctor function in the LKDTM rodata object. The Makefile moves the lkdtm_rodata_do_nothing() function into .rodata by renaming the file's .text section to .rodata, and consequently also moves the ctor function into .rodata, leading to a boot time crash (splat below) when the ctor is invoked by do_ctors(). Let's prevent this by marking the function as noinstr rather than notrace, and renaming the file's .noinstr.text to .rodata. Marking the function as noinstr will prevent tracing and kprobes, and will inhibit any undesireable compiler instrumentation. The ctor function (if any) will be placed in .text and will work correctly. Example splat before this patch is applied: [ 0.916359] Unable to handle kernel execute from non-executable memory at virtual address ffffa0006b60f5ac [ 0.922088] Mem abort info: [ 0.922828] ESR = 0x8600000e [ 0.923635] EC = 0x21: IABT (current EL), IL = 32 bits [ 0.925036] SET = 0, FnV = 0 [ 0.925838] EA = 0, S1PTW = 0 [ 0.926714] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000427b3000 [ 0.928489] [ffffa0006b60f5ac] pgd=000000023ffff003, p4d=000000023ffff003, pud=000000023fffe003, pmd=0068000042000f01 [ 0.931330] Internal error: Oops: 8600000e [#1] PREEMPT SMP [ 0.932806] Modules linked in: [ 0.933617] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.0-rc7 #2 [ 0.935620] Hardware name: linux,dummy-virt (DT) [ 0.936924] pstate: 40400005 (nZcv daif +PAN -UAO -TCO BTYPE=--) [ 0.938609] pc : asan.module_ctor+0x0/0x14 [ 0.939759] lr : do_basic_setup+0x4c/0x70 [ 0.940889] sp : ffff27b600177e30 [ 0.941815] x29: ffff27b600177e30 x28: 0000000000000000 [ 0.943306] x27: 0000000000000000 x26: 0000000000000000 [ 0.944803] x25: 0000000000000000 x24: 0000000000000000 [ 0.946289] x23: 0000000000000001 x22: 0000000000000000 [ 0.947777] x21: ffffa0006bf4a890 x20: ffffa0006befb6c0 [ 0.949271] x19: ffffa0006bef9358 x18: 0000000000000068 [ 0.950756] x17: fffffffffffffff8 x16: 0000000000000000 [ 0.952246] x15: 0000000000000000 x14: 0000000000000000 [ 0.953734] x13: 00000000838a16d5 x12: 0000000000000001 [ 0.955223] x11: ffff94000da74041 x10: dfffa00000000000 [ 0.956715] x9 : 0000000000000000 x8 : ffffa0006b60f5ac [ 0.958199] x7 : f9f9f9f9f9f9f9f9 x6 : 000000000000003f [ 0.959683] x5 : 0000000000000040 x4 : 0000000000000000 [ 0.961178] x3 : ffffa0006bdc15a0 x2 : 0000000000000005 [ 0.962662] x1 : 00000000000000f9 x0 : ffffa0006bef9350 [ 0.964155] Call trace: [ 0.964844] asan.module_ctor+0x0/0x14 [ 0.965895] kernel_init_freeable+0x158/0x198 [ 0.967115] kernel_init+0x14/0x19c [ 0.968104] ret_from_fork+0x10/0x30 [ 0.969110] Code: 00000003 00000000 00000000 00000000 (00000000) [ 0.970815] ---[ end trace b5339784e20d015c ]--- Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Kees Cook Acked-by: Kees Cook Signed-off-by: Mark Rutland Link: https://lore.kernel.org/r/20201207170533.10738-1-mark.rutland@arm.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Nicolas Boichat Signed-off-by: Greg Kroah-Hartman --- (no changes since v1) drivers/misc/lkdtm/Makefile | 2 +- drivers/misc/lkdtm/rodata.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/drivers/misc/lkdtm/Makefile +++ b/drivers/misc/lkdtm/Makefile @@ -13,7 +13,7 @@ KCOV_INSTRUMENT_rodata.o := n OBJCOPYFLAGS := OBJCOPYFLAGS_rodata_objcopy.o := \ - --rename-section .text=.rodata,alloc,readonly,load + --rename-section .noinstr.text=.rodata,alloc,readonly,load targets += rodata.o rodata_objcopy.o $(obj)/rodata_objcopy.o: $(obj)/rodata.o FORCE $(call if_changed,objcopy) --- a/drivers/misc/lkdtm/rodata.c +++ b/drivers/misc/lkdtm/rodata.c @@ -5,7 +5,7 @@ */ #include "lkdtm.h" -void notrace lkdtm_rodata_do_nothing(void) +void noinstr lkdtm_rodata_do_nothing(void) { /* Does nothing. We just want an architecture agnostic "return". */ }