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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 133DBC55ABD for ; Fri, 13 Nov 2020 22:45:59 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A675322255 for ; Fri, 13 Nov 2020 22:45:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kh84VA4y"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="iiW0miU/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A675322255 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=pCQ5oVgiYAV+MX28XA8H5DX8fJ2Wa2d7JIuoFKY7mkE=; b=kh84VA4yUOOg1C1nGEx0DLCmU 4LBDjf4aN/9BU13Z5TVNeSIf+wcOv/lTaVnh2LQl57xWBOA6M+JEV87SvEG7IAY5F6IX6Qwm07zLq Ql25mshKy54paZWV2OYS/dXymBrAADhxw9Ay5fE75d8ceZHOFbmR8GzN0epeqag8D2kgkI2jGyXv9 wt9WlW2XgDDCXoUNCj1QVAwE0xYqP/EpQTWpG6za+DMbdhrnbBwuuOWLbljiNex6ZbO8yu0xn4qFR 2oYF41YxFCKmCdL9vaVfm/wIB+A1uPOfx9AmFRLaNbWwl/3xNhg3gi8jak8BF1MOm2v/E/q2OwiEJ JTn2rv90A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdhok-0004bb-8u; Fri, 13 Nov 2020 22:45:18 +0000 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdheG-0007vv-5w for linux-arm-kernel@lists.infradead.org; Fri, 13 Nov 2020 22:34:32 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605306866; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8Rq1SwLUmuk5yTiT3dYLgLhG1v7f4gsVqDXVvnML+kQ=; b=iiW0miU/Wf46LMu701BcvKbeels5SbOrwnq9IVK2WyUG0sfTul2s80mMXeav1KZiogixAb 1GL2O1eOhLuxlgAL1LRv12egNL2TX4Nn1wUt7jBZ7D7BBfRGxj2u1pk31uecwKjQP7HKKy EsV6klylq23LXUNU1nAJMpkFcoUmof4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-508-kgiX0vPEOgWkK_HzwNLmJg-1; Fri, 13 Nov 2020 17:34:24 -0500 X-MC-Unique: kgiX0vPEOgWkK_HzwNLmJg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 11ACD186DD33; Fri, 13 Nov 2020 22:34:22 +0000 (UTC) Received: from treble (ovpn-117-69.rdu2.redhat.com [10.10.117.69]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 71FFA5D707; Fri, 13 Nov 2020 22:34:15 +0000 (UTC) Date: Fri, 13 Nov 2020 16:34:12 -0600 From: Josh Poimboeuf To: Sami Tolvanen Subject: Re: [PATCH v6 22/25] x86/asm: annotate indirect jumps Message-ID: <20201113223412.inono2ekrs7ky7rm@treble> References: <20201021085606.GZ2628@hirez.programming.kicks-ass.net> <20201023173617.GA3021099@google.com> <20201110022924.tekltjo25wtrao7z@treble> <20201110174606.mp5m33lgqksks4mt@treble> <20201113195408.atbpjizijnhuinzy@treble> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201113_173428_323057_C3D2DF8E X-CRM114-Status: GOOD ( 22.65 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch , Kees Cook , "Paul E. McKenney" , Jann Horn , Peter Zijlstra , Greg Kroah-Hartman , Masahiro Yamada , the arch/x86 maintainers , Nick Desaulniers , kernel list , Steven Rostedt , linux-kbuild , clang-built-linux , linux-pci@vger.kernel.org, Kernel Hardening , Will Deacon , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Nov 13, 2020 at 12:24:32PM -0800, Sami Tolvanen wrote: > > I still don't see this warning for some reason. > > Do you have CONFIG_XEN enabled? I can reproduce this on ToT master as follows: > > $ git rev-parse HEAD > 585e5b17b92dead8a3aca4e3c9876fbca5f7e0ba > $ make defconfig && \ > ./scripts/config -e HYPERVISOR_GUEST -e PARAVIRT -e XEN && \ > make olddefconfig && \ > make -j110 > ... > $ ./tools/objtool/objtool check -arfld vmlinux.o 2>&1 | grep secondary > vmlinux.o: warning: objtool: __startup_secondary_64()+0x2: return with > modified stack frame > > > Is it fixed by adding cpu_bringup_and_idle() to global_noreturns[] in > > tools/objtool/check.c? > > No, that didn't fix the warning. Here's what I tested: I think this fixes it: From: Josh Poimboeuf Subject: [PATCH] x86/xen: Fix objtool vmlinux.o validation of xen hypercalls Objtool vmlinux.o validation is showing warnings like the following: # tools/objtool/objtool check -barfld vmlinux.o vmlinux.o: warning: objtool: __startup_secondary_64()+0x2: return with modified stack frame vmlinux.o: warning: objtool: xen_hypercall_set_trap_table()+0x0: <=== (sym) Objtool falls through all the empty hypercall text and gets confused when it encounters the first real function afterwards. The empty unwind hints in the hypercalls aren't working for some reason. Replace them with a more straightforward use of STACK_FRAME_NON_STANDARD. Reported-by: Sami Tolvanen Signed-off-by: Josh Poimboeuf --- arch/x86/xen/xen-head.S | 9 ++++----- include/linux/objtool.h | 8 ++++++++ 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S index 2d7c8f34f56c..3c538b1ff4a6 100644 --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -6,6 +6,7 @@ #include #include +#include #include #include @@ -67,14 +68,12 @@ SYM_CODE_END(asm_cpu_bringup_and_idle) .pushsection .text .balign PAGE_SIZE SYM_CODE_START(hypercall_page) - .rept (PAGE_SIZE / 32) - UNWIND_HINT_EMPTY - .skip 32 - .endr + .skip PAGE_SIZE #define HYPERCALL(n) \ .equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \ - .type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32 + .type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32; \ + STACK_FRAME_NON_STANDARD xen_hypercall_##n #include #undef HYPERCALL SYM_CODE_END(hypercall_page) diff --git a/include/linux/objtool.h b/include/linux/objtool.h index 577f51436cf9..746617265236 100644 --- a/include/linux/objtool.h +++ b/include/linux/objtool.h @@ -109,6 +109,12 @@ struct unwind_hint { .popsection .endm +.macro STACK_FRAME_NON_STANDARD func:req + .pushsection .discard.func_stack_frame_non_standard + .long \func - . + .popsection +.endm + #endif /* __ASSEMBLY__ */ #else /* !CONFIG_STACK_VALIDATION */ @@ -123,6 +129,8 @@ struct unwind_hint { .macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0 .endm #endif +.macro STACK_FRAME_NON_STANDARD func:req +.endm #endif /* CONFIG_STACK_VALIDATION */ -- 2.25.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel