From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 3339E60764 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932516AbeFFHxV (ORCPT + 25 others); Wed, 6 Jun 2018 03:53:21 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:40771 "EHLO huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S932243AbeFFHxT (ORCPT ); Wed, 6 Jun 2018 03:53:19 -0400 Subject: Is this a kernel BUG? ///Re: [Question] Can we use SIGRTMIN when vdso disabled on X86? To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86l , Dominik Brodowski , Andy Lutomirski , linux-kernel References: <5B1672FE.4050705@huawei.com> CC: From: "Leizhen (ThunderTown)" Message-ID: <5B1792C9.8010203@huawei.com> Date: Wed, 6 Jun 2018 15:52:41 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <5B1672FE.4050705@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.23.164] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/6/5 19:24, Leizhen (ThunderTown) wrote: > After I executed "echo 0 > /proc/sys/abi/vsyscall32" to disable vdso, the rt_sigaction01 test case from ltp_2015 failed. > The test case source code please refer to the attachment, and the output as blow: > > ----------------- > ./rt_sigaction01 > rt_sigaction01 0 TINFO : signal: 34 > rt_sigaction01 1 TPASS : rt_sigaction call succeeded: result = 0 > rt_sigaction01 0 TINFO : sa.sa_flags = SA_RESETHAND|SA_SIGINFO > rt_sigaction01 0 TINFO : Signal Handler Called with signal number 34 > > Segmentation fault > ------------------ > > > Is this the desired result? In function ia32_setup_rt_frame, I found below code: > > if (ksig->ka.sa.sa_flags & SA_RESTORER) > restorer = ksig->ka.sa.sa_restorer; > else > restorer = current->mm->context.vdso + > vdso_image_32.sym___kernel_rt_sigreturn; > put_user_ex(ptr_to_compat(restorer), &frame->pretcode); > > Because the vdso is disabled, so current->mm->context.vdso is NULL, which cause the result of frame->pretcode invalid. > > I'm not sure whether this is a kernel bug or just an error of test case itself. Can anyone help me? > -- Thanks! BestRegards