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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 D6EA1C04AB4 for ; Fri, 17 May 2019 13:57:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ABBFB20873 for ; Fri, 17 May 2019 13:57:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558101427; bh=GykiXS/2dOvX6tWCzLuVJ+9+sTQOOXsEsCcwgosON8U=; h=Subject:To:Cc:References:From:Date:In-Reply-To:List-ID:From; b=vqewy09BFbbyRZYZKjMG7FjtFA9qzuVAMjlGfaO/Bv9PmjID9GSOHWtn/DdTS+V8z lhhRpPtcAkt+krIQRxILYBu4LcVpAFRsUzc2Bvom10Eeh8lUt0sme0o51NfGL+cYD6 UTn+awvUorE4VA0LCB/h8m7dgNOnDgUYNZBx8F4I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729005AbfEQN5G (ORCPT ); Fri, 17 May 2019 09:57:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:47176 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728920AbfEQN5F (ORCPT ); Fri, 17 May 2019 09:57:05 -0400 Received: from [192.168.1.112] (c-24-9-64-241.hsd1.co.comcast.net [24.9.64.241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5C4C120873; Fri, 17 May 2019 13:57:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558101424; bh=GykiXS/2dOvX6tWCzLuVJ+9+sTQOOXsEsCcwgosON8U=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=t7X8C7Ez4y7p5NOEBpIBgX4C+ZHPnMEJuO6m1lyUGnp294RuzzXIM8/f859bCFEaZ /u4+qS1l/7LLAKWdx2UMwZHtsyUSVs2BXaEo24NRzuEpkssL7p5YqUNVn14kXmqU0h SPTlzoXmwIVi8qc2zcSrVv2ECwDmojDBIUlUR3oQ= Subject: Re: [PATCH v3] selftests/x86: Support Atom for syscall_arg_fault test To: "Tong, Bo" , "luto@kernel.org" , "x86@kernel.org" Cc: "linux-kselftest@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "skhan@linuxfoundation.org" , shuah References: <1555657855-31855-1-git-send-email-bo.tong@intel.com> <263afb6f-48dc-fbe7-5b13-13ce3f322ecc@kernel.org> From: shuah Message-ID: <9e3e4e85-d1d8-a72f-d820-96f4fad9f23b@kernel.org> Date: Fri, 17 May 2019 07:56:53 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Bo, On 5/17/19 1:02 AM, Tong, Bo wrote: > Is this patch going to be merged? Or still any blocking issue there? > > Thanks, > Bo > > -----Original Message----- > From: shuah [mailto:shuah@kernel.org] > Sent: Friday, April 19, 2019 10:05 PM > To: Tong, Bo ; luto@kernel.org; x86@kernel.org > Cc: linux-kselftest@vger.kernel.org; linux-kernel@vger.kernel.org; skhan@linuxfoundation.org; shuah@kernel.org > Subject: Re: [PATCH v3] selftests/x86: Support Atom for syscall_arg_fault test > > On 4/19/19 1:10 AM, Tong Bo wrote: >> Atom-based CPUs trigger stack fault when invoke 32-bit SYSENTER >> instruction with invalid register values. So we also need SIGBUS handling in this case. >> >> Following is assembly when the fault exception happens. >> >> (gdb) disassemble $eip >> Dump of assembler code for function __kernel_vsyscall: >> 0xf7fd8fe0 <+0>: push %ecx >> 0xf7fd8fe1 <+1>: push %edx >> 0xf7fd8fe2 <+2>: push %ebp >> 0xf7fd8fe3 <+3>: mov %esp,%ebp >> 0xf7fd8fe5 <+5>: sysenter >> 0xf7fd8fe7 <+7>: int $0x80 >> => 0xf7fd8fe9 <+9>: pop %ebp >> 0xf7fd8fea <+10>: pop %edx >> 0xf7fd8feb <+11>: pop %ecx >> 0xf7fd8fec <+12>: ret >> End of assembler dump. >> >> According to Intel SDM, this could also be a Stack Segment Fault(#SS, >> 12), except a normal Page Fault(#PF, 14). Especially, in section 6.9 >> of Vol.3A, both stack and page faults are within the 10th(lowest >> priority) class, and as it said, "exceptions within each class are >> implementation-dependent and may vary from processor to processor". >> It's expected for processors like Intel Atom to trigger stack >> fault(SIGBUS), while we get page fault(SIGSEGV) from common Core processors. >> >> Signed-off-by: Tong Bo >> Acked-by: Andy Lutomirski >> --- >> tools/testing/selftests/x86/syscall_arg_fault.c | 10 ++++++++-- >> 1 file changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/tools/testing/selftests/x86/syscall_arg_fault.c >> b/tools/testing/selftests/x86/syscall_arg_fault.c >> index 7db4fc9..d2548401 100644 >> --- a/tools/testing/selftests/x86/syscall_arg_fault.c >> +++ b/tools/testing/selftests/x86/syscall_arg_fault.c >> @@ -43,7 +43,7 @@ static sigjmp_buf jmpbuf; >> >> static volatile sig_atomic_t n_errs; >> >> -static void sigsegv(int sig, siginfo_t *info, void *ctx_void) >> +static void sigsegv_or_sigbus(int sig, siginfo_t *info, void >> +*ctx_void) >> { >> ucontext_t *ctx = (ucontext_t*)ctx_void; >> >> @@ -73,7 +73,13 @@ int main() >> if (sigaltstack(&stack, NULL) != 0) >> err(1, "sigaltstack"); >> >> - sethandler(SIGSEGV, sigsegv, SA_ONSTACK); >> + sethandler(SIGSEGV, sigsegv_or_sigbus, SA_ONSTACK); >> + /* >> + * The actual exception can vary. On Atom CPUs, we get #SS >> + * instead of #PF when the vDSO fails to access the stack when >> + * ESP is too close to 2^32, and #SS causes SIGBUS. >> + */ >> + sethandler(SIGBUS, sigsegv_or_sigbus, SA_ONSTACK); >> sethandler(SIGILL, sigill, SA_ONSTACK); >> >> /* >> > > In case there is a dependency on x86 tree, here is my Ack > > Acked-by: Shuah Khan > Looks like it got left behind in the confusion of which tree. I will apply this to my tree. thanks, -- Shuah