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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 2341BC7618B for ; Sun, 28 Jul 2019 15:31:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF82D2087C for ; Sun, 28 Jul 2019 15:31:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726148AbfG1Pbz (ORCPT ); Sun, 28 Jul 2019 11:31:55 -0400 Received: from foss.arm.com ([217.140.110.172]:33560 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726032AbfG1Pbz (ORCPT ); Sun, 28 Jul 2019 11:31:55 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 906B5344; Sun, 28 Jul 2019 08:31:54 -0700 (PDT) Received: from [10.37.12.40] (unknown [10.37.12.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 45FE03F71F; Sun, 28 Jul 2019 08:31:53 -0700 (PDT) Subject: Re: [patch 3/5] lib/vdso/32: Provide legacy syscall fallbacks To: Thomas Gleixner , LKML Cc: x86@kernel.org, Andy Lutomirski , Sean Christopherson , Kees Cook , Paul Bolle , Will Deacon References: <20190728131251.622415456@linutronix.de> <20190728131648.786513965@linutronix.de> From: Vincenzo Frascino Message-ID: <3aba2ca9-5ed2-8bde-eb3e-ddb25410205d@arm.com> Date: Sun, 28 Jul 2019 16:33:04 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190728131648.786513965@linutronix.de> Content-Type: text/plain; charset=utf-8 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 On 7/28/19 2:12 PM, Thomas Gleixner wrote: > To address the regression which causes seccomp to deny applications the > access to clock_gettime64() and clock_getres64() syscalls because they > are not enabled in the existing filters. > > That trips over the fact that 32bit VDSOs use the new clock_gettime64() and > clock_getres64() syscalls in the fallback path. > > Implement a __cvdso_clock_get*time32() variants which invokes the legacy > 32bit syscalls when the architecture requests it. > > The conditional can go away once all architectures are converted. > Reviewed-by: Vincenzo Frascino Tested-by: Vincenzo Frascino > Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation") > Signed-off-by: Thomas Gleixner > --- > lib/vdso/gettimeofday.c | 46 +++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 45 insertions(+), 1 deletion(-) > > --- a/lib/vdso/gettimeofday.c > +++ b/lib/vdso/gettimeofday.c > @@ -117,6 +117,8 @@ static __maybe_unused int > return 0; > } > > +#ifndef VDSO_HAS_32BIT_FALLBACK > + > static __maybe_unused int > __cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res) > { > @@ -132,10 +134,29 @@ static __maybe_unused int > res->tv_sec = ts.tv_sec; > res->tv_nsec = ts.tv_nsec; > } > - > return ret; > } > > +#else > + > +static __maybe_unused int > +__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res) > +{ > + struct __kernel_timespec ts; > + int ret; > + > + ret = __cvdso_clock_gettime_common(clock, &ts); > + > + if (likely(!ret)) { > + res->tv_sec = ts.tv_sec; > + res->tv_nsec = ts.tv_nsec; > + return 0; > + } > + return clock_gettime32_fallback(clock, res); > +} > + > +#endif > + > static __maybe_unused int > __cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) > { > @@ -225,6 +246,8 @@ int __cvdso_clock_getres(clockid_t clock > return 0; > } > > +#ifndef VDSO_HAS_32BIT_FALLBACK > + > static __maybe_unused int > __cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res) > { > @@ -241,4 +264,25 @@ static __maybe_unused int > } > return ret; > } > + > +#else > + > +static __maybe_unused int > +__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res) > +{ > + struct __kernel_timespec ts; > + int ret; > + > + ret = __cvdso_clock_getres_common(clock, &ts); > + > + if (likely(!ret)) { > + res->tv_sec = ts.tv_sec; > + res->tv_nsec = ts.tv_nsec; > + return 0; > + } > + > + return clock_getres32_fallback(clock, res); > +} > +#endif > + > #endif /* VDSO_HAS_CLOCK_GETRES */ > > -- Regards, Vincenzo