From patchwork Fri Aug 30 13:58:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincenzo Frascino X-Patchwork-Id: 11124139 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 955E514DE for ; Fri, 30 Aug 2019 13:59:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7DAE92342B for ; Fri, 30 Aug 2019 13:59:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728535AbfH3N7X (ORCPT ); Fri, 30 Aug 2019 09:59:23 -0400 Received: from foss.arm.com ([217.140.110.172]:60810 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728497AbfH3N7U (ORCPT ); Fri, 30 Aug 2019 09:59:20 -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 CEF671596; Fri, 30 Aug 2019 06:59:19 -0700 (PDT) Received: from e119884-lin.cambridge.arm.com (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 412C23F703; Fri, 30 Aug 2019 06:59:18 -0700 (PDT) From: Vincenzo Frascino To: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: catalin.marinas@arm.com, will@kernel.org, paul.burton@mips.com, tglx@linutronix.de, salyzyn@android.com, 0x7f454c46@gmail.com, luto@kernel.org Subject: [PATCH v2 3/8] mips: compat: vdso: Use legacy syscalls as fallback Date: Fri, 30 Aug 2019 14:58:57 +0100 Message-Id: <20190830135902.20861-4-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190830135902.20861-1-vincenzo.frascino@arm.com> References: <20190830135902.20861-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org The generic VDSO implementation uses the Y2038 safe clock_gettime64() and clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks seccomp setups because these syscalls might be not (yet) allowed. Implement the 32bit variants which use the legacy syscalls and select the variant in the core library. The 64bit time variants are not removed because they are required for the time64 based vdso accessors. Cc: Paul Burton Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation") Signed-off-by: Vincenzo Frascino --- arch/mips/include/asm/vdso/gettimeofday.h | 45 +++++++++++++++++++++++ arch/mips/vdso/config-n32-o32-env.c | 1 + 2 files changed, 46 insertions(+) diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h index c59fe08b0347..e78462e8ca2e 100644 --- a/arch/mips/include/asm/vdso/gettimeofday.h +++ b/arch/mips/include/asm/vdso/gettimeofday.h @@ -105,6 +105,51 @@ static __always_inline int clock_getres_fallback( return error ? -ret : ret; } +#if _MIPS_SIM != _MIPS_SIM_ABI64 + +#define VDSO_HAS_32BIT_FALLBACK 1 + +static __always_inline long clock_gettime32_fallback( + clockid_t _clkid, + struct old_timespec32 *_ts) +{ + register struct old_timespec32 *ts asm("a1") = _ts; + register clockid_t clkid asm("a0") = _clkid; + register long ret asm("v0"); + register long nr asm("v0") = __NR_clock_gettime; + register long error asm("a3"); + + asm volatile( + " syscall\n" + : "=r" (ret), "=r" (error) + : "r" (clkid), "r" (ts), "r" (nr) + : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", + "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + + return error ? -ret : ret; +} + +static __always_inline int clock_getres32_fallback( + clockid_t _clkid, + struct old_timespec32 *_ts) +{ + register struct old_timespec32 *ts asm("a1") = _ts; + register clockid_t clkid asm("a0") = _clkid; + register long ret asm("v0"); + register long nr asm("v0") = __NR_clock_getres; + register long error asm("a3"); + + asm volatile( + " syscall\n" + : "=r" (ret), "=r" (error) + : "r" (clkid), "r" (ts), "r" (nr) + : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", + "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + + return error ? -ret : ret; +} +#endif + #ifdef CONFIG_CSRC_R4K static __always_inline u64 read_r4k_count(void) diff --git a/arch/mips/vdso/config-n32-o32-env.c b/arch/mips/vdso/config-n32-o32-env.c index 7f8d957abd4a..0011a632aef2 100644 --- a/arch/mips/vdso/config-n32-o32-env.c +++ b/arch/mips/vdso/config-n32-o32-env.c @@ -10,6 +10,7 @@ */ #undef CONFIG_64BIT +#define BUILD_VDSO32 #define CONFIG_32BIT 1 #define CONFIG_GENERIC_ATOMIC64 1 #define BUILD_VDSO32_64