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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAFD2C77B7A for ; Thu, 25 May 2023 07:22:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239229AbjEYHWf (ORCPT ); Thu, 25 May 2023 03:22:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238845AbjEYHW3 (ORCPT ); Thu, 25 May 2023 03:22:29 -0400 Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98C941B4; Thu, 25 May 2023 00:22:26 -0700 (PDT) Date: Thu, 25 May 2023 09:22:23 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=t-8ch.de; s=mail; t=1684999344; bh=WqUc/D7b6J+dZZ3k3J04dIED1dcPikypQw79086aY+I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A4qui0d6SFgquCtdZyX+rdW4NmFRU+MwSYXoz+NIOgAxuOFHJkA+W16BNaGXrAxwi d0tM4EyEQIRvkweDgiY07CEo3ZiJ5+1TnmhDDmOUYoqcsDtOdLbibs2POpPS07pecY KPcXGq5T2pYQ6SKBHWVTX7h02Mhr5OLA1nQx/nO4= From: Thomas =?utf-8?Q?Wei=C3=9Fschuh?= To: Zhangjin Wu Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-riscv@lists.infradead.org, palmer@dabbelt.com, paul.walmsley@sifive.com, w@1wt.eu Subject: Re: [PATCH 11/13] tools/nolibc: sys_select: riscv: use __NR_pselect6_time64 for rv32 Message-ID: <76a5f9a0-eec4-415a-9c5d-ac3bca4d4b0e@t-8ch.de> References: <83339ea6-6653-41fe-af75-e0d51a4fa920@t-8ch.de> <20230525071021.77223-1-falcon@tinylab.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230525071021.77223-1-falcon@tinylab.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023-05-25 15:10:21+0800, Zhangjin Wu wrote: > Hi, Thomas > > > On 2023-05-25 01:59:55+0800, Zhangjin Wu wrote: > > > rv32 uses the generic include/uapi/asm-generic/unistd.h and it has no > > > __NR_pselect6 after kernel commit d4c08b9776b3 ("riscv: Use latest > > > system call ABI"), use __NR_pselect6_time64 instead. > > > > > > Signed-off-by: Zhangjin Wu > > > --- > > > tools/include/nolibc/sys.h | 7 ++++++- > > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > > > diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h > > > index c0335a84f880..00c7197dcd50 100644 > > > --- a/tools/include/nolibc/sys.h > > > +++ b/tools/include/nolibc/sys.h > > > @@ -1041,8 +1041,13 @@ int sys_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeva > > > struct timeval *t; > > > } arg = { .n = nfds, .r = rfds, .w = wfds, .e = efds, .t = timeout }; > > > return my_syscall1(__NR_select, &arg); > > > -#elif defined(__ARCH_WANT_SYS_PSELECT6) && defined(__NR_pselect6) > > > +#elif defined(__ARCH_WANT_SYS_PSELECT6) && (defined(__NR_pselect6) || defined(__NR_pselect6_time64)) > > > +#ifdef __NR_pselect6 > > > struct timespec t; > > > +#else > > > + struct timespec64 t; > > > +#define __NR_pselect6 __NR_pselect6_time64 > > > > Wouldn't this #define leak to the users of nolibc and lead to calls to > > pselect6_time64 with the ABI of the __NR_pselect6 if userspace is doing > > its own raw syscalls? > > > > Yeah, it would break the user-side raw __NR_pselect6 syscall for nolibc is a > header-only libc, so, it is not safe to use such method like glibc. > > Something like this will let the syscall call to pselect6_time64 instead of the > user-required __NR_pselect6 and pass the wrong type of argument. > > #include "nolibc.h" // If no __NR_pselect6 defined, __NR_pselect6 = __NR_pselect6_time64 > > #ifdef __NR_pselect6 > struct timespec t; // come here for __NR_pselect6_time64, but t is not timespec64, broken > syscall(__NR_pselect6, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL); > #else > struct timespec64 t; > syscall(__NR_pselect6, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL); > #endif > > I have used something like __NR_pselect6_time3264 locally, before > sending the patchset, I found a cleaner method already used in sys.h: > > #ifndef __NR__newselect > #define __NR__newselect __NR_select > #endif > > But I forgot the arguments mixing issue, __NR__newselect and __NR_select > share the same type of arguments, but __NR_pselect6 and > __NR_pselect6_time64 not, so, I will use back the old method but still > need to find a better string, just like __NR__newselect, __NR__pselect6 > may be used in kernel space in the future, and __NR_pselect6_time3264 is > too long, what about this? > > #ifdef __NR_pselect6 > struct timespec t; > #define __NR_pselect6__ __NR_pselect6 > #else > struct timespec64 t; > #define __NR_pselect6__ __NR_pselect6_time64 > #endif > > Or even ___NR_pselect6? What about: #ifdef __NR_pselect6 struct timespec t; const long nr_pselect = __NR_pselect6; #else struct timespec64 t; const long nr_pselect = __NR_pselect6_time64; #endif > > The same issue is in this patch: > > [PATCH 13/13] tools/nolibc: sys_gettimeofday: riscv: use __NR_clock_gettime64 > > will solve it with the same method. Thanks!