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 49F78C77B7E for ; Thu, 25 May 2023 07:10:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236175AbjEYHKp (ORCPT ); Thu, 25 May 2023 03:10:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233652AbjEYHKm (ORCPT ); Thu, 25 May 2023 03:10:42 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.155.67.158]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8697E19D; Thu, 25 May 2023 00:10:29 -0700 (PDT) X-QQ-mid: bizesmtp66t1684998623tlsn9f2l Received: from linux-lab-host.localdomain ( [119.123.130.80]) by bizesmtp.qq.com (ESMTP) with id ; Thu, 25 May 2023 15:10:22 +0800 (CST) X-QQ-SSF: 01200000000000D0V000000A0000000 X-QQ-FEAT: CR3LFp2JE4kc3pygKDDUtJn39vE4Fmng3uwhG01MZ6x96u4i0xrEu8jidY6KF 5LIn2dky9FChTAvw70bQd9V3YXqgsFXT9XOcCHlIUtq/BlhasJ5GDPxSOVybTX2GzL2SdTF Cy9+lJVOpqy2BqRKTsa/7hvTm+6tLB3DQsVE8gfL77TWmpV1LIFxnTct1mL2DFCgrmbj44u yvlo+Ru0JKK/txynsYD2yYLA/lPIuJ4o3pwL3apINnuVVXdnlcZQBxrlMavqHxpGPQnYd1o 6pJ5c1eWvkUz6nPe1TRye4KJwMooBdw5zaKOuotp5LAcSVmcXevPRP0Y6q/veUNqJiCB63L caopRqfllIHHckm32A7Flqkwmt6aAbtHH68/+KQGqx9l95K/3eiVKStGIcsXb/tdFusUokR X-QQ-GoodBg: 0 X-BIZMAIL-ID: 15606333847527544035 From: Zhangjin Wu To: thomas@t-8ch.de Cc: falcon@tinylab.org, 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 Date: Thu, 25 May 2023 15:10:21 +0800 Message-Id: <20230525071021.77223-1-falcon@tinylab.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <83339ea6-6653-41fe-af75-e0d51a4fa920@t-8ch.de> References: <83339ea6-6653-41fe-af75-e0d51a4fa920@t-8ch.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtp:tinylab.org:qybglogicsvrsz:qybglogicsvrsz3a-3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? 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, Zhangjin > > > +#endif > > > > if (timeout) { > > t.tv_sec = timeout->tv_sec; > > -- > > 2.25.1 > >