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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 021B7C433B4 for ; Tue, 18 May 2021 23:13:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6C196124C for ; Tue, 18 May 2021 23:13:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234443AbhERXOw (ORCPT ); Tue, 18 May 2021 19:14:52 -0400 Received: from vmicros1.altlinux.org ([194.107.17.57]:55550 "EHLO vmicros1.altlinux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229660AbhERXOw (ORCPT ); Tue, 18 May 2021 19:14:52 -0400 Received: from mua.local.altlinux.org (mua.local.altlinux.org [192.168.1.14]) by vmicros1.altlinux.org (Postfix) with ESMTP id 1223A72C8BA; Wed, 19 May 2021 02:13:32 +0300 (MSK) Received: by mua.local.altlinux.org (Postfix, from userid 508) id E4BDE7CC8A6; Wed, 19 May 2021 02:13:31 +0300 (MSK) Date: Wed, 19 May 2021 02:13:31 +0300 From: "Dmitry V. Levin" To: Nicholas Piggin , Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, musl@lists.openwall.com, libc-dev@lists.llvm.org, linux-api@vger.kernel.org Subject: Re: Linux powerpc new system call instruction and ABI Message-ID: <20210518231331.GA8464@altlinux.org> References: <20200611081203.995112-1-npiggin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200611081203.995112-1-npiggin@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org Hi, On Thu, Jun 11, 2020 at 06:12:01PM +1000, Nicholas Piggin wrote: [...] > - Error handling: The consensus among kernel, glibc, and musl is to move to > using negative return values in r3 rather than CR0[SO]=1 to indicate error, > which matches most other architectures, and is closer to a function call. Apparently, the patchset merged by commit v5.9-rc1~100^2~164 was incomplete: all functions defined in arch/powerpc/include/asm/ptrace.h and arch/powerpc/include/asm/syscall.h that use ccr are broken when scv is used. This includes syscall_get_error() and all its users including PTRACE_GET_SYSCALL_INFO API, which in turn makes strace unusable when scv is used. See also https://bugzilla.redhat.com/1929836 -- ldv