From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.3 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 12232 invoked from network); 18 May 2021 23:13:45 -0000 Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with ESMTPUTF8; 18 May 2021 23:13:45 -0000 Received: (qmail 6123 invoked by uid 550); 18 May 2021 23:13:43 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 6090 invoked from network); 18 May 2021 23:13:43 -0000 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 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> Subject: [musl] Re: Linux powerpc new system call instruction and ABI 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