From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Subject: rseq system call incompletely wired up in microblaze Date: Sun, 14 Oct 2018 12:46:58 -0400 (EDT) Message-ID: <1913468383.3666.1539535618042.JavaMail.zimbra@efficios.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Michal Simek Cc: Thomas Gleixner , "Paul E. McKenney" , Peter Zijlstra , Boqun Feng , linux-kernel , linux-api List-Id: linux-api@vger.kernel.org Hi Michal, I notice the following commit went into 4.18: commit 54b0a2011dfcd2e3fe2c28062694fbbe3eb377a3 Author: Michal Simek Date: Thu Jun 14 08:24:39 2018 +0200 microblaze: Add new syscalls io_pgetevents and rseq Wire up new syscalls io_pgetevents and rseq. Signed-off-by: Michal Simek It adds the rseq system call to the microblaze syscall list, but does not add the required hooks in the architecture code, nor does it select HAVE_RSEQ. So effectively, even though sys_rseq is reserved on microblaze, it currently always returns ENOSYS. Is your intent to simply reserve the system call number, or to also get rseq to work on microblaze ? A good example of the architecture changes required to wire up rseq can be found here: commit 9d6d99e3ac8ccfd0945edb3c83cd912838775056 Author: Heiko Carstens Date: Sat Jun 30 10:54:15 2018 +0200 s390: wire up rseq system call Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Also, please make sure the tools/testing/selftests/rseq/ tests pass before pushing a commit enabling it for your architecture. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com