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=-0.8 required=3.0 tests=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 185FDC433E0 for ; Thu, 14 May 2020 10:33:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE8892073E for ; Thu, 14 May 2020 10:33:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726051AbgENKdF (ORCPT ); Thu, 14 May 2020 06:33:05 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:34615 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725925AbgENKdE (ORCPT ); Thu, 14 May 2020 06:33:04 -0400 Received: from ip5f5af183.dynamic.kabel-deutschland.de ([95.90.241.131] helo=wittgenstein) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jZBAi-0000rK-CJ; Thu, 14 May 2020 10:33:00 +0000 Date: Thu, 14 May 2020 12:32:59 +0200 From: Christian Brauner To: John Paul Adrian Glaubitz Cc: "Luck, Tony" , "Yu, Fenghua" , "linux-ia64@vger.kernel.org" , Al Viro , Arnd Bergmann , Thomas Gleixner , Ingo Molnar , Sebastian Andrzej Siewior , "Peter Zijlstra (Intel)" , Qais Yousef , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] ia64: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args Message-ID: <20200514103259.tdfjc5ds4igpmoxj@wittgenstein> References: <3908561D78D1C84285E8C5FCA982C28F7F6266E0@ORSMSX115.amr.corp.intel.com> <79e58d9b-5a39-390c-2f0c-0d87b63442b4@physik.fu-berlin.de> <20200514074606.vkc35syhdep23rzh@wittgenstein> <6b298416-1e64-eee7-0bb4-3b1f7f67adc6@physik.fu-berlin.de> <20200514100459.pt7dxq2faghdds2c@wittgenstein> <2e22b0d2-b9ce-420d-48a0-0d9134108a5c@physik.fu-berlin.de> <20200514101540.25hvle74w63t66fs@wittgenstein> <20200514101914.fu7xhgaxtb5fy2ky@wittgenstein> <4aad9ad5-b0e9-12b0-0ad2-ac23fceae87b@physik.fu-berlin.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <4aad9ad5-b0e9-12b0-0ad2-ac23fceae87b@physik.fu-berlin.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 14, 2020 at 12:21:13PM +0200, John Paul Adrian Glaubitz wrote: > On 5/14/20 12:19 PM, Christian Brauner wrote: > > Scratch that. It's even worse. On ia64 it is _invalid_ to pass a NULL > > stack. That's at least what the glibc assembly assumes: > > > > cmp.eq p6,p0=0,in0 > > cmp.eq p7,p0=0,in1 > > mov r8=EINVAL > > mov out0=in3 /* Flags are first syscall argument. */ > > mov out1=in1 /* Stack address. */ > > (p6) br.cond.spnt.many __syscall_error /* no NULL function pointers */ > > (p7) br.cond.spnt.many __syscall_error /* no NULL stack pointers */ > > ;; > > mov out2=in2 /* Stack size. */ > > > > so newer systemd just works by accident on ia64 if at all correctly > > afaict. > > Hmm, interesting. I really wasn't aware of that. Thanks for the heads-up. > > I'll ask Michael whether he can come up for a solution for that problem. > > Maybe that's also why systemd crashes. Do you have a very minimalistic ia64 userspace preferably without systemd where you could simply test. That should give us an idea whether things work: #define _GNU_SOURCE #include #include #include #include #include #include #include #include #define STACK_SIZE (8 * 1024 * 1024) /* standard stack size for threads in glibc */ int main(int argc, char *argv[]) { char *stack; pid_t pid; stack = mmap(NULL, STACK_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); if (stack == MAP_FAILED) exit(EXIT_FAILURE); /* * Note that legacy clone() has different argument ordering on * different architectures so this won't work everywhere. */ pid = syscall(189 /* __NR_clone2 */, SIGCHLD, stack, STACK_SIZE, NULL, NULL); if (pid < 0) exit(EXIT_FAILURE); if (pid == 0) exit(EXIT_SUCCESS); if (wait(NULL) != pid) exit(EXIT_FAILURE); exit(EXIT_SUCCESS); } From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Brauner Date: Thu, 14 May 2020 10:32:59 +0000 Subject: Re: [PATCH] ia64: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args Message-Id: <20200514103259.tdfjc5ds4igpmoxj@wittgenstein> List-Id: References: <3908561D78D1C84285E8C5FCA982C28F7F6266E0@ORSMSX115.amr.corp.intel.com> <79e58d9b-5a39-390c-2f0c-0d87b63442b4@physik.fu-berlin.de> <20200514074606.vkc35syhdep23rzh@wittgenstein> <6b298416-1e64-eee7-0bb4-3b1f7f67adc6@physik.fu-berlin.de> <20200514100459.pt7dxq2faghdds2c@wittgenstein> <2e22b0d2-b9ce-420d-48a0-0d9134108a5c@physik.fu-berlin.de> <20200514101540.25hvle74w63t66fs@wittgenstein> <20200514101914.fu7xhgaxtb5fy2ky@wittgenstein> <4aad9ad5-b0e9-12b0-0ad2-ac23fceae87b@physik.fu-berlin.de> In-Reply-To: <4aad9ad5-b0e9-12b0-0ad2-ac23fceae87b@physik.fu-berlin.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: John Paul Adrian Glaubitz Cc: "Luck, Tony" , "Yu, Fenghua" , "linux-ia64@vger.kernel.org" , Al Viro , Arnd Bergmann , Thomas Gleixner , Ingo Molnar , Sebastian Andrzej Siewior , "Peter Zijlstra (Intel)" , Qais Yousef , "linux-kernel@vger.kernel.org" On Thu, May 14, 2020 at 12:21:13PM +0200, John Paul Adrian Glaubitz wrote: > On 5/14/20 12:19 PM, Christian Brauner wrote: > > Scratch that. It's even worse. On ia64 it is _invalid_ to pass a NULL > > stack. That's at least what the glibc assembly assumes: > > > > cmp.eq p6,p0=0,in0 > > cmp.eq p7,p0=0,in1 > > mov r8=EINVAL > > mov out0=in3 /* Flags are first syscall argument. */ > > mov out1=in1 /* Stack address. */ > > (p6) br.cond.spnt.many __syscall_error /* no NULL function pointers */ > > (p7) br.cond.spnt.many __syscall_error /* no NULL stack pointers */ > > ;; > > mov out2=in2 /* Stack size. */ > > > > so newer systemd just works by accident on ia64 if at all correctly > > afaict. > > Hmm, interesting. I really wasn't aware of that. Thanks for the heads-up. > > I'll ask Michael whether he can come up for a solution for that problem. > > Maybe that's also why systemd crashes. Do you have a very minimalistic ia64 userspace preferably without systemd where you could simply test. That should give us an idea whether things work: #define _GNU_SOURCE #include #include #include #include #include #include #include #include #define STACK_SIZE (8 * 1024 * 1024) /* standard stack size for threads in glibc */ int main(int argc, char *argv[]) { char *stack; pid_t pid; stack = mmap(NULL, STACK_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); if (stack = MAP_FAILED) exit(EXIT_FAILURE); /* * Note that legacy clone() has different argument ordering on * different architectures so this won't work everywhere. */ pid = syscall(189 /* __NR_clone2 */, SIGCHLD, stack, STACK_SIZE, NULL, NULL); if (pid < 0) exit(EXIT_FAILURE); if (pid = 0) exit(EXIT_SUCCESS); if (wait(NULL) != pid) exit(EXIT_FAILURE); exit(EXIT_SUCCESS); }