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=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 3DBCDC28CC0 for ; Thu, 30 May 2019 11:43:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03C812586E for ; Thu, 30 May 2019 11:43:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=brauner.io header.i=@brauner.io header.b="V5ZBBqW2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726973AbfE3Lng (ORCPT ); Thu, 30 May 2019 07:43:36 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:43579 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726339AbfE3Lnf (ORCPT ); Thu, 30 May 2019 07:43:35 -0400 Received: by mail-wr1-f65.google.com with SMTP id l17so3984321wrm.10 for ; Thu, 30 May 2019 04:43:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brauner.io; s=google; h=date:user-agent:in-reply-to:references:mime-version :content-transfer-encoding:subject:to:cc:from:message-id; bh=x7Qyy1KyQMpKaNghFb+JOHZdFPq1/NIbfTjt3A+5EHs=; b=V5ZBBqW2T06RqnvJVzT3AO8/ouFOu/LNxk7BIU7QtYl4402Th+Nm1rmpB/wGMbPZwL Jj7mH5BsTRf0ANI4qiDv6PVjNRr+mwfmr0Zt6u07WXcC3j3VQkvuM/sAITId7ZIRvOKU OrmOToyll1UmmqRp6fr+JGZ/kEDZvbOqaCIcsDKr2tNA4CzUEgpDb0T2/i4Gt/QSoqSj RVmogbtHxynyT8dYrvNft6PPfDD+v/Rhxk1dUVj8A1XIjcyc53o+q/vY5pXJbBsCb/Ls bJBj5FQXvuwN6tPfmcuPaW8oOP/oCYkO2PBygQmfO2jf/7QUpihAhGrl1ZItIqgnGjdi X+pQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:user-agent:in-reply-to:references :mime-version:content-transfer-encoding:subject:to:cc:from :message-id; bh=x7Qyy1KyQMpKaNghFb+JOHZdFPq1/NIbfTjt3A+5EHs=; b=fO6THnM9g9/QiTnPIYArXrPbMpbQJKdKchPsxVyV9xBF9kmOoI7YVqGcQ3T8+GwzoE TJRgBjT/7EScjf7m8rGyJNzhcqTVG4SPF2joPPHWelrTEgZZcRzTLHGQXqdAY7m8RgIT orq/e/AFOULrUAsC1CUc0H2Qsfk6Ls4Qin739VkGX4qbnHCl+ib/N4O4OAeL7kEd4gHI cUyH5XkaKyUAtd0VNbhCtrGHRtKpFLIYCj4ucrhOssxGbFnc/21o+e5WZrA91uxMF2Uh n4srepD8+LzSwrbjRz+awzHzeqgIM8KhGn9lhg/JWi3Bw3XkrwuekoblX22tii3xNWSK YFyg== X-Gm-Message-State: APjAAAUYl+5Fz8WAwjDxXy1r2liRGru5Hg2eyBnyQ2GJ7G/PkqOnYUin HgxD+DRuho7qKdCyYSeDDjHumBzq9dLKbw== X-Google-Smtp-Source: APXvYqx7eo2IJq8TtX8+mg3zeaoQIHvU24aNQ2F00GoN/ZR8ZliFL6QkTniZ3/dMyJm1NRP2tp7kng== X-Received: by 2002:a5d:5048:: with SMTP id h8mr2358129wrt.177.1559216613878; Thu, 30 May 2019 04:43:33 -0700 (PDT) Received: from [192.168.1.161] (93-32-55-82.ip32.fastwebnet.it. [93.32.55.82]) by smtp.gmail.com with ESMTPSA id c18sm3206011wrm.7.2019.05.30.04.43.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 30 May 2019 04:43:33 -0700 (PDT) Date: Thu, 30 May 2019 13:43:31 +0200 User-Agent: K-9 Mail for Android In-Reply-To: <1559216447-28355-1-git-send-email-linux@roeck-us.net> References: <1559216447-28355-1-git-send-email-linux@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH] samples: pidfd: Fix compile error seen if __NR_pidfd_send_signal is undefined To: Guenter Roeck , Jann Horn CC: linux-kernel@vger.kernel.org From: Christian Brauner Message-ID: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On May 30, 2019 1:40:47 PM GMT+02:00, Guenter Roeck = wrote: >To make pidfd-metadata compile on all arches, irrespective of whether >or not syscall numbers are assigned, define the syscall number to -1 >if it isn't to cause the kernel to return -ENOSYS=2E > >Fixes: 43c6afee48d4 ("samples: show race-free pidfd metadata access") >Cc: Christian Brauner >Signed-off-by: Guenter Roeck >--- > samples/pidfd/pidfd-metadata=2Ec | 4 ++++ > 1 file changed, 4 insertions(+) > >diff --git a/samples/pidfd/pidfd-metadata=2Ec >b/samples/pidfd/pidfd-metadata=2Ec >index 640f5f757c57=2E=2E1e125ddde268 100644 >--- a/samples/pidfd/pidfd-metadata=2Ec >+++ b/samples/pidfd/pidfd-metadata=2Ec >@@ -21,6 +21,10 @@ > #define CLONE_PIDFD 0x00001000 > #endif >=20 >+#ifndef __NR_pidfd_send_signal >+#define __NR_pidfd_send_signal -1 >+#endif >+ > static int do_child(void *args) > { > printf("%d\n", getpid()); Couldn't you just use the actual syscall number?=20 That should still fail if the kernel is to old=20 and still work on kernels that support it but for whatever reason the unistd=2Eh h header doesn't have it defined=2E Thanks! Christian