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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 A1BCBC282DA for ; Tue, 16 Apr 2019 17:05:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 64B1420872 for ; Tue, 16 Apr 2019 17:05:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=brauner.io header.i=@brauner.io header.b="GGhdTz8p" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730109AbfDPRFH (ORCPT ); Tue, 16 Apr 2019 13:05:07 -0400 Received: from mail-vk1-f194.google.com ([209.85.221.194]:39173 "EHLO mail-vk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727618AbfDPRFG (ORCPT ); Tue, 16 Apr 2019 13:05:06 -0400 Received: by mail-vk1-f194.google.com with SMTP id s80so4592759vke.6 for ; Tue, 16 Apr 2019 10:05:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brauner.io; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=CB0a/z1DKBAR/CBfIEc1puxs5zWRnS7xbdC3R7PlbdE=; b=GGhdTz8ppAcpxB9rySOfzaqsT4qCqXaYudhe5AFls1xQkAKmn5IeLDoJCYlxqF+BVS IfYGSbxyZiGkjPoz6JHr53kN69HDudSEGApb6DVJDLlp6cS8eepkOVAsZSrID4qZTbuF DjpUldt8bI/hPpChuzV4rECckjSKjyV8pmkpMqGW+YGwFND5n1iMwQ3KKhkoqBci0dZV Bt3J8kBG8cotMYKLG5UDp5J9oyxxavoNl5TBEUDNAzWy5oFO+S29NkNjlyCWFT2WKoxj v78yskifIqsE52N6h7TEDaML1iDyoXLgjPxjehhu6MtxXeqi5h8PevxVGVHKJaAM5kMN MbGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=CB0a/z1DKBAR/CBfIEc1puxs5zWRnS7xbdC3R7PlbdE=; b=XrYNlxAlZQBdO0fEFm7Ge7y3ZPS3POnqg/g3GJhzkYV24Etq77kC2mi8GMjoVYDEDt T6KqrB7AADQ9mKBTn4bRnWxgvJt/V1qvy8fS3cy1xOnDE+2RA0OsY7D0NImup7KwjGnt X0cs0TSpvoJSUOE+R23zQldAXndW0lZDn4YcgkrPcNlKc1C9Ra6o+gPto2JUw3+gNdKN 0xYnKa9XD+k5ElcaS2u6bVlLg+dfmJvWO/gqwgMWGp4ojSzYeE6sa8NrsItpP/ZXp+oP bpy382bGdk7jxWHhcs/UVg8OQWHdQzRCOVrbiGsAjy6lvNazGFZ9R7aVv7YzZTSlrRUE YUIw== X-Gm-Message-State: APjAAAV5CdEKXXSEebw15mF/6HrHl2HzQUK6cfFO9Qp8o/b6pfr2TaC+ s6q4xGvmlscwBHIS+jVibp2J2A== X-Google-Smtp-Source: APXvYqxcqGZQ54N/Kyvp3jY/4YD/5ORZmupHzld08QiwP2bw/hJHYq41PbXAiqYc9pkwunXNrnZo2A== X-Received: by 2002:a1f:850c:: with SMTP id h12mr45481805vkd.70.1555434305219; Tue, 16 Apr 2019 10:05:05 -0700 (PDT) Received: from localhost.localdomain ([172.56.12.212]) by smtp.gmail.com with ESMTPSA id c192sm45178368vka.10.2019.04.16.10.04.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 16 Apr 2019 10:05:04 -0700 (PDT) From: Christian Brauner To: torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, jannh@google.com, dhowells@redhat.com, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Cc: serge@hallyn.com, luto@kernel.org, arnd@arndb.de, ebiederm@xmission.com, keescook@chromium.org, tglx@linutronix.de, mtk.manpages@gmail.com, akpm@linux-foundation.org, oleg@redhat.com, cyphar@cyphar.com, joel@joelfernandes.org, dancol@google.com, Christian Brauner Subject: [PATCH v1 3/4] signal: support CLONE_PIDFD with pidfd_send_signal Date: Tue, 16 Apr 2019 19:02:32 +0200 Message-Id: <20190416170233.10208-4-christian@brauner.io> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190416170233.10208-1-christian@brauner.io> References: <20190416170233.10208-1-christian@brauner.io> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Let pidfd_send_signal() use pidfds retrieved via CLONE_PIDFD. With this patch pidfd_send_signal() becomes independent of procfs. This fullfils the request made when we merged the pidfd_send_signal() patchset. The pidfd_send_signal() syscall is now always available allowing for it to be used by users without procfs mounted or even users without procfs support compiled into the kernel. Signed-off-by: Christian Brauner Signed-off-by: Jann Horn Cc: Arnd Bergmann Cc: "Eric W. Biederman" Cc: Kees Cook Cc: Thomas Gleixner Cc: David Howells Cc: "Michael Kerrisk (man-pages)" Cc: Andy Lutomirsky Cc: Andrew Morton Cc: Oleg Nesterov Cc: Aleksa Sarai Cc: Linus Torvalds Cc: Al Viro --- /* changelog */ v1: patch unchanged --- kernel/signal.c | 14 ++++++++++---- kernel/sys_ni.c | 3 --- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index f98448cf2def..cd83cc376767 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3513,7 +3513,6 @@ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) return kill_something_info(sig, &info, pid); } -#ifdef CONFIG_PROC_FS /* * Verify that the signaler and signalee either are in the same pid namespace * or that the signaler's pid namespace is an ancestor of the signalee's pid @@ -3550,6 +3549,14 @@ static int copy_siginfo_from_user_any(kernel_siginfo_t *kinfo, siginfo_t *info) return copy_siginfo_from_user(kinfo, info); } +static struct pid *pidfd_to_pid(const struct file *file) +{ + if (file->f_op == &pidfd_fops) + return file->private_data; + + return tgid_pidfd_to_pid(file); +} + /** * sys_pidfd_send_signal - send a signal to a process through a task file * descriptor @@ -3581,12 +3588,12 @@ SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig, if (flags) return -EINVAL; - f = fdget_raw(pidfd); + f = fdget(pidfd); if (!f.file) return -EBADF; /* Is this a pidfd? */ - pid = tgid_pidfd_to_pid(f.file); + pid = pidfd_to_pid(f.file); if (IS_ERR(pid)) { ret = PTR_ERR(pid); goto err; @@ -3620,7 +3627,6 @@ SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig, fdput(f); return ret; } -#endif /* CONFIG_PROC_FS */ static int do_send_specific(pid_t tgid, pid_t pid, int sig, struct kernel_siginfo *info) diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index d21f4befaea4..4d9ae5ea6caf 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -167,9 +167,6 @@ COND_SYSCALL(syslog); /* kernel/sched/core.c */ -/* kernel/signal.c */ -COND_SYSCALL(pidfd_send_signal); - /* kernel/sys.c */ COND_SYSCALL(setregid); COND_SYSCALL(setgid); -- 2.21.0