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=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 6C040C3F2D8 for ; Mon, 2 Mar 2020 19:36:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 341C82080C for ; Mon, 2 Mar 2020 19:36:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jdVlEcSD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 341C82080C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3FFF56B000C; Mon, 2 Mar 2020 14:36:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 387396B000D; Mon, 2 Mar 2020 14:36:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 276F46B000E; Mon, 2 Mar 2020 14:36:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0251.hostedemail.com [216.40.44.251]) by kanga.kvack.org (Postfix) with ESMTP id EFF566B000C for ; Mon, 2 Mar 2020 14:36:51 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id B2BB1180AD802 for ; Mon, 2 Mar 2020 19:36:51 +0000 (UTC) X-FDA: 76551429822.11.dress28_760eb3e18f237 X-HE-Tag: dress28_760eb3e18f237 X-Filterd-Recvd-Size: 7102 Received: from mail-pl1-f196.google.com (mail-pl1-f196.google.com [209.85.214.196]) by imf09.hostedemail.com (Postfix) with ESMTP for ; Mon, 2 Mar 2020 19:36:51 +0000 (UTC) Received: by mail-pl1-f196.google.com with SMTP id b22so173346pls.12 for ; Mon, 02 Mar 2020 11:36:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=pHysGZtRm9DpDxh7VwFObxgb2rj7KREaKfoe8EJ8zu8=; b=jdVlEcSDzo3ybdd7sN6kE2OKzk9oA7bpxTLKHadgEWCMOybjQ+xvZnJGVZ7fZjEfQg uMEDZ86LuVgP1Q6ZD7VtneBpW3iteqpuTrP3/PWga/dBDviAOIX7pwxJvpurzCqOj7fN jQT25IdzQdbEKTplDxwjaE6/Sp8da28vTFvaqYVQXWMS/ijYzC9/vT04XJhzJeUyFmi5 W1dY2xG14HMz217CZrrz7AQLnie7ovjZYjeZ46ICnLv/i7QSZQi050GPkvgyUDs+oPaF p9OjX1JTqSRH+dMbwMtnn3Yrjt7fT/yKlKug7rJY5AteQTiqrX7VGVvcPd+bOjNPIBRu c9OA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=pHysGZtRm9DpDxh7VwFObxgb2rj7KREaKfoe8EJ8zu8=; b=Zt1Ssv+HF0+/KczYH369v36gEdBLngBqCPcuz+XOeqx78FDaBoAjo8LOjTglX/jLi4 +BfTzzPHVav+Noyk94DzIkHa7tIj+NuopSF6ZiZkwmDjakoHOEiltwe25ULndihIQhj/ Vd6lxqgNW4WuLMyc5JO+LOJqjjEFYQCKwUflVaMiDqgYMbu8rUca4s8cV2ePBevP9On7 gzWtCKQCfS1qWIEDpkh7BeYlmH9NuPrBkAwIA4aZk6OAAn3FR1y0nQ7q1HCUVH2LSxo1 Szv60BKK8W9KCqKm3x1eosZhj2sp8lA5WZTxP9ylQ0RYtQ/mtmwGyiE0pR9YXalhQIL5 ty2Q== X-Gm-Message-State: ANhLgQ3NFMKxpirBAjotE2KhVUUjHDZLoU31trpjvZYhvNwq5Hs7VlaV OBnKtHbwExNdcBhMSTJE9tg= X-Google-Smtp-Source: ADFU+vuNMy9czC34xQNT/3L0cavE3HOPPROCVeNfLMB3n1LQxWwOUbMYURhKYhirIyIz1qSVT3nMgQ== X-Received: by 2002:a17:90a:ec10:: with SMTP id l16mr37690pjy.19.1583177810150; Mon, 02 Mar 2020 11:36:50 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:1:3e01:2939:5992:52da]) by smtp.gmail.com with ESMTPSA id hg6sm35441pjb.22.2020.03.02.11.36.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Mar 2020 11:36:49 -0800 (PST) From: Minchan Kim To: Andrew Morton Cc: LKML , linux-mm , linux-api@vger.kernel.org, oleksandr@redhat.com, Suren Baghdasaryan , Tim Murray , Daniel Colascione , Sandeep Patil , Sonny Rao , Brian Geffon , Michal Hocko , Johannes Weiner , Shakeel Butt , John Dias , Joel Fernandes , Jann Horn , alexander.h.duyck@linux.intel.com, sj38.park@gmail.com, Minchan Kim , Christian Brauner , Kirill Tkhai Subject: [PATCH v7 5/7] mm: support both pid and pidfd for process_madvise Date: Mon, 2 Mar 2020 11:36:28 -0800 Message-Id: <20200302193630.68771-6-minchan@kernel.org> X-Mailer: git-send-email 2.25.0.265.gbab2e86ba0-goog In-Reply-To: <20200302193630.68771-1-minchan@kernel.org> References: <20200302193630.68771-1-minchan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: There is a demand[1] to support pid as well pidfd for process_madvise to reduce unnecessary syscall to get pidfd if the user has control of the target process(ie, they could guarantee the process is not gone or pid is not reused). This patch aims for supporting both options like waitid(2). So, the syscall is currently, int process_madvise(int which, pid_t pid, void *addr, size_t length, int advise, unsigned long flag); @which is actually idtype_t for userspace libray and currently, it supports P_PID and P_PIDFD. [1] https://lore.kernel.org/linux-mm/9d849087-3359-c4ab-fbec-859e8186c50= 9@virtuozzo.com/ Cc: Christian Brauner Reviewed-by: Suren Baghdasaryan Suggested-by: Kirill Tkhai Signed-off-by: Minchan Kim --- include/linux/syscalls.h | 3 ++- mm/madvise.c | 34 ++++++++++++++++++++++------------ 2 files changed, 24 insertions(+), 13 deletions(-) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index e4cd2c2f8bb4..f5ada20e2943 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -876,7 +876,8 @@ asmlinkage long sys_munlockall(void); asmlinkage long sys_mincore(unsigned long start, size_t len, unsigned char __user * vec); asmlinkage long sys_madvise(unsigned long start, size_t len, int behavio= r); -asmlinkage long sys_process_madvise(int pidfd, unsigned long start, + +asmlinkage long sys_process_madvise(int which, pid_t pid, unsigned long = start, size_t len, int behavior, unsigned long flags); asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long = size, unsigned long prot, unsigned long pgoff, diff --git a/mm/madvise.c b/mm/madvise.c index 6543f2bfc3d8..e794367f681e 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1182,11 +1182,10 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, si= ze_t, len_in, int, behavior) return do_madvise(current, current->mm, start, len_in, behavior); } =20 -SYSCALL_DEFINE5(process_madvise, int, pidfd, unsigned long, start, +SYSCALL_DEFINE6(process_madvise, int, which, pid_t, upid, unsigned long,= start, size_t, len_in, int, behavior, unsigned long, flags) { int ret; - struct fd f; struct pid *pid; struct task_struct *task; struct mm_struct *mm; @@ -1197,20 +1196,31 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, unsi= gned long, start, if (!process_madvise_behavior_valid(behavior)) return -EINVAL; =20 - f =3D fdget(pidfd); - if (!f.file) - return -EBADF; + switch (which) { + case P_PID: + if (upid <=3D 0) + return -EINVAL; + + pid =3D find_get_pid(upid); + if (!pid) + return -ESRCH; + break; + case P_PIDFD: + if (upid < 0) + return -EINVAL; =20 - pid =3D pidfd_pid(f.file); - if (IS_ERR(pid)) { - ret =3D PTR_ERR(pid); - goto fdput; + pid =3D pidfd_get_pid(upid); + if (IS_ERR(pid)) + return PTR_ERR(pid); + break; + default: + return -EINVAL; } =20 task =3D get_pid_task(pid, PIDTYPE_PID); if (!task) { ret =3D -ESRCH; - goto fdput; + goto put_pid; } =20 mm =3D mm_access(task, PTRACE_MODE_ATTACH_FSCREDS); @@ -1223,7 +1233,7 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, unsign= ed long, start, mmput(mm); release_task: put_task_struct(task); -fdput: - fdput(f); +put_pid: + put_pid(pid); return ret; } --=20 2.25.0.265.gbab2e86ba0-goog