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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 90013C3F2D7 for ; Mon, 2 Mar 2020 19:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6C5D72467B for ; Mon, 2 Mar 2020 19:36:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583177811; bh=l6Iq8R5WUD+gYELiYmZrhrDE4k9cgh6XEQU9YqqCAp0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=H7g/pcwe+NulaiGiykar+hcdCTequVmLk6fi6cxzqAQizngHbiyg37up7/vfqBGvq ND4Z8+XoqpFFLTe0O5sDP4ibiV8+FWUGoeKtnMz4+1C+re1wb0bkUO8JQTa6LbNww/ j1JCOaD7SriSoCIrjIx4nKzNjoV65yNj5xgpEGHs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727414AbgCBTgo (ORCPT ); Mon, 2 Mar 2020 14:36:44 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:33776 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727427AbgCBTgn (ORCPT ); Mon, 2 Mar 2020 14:36:43 -0500 Received: by mail-pl1-f193.google.com with SMTP id ay11so203961plb.0; Mon, 02 Mar 2020 11:36:42 -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=KlN9Qimhdy4RvEi9bFjPyi9+Kx7k9yDnYsKX5Ifdst8=; b=pcBsPabXzLnNGy+dBVuD7J9l4SyVgK2q/5I4QlXaVptI83/+ayPllR7qofGCULHO6D HXckvql4YDuJ6wr84H/En94isnX4C/ISF4Ob1OGa2T+V4SAq+IEJp6gwmnIozdfr4AR0 dqtBpUKNYFmftVaNX2M3HoBfrOQz29kJ6lFnEx1rc2f7wLKOzA9MsTV+dm99OkJD6vOs lhtYG3Q8+UxXI3ffLhnqNvoSihAvcixhk00Kp1dzkwZlGUgAvuJY93BTami3VDAjcxcW 7SOUNGjJUWEyck+8JOFdDiQJjUXk+F0gkFLeVwGJiNQDw63vsPnarxdK3g45vah8+e+g nY0A== 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=KlN9Qimhdy4RvEi9bFjPyi9+Kx7k9yDnYsKX5Ifdst8=; b=Rm3hbMVMvhd/omYdv84HA4cbaWl81tVAGM0SZ/fYxGgXAMo7fW9QuPP0YIWvz8ff4i zlNzGeeami3IVyUK1Gunk/37O6ZfwxzxHC7tXvRW5A+W9LzuBLeE+kTvdaN054CoU+21 ff7WaArokBSScE+jfuaHf1uAYf/2EjTwa8hNjEDkzEC13nkyEGbTEfZlM5p1ljJNXxrP lFk8HRFMaD3WpDkNyavKl3NY9eoUWxEUa7/eupwvOHYUKkMOiOU9SNTaVI/E+n70mTkY TIp36IcY3WgcB/kMk2WW/OajmhZWxzu5VtLXPpMbuC9TDbhNGkXPbgc+AH0sJdhnKOms 0XYw== X-Gm-Message-State: ANhLgQ0PSsTWLtsFA1Jo7SjGhGCg6Zws7l5YgKkt1ZrUTfXF602gN7b6 G6wu7RfhZkZBu5P20g2YtAY= X-Google-Smtp-Source: ADFU+vveRhRCqXxNY6qm0kypogmeO2sPWNoaGmwPFGTp1E81N9uLbfib+occkG7euJm8x8vCRGWGrQ== X-Received: by 2002:a17:902:a603:: with SMTP id u3mr679327plq.105.1583177802227; Mon, 02 Mar 2020 11:36:42 -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.22.2020.03.02.11.36.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Mar 2020 11:36:41 -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 , Jens Axboe Subject: [PATCH v7 1/7] mm: pass task and mm to do_madvise Date: Mon, 2 Mar 2020 11:36:24 -0800 Message-Id: <20200302193630.68771-2-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: 8bit Sender: linux-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org In upcoming patches, do_madvise will be called from external process context so we shouldn't asssume "current" is always hinted process's task_struct. Furthermore, we couldn't access mm_struct via task->mm once it's verified by access_mm which will be introduced in next patch[1]. And let's pass *current* and current->mm as arguments of do_madvise so it shouldn't change existing behavior but prepare next patch to make review easy. Note: io_madvise pass NULL as target_task argument of do_madvise because it couldn't know who is target. [1] http://lore.kernel.org/r/CAG48ez27=pwm5m_N_988xT1huO7g7h6arTQL44zev6TD-h-7Tg@mail.gmail.com Cc: Jens Axboe Cc: Jann Horn Reviewed-by: Suren Baghdasaryan Signed-off-by: Minchan Kim --- fs/io_uring.c | 2 +- include/linux/mm.h | 3 ++- mm/madvise.c | 34 +++++++++++++++++++--------------- 3 files changed, 22 insertions(+), 17 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 8866bd60783f..8b53f150560e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2736,7 +2736,7 @@ static int io_madvise(struct io_kiocb *req, struct io_kiocb **nxt, if (force_nonblock) return -EAGAIN; - ret = do_madvise(ma->addr, ma->len, ma->advice); + ret = do_madvise(NULL, req->work.mm, ma->addr, ma->len, ma->advice); if (ret < 0) req_set_fail_links(req); io_cqring_add_event(req, ret); diff --git a/include/linux/mm.h b/include/linux/mm.h index c1180112102d..378de56d8c5b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2407,7 +2407,8 @@ extern int __do_munmap(struct mm_struct *, unsigned long, size_t, struct list_head *uf, bool downgrade); extern int do_munmap(struct mm_struct *, unsigned long, size_t, struct list_head *uf); -extern int do_madvise(unsigned long start, size_t len_in, int behavior); +extern int do_madvise(struct task_struct *target_task, struct mm_struct *mm, + unsigned long start, size_t len_in, int behavior); static inline unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, diff --git a/mm/madvise.c b/mm/madvise.c index 43b47d3fae02..f75c86b6c463 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -254,6 +254,7 @@ static long madvise_willneed(struct vm_area_struct *vma, struct vm_area_struct **prev, unsigned long start, unsigned long end) { + struct mm_struct *mm = vma->vm_mm; struct file *file = vma->vm_file; loff_t offset; @@ -288,12 +289,12 @@ static long madvise_willneed(struct vm_area_struct *vma, */ *prev = NULL; /* tell sys_madvise we drop mmap_sem */ get_file(file); - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); offset = (loff_t)(start - vma->vm_start) + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED); fput(file); - down_read(¤t->mm->mmap_sem); + down_read(&mm->mmap_sem); return 0; } @@ -676,7 +677,6 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, if (nr_swap) { if (current->mm == mm) sync_mm_rss(mm); - add_mm_counter(mm, MM_SWAPENTS, nr_swap); } arch_leave_lazy_mmu_mode(); @@ -756,6 +756,8 @@ static long madvise_dontneed_free(struct vm_area_struct *vma, unsigned long start, unsigned long end, int behavior) { + struct mm_struct *mm = vma->vm_mm; + *prev = vma; if (!can_madv_lru_vma(vma)) return -EINVAL; @@ -763,8 +765,8 @@ static long madvise_dontneed_free(struct vm_area_struct *vma, if (!userfaultfd_remove(vma, start, end)) { *prev = NULL; /* mmap_sem has been dropped, prev is stale */ - down_read(¤t->mm->mmap_sem); - vma = find_vma(current->mm, start); + down_read(&mm->mmap_sem); + vma = find_vma(mm, start); if (!vma) return -ENOMEM; if (start < vma->vm_start) { @@ -818,6 +820,7 @@ static long madvise_remove(struct vm_area_struct *vma, loff_t offset; int error; struct file *f; + struct mm_struct *mm = vma->vm_mm; *prev = NULL; /* tell sys_madvise we drop mmap_sem */ @@ -845,13 +848,13 @@ static long madvise_remove(struct vm_area_struct *vma, get_file(f); if (userfaultfd_remove(vma, start, end)) { /* mmap_sem was not released by userfaultfd_remove() */ - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); } error = vfs_fallocate(f, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, offset, end - start); fput(f); - down_read(¤t->mm->mmap_sem); + down_read(&mm->mmap_sem); return error; } @@ -1044,7 +1047,8 @@ madvise_behavior_valid(int behavior) * -EBADF - map exists, but area maps something that isn't a file. * -EAGAIN - a kernel resource was temporarily unavailable. */ -int do_madvise(unsigned long start, size_t len_in, int behavior) +int do_madvise(struct task_struct *target_task, struct mm_struct *mm, + unsigned long start, size_t len_in, int behavior) { unsigned long end, tmp; struct vm_area_struct *vma, *prev; @@ -1082,10 +1086,10 @@ int do_madvise(unsigned long start, size_t len_in, int behavior) write = madvise_need_mmap_write(behavior); if (write) { - if (down_write_killable(¤t->mm->mmap_sem)) + if (down_write_killable(&mm->mmap_sem)) return -EINTR; } else { - down_read(¤t->mm->mmap_sem); + down_read(&mm->mmap_sem); } /* @@ -1093,7 +1097,7 @@ int do_madvise(unsigned long start, size_t len_in, int behavior) * ranges, just ignore them, but return -ENOMEM at the end. * - different from the way of handling in mlock etc. */ - vma = find_vma_prev(current->mm, start, &prev); + vma = find_vma_prev(mm, start, &prev); if (vma && start > vma->vm_start) prev = vma; @@ -1130,19 +1134,19 @@ int do_madvise(unsigned long start, size_t len_in, int behavior) if (prev) vma = prev->vm_next; else /* madvise_remove dropped mmap_sem */ - vma = find_vma(current->mm, start); + vma = find_vma(mm, start); } out: blk_finish_plug(&plug); if (write) - up_write(¤t->mm->mmap_sem); + up_write(&mm->mmap_sem); else - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); return error; } SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) { - return do_madvise(start, len_in, behavior); + return do_madvise(current, current->mm, start, len_in, behavior); } -- 2.25.0.265.gbab2e86ba0-goog