From patchwork Thu Apr 2 04:09:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11469999 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2BB7115AB for ; Thu, 2 Apr 2020 04:09:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E3C6B2074D for ; Thu, 2 Apr 2020 04:09:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="d9ftkH7m" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E3C6B2074D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C075E8E0065; Thu, 2 Apr 2020 00:09:02 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id B8FA08E000D; Thu, 2 Apr 2020 00:09:02 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A57DD8E0065; Thu, 2 Apr 2020 00:09:02 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0049.hostedemail.com [216.40.44.49]) by kanga.kvack.org (Postfix) with ESMTP id 8857B8E000D for ; Thu, 2 Apr 2020 00:09:02 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 564068248047 for ; Thu, 2 Apr 2020 04:09:02 +0000 (UTC) X-FDA: 76661584524.20.geese68_4edfb3eb31d54 X-Spam-Summary: 2,0,0,e824d697097c6c36,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1535:1544:1711:1730:1747:1777:1792:2194:2199:2393:2525:2559:2563:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3354:3865:3867:3868:3870:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6119:6261:6653:6737:6738:7514:7576:7903:8599:8957:9025:9545:10004:10913:11026:11232:11473:11658:11914:12043:12048:12291:12296:12297:12438:12517:12519:12555:12679:12683:12783:12986:13161:13229:13846:14096:14181:14381:14721:14849:21080:21451:21627:21939:21987:21990:30012:30054:30064:30070,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:1,LUA_SUMMARY:none X-HE-Tag: geese68_4edfb3eb31d54 X-Filterd-Recvd-Size: 5798 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf44.hostedemail.com (Postfix) with ESMTP for ; Thu, 2 Apr 2020 04:09:01 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 781DF206E9; Thu, 2 Apr 2020 04:09:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585800541; bh=Zq3tOvb79ULrewyPk3GcyOodRsVCBSkEnjjbVVP9UBM=; h=Date:From:To:Subject:In-Reply-To:From; b=d9ftkH7mzqTpmZmhE760gxrSvMduU0oWBfWjdfoR759a71VjRfU7sWLlagmUrOxma LuvBMQznH6yVhnxGRj0bxcCjVfZaYtLMNECHShSU7MhV4zj1dvx8hxchrEqMiwnNXJ 5SrlT11ttZw75F7CGQPxLWjoHtbwdwk7H/RVqo5w= Date: Wed, 01 Apr 2020 21:09:00 -0700 From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, bgeffon@google.com, bobbypowers@gmail.com, cracauer@cons.org, david@redhat.com, dgilbert@redhat.com, dplotnikov@virtuozzo.com, gokhale2@llnl.gov, hannes@cmpxchg.org, hughd@google.com, jglisse@redhat.com, kirill@shutemov.name, linux-mm@kvack.org, mcfadden8@llnl.gov, mgorman@suse.de, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, peterx@redhat.com, rppt@linux.vnet.ibm.com, torvalds@linux-foundation.org, willy@infradead.org, xemul@openvz.org Subject: [patch 101/155] mm/userfaultfd: honor FAULT_FLAG_KILLABLE in fault path Message-ID: <20200402040900.GK_bZs6EM%akpm@linux-foundation.org> In-Reply-To: <20200401210155.09e3b9742e1c6e732f5a7250@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: Peter Xu Subject: mm/userfaultfd: honor FAULT_FLAG_KILLABLE in fault path Userfaultfd fault path was by default killable even if the caller does not have FAULT_FLAG_KILLABLE. That makes sense before in that when with gup we don't have FAULT_FLAG_KILLABLE properly set before. Now after previous patch we've got FAULT_FLAG_KILLABLE applied even for gup code so it should also make sense to let userfaultfd to honor the FAULT_FLAG_KILLABLE. Because we're unconditionally setting FAULT_FLAG_KILLABLE in gup code right now, this patch should have no functional change. It also cleaned the code a little bit by introducing some helpers. Link: http://lkml.kernel.org/r/20200220160300.9941-1-peterx@redhat.com Signed-off-by: Peter Xu Tested-by: Brian Geffon Cc: Andrea Arcangeli Cc: Bobby Powers Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Linus Torvalds Cc: Martin Cracauer Cc: Marty McFadden Cc: Matthew Wilcox Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Signed-off-by: Andrew Morton --- fs/userfaultfd.c | 36 ++++++++++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 8 deletions(-) --- a/fs/userfaultfd.c~mm-userfaultfd-honor-fault_flag_killable-in-fault-path +++ a/fs/userfaultfd.c @@ -334,6 +334,30 @@ out: return ret; } +/* Should pair with userfaultfd_signal_pending() */ +static inline long userfaultfd_get_blocking_state(unsigned int flags) +{ + if (flags & FAULT_FLAG_INTERRUPTIBLE) + return TASK_INTERRUPTIBLE; + + if (flags & FAULT_FLAG_KILLABLE) + return TASK_KILLABLE; + + return TASK_UNINTERRUPTIBLE; +} + +/* Should pair with userfaultfd_get_blocking_state() */ +static inline bool userfaultfd_signal_pending(unsigned int flags) +{ + if (flags & FAULT_FLAG_INTERRUPTIBLE) + return signal_pending(current); + + if (flags & FAULT_FLAG_KILLABLE) + return fatal_signal_pending(current); + + return false; +} + /* * The locking rules involved in returning VM_FAULT_RETRY depending on * FAULT_FLAG_ALLOW_RETRY, FAULT_FLAG_RETRY_NOWAIT and @@ -355,7 +379,7 @@ vm_fault_t handle_userfault(struct vm_fa struct userfaultfd_ctx *ctx; struct userfaultfd_wait_queue uwq; vm_fault_t ret = VM_FAULT_SIGBUS; - bool must_wait, return_to_userland; + bool must_wait; long blocking_state; /* @@ -462,9 +486,7 @@ vm_fault_t handle_userfault(struct vm_fa uwq.ctx = ctx; uwq.waken = false; - return_to_userland = vmf->flags & FAULT_FLAG_INTERRUPTIBLE; - blocking_state = return_to_userland ? TASK_INTERRUPTIBLE : - TASK_KILLABLE; + blocking_state = userfaultfd_get_blocking_state(vmf->flags); spin_lock_irq(&ctx->fault_pending_wqh.lock); /* @@ -490,8 +512,7 @@ vm_fault_t handle_userfault(struct vm_fa up_read(&mm->mmap_sem); if (likely(must_wait && !READ_ONCE(ctx->released) && - (return_to_userland ? !signal_pending(current) : - !fatal_signal_pending(current)))) { + !userfaultfd_signal_pending(vmf->flags))) { wake_up_poll(&ctx->fd_wqh, EPOLLIN); schedule(); ret |= VM_FAULT_MAJOR; @@ -513,8 +534,7 @@ vm_fault_t handle_userfault(struct vm_fa set_current_state(blocking_state); if (READ_ONCE(uwq.waken) || READ_ONCE(ctx->released) || - (return_to_userland ? signal_pending(current) : - fatal_signal_pending(current))) + userfaultfd_signal_pending(vmf->flags)) break; schedule(); }