From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f198.google.com (mail-qk0-f198.google.com [209.85.220.198]) by kanga.kvack.org (Postfix) with ESMTP id 4BFE26B0038 for ; Fri, 24 Feb 2017 13:20:02 -0500 (EST) Received: by mail-qk0-f198.google.com with SMTP id r90so25974747qki.0 for ; Fri, 24 Feb 2017 10:20:02 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id p13si6184448qtg.6.2017.02.24.10.20.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Feb 2017 10:20:01 -0800 (PST) From: Andrea Arcangeli Subject: [PATCH 3/3] userfaultfd: non-cooperative: release all ctx in dup_userfaultfd_complete Date: Fri, 24 Feb 2017 19:19:57 +0100 Message-Id: <20170224181957.19736-4-aarcange@redhat.com> In-Reply-To: <20170224181957.19736-1-aarcange@redhat.com> References: <20170224181957.19736-1-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, Andrew Morton Cc: Michael Rapoport , "Dr. David Alan Gilbert" , Mike Kravetz , Pavel Emelyanov , Hillf Danton Don't stop running dup_fctx() even if userfaultfd_event_wait_completion fails as it has to run userfaultfd_ctx_put on all ctx to pair against the userfaultfd_ctx_get that was run on all fctx->orig in dup_userfaultfd. Signed-off-by: Andrea Arcangeli --- fs/userfaultfd.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 3d7c248..0072f04 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -526,16 +526,12 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason) return ret; } -static int userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, - struct userfaultfd_wait_queue *ewq) +static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, + struct userfaultfd_wait_queue *ewq) { - int ret; - - ret = -1; if (WARN_ON_ONCE(current->flags & PF_EXITING)) goto out; - ret = 0; ewq->ctx = ctx; init_waitqueue_entry(&ewq->wq, current); @@ -551,7 +547,6 @@ static int userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, break; if (ACCESS_ONCE(ctx->released) || fatal_signal_pending(current)) { - ret = -1; __remove_wait_queue(&ctx->event_wqh, &ewq->wq); break; } @@ -572,7 +567,6 @@ static int userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, */ out: userfaultfd_ctx_put(ctx); - return ret; } static void userfaultfd_event_complete(struct userfaultfd_ctx *ctx, @@ -630,7 +624,7 @@ int dup_userfaultfd(struct vm_area_struct *vma, struct list_head *fcs) return 0; } -static int dup_fctx(struct userfaultfd_fork_ctx *fctx) +static void dup_fctx(struct userfaultfd_fork_ctx *fctx) { struct userfaultfd_ctx *ctx = fctx->orig; struct userfaultfd_wait_queue ewq; @@ -640,17 +634,15 @@ static int dup_fctx(struct userfaultfd_fork_ctx *fctx) ewq.msg.event = UFFD_EVENT_FORK; ewq.msg.arg.reserved.reserved1 = (unsigned long)fctx->new; - return userfaultfd_event_wait_completion(ctx, &ewq); + userfaultfd_event_wait_completion(ctx, &ewq); } void dup_userfaultfd_complete(struct list_head *fcs) { - int ret = 0; struct userfaultfd_fork_ctx *fctx, *n; list_for_each_entry_safe(fctx, n, fcs, list) { - if (!ret) - ret = dup_fctx(fctx); + dup_fctx(fctx); list_del(&fctx->list); kfree(fctx); } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org