From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f177.google.com (mail-wi0-f177.google.com [209.85.212.177]) by kanga.kvack.org (Postfix) with ESMTP id 834CE6B0098 for ; Thu, 14 May 2015 13:31:50 -0400 (EDT) Received: by wibt6 with SMTP id t6so23970392wib.0 for ; Thu, 14 May 2015 10:31:50 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id ua7si2595822wib.37.2015.05.14.10.31.42 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 May 2015 10:31:43 -0700 (PDT) From: Andrea Arcangeli Subject: [PATCH 11/23] userfaultfd: Rename uffd_api.bits into .features Date: Thu, 14 May 2015 19:31:08 +0200 Message-Id: <1431624680-20153-12-git-send-email-aarcange@redhat.com> In-Reply-To: <1431624680-20153-1-git-send-email-aarcange@redhat.com> References: <1431624680-20153-1-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-api@vger.kernel.org Cc: Pavel Emelyanov , Sanidhya Kashyap , zhang.zhanghailiang@huawei.com, Linus Torvalds , "Kirill A. Shutemov" , Andres Lagar-Cavilla , Dave Hansen , Paolo Bonzini , Rik van Riel , Mel Gorman , Andy Lutomirski , Hugh Dickins , Peter Feiner , "Dr. David Alan Gilbert" , Johannes Weiner , "Huangpeng (Peter)" From: Pavel Emelyanov This is (seem to be) the minimal thing that is required to unblock standard uffd usage from the non-cooperative one. Now more bits can be added to the features field indicating e.g. UFFD_FEATURE_FORK and others needed for the latter use-case. Signed-off-by: Pavel Emelyanov Signed-off-by: Andrea Arcangeli --- fs/userfaultfd.c | 4 ++-- include/uapi/linux/userfaultfd.h | 10 ++++++++-- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 1c9be61..9085365 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -856,7 +856,7 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx, goto out; } /* careful not to leak info, we only read the first 8 bytes */ - uffdio_api.bits = UFFD_API_BITS; + uffdio_api.features = UFFD_API_FEATURES; uffdio_api.ioctls = UFFD_API_IOCTLS; ret = -EFAULT; if (copy_to_user(buf, &uffdio_api, sizeof(uffdio_api))) @@ -913,7 +913,7 @@ static void userfaultfd_show_fdinfo(struct seq_file *m, struct file *f) * protocols: aa:... bb:... */ seq_printf(m, "pending:\t%lu\ntotal:\t%lu\nAPI:\t%Lx:%x:%Lx\n", - pending, total, UFFD_API, UFFD_API_BITS, + pending, total, UFFD_API, UFFD_API_FEATURES, UFFD_API_IOCTLS|UFFD_API_RANGE_IOCTLS); } #endif diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h index 9a8cd56..5e1c2f7 100644 --- a/include/uapi/linux/userfaultfd.h +++ b/include/uapi/linux/userfaultfd.h @@ -11,7 +11,7 @@ #define UFFD_API ((__u64)0xAA) /* FIXME: add "|UFFD_BIT_WP" to UFFD_API_BITS after implementing it */ -#define UFFD_API_BITS (UFFD_BIT_WRITE) +#define UFFD_API_FEATURES (UFFD_FEATURE_WRITE_BIT) #define UFFD_API_IOCTLS \ ((__u64)1 << _UFFDIO_REGISTER | \ (__u64)1 << _UFFDIO_UNREGISTER | \ @@ -51,12 +51,18 @@ #define UFFD_BIT_WP (1<<1) /* handle_userfault() reason VM_UFFD_WP */ #define UFFD_BITS 2 /* two above bits used for UFFD_BIT_* mask */ +/* + * Features reported in uffdio_api.features field + */ +#define UFFD_FEATURE_WRITE_BIT (1<<0) /* Corresponds to UFFD_BIT_WRITE */ +#define UFFD_FEATURE_WP_BIT (1<<1) /* Corresponds to UFFD_BIT_WP */ + struct uffdio_api { /* userland asks for an API number */ __u64 api; /* kernel answers below with the available features for the API */ - __u64 bits; + __u64 features; __u64 ioctls; }; -- 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