From nobody Fri Dec 19 19:56:49 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A94094A35 for ; Sun, 30 Mar 2025 12:17:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743337059; cv=none; b=QXMLpikDX6N0ICuUmN030MJ3Sxg5YzmIyUJ9KSVfaFZdUmrhB17D3c6+2EoyW6/kbxEq/ekpz++sUN+zVCwdyJMNbP9jvUD5s+9uPIBmonKCs+7dIf/dYgq+QEALv67ukW2jbnVuJvfCmcuE8RwSBi+qIMaNvzGtFhysgHoAB6g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743337059; c=relaxed/simple; bh=4jBP70Y+7GsAX14XssyUY9Y02msmYk6bryg0MZHnSqc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-type; b=pXKNhIgxBnqorWakQJIKvyYAvxhXOnC8ErVsdOheN3i6htduYCssQPmlw1UHronb5NwJ843pvZO1TFH94x+ngnVXih68qvgy9XEFdCO45EK3OpOYXrTq+d44+SE020tgsMhZpVf2OQqupOzvsQA2X123AA+2lWhGwlk4jM4WKJA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=iw/UC6xR; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="iw/UC6xR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1743337056; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=66JPNi1zYSbyVc7TO8PPyR6Yrn7uiScYJyyuaMI/UWs=; b=iw/UC6xRQ4LAhmdLHzeSEslZC0Fl7n6/vrfx2/JjjiNI/DtQOnIRPwI78ryuFkTf6n3Xcj ZTUGDmyMyTV1NIuhZBYimCp7ycCH77LLr6riDFSljM8XzvRNsiUxpNddW74UHdY5tauEen eWrHr5hJPqMq0kDLpye44MLjb4/fMq8= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-207-vuwXJPkUN92ViNpZjUnXmw-1; Sun, 30 Mar 2025 08:17:31 -0400 X-MC-Unique: vuwXJPkUN92ViNpZjUnXmw-1 X-Mimecast-MFC-AGG-ID: vuwXJPkUN92ViNpZjUnXmw_1743337050 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 992B5195E92A; Sun, 30 Mar 2025 12:17:30 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (unknown [10.72.112.17]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0E5C71801750; Sun, 30 Mar 2025 12:17:25 +0000 (UTC) From: Baoquan He To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Baoquan He Subject: [PATCH 1/7] mm/gup: fix wrongly calculated returned value in fault_in_safe_writeable() Date: Sun, 30 Mar 2025 20:17:11 +0800 Message-ID: <20250330121718.175815-2-bhe@redhat.com> In-Reply-To: <20250330121718.175815-1-bhe@redhat.com> References: <20250330121718.175815-1-bhe@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" Not like fault_in_writeable() or fault_in_writeable(), in fault_in_safe_writeable() local variable 'start' is increased page by page to loop till the whole address range is handled. However, it mistakenly calcalates the size of handled range with 'uaddr - start'. Fix it here. Signed-off-by: Baoquan He --- mm/gup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 855ab860f88b..73777b1de679 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2207,8 +2207,8 @@ size_t fault_in_safe_writeable(const char __user *uad= dr, size_t size) } while (start !=3D end); mmap_read_unlock(mm); =20 - if (size > (unsigned long)uaddr - start) - return size - ((unsigned long)uaddr - start); + if (size > start - (unsigned long)uaddr) + return size - (start - (unsigned long)uaddr); return 0; } EXPORT_SYMBOL(fault_in_safe_writeable); --=20 2.41.0