From nobody Fri Dec 19 21:27:56 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 BC7B91D5CFE for ; Mon, 31 Mar 2025 08:13:45 +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=1743408827; cv=none; b=Q5T4OGVwH5v3Zyp++KcSqmz2RDN/wSFgZFt5vVZJjd2cICEbDmgh0r3w9JAeA/WYo40NHXLsZP2BU9fcCRLl1msLObyjHdriumF6UMs9SyIWB1TJklfj5Sg0FlQ6I0Y4GqpBJiIRU3xMQWqVhB6LrEwr96yXwzXV+COEcBoNJ7c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743408827; c=relaxed/simple; bh=+4UX5hB7LOlseY8IDtLpOfVYFgMUwmkqQHjZeqNpum4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-type; b=AGEimkxhY7mluxPROGiwJEArYElRYRBXKpBbzydM1ddshSsfhu3L+NChwhyxMS8DOYSHBhLnSf0oTYp2VVxy7Yd+kdBG3dzw3aHvGyBsh2rB6YvB3/RV4Bk+l6IXLMljcehPxSU62PeIBy1BikF8XPw7bWPm41i1+bQTFSjR/VE= 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=NRhd73CI; 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="NRhd73CI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1743408824; 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=VpQkE/o6UqynMHBaEyGhtuzDswvJwtgU/N8i6Bf76yI=; b=NRhd73CIQN8UkT2dFrd0s1LgIJdbQUIDN3OAy28DKPdMpTqdry9AvkYzEaK1FaqwHUvM0K +aSNoc1PXM7QqGE2um7t9w1Py1ex2/i1iMgfh83BzPI2l2Ljcvi87JEetFl5VqEEky+fBU R/vh55GiCBJX3hlKrZqX5c71efMjPD8= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-641-fGwKGbB3NxqKefEQ3WVoQw-1; Mon, 31 Mar 2025 04:13:39 -0400 X-MC-Unique: fGwKGbB3NxqKefEQ3WVoQw-1 X-Mimecast-MFC-AGG-ID: fGwKGbB3NxqKefEQ3WVoQw_1743408818 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4C260180882E; Mon, 31 Mar 2025 08:13:38 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (unknown [10.72.112.9]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 2BCB11955BF1; Mon, 31 Mar 2025 08:13:34 +0000 (UTC) From: Baoquan He To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, yanjun.zhu@linux.dev, Baoquan He Subject: [PATCH v2 1/7] mm/gup: fix wrongly calculated returned value in fault_in_safe_writeable() Date: Mon, 31 Mar 2025 16:13:21 +0800 Message-ID: <20250331081327.256412-2-bhe@redhat.com> In-Reply-To: <20250331081327.256412-1-bhe@redhat.com> References: <20250331081327.256412-1-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 3.0 on 10.30.177.40 Content-Type: text/plain; charset="utf-8" Not like fault_in_readable() 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 --- v1->v2: - Fix a patch log typo caused by copy-and-paste error. Thanks to Yanjun. 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