From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_DBL_ABUSE_MALW,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90464C33CB2 for ; Tue, 28 Jan 2020 14:03:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63B4424685 for ; Tue, 28 Jan 2020 14:03:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220189; bh=HYdllY688tTh57TvTwrqRqOkvSRMoKMz3ctzfOQdcpA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wITmVSdujGZ5D5RcolbXE8atNK6apGNmapLm9y4mRjuJA/B3xzyDMzPGgQMBxUTms Hc8NGVESazhMGmj/O9jhN14e2BLL9xZnnaq2DSgS9Dq1gXWsBdPus5b8bJsRyWAcEv jXeSQtUc4ToX39uHbmRMZgA79fBZx17UfhUkLTZE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727809AbgA1ODI (ORCPT ); Tue, 28 Jan 2020 09:03:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:49638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727792AbgA1ODF (ORCPT ); Tue, 28 Jan 2020 09:03:05 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 EC1A224690; Tue, 28 Jan 2020 14:03:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220184; bh=HYdllY688tTh57TvTwrqRqOkvSRMoKMz3ctzfOQdcpA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JacGP60zbHkSC3TJKLft2dRCysdsOZ8izok6d59mAqncXX1dKqt9VFfT3jaGaCzX8 OCwzToRT69HEvAy8YCYQ1fXIaIOFgqXPt3/HuRS4pyuh6HYCxubUCB6RGpFHt7TLQ/ OyNVuxr0jmlY0Shm2Nry5Pw+2NW7UKxpeQgpXtTg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Matthew Wilcox (Oracle)" Subject: [PATCH 5.4 051/104] XArray: Fix xa_find_after with multi-index entries Date: Tue, 28 Jan 2020 15:00:12 +0100 Message-Id: <20200128135824.702029064@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135817.238524998@linuxfoundation.org> References: <20200128135817.238524998@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Matthew Wilcox (Oracle) commit 19c30f4dd0923ef191f35c652ee4058e91e89056 upstream. If the entry is of an order which is a multiple of XA_CHUNK_SIZE, the current detection of sibling entries does not work. Factor out an xas_sibling() function to make xa_find_after() a little more understandable, and write a new implementation that doesn't suffer from the same bug. Signed-off-by: Matthew Wilcox (Oracle) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- lib/test_xarray.c | 32 +++++++++++++++++++------------- lib/xarray.c | 20 +++++++++++++------- 2 files changed, 32 insertions(+), 20 deletions(-) --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -902,28 +902,30 @@ static noinline void check_store_iter(st XA_BUG_ON(xa, !xa_empty(xa)); } -static noinline void check_multi_find(struct xarray *xa) +static noinline void check_multi_find_1(struct xarray *xa, unsigned order) { #ifdef CONFIG_XARRAY_MULTI + unsigned long multi = 3 << order; + unsigned long next = 4 << order; unsigned long index; - xa_store_order(xa, 12, 2, xa_mk_value(12), GFP_KERNEL); - XA_BUG_ON(xa, xa_store_index(xa, 16, GFP_KERNEL) != NULL); + xa_store_order(xa, multi, order, xa_mk_value(multi), GFP_KERNEL); + XA_BUG_ON(xa, xa_store_index(xa, next, GFP_KERNEL) != NULL); index = 0; XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) != - xa_mk_value(12)); - XA_BUG_ON(xa, index != 12); - index = 13; + xa_mk_value(multi)); + XA_BUG_ON(xa, index != multi); + index = multi + 1; XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) != - xa_mk_value(12)); - XA_BUG_ON(xa, (index < 12) || (index >= 16)); + xa_mk_value(multi)); + XA_BUG_ON(xa, (index < multi) || (index >= next)); XA_BUG_ON(xa, xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT) != - xa_mk_value(16)); - XA_BUG_ON(xa, index != 16); + xa_mk_value(next)); + XA_BUG_ON(xa, index != next); - xa_erase_index(xa, 12); - xa_erase_index(xa, 16); + xa_erase_index(xa, multi); + xa_erase_index(xa, next); XA_BUG_ON(xa, !xa_empty(xa)); #endif } @@ -1064,11 +1066,15 @@ static noinline void check_find_4(struct static noinline void check_find(struct xarray *xa) { + unsigned i; + check_find_1(xa); check_find_2(xa); check_find_3(xa); check_find_4(xa); - check_multi_find(xa); + + for (i = 2; i < 10; i++) + check_multi_find_1(xa, i); check_multi_find_2(xa); } --- a/lib/xarray.c +++ b/lib/xarray.c @@ -1824,6 +1824,17 @@ void *xa_find(struct xarray *xa, unsigne } EXPORT_SYMBOL(xa_find); +static bool xas_sibling(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + unsigned long mask; + + if (!node) + return false; + mask = (XA_CHUNK_SIZE << node->shift) - 1; + return (xas->xa_index & mask) > (xas->xa_offset << node->shift); +} + /** * xa_find_after() - Search the XArray for a present entry. * @xa: XArray. @@ -1858,13 +1869,8 @@ void *xa_find_after(struct xarray *xa, u entry = xas_find(&xas, max); if (xas.xa_node == XAS_BOUNDS) break; - if (xas.xa_shift) { - if (xas.xa_index & ((1UL << xas.xa_shift) - 1)) - continue; - } else { - if (xas.xa_offset < (xas.xa_index & XA_CHUNK_MASK)) - continue; - } + if (xas_sibling(&xas)) + continue; if (!xas_retry(&xas, entry)) break; }