Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935497AbaBDV51 (ORCPT ); Tue, 4 Feb 2014 16:57:27 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56974 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934224AbaBDVJc (ORCPT ); Tue, 4 Feb 2014 16:09:32 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Annie Li , "David S. Miller" Subject: [PATCH 3.12 114/133] xen-netfront: fix resource leak in netfront Date: Tue, 4 Feb 2014 13:08:35 -0800 Message-Id: <20140204210740.254100466@linuxfoundation.org> X-Mailer: git-send-email 1.8.5.1.163.gd7aced9 In-Reply-To: <20140204210737.008598235@linuxfoundation.org> References: <20140204210737.008598235@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Annie Li [ Upstream commit cefe0078eea52af17411eb1248946a94afb84ca5 ] This patch removes grant transfer releasing code from netfront, and uses gnttab_end_foreign_access to end grant access since gnttab_end_foreign_access_ref may fail when the grant entry is currently used for reading or writing. * clean up grant transfer code kept from old netfront(2.6.18) which grants pages for access/map and transfer. But grant transfer is deprecated in current netfront, so remove corresponding release code for transfer. * fix resource leak, release grant access (through gnttab_end_foreign_access) and skb for tx/rx path, use get_page to ensure page is released when grant access is completed successfully. Xen-blkfront/xen-tpmfront/xen-pcifront also have similar issue, but patches for them will be created separately. V6: Correct subject line and commit message. V5: Remove unecessary change in xennet_end_access. V4: Revert put_page in gnttab_end_foreign_access, and keep netfront change in single patch. V3: Changes as suggestion from David Vrabel, ensure pages are not freed untill grant acess is ended. V2: Improve patch comments. Signed-off-by: Annie Li Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netfront.c | 88 +++++++++++++-------------------------------- 1 file changed, 26 insertions(+), 62 deletions(-) --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -117,6 +117,7 @@ struct netfront_info { } tx_skbs[NET_TX_RING_SIZE]; grant_ref_t gref_tx_head; grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; + struct page *grant_tx_page[NET_TX_RING_SIZE]; unsigned tx_skb_freelist; spinlock_t rx_lock ____cacheline_aligned_in_smp; @@ -395,6 +396,7 @@ static void xennet_tx_buf_gc(struct net_ gnttab_release_grant_reference( &np->gref_tx_head, np->grant_tx_ref[id]); np->grant_tx_ref[id] = GRANT_INVALID_REF; + np->grant_tx_page[id] = NULL; add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id); dev_kfree_skb_irq(skb); } @@ -451,6 +453,7 @@ static void xennet_make_frags(struct sk_ gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); + np->grant_tx_page[id] = virt_to_page(data); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; @@ -496,6 +499,7 @@ static void xennet_make_frags(struct sk_ np->xbdev->otherend_id, mfn, GNTMAP_readonly); + np->grant_tx_page[id] = page; tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = bytes; @@ -595,6 +599,7 @@ static int xennet_start_xmit(struct sk_b mfn = virt_to_mfn(data); gnttab_grant_foreign_access_ref( ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); + np->grant_tx_page[id] = virt_to_page(data); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; @@ -1119,10 +1124,11 @@ static void xennet_release_tx_bufs(struc continue; skb = np->tx_skbs[i].skb; - gnttab_end_foreign_access_ref(np->grant_tx_ref[i], - GNTMAP_readonly); - gnttab_release_grant_reference(&np->gref_tx_head, - np->grant_tx_ref[i]); + get_page(np->grant_tx_page[i]); + gnttab_end_foreign_access(np->grant_tx_ref[i], + GNTMAP_readonly, + (unsigned long)page_address(np->grant_tx_page[i])); + np->grant_tx_page[i] = NULL; np->grant_tx_ref[i] = GRANT_INVALID_REF; add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i); dev_kfree_skb_irq(skb); @@ -1131,78 +1137,35 @@ static void xennet_release_tx_bufs(struc static void xennet_release_rx_bufs(struct netfront_info *np) { - struct mmu_update *mmu = np->rx_mmu; - struct multicall_entry *mcl = np->rx_mcl; - struct sk_buff_head free_list; - struct sk_buff *skb; - unsigned long mfn; - int xfer = 0, noxfer = 0, unused = 0; int id, ref; - dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n", - __func__); - return; - - skb_queue_head_init(&free_list); - spin_lock_bh(&np->rx_lock); for (id = 0; id < NET_RX_RING_SIZE; id++) { - ref = np->grant_rx_ref[id]; - if (ref == GRANT_INVALID_REF) { - unused++; - continue; - } + struct sk_buff *skb; + struct page *page; skb = np->rx_skbs[id]; - mfn = gnttab_end_foreign_transfer_ref(ref); - gnttab_release_grant_reference(&np->gref_rx_head, ref); - np->grant_rx_ref[id] = GRANT_INVALID_REF; - - if (0 == mfn) { - skb_shinfo(skb)->nr_frags = 0; - dev_kfree_skb(skb); - noxfer++; + if (!skb) continue; - } - if (!xen_feature(XENFEAT_auto_translated_physmap)) { - /* Remap the page. */ - const struct page *page = - skb_frag_page(&skb_shinfo(skb)->frags[0]); - unsigned long pfn = page_to_pfn(page); - void *vaddr = page_address(page); + ref = np->grant_rx_ref[id]; + if (ref == GRANT_INVALID_REF) + continue; - MULTI_update_va_mapping(mcl, (unsigned long)vaddr, - mfn_pte(mfn, PAGE_KERNEL), - 0); - mcl++; - mmu->ptr = ((u64)mfn << PAGE_SHIFT) - | MMU_MACHPHYS_UPDATE; - mmu->val = pfn; - mmu++; + page = skb_frag_page(&skb_shinfo(skb)->frags[0]); - set_phys_to_machine(pfn, mfn); - } - __skb_queue_tail(&free_list, skb); - xfer++; - } - - dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n", - __func__, xfer, noxfer, unused); + /* gnttab_end_foreign_access() needs a page ref until + * foreign access is ended (which may be deferred). + */ + get_page(page); + gnttab_end_foreign_access(ref, 0, + (unsigned long)page_address(page)); + np->grant_rx_ref[id] = GRANT_INVALID_REF; - if (xfer) { - if (!xen_feature(XENFEAT_auto_translated_physmap)) { - /* Do all the remapping work and M2P updates. */ - MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu, - NULL, DOMID_SELF); - mcl++; - HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl); - } + kfree_skb(skb); } - __skb_queue_purge(&free_list); - spin_unlock_bh(&np->rx_lock); } @@ -1349,6 +1312,7 @@ static struct net_device *xennet_create_ for (i = 0; i < NET_RX_RING_SIZE; i++) { np->rx_skbs[i] = NULL; np->grant_rx_ref[i] = GRANT_INVALID_REF; + np->grant_tx_page[i] = NULL; } /* A grant for every tx ring slot */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/