Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756978Ab2KZRsZ (ORCPT ); Mon, 26 Nov 2012 12:48:25 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:47676 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933280Ab2KZRIz (ORCPT ); Mon, 26 Nov 2012 12:08:55 -0500 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Alex Elder , Herton Ronaldo Krzesinski Subject: [PATCH 145/270] libceph: only kunmap kmapped pages Date: Mon, 26 Nov 2012 14:57:15 -0200 Message-Id: <1353949160-26803-146-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> References: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1920 Lines: 57 3.5.7u1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Elder commit 5ce765a540f34d1e2005e1210f49f67fdf11e997 upstream. In write_partial_msg_pages(), pages need to be kmapped in order to perform a CRC-32c calculation on them. As an artifact of the way this code used to be structured, the kunmap() call was separated from the kmap() call and both were done conditionally. But the conditions under which the kmap() and kunmap() calls were made differed, so there was a chance a kunmap() call would be done on a page that had not been mapped. The symptom of this was tripping a BUG() in kunmap_high() when pkmap_count[nr] became 0. Reported-by: Bryan K. Wright Signed-off-by: Alex Elder Reviewed-by: Sage Weil Signed-off-by: Herton Ronaldo Krzesinski --- net/ceph/messenger.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index b141c86..8ba0eee 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -1069,16 +1069,13 @@ static int write_partial_msg_pages(struct ceph_connection *con) BUG_ON(kaddr == NULL); base = kaddr + con->out_msg_pos.page_pos + bio_offset; crc = crc32c(crc, base, len); + kunmap(page); msg->footer.data_crc = cpu_to_le32(crc); con->out_msg_pos.did_page_crc = true; } ret = ceph_tcp_sendpage(con->sock, page, con->out_msg_pos.page_pos + bio_offset, len, 1); - - if (do_datacrc) - kunmap(page); - if (ret <= 0) goto out; -- 1.7.9.5 -- 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/