From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756742AbcBIWw5 (ORCPT ); Tue, 9 Feb 2016 17:52:57 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:40877 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933080AbcBIWpz (ORCPT ); Tue, 9 Feb 2016 17:45:55 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: =?UTF-8?q?Mika=20Penttil=C3=A4?= , Will Deacon , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 26/47] arm64: mm: avoid calling apply_to_page_range on empty range Date: Tue, 9 Feb 2016 14:44:40 -0800 Message-Id: <1455057901-7468-27-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1455057901-7468-1-git-send-email-kamal@canonical.com> References: <1455057901-7468-1-git-send-email-kamal@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt15 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: =?UTF-8?q?Mika=20Penttil=C3=A4?= commit 57adec866c0440976c96a4b8f5b59fb411b1cacb upstream. Calling apply_to_page_range with an empty range results in a BUG_ON from the core code. This can be triggered by trying to load the st_drv module with CONFIG_DEBUG_SET_MODULE_RONX enabled: kernel BUG at mm/memory.c:1874! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 3 PID: 1764 Comm: insmod Not tainted 4.5.0-rc1+ #2 Hardware name: ARM Juno development board (r0) (DT) task: ffffffc9763b8000 ti: ffffffc975af8000 task.ti: ffffffc975af8000 PC is at apply_to_page_range+0x2cc/0x2d0 LR is at change_memory_common+0x80/0x108 This patch fixes the issue by making change_memory_common (called by the set_memory_* functions) a NOP when numpages == 0, therefore avoiding the erroneous call to apply_to_page_range and bringing us into line with x86 and s390. Reviewed-by: Laura Abbott Acked-by: David Rientjes Signed-off-by: Mika Penttilä Signed-off-by: Will Deacon Signed-off-by: Kamal Mostafa --- arch/arm64/mm/pageattr.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index bb0ea94..491acbb 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -54,6 +54,9 @@ static int change_memory_common(unsigned long addr, int numpages, if (!is_module_address(start) || !is_module_address(end - 1)) return -EINVAL; + if (!numpages) + return 0; + data.set_mask = set_mask; data.clear_mask = clear_mask; -- 1.9.1