From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755476AbaJUMPE (ORCPT ); Tue, 21 Oct 2014 08:15:04 -0400 Received: from mail-pd0-f180.google.com ([209.85.192.180]:36995 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755181AbaJUMPB (ORCPT ); Tue, 21 Oct 2014 08:15:01 -0400 From: Thierry Reding To: Andrew Morton , Marek Szyprowski Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm/cma: Make kmemleak ignore CMA regions Date: Tue, 21 Oct 2014 14:14:56 +0200 Message-Id: <1413893696-25484-1-git-send-email-thierry.reding@gmail.com> X-Mailer: git-send-email 2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thierry Reding kmemleak will add allocations as objects to a pool. The memory allocated for each object in this pool is periodically searched for pointers to other allocated objects. This only works for memory that is mapped into the kernel's virtual address space, which happens not to be the case for most CMA regions. Furthermore, CMA regions are typically used to store data transferred to or from a device and therefore don't contain pointers to other objects. Signed-off-by: Thierry Reding --- Note: I'm not sure this is really the right fix. But without this, the kernel crashes on the first execution of the scan_gray_list() because it tries to access highmem. Perhaps a more appropriate fix would be to reject any object that can't map to a kernel virtual address? --- mm/cma.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/cma.c b/mm/cma.c index 963bc4add9af..349f9266f6d3 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -280,6 +280,7 @@ int __init cma_declare_contiguous(phys_addr_t base, ret = -ENOMEM; goto err; } else { + kmemleak_ignore(phys_to_virt(addr)); base = addr; } } -- 2.1.2