From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754699AbbGTAXe (ORCPT ); Sun, 19 Jul 2015 20:23:34 -0400 Received: from mga03.intel.com ([134.134.136.65]:24169 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754582AbbGTAXc (ORCPT ); Sun, 19 Jul 2015 20:23:32 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,505,1432623600"; d="scan'208";a="767382102" Subject: [PATCH 03/10] mm: Fix bugs in region_is_ram() From: Dan Williams To: tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com Cc: linux-arch@vger.kernel.org, tony.luck@intel.com, linux@arm.linux.org.uk, arnd@arndb.de, benh@kernel.crashing.org, mcgrof@suse.com, x86@kernel.org, linux-kernel@vger.kernel.org, ralf@linux-mips.org, Mike Travis , geert@linux-m68k.org, ross.zwisler@linux.intel.com, toshi.kani@hp.com, Andrew Morton , hch@lst.de, linux-arm-kernel@lists.infradead.org Date: Sun, 19 Jul 2015 20:17:49 -0400 Message-ID: <20150720001749.30857.97562.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <20150720001614.30857.89063.stgit@dwillia2-desk3.amr.corp.intel.com> References: <20150720001614.30857.89063.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-8-g92dd MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Toshi Kani region_is_ram() looks up the iomem_resource table to check if a target range is in RAM. However, it always returns with -1 due to invalid range checks. It always breaks the loop at the first entry of the table. Another issue is that it compares p->flags and flags, but it always fails. The flags is declared as int, which makes it as a negative value with IORESOURCE_BUSY (0x80000000) set while p->flags is unsigned long. Fix the range check and flags so that region_is_ram() works as advertised. Signed-off-by: Toshi Kani Cc: Mike Travis Cc: Luis R. Rodriguez Cc: Dan Williams Cc: Andrew Morton Signed-off-by: Dan Williams --- kernel/resource.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 90552aab5f2d..fed052a1bc9f 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -504,13 +504,13 @@ int region_is_ram(resource_size_t start, unsigned long size) { struct resource *p; resource_size_t end = start + size - 1; - int flags = IORESOURCE_MEM | IORESOURCE_BUSY; + unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; const char *name = "System RAM"; int ret = -1; read_lock(&resource_lock); for (p = iomem_resource.child; p ; p = p->sibling) { - if (end < p->start) + if (p->end < start) continue; if (p->start <= start && end <= p->end) { @@ -521,7 +521,7 @@ int region_is_ram(resource_size_t start, unsigned long size) ret = 1; break; } - if (p->end < start) + if (end < p->start) break; /* not found */ } read_unlock(&resource_lock);