From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f172.google.com (mail-ob0-f172.google.com [209.85.214.172]) by kanga.kvack.org (Postfix) with ESMTP id 68379280312 for ; Thu, 16 Jul 2015 19:24:26 -0400 (EDT) Received: by obnw1 with SMTP id w1so56529329obn.3 for ; Thu, 16 Jul 2015 16:24:26 -0700 (PDT) Received: from g4t3426.houston.hp.com (g4t3426.houston.hp.com. [15.201.208.54]) by mx.google.com with ESMTPS id tv10si7688805oeb.47.2015.07.16.16.24.24 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Jul 2015 16:24:24 -0700 (PDT) From: Toshi Kani Subject: [PATCH RESEND 3/3] mm: Fix bugs in region_is_ram() Date: Thu, 16 Jul 2015 17:23:16 -0600 Message-Id: <1437088996-28511-4-git-send-email-toshi.kani@hp.com> In-Reply-To: <1437088996-28511-1-git-send-email-toshi.kani@hp.com> References: <1437088996-28511-1-git-send-email-toshi.kani@hp.com> Sender: owner-linux-mm@kvack.org List-ID: To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, akpm@linux-foundation.org Cc: travis@sgi.com, roland@purestorage.com, dan.j.williams@intel.com, mcgrof@suse.com, x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, 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 --- kernel/resource.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 90552aa..fed052a 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); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org