From 8c38de992be9aed0b34c4fab8f972c83d3b00dc4 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 16 Jul 2015 17:23:16 -0600 Subject: [PATCH] mm: Fix bugs in region_is_ram() 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. 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 Reviewed-by: Dan Williams Cc: Mike Travis Cc: Luis R. Rodriguez Cc: Andrew Morton Cc: Roland Dreier Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1437088996-28511-4-git-send-email-toshi.kani@hp.com Signed-off-by: Thomas Gleixner --- 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); -- 2.20.1