From mboxrd@z Thu Jan 1 00:00:00 1970 From: dan.j.williams@intel.com (Dan Williams) Date: Fri, 24 Jul 2015 22:38:16 -0400 Subject: [PATCH v2 03/25] mm: Fix bugs in region_is_ram() In-Reply-To: <20150725023649.8664.59145.stgit@dwillia2-desk3.amr.corp.intel.com> References: <20150725023649.8664.59145.stgit@dwillia2-desk3.amr.corp.intel.com> Message-ID: <20150725023816.8664.99926.stgit@dwillia2-desk3.amr.corp.intel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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);