commit bc9ffce27962c0c5fdc6adf74790ea0fcbe4a99c
author Myron Stowe <mstowe@redhat.com> Mon Nov 07 16:23:27 2011 -0700
committer Len Brown <len.brown@intel.com> Tue Jan 17 04:33:40 2012 -0500
tree 4708702e1d6302dd8b4c16df9f44853ed2128ee1
parent 4134b8c8811f23aa8a281db50dcee64dda414736

ACPI: Fix possible alignment issues with GAS 'address' references

Generic Address Structures (GAS) may reside within ACPI tables which
are byte aligned.  This patch copies GAS 'address' references to a local
variable, which will be naturally aligned, to be used going forward.

ACPI Generic Address Structure (GAS) reference:
  ACPI Specification, Revision 4.0, Section 5.2.3.1, "Generic Address
  Structure"

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/osl.c

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index f31c5c5..2e285cd 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -166,17 +166,21 @@
 	return supported;
 }
 
-static void __init acpi_request_region (struct acpi_generic_address *addr,
+static void __init acpi_request_region (struct acpi_generic_address *gas,
 	unsigned int length, char *desc)
 {
-	if (!addr->address || !length)
+	u64 addr;
+
+	/* Handle possible alignment issues */
+	memcpy(&addr, &gas->address, sizeof(addr));
+	if (!addr || !length)
 		return;
 
 	/* Resources are never freed */
-	if (addr->space_id == ACPI_ADR_SPACE_SYSTEM_IO)
-		request_region(addr->address, length, desc);
-	else if (addr->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
-		request_mem_region(addr->address, length, desc);
+	if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO)
+		request_region(addr, length, desc);
+	else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
+		request_mem_region(addr, length, desc);
 }
 
 static int __init acpi_reserve_resources(void)
@@ -427,35 +431,41 @@
 		__acpi_unmap_table(virt, size);
 }
 
-static int acpi_os_map_generic_address(struct acpi_generic_address *addr)
+static int acpi_os_map_generic_address(struct acpi_generic_address *gas)
 {
+	u64 addr;
 	void __iomem *virt;
 
-	if (addr->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
+	if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		return 0;
 
-	if (!addr->address || !addr->bit_width)
+	/* Handle possible alignment issues */
+	memcpy(&addr, &gas->address, sizeof(addr));
+	if (!addr || !gas->bit_width)
 		return -EINVAL;
 
-	virt = acpi_os_map_memory(addr->address, addr->bit_width / 8);
+	virt = acpi_os_map_memory(addr, gas->bit_width / 8);
 	if (!virt)
 		return -EIO;
 
 	return 0;
 }
 
-static void acpi_os_unmap_generic_address(struct acpi_generic_address *addr)
+static void acpi_os_unmap_generic_address(struct acpi_generic_address *gas)
 {
+	u64 addr;
 	struct acpi_ioremap *map;
 
-	if (addr->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
+	if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		return;
 
-	if (!addr->address || !addr->bit_width)
+	/* Handle possible alignment issues */
+	memcpy(&addr, &gas->address, sizeof(addr));
+	if (!addr || !gas->bit_width)
 		return;
 
 	mutex_lock(&acpi_ioremap_lock);
-	map = acpi_map_lookup(addr->address, addr->bit_width / 8);
+	map = acpi_map_lookup(addr, gas->bit_width / 8);
 	if (!map) {
 		mutex_unlock(&acpi_ioremap_lock);
 		return;