[3.8.y.z extended stable] Patch "ACPI / resources: ignore invalid ACPI device resources" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ACPI / resources: ignore invalid ACPI device resources

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.21.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 41ed85bfef2225b76b9ffc3df897c84855209f02 Mon Sep 17 00:00:00 2001
From: Zhang Rui <rui.zhang at intel.com>
Date: Thu, 27 Feb 2014 11:37:15 +0800
Subject: ACPI / resources: ignore invalid ACPI device resources

commit b355cee88e3b1a193f0e9a81db810f6f83ad728b upstream.

ACPI table may export resource entry with 0 length.
But the current code interprets this kind of resource in a wrong way.
It will create a resource structure with
res->end = acpi_resource->start + acpi_resource->len - 1;

This patch fixes a problem on my machine that a platform device fails
to be created because one of its ACPI IO resource entry (start = 0,
end = 0, length = 0) is translated into a generic resource with
start = 0, end = 0xffffffff.

Signed-off-by: Zhang Rui <rui.zhang at intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/acpi/resource.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index a3868f6..a6f1307 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -77,18 +77,24 @@ bool acpi_dev_resource_memory(struct acpi_resource *ares, struct resource *res)
 	switch (ares->type) {
 	case ACPI_RESOURCE_TYPE_MEMORY24:
 		memory24 = &ares->data.memory24;
+		if (!memory24->address_length)
+			return false;
 		acpi_dev_get_memresource(res, memory24->minimum,
 					 memory24->address_length,
 					 memory24->write_protect);
 		break;
 	case ACPI_RESOURCE_TYPE_MEMORY32:
 		memory32 = &ares->data.memory32;
+		if (!memory32->address_length)
+			return false;
 		acpi_dev_get_memresource(res, memory32->minimum,
 					 memory32->address_length,
 					 memory32->write_protect);
 		break;
 	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
 		fixed_memory32 = &ares->data.fixed_memory32;
+		if (!fixed_memory32->address_length)
+			return false;
 		acpi_dev_get_memresource(res, fixed_memory32->address,
 					 fixed_memory32->address_length,
 					 fixed_memory32->write_protect);
@@ -144,12 +150,16 @@ bool acpi_dev_resource_io(struct acpi_resource *ares, struct resource *res)
 	switch (ares->type) {
 	case ACPI_RESOURCE_TYPE_IO:
 		io = &ares->data.io;
+		if (!io->address_length)
+			return false;
 		acpi_dev_get_ioresource(res, io->minimum,
 					io->address_length,
 					io->io_decode);
 		break;
 	case ACPI_RESOURCE_TYPE_FIXED_IO:
 		fixed_io = &ares->data.fixed_io;
+		if (!fixed_io->address_length)
+			return false;
 		acpi_dev_get_ioresource(res, fixed_io->address,
 					fixed_io->address_length,
 					ACPI_DECODE_10);
--
1.8.3.2