ACPI / resources: ignore invalid ACPI device resources

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@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index b7201fc6f1e19c06c798889900c1e9c689494c8d..0bdacc5e26a3b9411b82a5fe4772c2c9f9b7d490 100644 (file)
--- 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);