[patch 068/164] x86/amd-iommu: Fix crash when request_mem_region fails

Greg KH
2010-07-01T22:09:35Z

2.6.33-stable review patch. If anyone has any objections, please let me know.

------------------

From: Joerg Roedel <joerg.roedel@amd.com>

commit e82752d8b5a7e0a5e4d607fd8713549e2a4e2741 upstream.

When request_mem_region fails the error path tries to
disable the IOMMUs. This accesses the mmio-region which was
not allocated leading to a kernel crash. This patch fixes
the issue.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/x86/kernel/amd_iommu_init.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -286,8 +286,12 @@ static u8 * __init iommu_map_mmio_space(
{
u8 *ret;

- if (!request_mem_region(address, MMIO_REGION_LENGTH, "amd_iommu"))
+ if (!request_mem_region(address, MMIO_REGION_LENGTH, "amd_iommu")) {
+ pr_err("AMD-Vi: Can not reserve memory region %llx for mmio\n",
+ address);
+ pr_err("AMD-Vi: This is a BIOS bug. Please contact your hardware vendor\n");
return NULL;
+ }

ret = ioremap_nocache(address, MMIO_REGION_LENGTH);
if (ret != NULL)
@@ -1296,7 +1300,7 @@ static int __init amd_iommu_init(void)
ret = amd_iommu_init_dma_ops();

if (ret)
- goto free;
+ goto free_disable;

amd_iommu_init_api();

@@ -1314,9 +1318,10 @@ static int __init amd_iommu_init(void)
out:
return ret;

-free:
+free_disable:
disable_iommus();

+free:
amd_iommu_uninit_devices();

free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,