From 767303349e052ae0cb9e6495a70870da3459eeb6 Mon Sep 17 00:00:00 2001
From: Nishanth Aravamudan <nacc@us.ibm.com>
Date: Fri, 6 May 2011 13:27:30 +0000
Subject: [PATCH] powerpc: Fix kexec with dynamic dma windows
When we kexec we look for a particular property added by the first
kernel, "linux,direct64-ddr-window-info", per-device where we already
have set up dynamic dma windows. The current code, though, wasn't
initializing the size of this property and thus when we kexec'd, we
would find the property but read uninitialized memory resulting in
garbage ddw values for the kexec'd kernel and panics. Fix this by
setting the size at enable_ddw() time and ensuring that the size of the
found property is valid at dupe_ddw_if_kexec() time.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
arch/powerpc/platforms/pseries/iommu.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 6d5412a18b26b..019009b10e628 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -730,16 +730,20 @@ static u64 dupe_ddw_if_kexec(struct pci_dev *dev, struct device_node *pdn)
pcidn = PCI_DN(dn);
direct64 = of_get_property(pdn, DIRECT64_PROPNAME, &len);
if (direct64) {
- window = kzalloc(sizeof(*window), GFP_KERNEL);
- if (!window) {
+ if (len < sizeof(struct dynamic_dma_window_prop)) {
remove_ddw(pdn);
} else {
- window->device = pdn;
- window->prop = direct64;
- spin_lock(&direct_window_list_lock);
- list_add(&window->list, &direct_window_list);
- spin_unlock(&direct_window_list_lock);
- dma_addr = direct64->dma_base;
+ window = kzalloc(sizeof(*window), GFP_KERNEL);
+ if (!window) {
+ remove_ddw(pdn);
+ } else {
+ window->device = pdn;
+ window->prop = direct64;
+ spin_lock(&direct_window_list_lock);
+ list_add(&window->list, &direct_window_list);
+ spin_unlock(&direct_window_list_lock);
+ dma_addr = direct64->dma_base;
+ }
}
}
@@ -833,7 +837,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
struct device_node *dn;
const u32 *uninitialized_var(ddr_avail);
struct direct_window *window;
- struct property *uninitialized_var(win64);
+ struct property *win64;
struct dynamic_dma_window_prop *ddwprop;
mutex_lock(&direct_window_init_mutex);
@@ -907,6 +911,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
}
win64->name = kstrdup(DIRECT64_PROPNAME, GFP_KERNEL);
win64->value = ddwprop = kmalloc(sizeof(*ddwprop), GFP_KERNEL);
+ win64->length = sizeof(*ddwprop);
if (!win64->name || !win64->value) {
dev_info(&dev->dev,
"couldn't allocate property name and value\n");
--
2.30.2