From 767303349e052ae0cb9e6495a70870da3459eeb6 Mon Sep 17 00:00:00 2001 From: Nishanth Aravamudan 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 Signed-off-by: Benjamin Herrenschmidt --- 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 6d5412a18b26..019009b10e62 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");