Q: Given the following code slice:
```
1 #define PCI_DN(dn)	((struct pci_dn *) (dn)->data)
2 
3 static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
4 {
5 	struct iommu_table *tbl;
6 	struct device_node *dn, *pdn;
7 	struct pci_dn *ppci;
8 	struct dynamic_dma_window_prop prop;
9 
10 	dn = pci_bus_to_OF_node(bus);
11 
12 	pr_debug("pci_dma_bus_setup_pSeriesLP: setting up bus %pOF\n",
13 		 dn);
14 
15 	pdn = pci_dma_find(dn, &prop);
16 
17 	/* In PPC architecture, there will always be DMA window on bus or one of the
18 	 * parent bus. During reboot, there will be ibm,dma-window property to
19 	 * define DMA window. For kdump, there will at least be default window or DDW
20 	 * or both.
21 	 */
22 
23 	ppci = PCI_DN(pdn);
24 
25 	pr_debug("  parent is %pOF, iommu_table: 0x%p\n",
26 		 pdn, ppci->table_group);
27 
28 	if (!ppci->table_group) {
29 		ppci->table_group = iommu_pseries_alloc_group(ppci->phb->node);
30 		tbl = ppci->table_group->tables[0];
31 
32 		iommu_table_setparms_common(tbl, ppci->phb->bus->number,
33 				be32_to_cpu(prop.liobn),
34 				be64_to_cpu(prop.dma_base),
35 				1ULL << be32_to_cpu(prop.window_shift),
36 				be32_to_cpu(prop.tce_shift), NULL,
37 				&iommu_table_lpar_multi_ops);
38 
39 		/* Only for normal boot with default window. Doesn't matter even
40 		 * if we set these with DDW which is 64bit during kdump, since
41 		 * these will not be used during kdump.
42 		 */
43 		ppci->table_group->tce32_start = be64_to_cpu(prop.dma_base);
44 		ppci->table_group->tce32_size = 1 << be32_to_cpu(prop.window_shift);
45 
46 		if (!iommu_init_table(tbl, ppci->phb->node, 0, 0))
47 			panic("Failed to initialize iommu table");
48 
49 		iommu_register_group(ppci->table_group,
50 				pci_domain_nr(bus), 0);
51 		pr_debug("  created table: %p\n", ppci->table_group);
52 	}
53 }
54 static struct device_node *pci_dma_find(struct device_node *dn,
55 					struct dynamic_dma_window_prop *prop)
56 {
57 	const __be32 *default_prop = NULL;
58 	const __be32 *ddw_prop = NULL;
59 	struct device_node *rdn = NULL;
60 	bool default_win = false, ddw_win = false;
61 
62 	for ( ; dn && PCI_DN(dn); dn = dn->parent) {
63 		default_prop = of_get_property(dn, "ibm,dma-window", NULL);
64 		if (default_prop) {
65 			rdn = dn;
66 			default_win = true;
67 		}
68 		ddw_prop = of_get_property(dn, DIRECT64_PROPNAME, NULL);
69 		if (ddw_prop) {
70 			rdn = dn;
71 			ddw_win = true;
72 			break;
73 		}
74 		ddw_prop = of_get_property(dn, DMA64_PROPNAME, NULL);
75 		if (ddw_prop) {
76 			rdn = dn;
77 			ddw_win = true;
78 			break;
79 		}
80 
81 		/* At least found default window, which is the case for normal boot */
82 		if (default_win)
83 			break;
84 	}
85 
86 	/* For PCI devices there will always be a DMA window, either on the device
87 	 * or parent bus
88 	 */
89 	WARN_ON(!(default_win | ddw_win));
90 
91 	/* caller doesn't want to get DMA window property */
92 	if (!prop)
93 		return rdn;
94 
95 	/* parse DMA window property. During normal system boot, only default
96 	 * DMA window is passed in OF. But, for kdump, a dedicated adapter might
97 	 * have both default and DDW in FDT. In this scenario, DDW takes precedence
98 	 * over default window.
99 	 */
100 	if (ddw_win) {
101 		struct dynamic_dma_window_prop *p;
102 
103 		p = (struct dynamic_dma_window_prop *)ddw_prop;
104 		prop->liobn = p->liobn;
105 		prop->dma_base = p->dma_base;
106 		prop->tce_shift = p->tce_shift;
107 		prop->window_shift = p->window_shift;
108 	} else if (default_win) {
109 		unsigned long offset, size, liobn;
110 
111 		of_parse_dma_window(rdn, default_prop, &liobn, &offset, &size);
112 
113 		prop->liobn = cpu_to_be32((u32)liobn);
114 		prop->dma_base = cpu_to_be64(offset);
115 		prop->tce_shift = cpu_to_be32(IOMMU_PAGE_SHIFT_4K);
116 		prop->window_shift = cpu_to_be32(order_base_2(size));
117 	}
118 
119 	return rdn;
120 }
121 static inline u64 of_read_number(const __be32 *cell, int size)
122 {
123 	u64 r = 0;
124 	for (; size--; cell++)
125 		r = (r << 32) | be32_to_cpu(*cell);
126 	return r;
127 }
128 void of_parse_dma_window(struct device_node *dn, const __be32 *dma_window,
129 			 unsigned long *busno, unsigned long *phys,
130 			 unsigned long *size)
131 {
132 	u32 cells;
133 	const __be32 *prop;
134 
135 	/* busno is always one cell */
136 	*busno = of_read_number(dma_window, 1);
137 	dma_window++;
138 
139 	prop = of_get_property(dn, "ibm,#dma-address-cells", NULL);
140 	if (!prop)
141 		prop = of_get_property(dn, "#address-cells", NULL);
142 
143 	cells = prop ? of_read_number(prop, 1) : of_n_addr_cells(dn);
144 	*phys = of_read_number(dma_window, cells);
145 
146 	dma_window += cells;
147 
148 	prop = of_get_property(dn, "ibm,#dma-size-cells", NULL);
149 	cells = prop ? of_read_number(prop, 1) : of_n_size_cells(dn);
150 	*size = of_read_number(dma_window, cells);
151 }
152 const void *of_get_property(const struct device_node *np, const char *name,
153 			    int *lenp)
154 {
155 	struct property *pp = of_find_property(np, name, lenp);
156 
157 	return pp ? pp->value : NULL;
158 }
159 int of_n_size_cells(struct device_node *np)
160 {
161 	if (np->parent)
162 		np = np->parent;
163 
164 	return of_bus_n_size_cells(np);
165 }
166 int of_n_addr_cells(struct device_node *np)
167 {
168 	if (np->parent)
169 		np = np->parent;
170 
171 	return of_bus_n_addr_cells(np);
172 }
173 struct property *of_find_property(const struct device_node *np,
174 				  const char *name,
175 				  int *lenp)
176 {
177 	struct property *pp;
178 	unsigned long flags;
179 
180 	raw_spin_lock_irqsave(&devtree_lock, flags);
181 	pp = __of_find_property(np, name, lenp);
182 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
183 
184 	return pp;
185 }
186 static inline struct device_node *pci_bus_to_OF_node(struct pci_bus *bus)
187 {
188 	return bus ? bus->dev.of_node : NULL;
189 }
```
which has a vulnerability among CWE-476 and among lines:
```
46 		if (!iommu_init_table(tbl, ppci->phb->node, 0, 0))
49 		iommu_register_group(ppci->table_group,
```
Please generate five possible patches for the vulnerability.