1 /*
2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 *
14 * Based on i386 version, copyright (C) 2001 Rusty Russell.
15 */
16
17 #include <linux/moduleloader.h>
18 #include <linux/elf.h>
19 #include <linux/vmalloc.h>
20 #include <linux/fs.h>
21 #include <linux/string.h>
22 #include <linux/kernel.h>
23 #include <asm/pgtable.h>
24 #include <asm/homecache.h>
25 #include <arch/opcode.h>
26
27 #ifdef __tilegx__
28 # define Elf_Rela Elf64_Rela
29 # define ELF_R_SYM ELF64_R_SYM
30 # define ELF_R_TYPE ELF64_R_TYPE
31 #else
32 # define Elf_Rela Elf32_Rela
33 # define ELF_R_SYM ELF32_R_SYM
34 # define ELF_R_TYPE ELF32_R_TYPE
35 #endif
36
37 #ifdef MODULE_DEBUG
38 #define DEBUGP printk
39 #else
40 #define DEBUGP(fmt...)
41 #endif
42
43 /*
44 * Allocate some address space in the range MEM_MODULE_START to
45 * MEM_MODULE_END and populate it with memory.
46 */
module_alloc(unsigned long size)47 void *module_alloc(unsigned long size)
48 {
49 struct page **pages;
50 pgprot_t prot_rwx = __pgprot(_PAGE_KERNEL | _PAGE_KERNEL_EXEC);
51 struct vm_struct *area;
52 int i = 0;
53 int npages;
54
55 if (size == 0)
56 return NULL;
57 npages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
58 pages = kmalloc(npages * sizeof(struct page *), GFP_KERNEL);
59 if (pages == NULL)
60 return NULL;
61 for (; i < npages; ++i) {
62 pages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
63 if (!pages[i])
64 goto error;
65 }
66
67 area = __get_vm_area(size, VM_ALLOC, MEM_MODULE_START, MEM_MODULE_END);
68 if (!area)
69 goto error;
70
71 if (map_vm_area(area, prot_rwx, &pages)) {
72 vunmap(area->addr);
73 goto error;
74 }
75
76 return area->addr;
77
78 error:
79 while (--i >= 0)
80 __free_page(pages[i]);
81 kfree(pages);
82 return NULL;
83 }
84
85
86 /* Free memory returned from module_alloc */
module_free(struct module * mod,void * module_region)87 void module_free(struct module *mod, void *module_region)
88 {
89 vfree(module_region);
90
91 /* Globally flush the L1 icache. */
92 flush_remote(0, HV_FLUSH_EVICT_L1I, cpu_online_mask,
93 0, 0, 0, NULL, NULL, 0);
94
95 /*
96 * FIXME: If module_region == mod->module_init, trim exception
97 * table entries.
98 */
99 }
100
101 #ifdef __tilegx__
102 /*
103 * Validate that the high 16 bits of "value" is just the sign-extension of
104 * the low 48 bits.
105 */
validate_hw2_last(long value,struct module * me)106 static int validate_hw2_last(long value, struct module *me)
107 {
108 if (((value << 16) >> 16) != value) {
109 pr_warning("module %s: Out of range HW2_LAST value %#lx\n",
110 me->name, value);
111 return 0;
112 }
113 return 1;
114 }
115
116 /*
117 * Validate that "value" isn't too big to hold in a JumpOff relocation.
118 */
validate_jumpoff(long value)119 static int validate_jumpoff(long value)
120 {
121 /* Determine size of jump offset. */
122 int shift = __builtin_clzl(get_JumpOff_X1(create_JumpOff_X1(-1)));
123
124 /* Check to see if it fits into the relocation slot. */
125 long f = get_JumpOff_X1(create_JumpOff_X1(value));
126 f = (f << shift) >> shift;
127
128 return f == value;
129 }
130 #endif
131
apply_relocate_add(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)132 int apply_relocate_add(Elf_Shdr *sechdrs,
133 const char *strtab,
134 unsigned int symindex,
135 unsigned int relsec,
136 struct module *me)
137 {
138 unsigned int i;
139 Elf_Rela *rel = (void *)sechdrs[relsec].sh_addr;
140 Elf_Sym *sym;
141 u64 *location;
142 unsigned long value;
143
144 DEBUGP("Applying relocate section %u to %u\n", relsec,
145 sechdrs[relsec].sh_info);
146 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
147 /* This is where to make the change */
148 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
149 + rel[i].r_offset;
150 /*
151 * This is the symbol it is referring to.
152 * Note that all undefined symbols have been resolved.
153 */
154 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
155 + ELF_R_SYM(rel[i].r_info);
156 value = sym->st_value + rel[i].r_addend;
157
158 switch (ELF_R_TYPE(rel[i].r_info)) {
159
160 #define MUNGE(func) (*location = ((*location & ~func(-1)) | func(value)))
161
162 #ifndef __tilegx__
163 case R_TILE_32:
164 *(uint32_t *)location = value;
165 break;
166 case R_TILE_IMM16_X0_HA:
167 value = (value + 0x8000) >> 16;
168 /*FALLTHROUGH*/
169 case R_TILE_IMM16_X0_LO:
170 MUNGE(create_Imm16_X0);
171 break;
172 case R_TILE_IMM16_X1_HA:
173 value = (value + 0x8000) >> 16;
174 /*FALLTHROUGH*/
175 case R_TILE_IMM16_X1_LO:
176 MUNGE(create_Imm16_X1);
177 break;
178 case R_TILE_JOFFLONG_X1:
179 value -= (unsigned long) location; /* pc-relative */
180 value = (long) value >> 3; /* count by instrs */
181 MUNGE(create_JOffLong_X1);
182 break;
183 #else
184 case R_TILEGX_64:
185 *location = value;
186 break;
187 case R_TILEGX_IMM16_X0_HW2_LAST:
188 if (!validate_hw2_last(value, me))
189 return -ENOEXEC;
190 value >>= 16;
191 /*FALLTHROUGH*/
192 case R_TILEGX_IMM16_X0_HW1:
193 value >>= 16;
194 /*FALLTHROUGH*/
195 case R_TILEGX_IMM16_X0_HW0:
196 MUNGE(create_Imm16_X0);
197 break;
198 case R_TILEGX_IMM16_X1_HW2_LAST:
199 if (!validate_hw2_last(value, me))
200 return -ENOEXEC;
201 value >>= 16;
202 /*FALLTHROUGH*/
203 case R_TILEGX_IMM16_X1_HW1:
204 value >>= 16;
205 /*FALLTHROUGH*/
206 case R_TILEGX_IMM16_X1_HW0:
207 MUNGE(create_Imm16_X1);
208 break;
209 case R_TILEGX_JUMPOFF_X1:
210 value -= (unsigned long) location; /* pc-relative */
211 value = (long) value >> 3; /* count by instrs */
212 if (!validate_jumpoff(value)) {
213 pr_warning("module %s: Out of range jump to"
214 " %#llx at %#llx (%p)\n", me->name,
215 sym->st_value + rel[i].r_addend,
216 rel[i].r_offset, location);
217 return -ENOEXEC;
218 }
219 MUNGE(create_JumpOff_X1);
220 break;
221 #endif
222
223 #undef MUNGE
224
225 default:
226 pr_err("module %s: Unknown relocation: %d\n",
227 me->name, (int) ELF_R_TYPE(rel[i].r_info));
228 return -ENOEXEC;
229 }
230 }
231 return 0;
232 }
233