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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 */
47void *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 area->nr_pages = npages;
71 area->pages = pages;
72
73 if (map_vm_area(area, prot_rwx, &pages)) {
74 vunmap(area->addr);
75 goto error;
76 }
77
78 return area->addr;
79
80error:
81 while (--i >= 0)
82 __free_page(pages[i]);
83 kfree(pages);
84 return NULL;
85}
86
87
88/* Free memory returned from module_alloc */
89void module_free(struct module *mod, void *module_region)
90{
91 vfree(module_region);
92
93 /* Globally flush the L1 icache. */
94 flush_remote(0, HV_FLUSH_EVICT_L1I, cpu_online_mask,
95 0, 0, 0, NULL, NULL, 0);
96
97 /*
98 * FIXME: If module_region == mod->module_init, trim exception
99 * table entries.
100 */
101}
102
103#ifdef __tilegx__
104/*
105 * Validate that the high 16 bits of "value" is just the sign-extension of
106 * the low 48 bits.
107 */
108static int validate_hw2_last(long value, struct module *me)
109{
110 if (((value << 16) >> 16) != value) {
111 pr_warning("module %s: Out of range HW2_LAST value %#lx\n",
112 me->name, value);
113 return 0;
114 }
115 return 1;
116}
117
118/*
119 * Validate that "value" isn't too big to hold in a JumpOff relocation.
120 */
121static int validate_jumpoff(long value)
122{
123 /* Determine size of jump offset. */
124 int shift = __builtin_clzl(get_JumpOff_X1(create_JumpOff_X1(-1)));
125
126 /* Check to see if it fits into the relocation slot. */
127 long f = get_JumpOff_X1(create_JumpOff_X1(value));
128 f = (f << shift) >> shift;
129
130 return f == value;
131}
132#endif
133
134int apply_relocate_add(Elf_Shdr *sechdrs,
135 const char *strtab,
136 unsigned int symindex,
137 unsigned int relsec,
138 struct module *me)
139{
140 unsigned int i;
141 Elf_Rela *rel = (void *)sechdrs[relsec].sh_addr;
142 Elf_Sym *sym;
143 u64 *location;
144 unsigned long value;
145
146 DEBUGP("Applying relocate section %u to %u\n", relsec,
147 sechdrs[relsec].sh_info);
148 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
149 /* This is where to make the change */
150 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
151 + rel[i].r_offset;
152 /*
153 * This is the symbol it is referring to.
154 * Note that all undefined symbols have been resolved.
155 */
156 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
157 + ELF_R_SYM(rel[i].r_info);
158 value = sym->st_value + rel[i].r_addend;
159
160 switch (ELF_R_TYPE(rel[i].r_info)) {
161
162#ifdef __LITTLE_ENDIAN
163# define MUNGE(func) \
164 (*location = ((*location & ~func(-1)) | func(value)))
165#else
166/*
167 * Instructions are always little-endian, so when we read them as data,
168 * we have to swap them around before and after modifying them.
169 */
170# define MUNGE(func) \
171 (*location = swab64((swab64(*location) & ~func(-1)) | func(value)))
172#endif
173
174#ifndef __tilegx__
175 case R_TILE_32:
176 *(uint32_t *)location = value;
177 break;
178 case R_TILE_IMM16_X0_HA:
179 value = (value + 0x8000) >> 16;
180 /*FALLTHROUGH*/
181 case R_TILE_IMM16_X0_LO:
182 MUNGE(create_Imm16_X0);
183 break;
184 case R_TILE_IMM16_X1_HA:
185 value = (value + 0x8000) >> 16;
186 /*FALLTHROUGH*/
187 case R_TILE_IMM16_X1_LO:
188 MUNGE(create_Imm16_X1);
189 break;
190 case R_TILE_JOFFLONG_X1:
191 value -= (unsigned long) location; /* pc-relative */
192 value = (long) value >> 3; /* count by instrs */
193 MUNGE(create_JOffLong_X1);
194 break;
195#else
196 case R_TILEGX_64:
197 *location = value;
198 break;
199 case R_TILEGX_IMM16_X0_HW2_LAST:
200 if (!validate_hw2_last(value, me))
201 return -ENOEXEC;
202 value >>= 16;
203 /*FALLTHROUGH*/
204 case R_TILEGX_IMM16_X0_HW1:
205 value >>= 16;
206 /*FALLTHROUGH*/
207 case R_TILEGX_IMM16_X0_HW0:
208 MUNGE(create_Imm16_X0);
209 break;
210 case R_TILEGX_IMM16_X1_HW2_LAST:
211 if (!validate_hw2_last(value, me))
212 return -ENOEXEC;
213 value >>= 16;
214 /*FALLTHROUGH*/
215 case R_TILEGX_IMM16_X1_HW1:
216 value >>= 16;
217 /*FALLTHROUGH*/
218 case R_TILEGX_IMM16_X1_HW0:
219 MUNGE(create_Imm16_X1);
220 break;
221 case R_TILEGX_JUMPOFF_X1:
222 value -= (unsigned long) location; /* pc-relative */
223 value = (long) value >> 3; /* count by instrs */
224 if (!validate_jumpoff(value)) {
225 pr_warning("module %s: Out of range jump to"
226 " %#llx at %#llx (%p)\n", me->name,
227 sym->st_value + rel[i].r_addend,
228 rel[i].r_offset, location);
229 return -ENOEXEC;
230 }
231 MUNGE(create_JumpOff_X1);
232 break;
233#endif
234
235#undef MUNGE
236
237 default:
238 pr_err("module %s: Unknown relocation: %d\n",
239 me->name, (int) ELF_R_TYPE(rel[i].r_info));
240 return -ENOEXEC;
241 }
242 }
243 return 0;
244}