1 /* Kernel module help for M32R.
2
3 This program is free software; you can redistribute it and/or modify
4 it under the terms of the GNU General Public License as published by
5 the Free Software Foundation; either version 2 of the License, or
6 (at your option) any later version.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with this program; if not, write to the Free Software
15 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 */
17
18 #include <linux/moduleloader.h>
19 #include <linux/elf.h>
20 #include <linux/vmalloc.h>
21 #include <linux/fs.h>
22 #include <linux/string.h>
23 #include <linux/kernel.h>
24
25 #if 0
26 #define DEBUGP printk
27 #else
28 #define DEBUGP(fmt...)
29 #endif
30
31 #define COPY_UNALIGNED_WORD(sw, tw, align) \
32 { \
33 void *__s = &(sw), *__t = &(tw); \
34 unsigned short *__s2 = __s, *__t2 =__t; \
35 unsigned char *__s1 = __s, *__t1 =__t; \
36 switch ((align)) \
37 { \
38 case 0: \
39 *(unsigned long *) __t = *(unsigned long *) __s; \
40 break; \
41 case 2: \
42 *__t2++ = *__s2++; \
43 *__t2 = *__s2; \
44 break; \
45 default: \
46 *__t1++ = *__s1++; \
47 *__t1++ = *__s1++; \
48 *__t1++ = *__s1++; \
49 *__t1 = *__s1; \
50 break; \
51 } \
52 }
53
54 #define COPY_UNALIGNED_HWORD(sw, tw, align) \
55 { \
56 void *__s = &(sw), *__t = &(tw); \
57 unsigned short *__s2 = __s, *__t2 =__t; \
58 unsigned char *__s1 = __s, *__t1 =__t; \
59 switch ((align)) \
60 { \
61 case 0: \
62 *__t2 = *__s2; \
63 break; \
64 default: \
65 *__t1++ = *__s1++; \
66 *__t1 = *__s1; \
67 break; \
68 } \
69 }
70
apply_relocate_add(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)71 int apply_relocate_add(Elf32_Shdr *sechdrs,
72 const char *strtab,
73 unsigned int symindex,
74 unsigned int relsec,
75 struct module *me)
76 {
77 unsigned int i;
78 Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
79 Elf32_Sym *sym;
80 Elf32_Addr relocation;
81 uint32_t *location;
82 uint32_t value;
83 unsigned short *hlocation;
84 unsigned short hvalue;
85 int svalue;
86 int align;
87
88 DEBUGP("Applying relocate section %u to %u\n", relsec,
89 sechdrs[relsec].sh_info);
90 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
91 /* This is where to make the change */
92 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
93 + rel[i].r_offset;
94 /* This is the symbol it is referring to. Note that all
95 undefined symbols have been resolved. */
96 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
97 + ELF32_R_SYM(rel[i].r_info);
98 relocation = sym->st_value + rel[i].r_addend;
99 align = (int)location & 3;
100
101 switch (ELF32_R_TYPE(rel[i].r_info)) {
102 case R_M32R_32_RELA:
103 COPY_UNALIGNED_WORD (*location, value, align);
104 value += relocation;
105 COPY_UNALIGNED_WORD (value, *location, align);
106 break;
107 case R_M32R_HI16_ULO_RELA:
108 COPY_UNALIGNED_WORD (*location, value, align);
109 relocation = (relocation >>16) & 0xffff;
110 /* RELA must has 0 at relocation field. */
111 value += relocation;
112 COPY_UNALIGNED_WORD (value, *location, align);
113 break;
114 case R_M32R_HI16_SLO_RELA:
115 COPY_UNALIGNED_WORD (*location, value, align);
116 if (relocation & 0x8000) relocation += 0x10000;
117 relocation = (relocation >>16) & 0xffff;
118 /* RELA must has 0 at relocation field. */
119 value += relocation;
120 COPY_UNALIGNED_WORD (value, *location, align);
121 break;
122 case R_M32R_16_RELA:
123 hlocation = (unsigned short *)location;
124 relocation = relocation & 0xffff;
125 /* RELA must has 0 at relocation field. */
126 hvalue = relocation;
127 COPY_UNALIGNED_WORD (hvalue, *hlocation, align);
128 break;
129 case R_M32R_SDA16_RELA:
130 case R_M32R_LO16_RELA:
131 COPY_UNALIGNED_WORD (*location, value, align);
132 relocation = relocation & 0xffff;
133 /* RELA must has 0 at relocation field. */
134 value += relocation;
135 COPY_UNALIGNED_WORD (value, *location, align);
136 break;
137 case R_M32R_24_RELA:
138 COPY_UNALIGNED_WORD (*location, value, align);
139 relocation = relocation & 0xffffff;
140 /* RELA must has 0 at relocation field. */
141 value += relocation;
142 COPY_UNALIGNED_WORD (value, *location, align);
143 break;
144 case R_M32R_18_PCREL_RELA:
145 relocation = (relocation - (Elf32_Addr) location);
146 if (relocation < -0x20000 || 0x1fffc < relocation)
147 {
148 printk(KERN_ERR "module %s: relocation overflow: %u\n",
149 me->name, relocation);
150 return -ENOEXEC;
151 }
152 COPY_UNALIGNED_WORD (*location, value, align);
153 if (value & 0xffff)
154 {
155 /* RELA must has 0 at relocation field. */
156 printk(KERN_ERR "module %s: illegal relocation field: %u\n",
157 me->name, value);
158 return -ENOEXEC;
159 }
160 relocation = (relocation >> 2) & 0xffff;
161 value += relocation;
162 COPY_UNALIGNED_WORD (value, *location, align);
163 break;
164 case R_M32R_10_PCREL_RELA:
165 hlocation = (unsigned short *)location;
166 relocation = (relocation - (Elf32_Addr) location);
167 COPY_UNALIGNED_HWORD (*hlocation, hvalue, align);
168 svalue = (int)hvalue;
169 svalue = (signed char)svalue << 2;
170 relocation += svalue;
171 relocation = (relocation >> 2) & 0xff;
172 hvalue = hvalue & 0xff00;
173 hvalue += relocation;
174 COPY_UNALIGNED_HWORD (hvalue, *hlocation, align);
175 break;
176 case R_M32R_26_PCREL_RELA:
177 relocation = (relocation - (Elf32_Addr) location);
178 if (relocation < -0x2000000 || 0x1fffffc < relocation)
179 {
180 printk(KERN_ERR "module %s: relocation overflow: %u\n",
181 me->name, relocation);
182 return -ENOEXEC;
183 }
184 COPY_UNALIGNED_WORD (*location, value, align);
185 if (value & 0xffffff)
186 {
187 /* RELA must has 0 at relocation field. */
188 printk(KERN_ERR "module %s: illegal relocation field: %u\n",
189 me->name, value);
190 return -ENOEXEC;
191 }
192 relocation = (relocation >> 2) & 0xffffff;
193 value += relocation;
194 COPY_UNALIGNED_WORD (value, *location, align);
195 break;
196 default:
197 printk(KERN_ERR "module %s: Unknown relocation: %u\n",
198 me->name, ELF32_R_TYPE(rel[i].r_info));
199 return -ENOEXEC;
200 }
201 }
202 return 0;
203 }
204