aboutsummaryrefslogtreecommitdiff
path: root/arch/m32r/kernel/module.c
blob: 38233b6596b6e837e7cdf67ccad02f93834fe1ef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
/*  Kernel module help for M32R.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>

#if 0
#define DEBUGP printk
#else
#define DEBUGP(fmt...)
#endif

#define COPY_UNALIGNED_WORD(sw, tw, align) \
{ \
	void *__s = &(sw), *__t = &(tw); \
	unsigned short *__s2 = __s, *__t2 =__t; \
	unsigned char *__s1 = __s, *__t1 =__t; \
	switch ((align)) \
	{ \
	case 0: \
		*(unsigned long *) __t = *(unsigned long *) __s; \
		break; \
	case 2: \
		*__t2++ = *__s2++; \
		*__t2 = *__s2; \
		break; \
	default: \
		*__t1++ = *__s1++; \
		*__t1++ = *__s1++; \
		*__t1++ = *__s1++; \
		*__t1 = *__s1; \
		break; \
	} \
}

#define COPY_UNALIGNED_HWORD(sw, tw, align) \
  { \
    void *__s = &(sw), *__t = &(tw); \
    unsigned short *__s2 = __s, *__t2 =__t; \
    unsigned char *__s1 = __s, *__t1 =__t; \
    switch ((align)) \
    { \
    case 0: \
      *__t2 = *__s2; \
      break; \
    default: \
      *__t1++ = *__s1++; \
      *__t1 = *__s1; \
      break; \
    } \
  }

int apply_relocate_add(Elf32_Shdr *sechdrs,
		   const char *strtab,
		   unsigned int symindex,
		   unsigned int relsec,
		   struct module *me)
{
	unsigned int i;
	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
	Elf32_Sym *sym;
	Elf32_Addr relocation;
	uint32_t *location;
	uint32_t value;
	unsigned short *hlocation;
	unsigned short hvalue;
	int svalue;
	int align;

	DEBUGP("Applying relocate section %u to %u\n", relsec,
	       sechdrs[relsec].sh_info);
	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
		/* This is where to make the change */
		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
			+ rel[i].r_offset;
		/* This is the symbol it is referring to.  Note that all
		   undefined symbols have been resolved.  */
		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
			+ ELF32_R_SYM(rel[i].r_info);
		relocation = sym->st_value + rel[i].r_addend;
		align = (int)location & 3;

		switch (ELF32_R_TYPE(rel[i].r_info)) {
		case R_M32R_32_RELA:
	    		COPY_UNALIGNED_WORD (*location, value, align);
			value += relocation;
	    		COPY_UNALIGNED_WORD (value, *location, align);
			break;
		case R_M32R_HI16_ULO_RELA:
	    		COPY_UNALIGNED_WORD (*location, value, align);
                        relocation = (relocation >>16) & 0xffff;
			/* RELA must has 0 at relocation field. */
			value += relocation;
	    		COPY_UNALIGNED_WORD (value, *location, align);
			break;
		case R_M32R_HI16_SLO_RELA:
	    		COPY_UNALIGNED_WORD (*location, value, align);
			if (relocation & 0x8000) relocation += 0x10000;
                        relocation = (relocation >>16) & 0xffff;
			/* RELA must has 0 at relocation field. */
			value += relocation;
	    		COPY_UNALIGNED_WORD (value, *location, align);
			break;
		case R_M32R_16_RELA:
			hlocation = (unsigned short *)location;
                        relocation = relocation & 0xffff;
			/* RELA must has 0 at relocation field. */
			hvalue = relocation;
	    		COPY_UNALIGNED_WORD (hvalue, *hlocation, align);
			break;
		case R_M32R_SDA16_RELA:
		case R_M32R_LO16_RELA:
	    		COPY_UNALIGNED_WORD (*location, value, align);
                        relocation = relocation & 0xffff;
			/* RELA must has 0 at relocation field. */
			value += relocation;
	    		COPY_UNALIGNED_WORD (value, *location, align);
			break;
		case R_M32R_24_RELA:
	    		COPY_UNALIGNED_WORD (*location, value, align);
                        relocation = relocation & 0xffffff;
			/* RELA must has 0 at relocation field. */
			value += relocation;
	    		COPY_UNALIGNED_WORD (value, *location, align);
			break;
		case R_M32R_18_PCREL_RELA:
	  		relocation = (relocation - (Elf32_Addr) location);
			if (relocation < -0x20000 || 0x1fffc < relocation)
				{
					printk(KERN_ERR "module %s: relocation overflow: %u\n",
					me->name, relocation);
					return -ENOEXEC;
				}
	    		COPY_UNALIGNED_WORD (*location, value, align);
			if (value & 0xffff)
				{
					/* RELA must has 0 at relocation field. */
					printk(KERN_ERR "module %s: illegal relocation field: %u\n",
					me->name, value);
					return -ENOEXEC;
				}
                        relocation = (relocation >> 2) & 0xffff;
			value += relocation;
	    		COPY_UNALIGNED_WORD (value, *location, align);
			break;
		case R_M32R_10_PCREL_RELA:
			hlocation = (unsigned short *)location;
	  		relocation = (relocation - (Elf32_Addr) location);
	    		COPY_UNALIGNED_HWORD (*hlocation, hvalue, align);
			svalue = (int)hvalue;
			svalue = (signed char)svalue << 2;
			relocation += svalue;
                        relocation = (relocation >> 2) & 0xff;
			hvalue = hvalue & 0xff00;
			hvalue += relocation;
	    		COPY_UNALIGNED_HWORD (hvalue, *hlocation, align);
			break;
		case R_M32R_26_PCREL_RELA:
	  		relocation = (relocation - (Elf32_Addr) location);
			if (relocation < -0x2000000 || 0x1fffffc < relocation)
				{
					printk(KERN_ERR "module %s: relocation overflow: %u\n",
					me->name, relocation);
					return -ENOEXEC;
				}
	    		COPY_UNALIGNED_WORD (*location, value, align);
			if (value & 0xffffff)
				{
					/* RELA must has 0 at relocation field. */
					printk(KERN_ERR "module %s: illegal relocation field: %u\n",
					me->name, value);
					return -ENOEXEC;
				}
                        relocation = (relocation >> 2) & 0xffffff;
			value += relocation;
	    		COPY_UNALIGNED_WORD (value, *location, align);
			break;
		default:
			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
			       me->name, ELF32_R_TYPE(rel[i].r_info));
			return -ENOEXEC;
		}
	}
	return 0;
}