1 /*
2 * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2007-2009 PetaLogix
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10 #include <linux/module.h>
11 #include <linux/moduleloader.h>
12 #include <linux/kernel.h>
13 #include <linux/elf.h>
14 #include <linux/vmalloc.h>
15 #include <linux/fs.h>
16 #include <linux/string.h>
17
18 #include <asm/pgtable.h>
19 #include <asm/cacheflush.h>
20
apply_relocate_add(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * module)21 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
22 unsigned int symindex, unsigned int relsec, struct module *module)
23 {
24
25 unsigned int i;
26 Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
27 Elf32_Sym *sym;
28 unsigned long int *location;
29 unsigned long int value;
30 #if __GNUC__ < 4
31 unsigned long int old_value;
32 #endif
33
34 pr_debug("Applying add relocation section %u to %u\n",
35 relsec, sechdrs[relsec].sh_info);
36
37 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
38
39 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
40 rela[i].r_offset;
41 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr +
42 ELF32_R_SYM(rela[i].r_info);
43 value = sym->st_value + rela[i].r_addend;
44
45 switch (ELF32_R_TYPE(rela[i].r_info)) {
46
47 /*
48 * Be careful! mb-gcc / mb-ld splits the relocs between the
49 * text and the reloc table. In general this means we must
50 * read the current contents of (*location), add any offset
51 * then store the result back in
52 */
53
54 case R_MICROBLAZE_32:
55 #if __GNUC__ < 4
56 old_value = *location;
57 *location = value + old_value;
58
59 pr_debug("R_MICROBLAZE_32 (%08lx->%08lx)\n",
60 old_value, value);
61 #else
62 *location = value;
63 #endif
64 break;
65
66 case R_MICROBLAZE_64:
67 #if __GNUC__ < 4
68 /* Split relocs only required/used pre gcc4.1.1 */
69 old_value = ((location[0] & 0x0000FFFF) << 16) |
70 (location[1] & 0x0000FFFF);
71 value += old_value;
72 #endif
73 location[0] = (location[0] & 0xFFFF0000) |
74 (value >> 16);
75 location[1] = (location[1] & 0xFFFF0000) |
76 (value & 0xFFFF);
77 #if __GNUC__ < 4
78 pr_debug("R_MICROBLAZE_64 (%08lx->%08lx)\n",
79 old_value, value);
80 #endif
81 break;
82
83 case R_MICROBLAZE_64_PCREL:
84 #if __GNUC__ < 4
85 old_value = (location[0] & 0xFFFF) << 16 |
86 (location[1] & 0xFFFF);
87 value -= old_value;
88 #endif
89 value -= (unsigned long int)(location) + 4;
90 location[0] = (location[0] & 0xFFFF0000) |
91 (value >> 16);
92 location[1] = (location[1] & 0xFFFF0000) |
93 (value & 0xFFFF);
94 pr_debug("R_MICROBLAZE_64_PCREL (%08lx)\n",
95 value);
96 break;
97
98 case R_MICROBLAZE_32_PCREL_LO:
99 pr_debug("R_MICROBLAZE_32_PCREL_LO\n");
100 break;
101
102 case R_MICROBLAZE_64_NONE:
103 pr_debug("R_MICROBLAZE_64_NONE\n");
104 break;
105
106 case R_MICROBLAZE_NONE:
107 pr_debug("R_MICROBLAZE_NONE\n");
108 break;
109
110 default:
111 printk(KERN_ERR "module %s: "
112 "Unknown relocation: %u\n",
113 module->name,
114 ELF32_R_TYPE(rela[i].r_info));
115 return -ENOEXEC;
116 }
117 }
118 return 0;
119 }
120
module_finalize(const Elf32_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * module)121 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
122 struct module *module)
123 {
124 flush_dcache();
125 return 0;
126 }
127