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42381bf1 LFT |
1 | /* |
2 | * Kernel module support for Nios II. | |
3 | * | |
4 | * Copyright (C) 2004 Microtronix Datacom Ltd. | |
5 | * Written by Wentao Xu <xuwentao@microtronix.com> | |
6 | * Copyright (C) 2001, 2003 Rusty Russell | |
7 | * | |
8 | * This file is subject to the terms and conditions of the GNU General | |
9 | * Public License. See the file COPYING in the main directory of this | |
10 | * archive for more details. | |
11 | */ | |
12 | ||
13 | #include <linux/moduleloader.h> | |
14 | #include <linux/elf.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/vmalloc.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/fs.h> | |
19 | #include <linux/string.h> | |
20 | #include <linux/kernel.h> | |
21 | ||
22 | #include <asm/pgtable.h> | |
23 | #include <asm/cacheflush.h> | |
24 | ||
25 | /* | |
26 | * Modules should NOT be allocated with kmalloc for (obvious) reasons. | |
27 | * But we do it for now to avoid relocation issues. CALL26/PCREL26 cannot reach | |
28 | * from 0x80000000 (vmalloc area) to 0xc00000000 (kernel) (kmalloc returns | |
29 | * addresses in 0xc0000000) | |
30 | */ | |
31 | void *module_alloc(unsigned long size) | |
32 | { | |
33 | if (size == 0) | |
34 | return NULL; | |
35 | return kmalloc(size, GFP_KERNEL); | |
36 | } | |
37 | ||
38 | /* Free memory returned from module_alloc */ | |
be1f221c | 39 | void module_memfree(void *module_region) |
42381bf1 LFT |
40 | { |
41 | kfree(module_region); | |
42 | } | |
43 | ||
44 | int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, | |
45 | unsigned int symindex, unsigned int relsec, | |
46 | struct module *mod) | |
47 | { | |
48 | unsigned int i; | |
49 | Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr; | |
50 | ||
51 | pr_debug("Applying relocate section %u to %u\n", relsec, | |
52 | sechdrs[relsec].sh_info); | |
53 | ||
54 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) { | |
55 | /* This is where to make the change */ | |
56 | uint32_t word; | |
57 | uint32_t *loc | |
58 | = ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
59 | + rela[i].r_offset); | |
60 | /* This is the symbol it is referring to. Note that all | |
61 | undefined symbols have been resolved. */ | |
62 | Elf32_Sym *sym | |
63 | = ((Elf32_Sym *)sechdrs[symindex].sh_addr | |
64 | + ELF32_R_SYM(rela[i].r_info)); | |
65 | uint32_t v = sym->st_value + rela[i].r_addend; | |
66 | ||
67 | pr_debug("reltype %d 0x%x name:<%s>\n", | |
68 | ELF32_R_TYPE(rela[i].r_info), | |
69 | rela[i].r_offset, strtab + sym->st_name); | |
70 | ||
71 | switch (ELF32_R_TYPE(rela[i].r_info)) { | |
72 | case R_NIOS2_NONE: | |
73 | break; | |
74 | case R_NIOS2_BFD_RELOC_32: | |
75 | *loc += v; | |
76 | break; | |
77 | case R_NIOS2_PCREL16: | |
78 | v -= (uint32_t)loc + 4; | |
79 | if ((int32_t)v > 0x7fff || | |
80 | (int32_t)v < -(int32_t)0x8000) { | |
81 | pr_err("module %s: relocation overflow\n", | |
82 | mod->name); | |
83 | return -ENOEXEC; | |
84 | } | |
85 | word = *loc; | |
86 | *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) | | |
87 | (word & 0x3f); | |
88 | break; | |
89 | case R_NIOS2_CALL26: | |
90 | if (v & 3) { | |
91 | pr_err("module %s: dangerous relocation\n", | |
92 | mod->name); | |
93 | return -ENOEXEC; | |
94 | } | |
95 | if ((v >> 28) != ((uint32_t)loc >> 28)) { | |
96 | pr_err("module %s: relocation overflow\n", | |
97 | mod->name); | |
98 | return -ENOEXEC; | |
99 | } | |
100 | *loc = (*loc & 0x3f) | ((v >> 2) << 6); | |
101 | break; | |
102 | case R_NIOS2_HI16: | |
103 | word = *loc; | |
104 | *loc = ((((word >> 22) << 16) | | |
105 | ((v >> 16) & 0xffff)) << 6) | (word & 0x3f); | |
106 | break; | |
107 | case R_NIOS2_LO16: | |
108 | word = *loc; | |
109 | *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) | | |
110 | (word & 0x3f); | |
111 | break; | |
112 | case R_NIOS2_HIADJ16: | |
113 | { | |
114 | Elf32_Addr word2; | |
115 | ||
116 | word = *loc; | |
117 | word2 = ((v >> 16) + ((v >> 15) & 1)) & 0xffff; | |
118 | *loc = ((((word >> 22) << 16) | word2) << 6) | | |
119 | (word & 0x3f); | |
120 | } | |
121 | break; | |
122 | ||
123 | default: | |
124 | pr_err("module %s: Unknown reloc: %u\n", | |
125 | mod->name, ELF32_R_TYPE(rela[i].r_info)); | |
126 | return -ENOEXEC; | |
127 | } | |
128 | } | |
129 | ||
130 | return 0; | |
131 | } | |
132 | ||
133 | int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, | |
134 | struct module *me) | |
135 | { | |
136 | flush_cache_all(); | |
137 | return 0; | |
138 | } |