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