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 */
module_alloc(unsigned long size)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 */
module_memfree(void * module_region)39 void module_memfree(void *module_region)
40 {
41 kfree(module_region);
42 }
43
apply_relocate_add(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * mod)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
module_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * me)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 }
139