xref: /openbmc/linux/arch/m68k/kernel/module.c (revision b6dcefde)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file COPYING in the main directory of this archive
4  * for more details.
5  */
6 
7 #include <linux/moduleloader.h>
8 #include <linux/elf.h>
9 #include <linux/vmalloc.h>
10 #include <linux/fs.h>
11 #include <linux/string.h>
12 #include <linux/kernel.h>
13 
14 #if 0
15 #define DEBUGP printk
16 #else
17 #define DEBUGP(fmt...)
18 #endif
19 
20 #ifdef CONFIG_MODULES
21 
22 void *module_alloc(unsigned long size)
23 {
24 	if (size == 0)
25 		return NULL;
26 	return vmalloc(size);
27 }
28 
29 
30 /* Free memory returned from module_alloc */
31 void module_free(struct module *mod, void *module_region)
32 {
33 	vfree(module_region);
34 }
35 
36 /* We don't need anything special. */
37 int module_frob_arch_sections(Elf_Ehdr *hdr,
38 			      Elf_Shdr *sechdrs,
39 			      char *secstrings,
40 			      struct module *mod)
41 {
42 	return 0;
43 }
44 
45 int apply_relocate(Elf32_Shdr *sechdrs,
46 		   const char *strtab,
47 		   unsigned int symindex,
48 		   unsigned int relsec,
49 		   struct module *me)
50 {
51 	unsigned int i;
52 	Elf32_Rel *rel = (void *)sechdrs[relsec].sh_addr;
53 	Elf32_Sym *sym;
54 	uint32_t *location;
55 
56 	DEBUGP("Applying relocate section %u to %u\n", relsec,
57 	       sechdrs[relsec].sh_info);
58 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
59 		/* This is where to make the change */
60 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
61 			+ rel[i].r_offset;
62 		/* This is the symbol it is referring to.  Note that all
63 		   undefined symbols have been resolved.  */
64 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
65 			+ ELF32_R_SYM(rel[i].r_info);
66 
67 		switch (ELF32_R_TYPE(rel[i].r_info)) {
68 		case R_68K_32:
69 			/* We add the value into the location given */
70 			*location += sym->st_value;
71 			break;
72 		case R_68K_PC32:
73 			/* Add the value, subtract its postition */
74 			*location += sym->st_value - (uint32_t)location;
75 			break;
76 		default:
77 			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
78 			       me->name, ELF32_R_TYPE(rel[i].r_info));
79 			return -ENOEXEC;
80 		}
81 	}
82 	return 0;
83 }
84 
85 int apply_relocate_add(Elf32_Shdr *sechdrs,
86 		       const char *strtab,
87 		       unsigned int symindex,
88 		       unsigned int relsec,
89 		       struct module *me)
90 {
91 	unsigned int i;
92 	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
93 	Elf32_Sym *sym;
94 	uint32_t *location;
95 
96 	DEBUGP("Applying relocate_add section %u to %u\n", relsec,
97 	       sechdrs[relsec].sh_info);
98 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
99 		/* This is where to make the change */
100 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
101 			+ rel[i].r_offset;
102 		/* This is the symbol it is referring to.  Note that all
103 		   undefined symbols have been resolved.  */
104 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
105 			+ ELF32_R_SYM(rel[i].r_info);
106 
107 		switch (ELF32_R_TYPE(rel[i].r_info)) {
108 		case R_68K_32:
109 			/* We add the value into the location given */
110 			*location = rel[i].r_addend + sym->st_value;
111 			break;
112 		case R_68K_PC32:
113 			/* Add the value, subtract its postition */
114 			*location = rel[i].r_addend + sym->st_value - (uint32_t)location;
115 			break;
116 		default:
117 			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
118 			       me->name, ELF32_R_TYPE(rel[i].r_info));
119 			return -ENOEXEC;
120 		}
121 	}
122 	return 0;
123 }
124 
125 int module_finalize(const Elf_Ehdr *hdr,
126 		    const Elf_Shdr *sechdrs,
127 		    struct module *mod)
128 {
129 	module_fixup(mod, mod->arch.fixup_start, mod->arch.fixup_end);
130 
131 	return 0;
132 }
133 
134 void module_arch_cleanup(struct module *mod)
135 {
136 }
137 
138 #endif /* CONFIG_MODULES */
139 
140 void module_fixup(struct module *mod, struct m68k_fixup_info *start,
141 		  struct m68k_fixup_info *end)
142 {
143 	struct m68k_fixup_info *fixup;
144 
145 	for (fixup = start; fixup < end; fixup++) {
146 		switch (fixup->type) {
147 		case m68k_fixup_memoffset:
148 			*(u32 *)fixup->addr = m68k_memoffset;
149 			break;
150 		case m68k_fixup_vnode_shift:
151 			*(u16 *)fixup->addr += m68k_virt_to_node_shift;
152 			break;
153 		}
154 	}
155 }
156