xref: /openbmc/linux/arch/m68k/kernel/module.c (revision 384740dc)
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 	/* FIXME: If module_region == mod->init_region, trim exception
35            table entries. */
36 }
37 
38 /* We don't need anything special. */
39 int module_frob_arch_sections(Elf_Ehdr *hdr,
40 			      Elf_Shdr *sechdrs,
41 			      char *secstrings,
42 			      struct module *mod)
43 {
44 	return 0;
45 }
46 
47 int apply_relocate(Elf32_Shdr *sechdrs,
48 		   const char *strtab,
49 		   unsigned int symindex,
50 		   unsigned int relsec,
51 		   struct module *me)
52 {
53 	unsigned int i;
54 	Elf32_Rel *rel = (void *)sechdrs[relsec].sh_addr;
55 	Elf32_Sym *sym;
56 	uint32_t *location;
57 
58 	DEBUGP("Applying relocate section %u to %u\n", relsec,
59 	       sechdrs[relsec].sh_info);
60 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
61 		/* This is where to make the change */
62 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
63 			+ rel[i].r_offset;
64 		/* This is the symbol it is referring to.  Note that all
65 		   undefined symbols have been resolved.  */
66 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
67 			+ ELF32_R_SYM(rel[i].r_info);
68 
69 		switch (ELF32_R_TYPE(rel[i].r_info)) {
70 		case R_68K_32:
71 			/* We add the value into the location given */
72 			*location += sym->st_value;
73 			break;
74 		case R_68K_PC32:
75 			/* Add the value, subtract its postition */
76 			*location += sym->st_value - (uint32_t)location;
77 			break;
78 		default:
79 			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
80 			       me->name, ELF32_R_TYPE(rel[i].r_info));
81 			return -ENOEXEC;
82 		}
83 	}
84 	return 0;
85 }
86 
87 int apply_relocate_add(Elf32_Shdr *sechdrs,
88 		       const char *strtab,
89 		       unsigned int symindex,
90 		       unsigned int relsec,
91 		       struct module *me)
92 {
93 	unsigned int i;
94 	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
95 	Elf32_Sym *sym;
96 	uint32_t *location;
97 
98 	DEBUGP("Applying relocate_add section %u to %u\n", relsec,
99 	       sechdrs[relsec].sh_info);
100 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
101 		/* This is where to make the change */
102 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
103 			+ rel[i].r_offset;
104 		/* This is the symbol it is referring to.  Note that all
105 		   undefined symbols have been resolved.  */
106 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
107 			+ ELF32_R_SYM(rel[i].r_info);
108 
109 		switch (ELF32_R_TYPE(rel[i].r_info)) {
110 		case R_68K_32:
111 			/* We add the value into the location given */
112 			*location = rel[i].r_addend + sym->st_value;
113 			break;
114 		case R_68K_PC32:
115 			/* Add the value, subtract its postition */
116 			*location = rel[i].r_addend + sym->st_value - (uint32_t)location;
117 			break;
118 		default:
119 			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
120 			       me->name, ELF32_R_TYPE(rel[i].r_info));
121 			return -ENOEXEC;
122 		}
123 	}
124 	return 0;
125 }
126 
127 int module_finalize(const Elf_Ehdr *hdr,
128 		    const Elf_Shdr *sechdrs,
129 		    struct module *mod)
130 {
131 	module_fixup(mod, mod->arch.fixup_start, mod->arch.fixup_end);
132 
133 	return 0;
134 }
135 
136 void module_arch_cleanup(struct module *mod)
137 {
138 }
139 
140 #endif /* CONFIG_MODULES */
141 
142 void module_fixup(struct module *mod, struct m68k_fixup_info *start,
143 		  struct m68k_fixup_info *end)
144 {
145 	struct m68k_fixup_info *fixup;
146 
147 	for (fixup = start; fixup < end; fixup++) {
148 		switch (fixup->type) {
149 		case m68k_fixup_memoffset:
150 			*(u32 *)fixup->addr = m68k_memoffset;
151 			break;
152 		case m68k_fixup_vnode_shift:
153 			*(u16 *)fixup->addr += m68k_virt_to_node_shift;
154 			break;
155 		}
156 	}
157 }
158