xref: /openbmc/linux/arch/sparc/kernel/module.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /* Kernel module help for sparc32.
2  *
3  * Copyright (C) 2001 Rusty Russell.
4  * Copyright (C) 2002 David S. Miller.
5  */
6 
7 #include <linux/moduleloader.h>
8 #include <linux/kernel.h>
9 #include <linux/elf.h>
10 #include <linux/vmalloc.h>
11 #include <linux/fs.h>
12 #include <linux/string.h>
13 
14 void *module_alloc(unsigned long size)
15 {
16 	void *ret;
17 
18 	/* We handle the zero case fine, unlike vmalloc */
19 	if (size == 0)
20 		return NULL;
21 
22 	ret = vmalloc(size);
23 	if (!ret)
24 		ret = ERR_PTR(-ENOMEM);
25 	else
26 		memset(ret, 0, size);
27 
28 	return ret;
29 }
30 
31 /* Free memory returned from module_core_alloc/module_init_alloc */
32 void module_free(struct module *mod, void *module_region)
33 {
34 	vfree(module_region);
35 	/* FIXME: If module_region == mod->init_region, trim exception
36            table entries. */
37 }
38 
39 /* Make generic code ignore STT_REGISTER dummy undefined symbols,
40  * and replace references to .func with func as in ppc64's dedotify.
41  */
42 int module_frob_arch_sections(Elf_Ehdr *hdr,
43 			      Elf_Shdr *sechdrs,
44 			      char *secstrings,
45 			      struct module *mod)
46 {
47 	unsigned int symidx;
48 	Elf32_Sym *sym;
49 	char *strtab;
50 	int i;
51 
52 	for (symidx = 0; sechdrs[symidx].sh_type != SHT_SYMTAB; symidx++) {
53 		if (symidx == hdr->e_shnum-1) {
54 			printk("%s: no symtab found.\n", mod->name);
55 			return -ENOEXEC;
56 		}
57 	}
58 	sym = (Elf32_Sym *)sechdrs[symidx].sh_addr;
59 	strtab = (char *)sechdrs[sechdrs[symidx].sh_link].sh_addr;
60 
61 	for (i = 1; i < sechdrs[symidx].sh_size / sizeof(Elf_Sym); i++) {
62 		if (sym[i].st_shndx == SHN_UNDEF) {
63 			if (ELF32_ST_TYPE(sym[i].st_info) == STT_REGISTER)
64 				sym[i].st_shndx = SHN_ABS;
65 			else {
66 				char *name = strtab + sym[i].st_name;
67 				if (name[0] == '.')
68 					memmove(name, name+1, strlen(name));
69 			}
70 		}
71 	}
72 	return 0;
73 }
74 
75 int apply_relocate(Elf32_Shdr *sechdrs,
76 		   const char *strtab,
77 		   unsigned int symindex,
78 		   unsigned int relsec,
79 		   struct module *me)
80 {
81 	printk(KERN_ERR "module %s: non-ADD RELOCATION unsupported\n",
82 	       me->name);
83 	return -ENOEXEC;
84 }
85 
86 int apply_relocate_add(Elf32_Shdr *sechdrs,
87 		       const char *strtab,
88 		       unsigned int symindex,
89 		       unsigned int relsec,
90 		       struct module *me)
91 {
92 	unsigned int i;
93 	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
94 	Elf32_Sym *sym;
95 	u8 *location;
96 	u32 *loc32;
97 
98 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
99 		Elf32_Addr v;
100 
101 		/* This is where to make the change */
102 		location = (u8 *)sechdrs[sechdrs[relsec].sh_info].sh_addr
103 			+ rel[i].r_offset;
104 		loc32 = (u32 *) location;
105 		/* This is the symbol it is referring to.  Note that all
106 		   undefined symbols have been resolved.  */
107 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
108 			+ ELF32_R_SYM(rel[i].r_info);
109 		v = sym->st_value + rel[i].r_addend;
110 
111 		switch (ELF32_R_TYPE(rel[i].r_info)) {
112 		case R_SPARC_32:
113 			location[0] = v >> 24;
114 			location[1] = v >> 16;
115 			location[2] = v >>  8;
116 			location[3] = v >>  0;
117 			break;
118 
119 		case R_SPARC_WDISP30:
120 			v -= (Elf32_Addr) location;
121 			*loc32 = (*loc32 & ~0x3fffffff) |
122 				((v >> 2) & 0x3fffffff);
123 			break;
124 
125 		case R_SPARC_WDISP22:
126 			v -= (Elf32_Addr) location;
127 			*loc32 = (*loc32 & ~0x3fffff) |
128 				((v >> 2) & 0x3fffff);
129 			break;
130 
131 		case R_SPARC_LO10:
132 			*loc32 = (*loc32 & ~0x3ff) | (v & 0x3ff);
133 			break;
134 
135 		case R_SPARC_HI22:
136 			*loc32 = (*loc32 & ~0x3fffff) |
137 				((v >> 10) & 0x3fffff);
138 			break;
139 
140 		default:
141 			printk(KERN_ERR "module %s: Unknown relocation: %x\n",
142 			       me->name,
143 			       (int) (ELF32_R_TYPE(rel[i].r_info) & 0xff));
144 			return -ENOEXEC;
145 		};
146 	}
147 	return 0;
148 }
149 
150 int module_finalize(const Elf_Ehdr *hdr,
151 		    const Elf_Shdr *sechdrs,
152 		    struct module *me)
153 {
154 	return 0;
155 }
156 
157 void module_arch_cleanup(struct module *mod)
158 {
159 }
160