xref: /openbmc/linux/arch/sparc/kernel/module.c (revision 384740dc)
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 #include <linux/ctype.h>
14 
15 void *module_alloc(unsigned long size)
16 {
17 	void *ret;
18 
19 	/* We handle the zero case fine, unlike vmalloc */
20 	if (size == 0)
21 		return NULL;
22 
23 	ret = vmalloc(size);
24 	if (!ret)
25 		ret = ERR_PTR(-ENOMEM);
26 	else
27 		memset(ret, 0, size);
28 
29 	return ret;
30 }
31 
32 /* Free memory returned from module_core_alloc/module_init_alloc */
33 void module_free(struct module *mod, void *module_region)
34 {
35 	vfree(module_region);
36 	/* FIXME: If module_region == mod->init_region, trim exception
37            table entries. */
38 }
39 
40 /* Make generic code ignore STT_REGISTER dummy undefined symbols,
41  * and replace references to .func with _Func
42  */
43 int module_frob_arch_sections(Elf_Ehdr *hdr,
44 			      Elf_Shdr *sechdrs,
45 			      char *secstrings,
46 			      struct module *mod)
47 {
48 	unsigned int symidx;
49 	Elf32_Sym *sym;
50 	char *strtab;
51 	int i;
52 
53 	for (symidx = 0; sechdrs[symidx].sh_type != SHT_SYMTAB; symidx++) {
54 		if (symidx == hdr->e_shnum-1) {
55 			printk("%s: no symtab found.\n", mod->name);
56 			return -ENOEXEC;
57 		}
58 	}
59 	sym = (Elf32_Sym *)sechdrs[symidx].sh_addr;
60 	strtab = (char *)sechdrs[sechdrs[symidx].sh_link].sh_addr;
61 
62 	for (i = 1; i < sechdrs[symidx].sh_size / sizeof(Elf_Sym); i++) {
63 		if (sym[i].st_shndx == SHN_UNDEF) {
64 			if (ELF32_ST_TYPE(sym[i].st_info) == STT_REGISTER)
65 				sym[i].st_shndx = SHN_ABS;
66 			else {
67 				char *name = strtab + sym[i].st_name;
68 				if (name[0] == '.') {
69 					name[0] = '_';
70 					name[1] = toupper(name[1]);
71 				}
72 			}
73 		}
74 	}
75 	return 0;
76 }
77 
78 int apply_relocate(Elf32_Shdr *sechdrs,
79 		   const char *strtab,
80 		   unsigned int symindex,
81 		   unsigned int relsec,
82 		   struct module *me)
83 {
84 	printk(KERN_ERR "module %s: non-ADD RELOCATION unsupported\n",
85 	       me->name);
86 	return -ENOEXEC;
87 }
88 
89 int apply_relocate_add(Elf32_Shdr *sechdrs,
90 		       const char *strtab,
91 		       unsigned int symindex,
92 		       unsigned int relsec,
93 		       struct module *me)
94 {
95 	unsigned int i;
96 	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
97 	Elf32_Sym *sym;
98 	u8 *location;
99 	u32 *loc32;
100 
101 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
102 		Elf32_Addr v;
103 
104 		/* This is where to make the change */
105 		location = (u8 *)sechdrs[sechdrs[relsec].sh_info].sh_addr
106 			+ rel[i].r_offset;
107 		loc32 = (u32 *) location;
108 		/* This is the symbol it is referring to.  Note that all
109 		   undefined symbols have been resolved.  */
110 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
111 			+ ELF32_R_SYM(rel[i].r_info);
112 		v = sym->st_value + rel[i].r_addend;
113 
114 		switch (ELF32_R_TYPE(rel[i].r_info)) {
115 		case R_SPARC_32:
116 		case R_SPARC_UA32:
117 			location[0] = v >> 24;
118 			location[1] = v >> 16;
119 			location[2] = v >>  8;
120 			location[3] = v >>  0;
121 			break;
122 
123 		case R_SPARC_WDISP30:
124 			v -= (Elf32_Addr) location;
125 			*loc32 = (*loc32 & ~0x3fffffff) |
126 				((v >> 2) & 0x3fffffff);
127 			break;
128 
129 		case R_SPARC_WDISP22:
130 			v -= (Elf32_Addr) location;
131 			*loc32 = (*loc32 & ~0x3fffff) |
132 				((v >> 2) & 0x3fffff);
133 			break;
134 
135 		case R_SPARC_LO10:
136 			*loc32 = (*loc32 & ~0x3ff) | (v & 0x3ff);
137 			break;
138 
139 		case R_SPARC_HI22:
140 			*loc32 = (*loc32 & ~0x3fffff) |
141 				((v >> 10) & 0x3fffff);
142 			break;
143 
144 		default:
145 			printk(KERN_ERR "module %s: Unknown relocation: %x\n",
146 			       me->name,
147 			       (int) (ELF32_R_TYPE(rel[i].r_info) & 0xff));
148 			return -ENOEXEC;
149 		};
150 	}
151 	return 0;
152 }
153 
154 int module_finalize(const Elf_Ehdr *hdr,
155 		    const Elf_Shdr *sechdrs,
156 		    struct module *me)
157 {
158 	return 0;
159 }
160 
161 void module_arch_cleanup(struct module *mod)
162 {
163 }
164