2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
9 #include <linux/module.h>
10 #include <linux/moduleloader.h>
11 #include <linux/kernel.h>
12 #include <linux/elf.h>
13 #include <linux/vmalloc.h>
14 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include <asm/unwind.h>
19 static inline void arc_write_me(unsigned short *addr, unsigned long value)
21 *addr = (value & 0xffff0000) >> 16;
22 *(addr + 1) = (value & 0xffff);
26 * This gets called before relocation loop in generic loader
27 * Make a note of the section index of unwinding section
29 int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
30 char *secstr, struct module *mod)
32 #ifdef CONFIG_ARC_DW2_UNWIND
33 mod->arch.unw_sec_idx = 0;
34 mod->arch.unw_info = NULL;
35 mod->arch.secstr = secstr;
40 void module_arch_cleanup(struct module *mod)
42 #ifdef CONFIG_ARC_DW2_UNWIND
43 if (mod->arch.unw_info)
44 unwind_remove_table(mod->arch.unw_info, 0);
48 int apply_relocate_add(Elf32_Shdr *sechdrs,
50 unsigned int symindex, /* sec index for sym tbl */
51 unsigned int relsec, /* sec index for relo sec */
52 struct module *module)
55 Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr;
56 Elf32_Sym *sym_entry, *sym_sec;
57 Elf32_Addr relocation;
59 Elf32_Addr sec_to_patch;
63 tgtsec = sechdrs[relsec].sh_info;
64 sec_to_patch = sechdrs[tgtsec].sh_addr;
65 sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr;
66 n = sechdrs[relsec].sh_size / sizeof(*rel_entry);
68 pr_debug("\n========== Module Sym reloc ===========================\n");
69 pr_debug("Section to fixup %x\n", sec_to_patch);
70 pr_debug("=========================================================\n");
71 pr_debug("rela->r_off | rela->addend | sym->st_value | ADDR | VALUE\n");
72 pr_debug("=========================================================\n");
74 /* Loop thru entries in relocation section */
75 for (i = 0; i < n; i++) {
77 /* This is where to make the change */
78 location = sec_to_patch + rel_entry[i].r_offset;
80 /* This is the symbol it is referring to. Note that all
81 undefined symbols have been resolved. */
82 sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info);
84 relocation = sym_entry->st_value + rel_entry[i].r_addend;
86 pr_debug("\t%x\t\t%x\t\t%x %x %x [%s]\n",
87 rel_entry[i].r_offset, rel_entry[i].r_addend,
88 sym_entry->st_value, location, relocation,
89 strtab + sym_entry->st_name);
91 /* This assumes modules are built with -mlong-calls
92 * so any branches/jumps are absolute 32 bit jmps
93 * global data access again is abs 32 bit.
94 * Both of these are handled by same relocation type
96 relo_type = ELF32_R_TYPE(rel_entry[i].r_info);
98 if (likely(R_ARC_32_ME == relo_type)) /* ME ( S + A ) */
99 arc_write_me((unsigned short *)location, relocation);
100 else if (R_ARC_32 == relo_type) /* ( S + A ) */
101 *((Elf32_Addr *) location) = relocation;
102 else if (R_ARC_32_PCREL == relo_type) /* ( S + A ) - PDATA ) */
103 *((Elf32_Addr *) location) = relocation - location;
109 if (strcmp(module->arch.secstr+sechdrs[tgtsec].sh_name, ".eh_frame") == 0)
110 module->arch.unw_sec_idx = tgtsec;
115 pr_err("%s: unknown relocation: %u\n",
116 module->name, ELF32_R_TYPE(rel_entry[i].r_info));
121 /* Just before lift off: After sections have been relocated, we add the
122 * dwarf section to unwinder table pool
123 * This couldn't be done in module_frob_arch_sections() because
124 * relocations had not been applied by then
126 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
129 #ifdef CONFIG_ARC_DW2_UNWIND
131 int unwsec = mod->arch.unw_sec_idx;
134 unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr,
135 sechdrs[unwsec].sh_size);
136 mod->arch.unw_info = unw;