| Vineet Gupta | fa1c3ff | 2013-01-29 19:28:05 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| 3 | * |
| 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. |
| 7 | */ |
| 8 | |
| 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> |
| 15 | #include <linux/fs.h> |
| 16 | #include <linux/string.h> |
| 17 | |
| 18 | static inline void arc_write_me(unsigned short *addr, unsigned long value) |
| 19 | { |
| 20 | *addr = (value & 0xffff0000) >> 16; |
| 21 | *(addr + 1) = (value & 0xffff); |
| 22 | } |
| 23 | |
| 24 | int apply_relocate_add(Elf32_Shdr *sechdrs, |
| 25 | const char *strtab, |
| 26 | unsigned int symindex, /* sec index for sym tbl */ |
| 27 | unsigned int relsec, /* sec index for relo sec */ |
| 28 | struct module *module) |
| 29 | { |
| 30 | int i, n; |
| 31 | Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr; |
| 32 | Elf32_Sym *sym_entry, *sym_sec; |
| 33 | Elf32_Addr relocation; |
| 34 | Elf32_Addr location; |
| 35 | Elf32_Addr sec_to_patch; |
| 36 | int relo_type; |
| 37 | |
| 38 | sec_to_patch = sechdrs[sechdrs[relsec].sh_info].sh_addr; |
| 39 | sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr; |
| 40 | n = sechdrs[relsec].sh_size / sizeof(*rel_entry); |
| 41 | |
| 42 | pr_debug("\n========== Module Sym reloc ===========================\n"); |
| 43 | pr_debug("Section to fixup %x\n", sec_to_patch); |
| 44 | pr_debug("=========================================================\n"); |
| 45 | pr_debug("rela->r_off | rela->addend | sym->st_value | ADDR | VALUE\n"); |
| 46 | pr_debug("=========================================================\n"); |
| 47 | |
| 48 | /* Loop thru entries in relocation section */ |
| 49 | for (i = 0; i < n; i++) { |
| 50 | |
| 51 | /* This is where to make the change */ |
| 52 | location = sec_to_patch + rel_entry[i].r_offset; |
| 53 | |
| 54 | /* This is the symbol it is referring to. Note that all |
| 55 | undefined symbols have been resolved. */ |
| 56 | sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info); |
| 57 | |
| 58 | relocation = sym_entry->st_value + rel_entry[i].r_addend; |
| 59 | |
| 60 | pr_debug("\t%x\t\t%x\t\t%x %x %x [%s]\n", |
| 61 | rel_entry[i].r_offset, rel_entry[i].r_addend, |
| 62 | sym_entry->st_value, location, relocation, |
| 63 | strtab + sym_entry->st_name); |
| 64 | |
| 65 | /* This assumes modules are built with -mlong-calls |
| 66 | * so any branches/jumps are absolute 32 bit jmps |
| 67 | * global data access again is abs 32 bit. |
| 68 | * Both of these are handled by same relocation type |
| 69 | */ |
| 70 | relo_type = ELF32_R_TYPE(rel_entry[i].r_info); |
| 71 | |
| 72 | if (likely(R_ARC_32_ME == relo_type)) |
| 73 | arc_write_me((unsigned short *)location, relocation); |
| 74 | else if (R_ARC_32 == relo_type) |
| 75 | *((Elf32_Addr *) location) = relocation; |
| 76 | else |
| 77 | goto relo_err; |
| 78 | |
| 79 | } |
| 80 | return 0; |
| 81 | |
| 82 | relo_err: |
| 83 | pr_err("%s: unknown relocation: %u\n", |
| 84 | module->name, ELF32_R_TYPE(rel_entry[i].r_info)); |
| 85 | return -ENOEXEC; |
| 86 | |
| 87 | } |