1 /* 2 * Kernel module support for Nios II. 3 * 4 * Copyright (C) 2004 Microtronix Datacom Ltd. 5 * Written by Wentao Xu <xuwentao@microtronix.com> 6 * Copyright (C) 2001, 2003 Rusty Russell 7 * 8 * This file is subject to the terms and conditions of the GNU General 9 * Public License. See the file COPYING in the main directory of this 10 * archive for more details. 11 */ 12 13 #include <linux/moduleloader.h> 14 #include <linux/elf.h> 15 #include <linux/mm.h> 16 #include <linux/vmalloc.h> 17 #include <linux/slab.h> 18 #include <linux/fs.h> 19 #include <linux/string.h> 20 #include <linux/kernel.h> 21 22 #include <asm/cacheflush.h> 23 24 /* 25 * Modules should NOT be allocated with kmalloc for (obvious) reasons. 26 * But we do it for now to avoid relocation issues. CALL26/PCREL26 cannot reach 27 * from 0x80000000 (vmalloc area) to 0xc00000000 (kernel) (kmalloc returns 28 * addresses in 0xc0000000) 29 */ 30 void *module_alloc(unsigned long size) 31 { 32 if (size == 0) 33 return NULL; 34 return kmalloc(size, GFP_KERNEL); 35 } 36 37 /* Free memory returned from module_alloc */ 38 void module_memfree(void *module_region) 39 { 40 kfree(module_region); 41 } 42 43 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, 44 unsigned int symindex, unsigned int relsec, 45 struct module *mod) 46 { 47 unsigned int i; 48 Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr; 49 50 pr_debug("Applying relocate section %u to %u\n", relsec, 51 sechdrs[relsec].sh_info); 52 53 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) { 54 /* This is where to make the change */ 55 uint32_t word; 56 uint32_t *loc 57 = ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr 58 + rela[i].r_offset); 59 /* This is the symbol it is referring to. Note that all 60 undefined symbols have been resolved. */ 61 Elf32_Sym *sym 62 = ((Elf32_Sym *)sechdrs[symindex].sh_addr 63 + ELF32_R_SYM(rela[i].r_info)); 64 uint32_t v = sym->st_value + rela[i].r_addend; 65 66 pr_debug("reltype %d 0x%x name:<%s>\n", 67 ELF32_R_TYPE(rela[i].r_info), 68 rela[i].r_offset, strtab + sym->st_name); 69 70 switch (ELF32_R_TYPE(rela[i].r_info)) { 71 case R_NIOS2_NONE: 72 break; 73 case R_NIOS2_BFD_RELOC_32: 74 *loc += v; 75 break; 76 case R_NIOS2_PCREL16: 77 v -= (uint32_t)loc + 4; 78 if ((int32_t)v > 0x7fff || 79 (int32_t)v < -(int32_t)0x8000) { 80 pr_err("module %s: relocation overflow\n", 81 mod->name); 82 return -ENOEXEC; 83 } 84 word = *loc; 85 *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) | 86 (word & 0x3f); 87 break; 88 case R_NIOS2_CALL26: 89 if (v & 3) { 90 pr_err("module %s: dangerous relocation\n", 91 mod->name); 92 return -ENOEXEC; 93 } 94 if ((v >> 28) != ((uint32_t)loc >> 28)) { 95 pr_err("module %s: relocation overflow\n", 96 mod->name); 97 return -ENOEXEC; 98 } 99 *loc = (*loc & 0x3f) | ((v >> 2) << 6); 100 break; 101 case R_NIOS2_HI16: 102 word = *loc; 103 *loc = ((((word >> 22) << 16) | 104 ((v >> 16) & 0xffff)) << 6) | (word & 0x3f); 105 break; 106 case R_NIOS2_LO16: 107 word = *loc; 108 *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) | 109 (word & 0x3f); 110 break; 111 case R_NIOS2_HIADJ16: 112 { 113 Elf32_Addr word2; 114 115 word = *loc; 116 word2 = ((v >> 16) + ((v >> 15) & 1)) & 0xffff; 117 *loc = ((((word >> 22) << 16) | word2) << 6) | 118 (word & 0x3f); 119 } 120 break; 121 122 default: 123 pr_err("module %s: Unknown reloc: %u\n", 124 mod->name, ELF32_R_TYPE(rela[i].r_info)); 125 return -ENOEXEC; 126 } 127 } 128 129 return 0; 130 } 131 132 int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, 133 struct module *me) 134 { 135 flush_cache_all(); 136 return 0; 137 } 138