diff options
Diffstat (limited to 'arch/avr32/kernel/module.c')
| -rw-r--r-- | arch/avr32/kernel/module.c | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/arch/avr32/kernel/module.c b/arch/avr32/kernel/module.c new file mode 100644 index 00000000000..dfc32f2817b --- /dev/null +++ b/arch/avr32/kernel/module.c @@ -0,0 +1,324 @@ +/* + * AVR32-specific kernel module loader + * + * Copyright (C) 2005-2006 Atmel Corporation + * + * GOT initialization parts are based on the s390 version + * Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH, + * IBM Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/moduleloader.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/elf.h> +#include <linux/vmalloc.h> + +void *module_alloc(unsigned long size) +{ + if (size == 0) + return NULL; + return vmalloc(size); +} + +void module_free(struct module *mod, void *module_region) +{ + vfree(mod->arch.syminfo); + mod->arch.syminfo = NULL; + + vfree(module_region); + /* FIXME: if module_region == mod->init_region, trim exception + * table entries. */ +} + +static inline int check_rela(Elf32_Rela *rela, struct module *module, + char *strings, Elf32_Sym *symbols) +{ + struct mod_arch_syminfo *info; + + info = module->arch.syminfo + ELF32_R_SYM(rela->r_info); + switch (ELF32_R_TYPE(rela->r_info)) { + case R_AVR32_GOT32: + case R_AVR32_GOT16: + case R_AVR32_GOT8: + case R_AVR32_GOT21S: + case R_AVR32_GOT18SW: /* mcall */ + case R_AVR32_GOT16S: /* ld.w */ + if (rela->r_addend != 0) { + printk(KERN_ERR + "GOT relocation against %s at offset %u with addend\n", + strings + symbols[ELF32_R_SYM(rela->r_info)].st_name, + rela->r_offset); + return -ENOEXEC; + } + if (info->got_offset == -1UL) { + info->got_offset = module->arch.got_size; + module->arch.got_size += sizeof(void *); + } + pr_debug("GOT[%3lu] %s\n", info->got_offset, + strings + symbols[ELF32_R_SYM(rela->r_info)].st_name); + break; + } + + return 0; +} + +int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, + char *secstrings, struct module *module) +{ + Elf32_Shdr *symtab; + Elf32_Sym *symbols; + Elf32_Rela *rela; + char *strings; + int nrela, i, j; + int ret; + + /* Find the symbol table */ + symtab = NULL; + for (i = 0; i < hdr->e_shnum; i++) + switch (sechdrs[i].sh_type) { + case SHT_SYMTAB: + symtab = &sechdrs[i]; + break; + } + if (!symtab) { + printk(KERN_ERR "module %s: no symbol table\n", module->name); + return -ENOEXEC; + } + + /* Allocate room for one syminfo structure per symbol. */ + module->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym); + module->arch.syminfo = vmalloc(module->arch.nsyms + * sizeof(struct mod_arch_syminfo)); + if (!module->arch.syminfo) + return -ENOMEM; + + symbols = (void *)hdr + symtab->sh_offset; + strings = (void *)hdr + sechdrs[symtab->sh_link].sh_offset; + for (i = 0; i < module->arch.nsyms; i++) { + if (symbols[i].st_shndx == SHN_UNDEF && + strcmp(strings + symbols[i].st_name, + "_GLOBAL_OFFSET_TABLE_") == 0) + /* "Define" it as absolute. */ + symbols[i].st_shndx = SHN_ABS; + module->arch.syminfo[i].got_offset = -1UL; + module->arch.syminfo[i].got_initialized = 0; + } + + /* Allocate GOT entries for symbols that need it. */ + module->arch.got_size = 0; + for (i = 0; i < hdr->e_shnum; i++) { + if (sechdrs[i].sh_type != SHT_RELA) + continue; + nrela = sechdrs[i].sh_size / sizeof(Elf32_Rela); + rela = (void *)hdr + sechdrs[i].sh_offset; + for (j = 0; j < nrela; j++) { + ret = check_rela(rela + j, module, + strings, symbols); + if (ret) + goto out_free_syminfo; + } + } + + /* + * Increase core size to make room for GOT and set start + * offset for GOT. + */ + module->core_size = ALIGN(module->core_size, 4); + module->arch.got_offset = module->core_size; + module->core_size += module->arch.got_size; + + return 0; + +out_free_syminfo: + vfree(module->arch.syminfo); + module->arch.syminfo = NULL; + + return ret; +} + +static inline int reloc_overflow(struct module *module, const char *reloc_name, + Elf32_Addr relocation) +{ + printk(KERN_ERR "module %s: Value %lx does not fit relocation %s\n", + module->name, (unsigned long)relocation, reloc_name); + return -ENOEXEC; +} + +#define get_u16(loc) (*((uint16_t *)loc)) +#define put_u16(loc, val) (*((uint16_t *)loc) = (val)) + +int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, + unsigned int symindex, unsigned int relindex, + struct module *module) +{ + Elf32_Shdr *symsec = sechdrs + symindex; + Elf32_Shdr *relsec = sechdrs + relindex; + Elf32_Shdr *dstsec = sechdrs + relsec->sh_info; + Elf32_Rela *rel = (void *)relsec->sh_addr; + unsigned int i; + int ret = 0; + + for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rela); i++, rel++) { + struct mod_arch_syminfo *info; + Elf32_Sym *sym; + Elf32_Addr relocation; + uint32_t *location; + uint32_t value; + + location = (void *)dstsec->sh_addr + rel->r_offset; + sym = (Elf32_Sym *)symsec->sh_addr + ELF32_R_SYM(rel->r_info); + relocation = sym->st_value + rel->r_addend; + + info = module->arch.syminfo + ELF32_R_SYM(rel->r_info); + + /* Initialize GOT entry if necessary */ + switch (ELF32_R_TYPE(rel->r_info)) { + case R_AVR32_GOT32: + case R_AVR32_GOT16: + case R_AVR32_GOT8: + case R_AVR32_GOT21S: + case R_AVR32_GOT18SW: + case R_AVR32_GOT16S: + if (!info->got_initialized) { + Elf32_Addr *gotent; + + gotent = (module->module_core + + module->arch.got_offset + + info->got_offset); + *gotent = relocation; + info->got_initialized = 1; + } + + relocation = info->got_offset; + break; + } + + switch (ELF32_R_TYPE(rel->r_info)) { + case R_AVR32_32: + case R_AVR32_32_CPENT: + *location = relocation; + break; + case R_AVR32_22H_PCREL: + relocation -= (Elf32_Addr)location; + if ((relocation & 0xffe00001) != 0 + && (relocation & 0xffc00001) != 0xffc00000) + return reloc_overflow(module, + "R_AVR32_22H_PCREL", + relocation); + relocation >>= 1; + + value = *location; + value = ((value & 0xe1ef0000) + | (relocation & 0xffff) + | ((relocation & 0x10000) << 4) + | ((relocation & 0x1e0000) << 8)); + *location = value; + break; + case R_AVR32_11H_PCREL: + relocation -= (Elf32_Addr)location; + if ((relocation & 0xfffffc01) != 0 + && (relocation & 0xfffff801) != 0xfffff800) + return reloc_overflow(module, + "R_AVR32_11H_PCREL", + relocation); + value = get_u16(location); + value = ((value & 0xf00c) + | ((relocation & 0x1fe) << 3) + | ((relocation & 0x600) >> 9)); + put_u16(location, value); + break; + case R_AVR32_9H_PCREL: + relocation -= (Elf32_Addr)location; + if ((relocation & 0xffffff01) != 0 + && (relocation & 0xfffffe01) != 0xfffffe00) + return reloc_overflow(module, + "R_AVR32_9H_PCREL", + relocation); + value = get_u16(location); + value = ((value & 0xf00f) + | ((relocation & 0x1fe) << 3)); + put_u16(location, value); + break; + case R_AVR32_9UW_PCREL: + relocation -= ((Elf32_Addr)location) & 0xfffffffc; + if ((relocation & 0xfffffc03) != 0) + return reloc_overflow(module, + "R_AVR32_9UW_PCREL", + relocation); + value = get_u16(location); + value = ((value & 0xf80f) + | ((relocation & 0x1fc) << 2)); + put_u16(location, value); + break; + case R_AVR32_GOTPC: + /* + * R6 = PC - (PC - GOT) + * + * At this point, relocation contains the + * value of PC. Just subtract the value of + * GOT, and we're done. + */ + pr_debug("GOTPC: PC=0x%lx, got_offset=0x%lx, core=0x%p\n", + relocation, module->arch.got_offset, + module->module_core); + relocation -= ((unsigned long)module->module_core + + module->arch.got_offset); + *location = relocation; + break; + case R_AVR32_GOT18SW: + if ((relocation & 0xfffe0003) != 0 + && (relocation & 0xfffc0003) != 0xffff0000) + return reloc_overflow(module, "R_AVR32_GOT18SW", + relocation); + relocation >>= 2; + /* fall through */ + case R_AVR32_GOT16S: + if ((relocation & 0xffff8000) != 0 + && (relocation & 0xffff0000) != 0xffff0000) + return reloc_overflow(module, "R_AVR32_GOT16S", + relocation); + pr_debug("GOT reloc @ 0x%lx -> %lu\n", + rel->r_offset, relocation); + value = *location; + value = ((value & 0xffff0000) + | (relocation & 0xffff)); + *location = value; + break; + + default: + printk(KERN_ERR "module %s: Unknown relocation: %u\n", + module->name, ELF32_R_TYPE(rel->r_info)); + return -ENOEXEC; + } + } + + return ret; +} + +int apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, + unsigned int symindex, unsigned int relindex, + struct module *module) +{ + printk(KERN_ERR "module %s: REL relocations are not supported\n", + module->name); + return -ENOEXEC; +} + +int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, + struct module *module) +{ + vfree(module->arch.syminfo); + module->arch.syminfo = NULL; + + return 0; +} + +void module_arch_cleanup(struct module *module) +{ + +} |