--- /dev/null
+/*
+ * 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%x, 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%x -> %u\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)
+{
+
+}
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