/* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Copyright (C) 2001 Rusty Russell. * Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org) * Copyright (C) 2005 Thiemo Seufer */ #undef DEBUG #include <linux/moduleloader.h> #include <linux/elf.h> #include <linux/vmalloc.h> #include <linux/slab.h> #include <linux/fs.h> #include <linux/string.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/spinlock.h> #include <asm/pgtable.h> /* MODULE_START */ struct mips_hi16 { struct mips_hi16 *next; Elf_Addr *addr; Elf_Addr value; }; static struct mips_hi16 *mips_hi16_list; static LIST_HEAD(dbe_list); static DEFINE_SPINLOCK(dbe_lock); void *module_alloc(unsigned long size) { #ifdef MODULE_START struct vm_struct *area; size = PAGE_ALIGN(size); if (!size) return NULL; area = __get_vm_area(size, VM_ALLOC, MODULE_START, MODULE_END); if (!area) return NULL; return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL); #else if (size == 0) return NULL; return vmalloc(size); #endif } /* Free memory returned from module_alloc */ void module_free(struct module *mod, void *module_region) { vfree(module_region); /* FIXME: If module_region == mod->init_region, trim exception table entries. */ } int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod) { return 0; } static int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v) { return 0; } static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v) { *location += v; return 0; } static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v) { *location = v; return 0; } static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v) { if (v % 4) { printk(KERN_ERR "module %s: dangerous relocation\n", me->name); return -ENOEXEC; } if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { printk(KERN_ERR "module %s: relocation overflow\n", me->name); return -ENOEXEC; } *location = (*location & ~0x03ffffff) | ((*location + (v >> 2)) & 0x03ffffff); return 0; } static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v) { if (v % 4) { printk(KERN_ERR "module %s: dangerous relocation\n", me->name); return -ENOEXEC; } if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { printk(KERN_ERR "module %s: relocation overflow\n", me->name); return -ENOEXEC; } *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff); return 0; } static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v) { struct mips_hi16 *n; /* * We cannot relocate this one now because we don't know the value of * the carry we need to add. Save the information, and let LO16 do the * actual relocation. */ n = kmalloc(sizeof *n, GFP_KERNEL); if (!n) return -ENOMEM; n->addr = (Elf_Addr *)location; n->value = v; n->next = mips_hi16_list; mips_hi16_list = n; return 0; } static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v) { *location = (*location & 0xffff0000) | ((((long long) v + 0x8000LL) >> 16) & 0xffff); return 0; } static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v) { unsigned long insnlo = *location; Elf_Addr val, vallo; /* Sign extend the addend we extract from the lo insn. */ vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000; if (mips_hi16_list != NULL) { struct mips_hi16 *l; l = mips_hi16_list; while (l != NULL) { struct mips_hi16 *next; unsigned long insn; /* * The value for the HI16 had best be the same. */ if (v != l->value) goto out_danger; /* * Do the HI16 relocation. Note that we actually don't * need to know anything about the LO16 itself, except * where to find the low 16 bits of the addend needed * by the LO16. */ insn = *l->addr; val = ((insn & 0xffff) << 16) + vallo; val += v; /* * Account for the sign extension that will happen in * the low bits. */ val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff; insn = (insn & ~0xffff) | val; *l->addr = insn; next = l->next; kfree(l); l = next; } mips_hi16_list = NULL; } /* * Ok, we're done with the HI16 relocs. Now deal with the LO16. */ val = v + vallo; insnlo = (insnlo & ~0xffff) | (val & 0xffff); *location = insnlo; return 0; out_danger: printk(KERN_ERR "module %s: dangerous " "relocation\n", me->name); return -ENOEXEC; } static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v) { *location = (*location & 0xffff0000) | (v & 0xffff); return 0; } static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v) { *(Elf_Addr *)location = v; return 0; } static int apply_r_mips_higher_rela(struct module *me, u32 *location, Elf_Addr v) { *location = (*location & 0xffff0000) | ((((long long) v + 0x80008000LL) >> 32) & 0xffff); return 0; } static int apply_r_mips_highest_rela(struct module *me, u32 *location, Elf_Addr v) { *location = (*location & 0xffff0000) | ((((long long) v + 0x800080008000LL) >> 48) & 0xffff); return 0; } static int (*reloc_handlers_rel[]) (struct module *me, u32 *location, Elf_Addr v) = { [R_MIPS_NONE] = apply_r_mips_none, [R_MIPS_32] = apply_r_mips_32_rel, [R_MIPS_26] = apply_r_mips_26_rel, [R_MIPS_HI16] = apply_r_mips_hi16_rel, [R_MIPS_LO16] = apply_r_mips_lo16_rel }; static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, Elf_Addr v) = { [R_MIPS_NONE] = apply_r_mips_none, [R_MIPS_32] = apply_r_mips_32_rela, [R_MIPS_26] = apply_r_mips_26_rela, [R_MIPS_HI16] = apply_r_mips_hi16_rela, [R_MIPS_LO16] = apply_r_mips_lo16_rela, [R_MIPS_64] = apply_r_mips_64_rela, [R_MIPS_HIGHER] = apply_r_mips_higher_rela, [R_MIPS_HIGHEST] = apply_r_mips_highest_rela }; int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr; Elf_Sym *sym; u32 *location; unsigned int i; Elf_Addr v; int res; pr_debug("Applying relocate section %u to %u\n", relsec, sechdrs[relsec].sh_info); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[i].r_offset; /* This is the symbol it is referring to */ sym = (Elf_Sym *)sechdrs[symindex].sh_addr + ELF_MIPS_R_SYM(rel[i]); if (!sym->st_value) { /* Ignore unresolved weak symbol */ if (ELF_ST_BIND(sym->st_info) == STB_WEAK) continue; printk(KERN_WARNING "%s: Unknown symbol %s\n", me->name, strtab + sym->st_name); return -ENOENT; } v = sym->st_value; res = reloc_handlers_rel[ELF_MIPS_R_TYPE(rel[i])](me, location, v); if (res) return res; } return 0; } int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr; Elf_Sym *sym; u32 *location; unsigned int i; Elf_Addr v; int res; pr_debug("Applying relocate section %u to %u\n", relsec, sechdrs[relsec].sh_info); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[i].r_offset; /* This is the symbol it is referring to */ sym = (Elf_Sym *)sechdrs[symindex].sh_addr + ELF_MIPS_R_SYM(rel[i]); if (!sym->st_value) { /* Ignore unresolved weak symbol */ if (ELF_ST_BIND(sym->st_info) == STB_WEAK) continue; printk(KERN_WARNING "%s: Unknown symbol %s\n", me->name, strtab + sym->st_name); return -ENOENT; } v = sym->st_value + rel[i].r_addend; res = reloc_handlers_rela[ELF_MIPS_R_TYPE(rel[i])](me, location, v); if (res) return res; } return 0; } /* Given an address, look for it in the module exception tables. */ const struct exception_table_entry *search_module_dbetables(unsigned long addr) { unsigned long flags; const struct exception_table_entry *e = NULL; struct mod_arch_specific *dbe; spin_lock_irqsave(&dbe_lock, flags); list_for_each_entry(dbe, &dbe_list, dbe_list) { e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr); if (e) break; } spin_unlock_irqrestore(&dbe_lock, flags); /* Now, if we found one, we are running inside it now, hence we cannot unload the module, hence no refcnt needed. */ return e; } /* Put in dbe list if neccessary. */ int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { const Elf_Shdr *s; char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; INIT_LIST_HEAD(&me->arch.dbe_list); for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { if (strcmp("__dbe_table", secstrings + s->sh_name) != 0) continue; me->arch.dbe_start = (void *)s->sh_addr; me->arch.dbe_end = (void *)s->sh_addr + s->sh_size; spin_lock_irq(&dbe_lock); list_add(&me->arch.dbe_list, &dbe_list); spin_unlock_irq(&dbe_lock); } return 0; } void module_arch_cleanup(struct module *mod) { spin_lock_irq(&dbe_lock); list_del(&mod->arch.dbe_list); spin_unlock_irq(&dbe_lock); }