| /* |
| * 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/mm.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 <linux/jump_label.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 |
| return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END, |
| GFP_KERNEL, PAGE_KERNEL, -1, |
| __builtin_return_address(0)); |
| #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); |
| } |
| |
| 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) { |
| pr_err("module %s: dangerous R_MIPS_26 REL 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) { |
| pr_err("module %s: dangerous R_MIPS_26 RELArelocation\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: |
| pr_err("module %s: dangerous R_MIPS_LO16 REL 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 (IS_ERR_VALUE(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 (IS_ERR_VALUE(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 necessary. */ |
| 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; |
| |
| /* Make jump label nops. */ |
| jump_label_apply_nops(me); |
| |
| 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); |
| } |