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author | Thiemo Seufer <ths@networkno.de> | 2005-02-21 10:45:09 +0000 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 2005-10-29 19:30:39 +0100 |
commit | 4e6a05fe5f87efd58da16fbf61e1f6329575fcfd (patch) | |
tree | ed16ed0f4f0307373bba6f83e91fc6495add020b /arch/mips/kernel/module.c | |
parent | 7ee8798f3756fc473e63abeba56fae3e192ce71f (diff) | |
download | linux-4e6a05fe5f87efd58da16fbf61e1f6329575fcfd.tar.bz2 |
Improved modules loader, more robust and works on 64bit kernels.
Signed-off-by: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/module.c')
-rw-r--r-- | arch/mips/kernel/module.c | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c index 458af3c7a639..e54a7f442f8a 100644 --- a/arch/mips/kernel/module.c +++ b/arch/mips/kernel/module.c @@ -1,9 +1,345 @@ +/* + * 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> +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) +{ + if (size == 0) + return NULL; + return vmalloc(size); +} + +/* 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) { + 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) { + 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) { |