diff options
| -rw-r--r-- | kernel/module.c | 228 |
1 files changed, 125 insertions, 103 deletions
diff --git a/kernel/module.c b/kernel/module.c index 79545bda358a..cb40a4e64a0e 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2148,8 +2148,17 @@ static inline void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr, } #endif -static int copy_and_check(Elf_Ehdr **hdrp, - const void __user *umod, unsigned long len) +struct load_info { + Elf_Ehdr *hdr; + unsigned long len; + Elf_Shdr *sechdrs; + char *secstrings, *args, *strtab; + struct { + unsigned int sym, str, mod, vers, info, pcpu; + } index; +}; + +static int copy_and_check(struct load_info *info, const void __user *umod, unsigned long len) { int err; Elf_Ehdr *hdr; @@ -2159,7 +2168,7 @@ static int copy_and_check(Elf_Ehdr **hdrp, /* Suck in entire file: we'll want most of it. */ /* vmalloc barfs on "unusual" numbers. Check here */ - if (len > 64 * 1024 * 1024 || (hdr = *hdrp = vmalloc(len)) == NULL) + if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL) return -ENOMEM; if (copy_from_user(hdr, umod, len) != 0) { @@ -2181,6 +2190,8 @@ static int copy_and_check(Elf_Ehdr **hdrp, err = -ENOEXEC; goto free_hdr; } + info->hdr = hdr; + info->len = len; return 0; free_hdr: @@ -2188,6 +2199,80 @@ free_hdr: return err; } +/* + * Set up our basic convenience variables (pointers to section headers, + * search for module section index etc), and do some basic section + * verification. + * + * Return the temporary module pointer (we'll replace it with the final + * one when we move the module sections around). + */ +static struct module *setup_load_info(struct load_info *info) +{ + unsigned int i; + struct module *mod; + + /* Set up the convenience variables */ + info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; + info->secstrings = (void *)info->hdr + info->sechdrs[info->hdr->e_shstrndx].sh_offset; + info->sechdrs[0].sh_addr = 0; + + for (i = 1; i < info->hdr->e_shnum; i++) { + if (info->sechdrs[i].sh_type != SHT_NOBITS + && info->len < info->sechdrs[i].sh_offset + info->sechdrs[i].sh_size) + goto truncated; + + /* Mark all sections sh_addr with their address in the + temporary image. */ + info->sechdrs[i].sh_addr = (size_t)info->hdr + info->sechdrs[i].sh_offset; + + /* Internal symbols and strings. */ + if (info->sechdrs[i].sh_type == SHT_SYMTAB) { + info->index.sym = i; + info->index.str = info->sechdrs[i].sh_link; + info->strtab = (char *)info->hdr + info->sechdrs[info->index.str].sh_offset; + } +#ifndef CONFIG_MODULE_UNLOAD + /* Don't load .exit sections */ + if (strstarts(info->secstrings+info->sechdrs[i].sh_name, ".exit")) + info->sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC; +#endif + } + + info->index.mod = find_sec(info->hdr, info->sechdrs, info->secstrings, + ".gnu.linkonce.this_module"); + if (!info->index.mod) { + printk(KERN_WARNING "No module found in object\n"); + return ERR_PTR(-ENOEXEC); + } + /* This is temporary: point mod into copy of data. */ + mod = (void *)info->sechdrs[info->index.mod].sh_addr; + + if (info->index.sym == 0) { + printk(KERN_WARNING "%s: module has no symbols (stripped?)\n", + mod->name); + return ERR_PTR(-ENOEXEC); + } + + info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); + info->index.info = find_sec(info->hdr, info->sechdrs, info->secstrings, ".modinfo"); + info->index.pcpu = find_pcpusec(info->hdr, info->sechdrs, info->secstrings); + + /* Don't keep modinfo and version sections. */ + info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; + info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; + + /* Check module struct version now, before we try to use module. */ + if (!check_modstruct_version(info->sechdrs, info->index.vers, mod)) + return ERR_PTR(-ENOEXEC); + + return mod; + + truncated: + printk(KERN_ERR "Module len %lu truncated\n", info->len); + return ERR_PTR(-ENOEXEC); +} + static int check_modinfo(struct module *mod, const Elf_Shdr *sechdrs, unsigned int infoindex, unsigned int versindex) @@ -2412,13 +2497,7 @@ static noinline struct module *load_module(void __user *umod, unsigned long len, const char __user *uargs) { - Elf_Ehdr *hdr; - Elf_Shdr *sechdrs; - char *secstrings, *args, *strtab = NULL; - unsigned int i; - unsigned int symindex = 0; - unsigned int strindex = 0; - unsigned int modindex, versindex, infoindex, pcpuindex; + struct load_info info = { NULL, }; struct module *mod; long err; unsigned long symoffs, stroffs, *strmap; @@ -2429,80 +2508,28 @@ static noinline struct module *load_module(void __user *umod, DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", umod, len, uargs); - err = copy_and_check(&hdr, umod, len); + err = copy_and_check(&info, umod, len); if (err) return ERR_PTR(err); - /* Convenience variables */ - sechdrs = (void *)hdr + hdr->e_shoff; - secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - sechdrs[0].sh_addr = 0; - - for (i = 1; i < hdr->e_shnum; i++) { - if (sechdrs[i].sh_type != SHT_NOBITS - && len < sechdrs[i].sh_offset + sechdrs[i].sh_size) - goto truncated; - - /* Mark all sections sh_addr with their address in the - temporary image. */ - sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset; - - /* Internal symbols and strings. */ - if (sechdrs[i].sh_type == SHT_SYMTAB) { - symindex = i; - strindex = sechdrs[i].sh_link; - strtab = (char *)hdr + sechdrs[strindex].sh_offset; - } -#ifndef CONFIG_MODULE_UNLOAD - /* Don't load .exit sections */ - if (strstarts(secstrings+sechdrs[i].sh_name, ".exit")) - sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC; -#endif - } - - modindex = find_sec(hdr, sechdrs, secstrings, - ".gnu.linkonce.this_module"); - if (!modindex) { - printk(KERN_WARNING "No module found in object\n"); - err = -ENOEXEC; - goto free_hdr; - } - /* This is temporary: point mod into copy of data. */ - mod = (void *)sechdrs[modindex].sh_addr; - - if (symindex == 0) { - printk(KERN_WARNING "%s: module has no symbols (stripped?)\n", - mod->name); - err = -ENOEXEC; - goto free_hdr; - } - - versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); - infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo"); - pcpuindex = find_pcpusec(hdr, sechdrs, secstrings); - - /* Don't keep modinfo and version sections. */ - sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC; - sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC; - - /* Check module struct version now, before we try to use module. */ - if (!check_modstruct_version(sechdrs, versindex, mod)) { - err = -ENOEXEC; + mod = setup_load_info(&info); + if (IS_ERR(mod)) { + err = PTR_ERR(mod); goto free_hdr; } - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); if (err) goto free_hdr; /* Now copy in args */ - args = strndup_user(uargs, ~0UL >> 1); - if (IS_ERR(args)) { - err = PTR_ERR(args); + info.args = strndup_user(uargs, ~0UL >> 1); + if (IS_ERR(info.args)) { + err = PTR_ERR(info.args); goto free_hdr; } - strmap = kzalloc(BITS_TO_LONGS(sechdrs[strindex].sh_size) + strmap = kzalloc(BITS_TO_LONGS(info.sechdrs[info.index.str].sh_size) * sizeof(long), GFP_KERNEL); if (!strmap) { err = -ENOMEM; @@ -2512,17 +2539,17 @@ static noinline struct module *load_module(void __user *umod, mod->state = MODULE_STATE_COMING; /* Allow arches to frob section contents and sizes. */ - err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod); + err = module_frob_arch_sections(info.hdr, info.sechdrs, info.secstrings, mod); if (err < 0) goto free_mod; - if (pcpuindex) { + if (info.index.pcpu) { /* We have a special allocation for this section. */ - err = percpu_modalloc(mod, sechdrs[pcpuindex].sh_size, - sechdrs[pcpuindex].sh_addralign); + err = percpu_modalloc(mod, info.sechdrs[info.index.pcpu].sh_size, + info.sechdrs[info.index.pcpu].sh_addralign); if (err) goto free_mod; - sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC; + info.sechdrs[info.index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; } /* Keep this around for failure path. */ percpu = mod_percpu(mod); @@ -2530,12 +2557,12 @@ static noinline struct module *load_module(void __user *umod, /* Determine total sizes, and put offsets in sh_entsize. For now this is done generically; there doesn't appear to be any special cases for the architectures. */ - layout_sections(mod, hdr, sechdrs, secstrings); - symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr, - secstrings, &stroffs, strmap); + layout_sections(mod, info.hdr, info.sechdrs, info.secstrings); + symoffs = layout_symtab(mod, info.sechdrs, info.index.sym, info.index.str, info.hdr, + info.secstrings, &stroffs, strmap); /* Allocate and move to the final place */ - mod = move_module(mod, hdr, sechdrs, secstrings, modindex); + mod = move_module(mod, info.hdr, info.sechdrs, info.secstrings, info.index.mod); if (IS_ERR(mod)) { err = PTR_ERR(mod); goto free_percpu; @@ -2548,50 +2575,50 @@ static noinline struct module *load_module(void __user *umod, /* Now we've got everything in the final locations, we can * find optional sections. */ - find_module_sections(mod, hdr, sechdrs, secstrings); + find_module_sections(mod, info.hdr, info.sechdrs, info.secstrings); - err = check_module_license_and_versions(mod, sechdrs); + err = check_module_license_and_versions(mod, info.sechdrs); if (err) goto free_unload; /* Set up MODINFO_ATTR fields */ - setup_modinfo(mod, sechdrs, infoindex); + setup_modinfo(mod, info.sechdrs, info.index.info); /* Fix up syms, so that st_value is a pointer to location. */ - err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex, + err = simplify_symbols(info.sechdrs, info.index.sym, info.strtab, info.index.vers, info.index.pcpu, mod); if (err < 0) goto cleanup; - err = apply_relocations(mod, hdr, sechdrs, symindex, strindex); + err = apply_relocations(mod, info.hdr, info.sechdrs, info.index.sym, info.index.str); if (err < 0) goto cleanup; /* Set up and sort exception table */ - mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table", + mod->extable = section_objs(info.hdr, info.sechdrs, info.secstrings, "__ex_table", sizeof(*mod->extable), &mod->num_exentries); sort_extable(mod->extable, mod->extable + mod->num_exentries); /* Finally, copy percpu area over. */ - percpu_modcopy(mod, (void *)sechdrs[pcpuindex].sh_addr, - sechdrs[pcpuindex].sh_size); + percpu_modcopy(mod, (void *)info.sechdrs[info.index.pcpu].sh_addr, + info.sechdrs[info.index.pcpu].sh_size); - add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex, - symoffs, stroffs, secstrings, strmap); + add_kallsyms(mod, info.sechdrs, info.hdr->e_shnum, info.index.sym, info.index.str, + symoffs, stroffs, info.secstrings, strmap); kfree(strmap); strmap = NULL; if (!mod->taints) - debug = section_objs(hdr, sechdrs, secstrings, "__verbose", + debug = section_objs(info.hdr, info.sechdrs, info.secstrings, "__verbose", sizeof(*debug), &num_debug); - err = module_finalize(hdr, sechdrs, mod); + err = module_finalize(info.hdr, info.sechdrs, mod); if (err < 0) goto cleanup; flush_module_icache(mod); - mod->args = args; + mod->args = info.args; /* Now sew it into the lists so we can get lockdep and oops * info during argument parsing. Noone should access us, since @@ -2625,11 +2652,11 @@ static noinline struct module *load_module(void __user *umod, if (err < 0) goto unlink; - add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); - add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs); + add_sect_attrs(mod, info.hdr->e_shnum, info.secstrings, info.sechdrs); + add_notes_attrs(mod, info.hdr->e_shnum, info.secstrings, info.sechdrs); /* Get rid of temporary copy */ - vfree(hdr); + vfree(info.hdr); trace_module_load(mod); @@ -2657,16 +2684,11 @@ static noinline struct module *load_module(void __user *umod, free_percpu: free_percpu(percpu); free_mod: - kfree(args); + kfree(info.args); kfree(strmap); free_hdr: - vfree(hdr); + vfree(info.hdr); return ERR_PTR(err); - - truncated: - printk(KERN_ERR "Module len %lu truncated\n", len); - err = -ENOEXEC; - goto free_hdr; } /* Call module constructors. */ |