diff options
| -rw-r--r-- | kernel/module.c | 224 |
1 files changed, 125 insertions, 99 deletions
diff --git a/kernel/module.c b/kernel/module.c index 60cdd0459eac..fb11e2a88233 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -115,6 +115,8 @@ struct load_info { unsigned long len; Elf_Shdr *sechdrs; char *secstrings, *args, *strtab; + unsigned long *strmap; + unsigned long symoffs, stroffs; struct { unsigned int sym, str, mod, vers, info, pcpu; } index; @@ -402,7 +404,8 @@ static int percpu_modalloc(struct module *mod, mod->percpu = __alloc_reserved_percpu(size, align); if (!mod->percpu) { printk(KERN_WARNING - "Could not allocate %lu bytes percpu data\n", size); + "%s: Could not allocate %lu bytes percpu data\n", + mod->name, size); return -ENOMEM; } mod->percpu_size = size; @@ -2032,10 +2035,7 @@ static unsigned long layout_symtab(struct module *mod, return symoffs; } -static void add_kallsyms(struct module *mod, struct load_info *info, - unsigned long symoffs, - unsigned long stroffs, - unsigned long *strmap) +static void add_kallsyms(struct module *mod, struct load_info *info) { unsigned int i, ndst; const Elf_Sym *src; @@ -2052,21 +2052,22 @@ static void add_kallsyms(struct module *mod, struct load_info *info, for (i = 0; i < mod->num_symtab; i++) mod->symtab[i].st_info = elf_type(&mod->symtab[i], info); - mod->core_symtab = dst = mod->module_core + symoffs; + mod->core_symtab = dst = mod->module_core + info->symoffs; src = mod->symtab; *dst = *src; for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) { if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) continue; dst[ndst] = *src; - dst[ndst].st_name = bitmap_weight(strmap, dst[ndst].st_name); + dst[ndst].st_name = bitmap_weight(info->strmap, + dst[ndst].st_name); ++ndst; } mod->core_num_syms = ndst; - mod->core_strtab = s = mod->module_core + stroffs; + mod->core_strtab = s = mod->module_core + info->stroffs; for (*s = 0, i = 1; i < info->sechdrs[info->index.str].sh_size; ++i) - if (test_bit(i, strmap)) + if (test_bit(i, info->strmap)) *++s = mod->strtab[i]; } #else @@ -2082,10 +2083,7 @@ static inline unsigned long layout_symtab(struct module *mod, return 0; } -static void add_kallsyms(struct module *mod, struct load_info *info, - unsigned long symoffs, - unsigned long stroffs, - unsigned long *strmap) +static void add_kallsyms(struct module *mod, struct load_info *info) { } #endif /* CONFIG_KALLSYMS */ @@ -2150,8 +2148,10 @@ static inline void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr, } #endif -/* Sets info->hdr and info->len. */ -static int copy_and_check(struct load_info *info, const void __user *umod, unsigned long len) +/* Sets info->hdr, info->len and info->args. */ +static int copy_and_check(struct load_info *info, + const void __user *umod, unsigned long len, + const char __user *uargs) { int err; Elf_Ehdr *hdr; @@ -2183,6 +2183,14 @@ static int copy_and_check(struct load_info *info, const void __user *umod, unsig err = -ENOEXEC; goto free_hdr; } + + /* Now copy in args */ + info->args = strndup_user(uargs, ~0UL >> 1); + if (IS_ERR(info->args)) { + err = PTR_ERR(info->args); + goto free_hdr; + } + info->hdr = hdr; info->len = len; return 0; @@ -2192,6 +2200,12 @@ free_hdr: return err; } +static void free_copy(struct load_info *info) +{ + kfree(info->args); + vfree(info->hdr); +} + static int rewrite_section_headers(struct load_info *info) { unsigned int i; @@ -2385,9 +2399,9 @@ static void find_module_sections(struct module *mod, Elf_Ehdr *hdr, mod->name); } -static struct module *move_module(struct module *mod, - Elf_Ehdr *hdr, Elf_Shdr *sechdrs, - const char *secstrings, unsigned modindex) +static int move_module(struct module *mod, + Elf_Ehdr *hdr, Elf_Shdr *sechdrs, + const char *secstrings, unsigned modindex) { int i; void *ptr; @@ -2401,7 +2415,7 @@ static struct module *move_module(struct module *mod, */ kmemleak_not_leak(ptr); if (!ptr) - return ERR_PTR(-ENOMEM); + return -ENOMEM; memset(ptr, 0, mod->core_size); mod->module_core = ptr; @@ -2416,7 +2430,7 @@ static struct module *move_module(struct module *mod, kmemleak_ignore(ptr); if (!ptr && mod->init_size) { module_free(mod, mod->module_core); - return ERR_PTR(-ENOMEM); + return -ENOMEM; } memset(ptr, 0, mod->init_size); mod->module_init = ptr; @@ -2443,10 +2457,8 @@ static struct module *move_module(struct module *mod, DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name); } - /* Module has been moved. */ - mod = (void *)sechdrs[modindex].sh_addr; - kmemleak_load_module(mod, hdr, sechdrs, secstrings); - return mod; + + return 0; } static int check_module_license_and_versions(struct module *mod, @@ -2503,87 +2515,107 @@ static void flush_module_icache(const struct module *mod) set_fs(old_fs); } -/* Allocate and load the module: note that size of section 0 is always - zero, and we rely on this for optional sections. */ -static noinline struct module *load_module(void __user *umod, - unsigned long len, - const char __user *uargs) +static struct module *layout_and_allocate(struct load_info *info) { - struct load_info info = { NULL, }; + /* Module within temporary copy. */ struct module *mod; - long err; - unsigned long symoffs, stroffs, *strmap; - void __percpu *percpu; - struct _ddebug *debug = NULL; - unsigned int num_debug = 0; + int err; - DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", - umod, len, uargs); + mod = setup_load_info(info); + if (IS_ERR(mod)) + return mod; - err = copy_and_check(&info, umod, len); + err = check_modinfo(mod, info->sechdrs, info->index.info, info->index.vers); if (err) return ERR_PTR(err); - mod = setup_load_info(&info); - if (IS_ERR(mod)) { - err = PTR_ERR(mod); - goto free_hdr; - } - - err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); - if (err) - goto free_hdr; - - /* Now copy in 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(info.sechdrs[info.index.str].sh_size) - * sizeof(long), GFP_KERNEL); - if (!strmap) { - err = -ENOMEM; - goto free_mod; - } - - mod->state = MODULE_STATE_COMING; - /* Allow arches to frob section contents and sizes. */ - err = module_frob_arch_sections(info.hdr, info.sechdrs, info.secstrings, mod); + err = module_frob_arch_sections(info->hdr, info->sechdrs, info->secstrings, mod); if (err < 0) - goto free_mod; + goto free_args; - if (info.index.pcpu) { + if (info->index.pcpu) { /* We have a special allocation for this section. */ - err = percpu_modalloc(mod, info.sechdrs[info.index.pcpu].sh_size, - info.sechdrs[info.index.pcpu].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; - info.sechdrs[info.index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; + goto free_args; + info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; } - /* Keep this around for failure path. */ - percpu = mod_percpu(mod); /* 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, info.hdr, info.sechdrs, info.secstrings); - symoffs = layout_symtab(mod, info.sechdrs, info.index.sym, info.index.str, info.hdr, - info.secstrings, &stroffs, strmap); + layout_sections(mod, info->hdr, info->sechdrs, info->secstrings); + + info->strmap = kzalloc(BITS_TO_LONGS(info->sechdrs[info->index.str].sh_size) + * sizeof(long), GFP_KERNEL); + if (!info->strmap) { + err = -ENOMEM; + goto free_percpu; + } + info->symoffs = layout_symtab(mod, info->sechdrs, info->index.sym, info->index.str, info->hdr, + info->secstrings, &info->stroffs, info->strmap); /* Allocate and move to the final place */ - mod = move_module(mod, info.hdr, info.sechdrs, info.secstrings, info.index.mod); + err = move_module(mod, info->hdr, info->sechdrs, info->secstrings, info->index.mod); + if (err) + goto free_strmap; + + /* Module has been copied to its final place now: return it. */ + mod = (void *)info->sechdrs[info->index.mod].sh_addr; + kmemleak_load_module(mod, info->hdr, info->sechdrs, info->secstrings); + return mod; + +free_strmap: + kfree(info->strmap); +free_percpu: + percpu_modfree(mod); +free_args: + kfree(info->args); + return ERR_PTR(err); +} + +/* mod is no longer valid after this! */ +static void module_deallocate(struct module *mod, struct load_info *info) +{ + kfree(info->strmap); + percpu_modfree(mod); + module_free(mod, mod->module_init); + module_free(mod, mod->module_core); +} + +/* Allocate and load the module: note that size of section 0 is always + zero, and we rely on this for optional sections. */ +static noinline struct module *load_module(void __user *umod, + unsigned long len, + const char __user *uargs) +{ + struct load_info info = { NULL, }; + struct module *mod; + long err; + struct _ddebug *debug = NULL; + unsigned int num_debug = 0; + + DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", + umod, len, uargs); + + /* Copy in the blobs from userspace, check they are vaguely sane. */ + err = copy_and_check(&info, umod, len, uargs); + if (err) + return ERR_PTR(err); + + /* Figure out module layout, and allocate all the memory. */ + mod = layout_and_allocate(&info); if (IS_ERR(mod)) { err = PTR_ERR(mod); - goto free_percpu; + goto free_copy; } /* Now we've moved module, initialize linked lists, etc. */ err = module_unload_init(mod); if (err) - goto free_init; + goto free_module; /* Now we've got everything in the final locations, we can * find optional sections. */ @@ -2600,11 +2632,11 @@ static noinline struct module *load_module(void __user *umod, err = simplify_symbols(info.sechdrs, info.index.sym, info.strtab, info.index.vers, info.index.pcpu, mod); if (err < 0) - goto cleanup; + goto free_modinfo; err = apply_relocations(mod, info.hdr, info.sechdrs, info.index.sym, info.index.str); if (err < 0) - goto cleanup; + goto free_modinfo; /* Set up and sort exception table */ mod->extable = section_objs(info.hdr, info.sechdrs, info.secstrings, "__ex_table", @@ -2615,9 +2647,7 @@ static noinline struct module *load_module(void __user *umod, percpu_modcopy(mod, (void *)info.sechdrs[info.index.pcpu].sh_addr, info.sechdrs[info.index.pcpu].sh_size); - add_kallsyms(mod, &info, symoffs, stroffs, strmap); - kfree(strmap); - strmap = NULL; + add_kallsyms(mod, &info); if (!mod->taints) debug = section_objs(info.hdr, info.sechdrs, info.secstrings, "__verbose", @@ -2625,12 +2655,14 @@ static noinline struct module *load_module(void __user *umod, err = module_finalize(info.hdr, info.sechdrs, mod); if (err < 0) - goto cleanup; + goto free_modinfo; flush_module_icache(mod); mod->args = info.args; + mod->state = MODULE_STATE_COMING; + /* Now sew it into the lists so we can get lockdep and oops * info during argument parsing. Noone should access us, since * strong_try_module_get() will fail. @@ -2666,8 +2698,9 @@ static noinline struct module *load_module(void __user *umod, 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(info.hdr); + /* Get rid of temporary copy and strmap. */ + kfree(info.strmap); + free_copy(&info); trace_module_load(mod); @@ -2684,21 +2717,14 @@ static noinline struct module *load_module(void __user *umod, mutex_unlock(&module_mutex); synchronize_sched(); module_arch_cleanup(mod); - cleanup: + free_modinfo: free_modinfo(mod); free_unload: module_unload_free(mod); - free_init: - module_free(mod, mod->module_init); - module_free(mod, mod->module_core); - /* mod will be freed with core. Don't access it beyond this line! */ - free_percpu: - free_percpu(percpu); - free_mod: - kfree(info.args); - kfree(strmap); - free_hdr: - vfree(info.hdr); + free_module: + module_deallocate(mod, &info); + free_copy: + free_copy(&info); return ERR_PTR(err); } |