diff options
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 200 |
1 files changed, 117 insertions, 83 deletions
diff --git a/kernel/module.c b/kernel/module.c index c3a9e972d3b2..4bf30e4b3eaa 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1,9 +1,8 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* - Copyright (C) 2002 Richard Henderson - Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. - -*/ + * Copyright (C) 2002 Richard Henderson + * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. + */ #define INCLUDE_VERMAGIC @@ -86,7 +85,8 @@ * 1) List of modules (also safely readable with preempt_disable), * 2) module_use links, * 3) module_addr_min/module_addr_max. - * (delete and add uses RCU list operations). */ + * (delete and add uses RCU list operations). + */ DEFINE_MUTEX(module_mutex); EXPORT_SYMBOL_GPL(module_mutex); static LIST_HEAD(modules); @@ -615,8 +615,10 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms, return false; } -/* Find an exported symbol and return it, along with, (optional) crc and - * (optional) module which owns it. Needs preempt disabled or module_mutex. */ +/* + * Find an exported symbol and return it, along with, (optional) crc and + * (optional) module which owns it. Needs preempt disabled or module_mutex. + */ static const struct kernel_symbol *find_symbol(const char *name, struct module **owner, const s32 **crc, @@ -756,13 +758,12 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) } /** - * is_module_percpu_address - test whether address is from module static percpu + * is_module_percpu_address() - test whether address is from module static percpu * @addr: address to test * * Test whether @addr belongs to module static percpu area. * - * RETURNS: - * %true if @addr is from module static percpu area + * Return: %true if @addr is from module static percpu area */ bool is_module_percpu_address(unsigned long addr) { @@ -986,11 +987,10 @@ static int try_stop_module(struct module *mod, int flags, int *forced) } /** - * module_refcount - return the refcount or -1 if unloading - * + * module_refcount() - return the refcount or -1 if unloading * @mod: the module we're checking * - * Returns: + * Return: * -1 if the module is in the process of unloading * otherwise the number of references in the kernel to the module */ @@ -1675,8 +1675,10 @@ static void remove_sect_attrs(struct module *mod) if (mod->sect_attrs) { sysfs_remove_group(&mod->mkobj.kobj, &mod->sect_attrs->grp); - /* We are positive that no one is using any sect attrs - * at this point. Deallocate immediately. */ + /* + * We are positive that no one is using any sect attrs + * at this point. Deallocate immediately. + */ free_sect_attrs(mod->sect_attrs); mod->sect_attrs = NULL; } @@ -1924,7 +1926,6 @@ static int mod_sysfs_init(struct module *mod) if (err) mod_kobject_put(mod); - /* delay uevent until full sysfs population */ out: return err; } @@ -1961,7 +1962,6 @@ static int mod_sysfs_setup(struct module *mod, add_sect_attrs(mod, info); add_notes_attrs(mod, info); - kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); return 0; out_unreg_modinfo_attrs: @@ -2247,8 +2247,10 @@ static void free_module(struct module *mod) mod_sysfs_teardown(mod); - /* We leave it in list to prevent duplicate loads, but make sure - * that noone uses it while it's being deconstructed. */ + /* + * We leave it in list to prevent duplicate loads, but make sure + * that noone uses it while it's being deconstructed. + */ mutex_lock(&module_mutex); mod->state = MODULE_STATE_UNFORMED; mutex_unlock(&module_mutex); @@ -2365,8 +2367,10 @@ static int simplify_symbols(struct module *mod, const struct load_info *info) if (!strncmp(name, "__gnu_lto", 9)) break; - /* We compiled with -fno-common. These are not - supposed to happen. */ + /* + * We compiled with -fno-common. These are not + * supposed to happen. + */ pr_debug("Common symbol: %s\n", name); pr_warn("%s: please compile with -fno-common\n", mod->name); @@ -2469,16 +2473,20 @@ static long get_offset(struct module *mod, unsigned int *size, return ret; } -/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld - might -- code, read-only data, read-write data, small data. Tally - sizes, and place the offsets into sh_entsize fields: high bit means it - belongs in init. */ +/* + * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld + * might -- code, read-only data, read-write data, small data. Tally + * sizes, and place the offsets into sh_entsize fields: high bit means it + * belongs in init. + */ static void layout_sections(struct module *mod, struct load_info *info) { static unsigned long const masks[][2] = { - /* NOTE: all executable code must be the first section + /* + * NOTE: all executable code must be the first section * in this array; otherwise modify the text_size - * finder in the two loops below */ + * finder in the two loops below + */ { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, @@ -2924,40 +2932,43 @@ static int module_sig_check(struct load_info *info, int flags) /* We truncate the module to discard the signature */ info->len -= markerlen; err = mod_verify_sig(mod, info); + if (!err) { + info->sig_ok = true; + return 0; + } } + /* + * We don't permit modules to be loaded into the trusted kernels + * without a valid signature on them, but if we're not enforcing, + * certain errors are non-fatal. + */ switch (err) { - case 0: - info->sig_ok = true; - return 0; - - /* We don't permit modules to be loaded into trusted kernels - * without a valid signature on them, but if we're not - * enforcing, certain errors are non-fatal. - */ case -ENODATA: - reason = "Loading of unsigned module"; - goto decide; + reason = "unsigned module"; + break; case -ENOPKG: - reason = "Loading of module with unsupported crypto"; - goto decide; + reason = "module with unsupported crypto"; + break; case -ENOKEY: - reason = "Loading of module with unavailable key"; - decide: - if (is_module_sig_enforced()) { - pr_notice("%s: %s is rejected\n", info->name, reason); - return -EKEYREJECTED; - } - - return security_locked_down(LOCKDOWN_MODULE_SIGNATURE); + reason = "module with unavailable key"; + break; - /* All other errors are fatal, including nomem, unparseable - * signatures and signature check failures - even if signatures - * aren't required. - */ default: + /* + * All other errors are fatal, including lack of memory, + * unparseable signatures, and signature check failures -- + * even if signatures aren't required. + */ return err; } + + if (is_module_sig_enforced()) { + pr_notice("%s: loading of %s is rejected\n", info->name, reason); + return -EKEYREJECTED; + } + + return security_locked_down(LOCKDOWN_MODULE_SIGNATURE); } #else /* !CONFIG_MODULE_SIG */ static int module_sig_check(struct load_info *info, int flags) @@ -3090,8 +3101,10 @@ static int rewrite_section_headers(struct load_info *info, int flags) return -ENOEXEC; } - /* Mark all sections sh_addr with their address in the - temporary image. */ + /* + * Mark all sections sh_addr with their address in the + * temporary image. + */ shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; #ifndef CONFIG_MODULE_UNLOAD @@ -3525,9 +3538,11 @@ static struct module *layout_and_allocate(struct load_info *info, int flags) if (ndx) info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; - /* 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. */ + /* + * 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(info->mod, info); layout_symtab(info->mod, info); @@ -3671,6 +3686,9 @@ static noinline int do_init_module(struct module *mod) blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_LIVE, mod); + /* Delay uevent until module has finished its init routine */ + kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); + /* * We need to finish all async code before the module init sequence * is done. This has potential to deadlock. For example, a newly @@ -3815,8 +3833,10 @@ static int complete_formation(struct module *mod, struct load_info *info) module_enable_nx(mod); module_enable_x(mod); - /* Mark state as coming so strong_try_module_get() ignores us, - * but kallsyms etc. can see us. */ + /* + * Mark state as coming so strong_try_module_get() ignores us, + * but kallsyms etc. can see us. + */ mod->state = MODULE_STATE_COMING; mutex_unlock(&module_mutex); @@ -3863,8 +3883,10 @@ static int unknown_module_param_cb(char *param, char *val, const char *modname, return 0; } -/* Allocate and load the module: note that size of section 0 is always - zero, and we rely on this for optional sections. */ +/* + * Allocate and load the module: note that size of section 0 is always + * zero, and we rely on this for optional sections. + */ static int load_module(struct load_info *info, const char __user *uargs, int flags) { @@ -3938,8 +3960,10 @@ static int load_module(struct load_info *info, const char __user *uargs, init_param_lock(mod); - /* Now we've got everything in the final locations, we can - * find optional sections. */ + /* + * Now we've got everything in the final locations, we can + * find optional sections. + */ err = find_module_sections(mod, info); if (err) goto free_unload; @@ -4027,6 +4051,7 @@ static int load_module(struct load_info *info, const char __user *uargs, MODULE_STATE_GOING, mod); klp_module_going(mod); bug_cleanup: + mod->state = MODULE_STATE_GOING; /* module_bug_cleanup needs module_mutex protection */ mutex_lock(&module_mutex); module_bug_cleanup(mod); @@ -4152,8 +4177,10 @@ static const char *find_kallsyms_symbol(struct module *mod, bestval = kallsyms_symbol_value(&kallsyms->symtab[best]); - /* Scan for closest preceding symbol, and next symbol. (ELF - starts real symbols at 1). */ + /* + * Scan for closest preceding symbol, and next symbol. (ELF + * starts real symbols at 1). + */ for (i = 1; i < kallsyms->num_symtab; i++) { const Elf_Sym *sym = &kallsyms->symtab[i]; unsigned long thisval = kallsyms_symbol_value(sym); @@ -4161,8 +4188,10 @@ static const char *find_kallsyms_symbol(struct module *mod, if (sym->st_shndx == SHN_UNDEF) continue; - /* We ignore unnamed symbols: they're uninformative - * and inserted at a whim. */ + /* + * We ignore unnamed symbols: they're uninformative + * and inserted at a whim. + */ if (*kallsyms_symbol_name(kallsyms, i) == '\0' || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i))) continue; @@ -4192,8 +4221,10 @@ void * __weak dereference_module_function_descriptor(struct module *mod, return ptr; } -/* For kallsyms to ask for address resolution. NULL means not found. Careful - * not to lock to avoid deadlock on oopses, simply disable preemption. */ +/* + * For kallsyms to ask for address resolution. NULL means not found. Careful + * not to lock to avoid deadlock on oopses, simply disable preemption. + */ const char *module_address_lookup(unsigned long addr, unsigned long *size, unsigned long *offset, @@ -4451,11 +4482,12 @@ static int m_show(struct seq_file *m, void *p) return 0; } -/* Format: modulename size refcount deps address - - Where refcount is a number or -, and deps is a comma-separated list - of depends or -. -*/ +/* + * Format: modulename size refcount deps address + * + * Where refcount is a number or -, and deps is a comma-separated list + * of depends or -. + */ static const struct seq_operations modules_op = { .start = m_start, .next = m_next, @@ -4525,8 +4557,8 @@ out: return e; } -/* - * is_module_address - is this address inside a module? +/** + * is_module_address() - is this address inside a module? * @addr: the address to check. * * See is_module_text_address() if you simply want to see if the address @@ -4543,8 +4575,8 @@ bool is_module_address(unsigned long addr) return ret; } -/* - * __module_address - get the module which contains an address. +/** + * __module_address() - get the module which contains an address. * @addr: the address. * * Must be called with preempt disabled or module mutex held so that @@ -4568,8 +4600,8 @@ struct module *__module_address(unsigned long addr) return mod; } -/* - * is_module_text_address - is this address inside module code? +/** + * is_module_text_address() - is this address inside module code? * @addr: the address to check. * * See is_module_address() if you simply want to see if the address is @@ -4587,8 +4619,8 @@ bool is_module_text_address(unsigned long addr) return ret; } -/* - * __module_text_address - get the module whose code contains an address. +/** + * __module_text_address() - get the module whose code contains an address. * @addr: the address. * * Must be called with preempt disabled or module mutex held so that @@ -4627,8 +4659,10 @@ void print_modules(void) } #ifdef CONFIG_MODVERSIONS -/* Generate the signature for all relevant module structures here. - * If these change, we don't want to try to parse the module. */ +/* + * Generate the signature for all relevant module structures here. + * If these change, we don't want to try to parse the module. + */ void module_layout(struct module *mod, struct modversion_info *ver, struct kernel_param *kp, |