From cfc1d277891eb499b3b5354df33b30f598683e90 Mon Sep 17 00:00:00 2001 From: Aaron Tomlin Date: Tue, 22 Mar 2022 14:03:31 +0000 Subject: module: Move all into module/ No functional changes. This patch moves all module related code into a separate directory, modifies each file name and creates a new Makefile. Note: this effort is in preparation to refactor core module code. Reviewed-by: Christophe Leroy Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain --- kernel/module/Makefile | 12 + kernel/module/decompress.c | 273 +++ kernel/module/internal.h | 50 + kernel/module/main.c | 4810 ++++++++++++++++++++++++++++++++++++++++++++ kernel/module/signing.c | 45 + 5 files changed, 5190 insertions(+) create mode 100644 kernel/module/Makefile create mode 100644 kernel/module/decompress.c create mode 100644 kernel/module/internal.h create mode 100644 kernel/module/main.c create mode 100644 kernel/module/signing.c (limited to 'kernel/module') diff --git a/kernel/module/Makefile b/kernel/module/Makefile new file mode 100644 index 000000000000..cdd5c61b8c7f --- /dev/null +++ b/kernel/module/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for linux kernel module support +# + +# These are called from save_stack_trace() on slub debug path, +# and produce insane amounts of uninteresting coverage. +KCOV_INSTRUMENT_module.o := n + +obj-y += main.o +obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o +obj-$(CONFIG_MODULE_SIG) += signing.o diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c new file mode 100644 index 000000000000..d14d6443225a --- /dev/null +++ b/kernel/module/decompress.c @@ -0,0 +1,273 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2021 Google LLC. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" + +static int module_extend_max_pages(struct load_info *info, unsigned int extent) +{ + struct page **new_pages; + + new_pages = kvmalloc_array(info->max_pages + extent, + sizeof(info->pages), GFP_KERNEL); + if (!new_pages) + return -ENOMEM; + + memcpy(new_pages, info->pages, info->max_pages * sizeof(info->pages)); + kvfree(info->pages); + info->pages = new_pages; + info->max_pages += extent; + + return 0; +} + +static struct page *module_get_next_page(struct load_info *info) +{ + struct page *page; + int error; + + if (info->max_pages == info->used_pages) { + error = module_extend_max_pages(info, info->used_pages); + if (error) + return ERR_PTR(error); + } + + page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); + if (!page) + return ERR_PTR(-ENOMEM); + + info->pages[info->used_pages++] = page; + return page; +} + +#ifdef CONFIG_MODULE_COMPRESS_GZIP +#include +#define MODULE_COMPRESSION gzip +#define MODULE_DECOMPRESS_FN module_gzip_decompress + +/* + * Calculate length of the header which consists of signature, header + * flags, time stamp and operating system ID (10 bytes total), plus + * an optional filename. + */ +static size_t module_gzip_header_len(const u8 *buf, size_t size) +{ + const u8 signature[] = { 0x1f, 0x8b, 0x08 }; + size_t len = 10; + + if (size < len || memcmp(buf, signature, sizeof(signature))) + return 0; + + if (buf[3] & 0x08) { + do { + /* + * If we can't find the end of the file name we must + * be dealing with a corrupted file. + */ + if (len == size) + return 0; + } while (buf[len++] != '\0'); + } + + return len; +} + +static ssize_t module_gzip_decompress(struct load_info *info, + const void *buf, size_t size) +{ + struct z_stream_s s = { 0 }; + size_t new_size = 0; + size_t gzip_hdr_len; + ssize_t retval; + int rc; + + gzip_hdr_len = module_gzip_header_len(buf, size); + if (!gzip_hdr_len) { + pr_err("not a gzip compressed module\n"); + return -EINVAL; + } + + s.next_in = buf + gzip_hdr_len; + s.avail_in = size - gzip_hdr_len; + + s.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); + if (!s.workspace) + return -ENOMEM; + + rc = zlib_inflateInit2(&s, -MAX_WBITS); + if (rc != Z_OK) { + pr_err("failed to initialize decompressor: %d\n", rc); + retval = -EINVAL; + goto out; + } + + do { + struct page *page = module_get_next_page(info); + if (!page) { + retval = -ENOMEM; + goto out_inflate_end; + } + + s.next_out = kmap(page); + s.avail_out = PAGE_SIZE; + rc = zlib_inflate(&s, 0); + kunmap(page); + + new_size += PAGE_SIZE - s.avail_out; + } while (rc == Z_OK); + + if (rc != Z_STREAM_END) { + pr_err("decompression failed with status %d\n", rc); + retval = -EINVAL; + goto out_inflate_end; + } + + retval = new_size; + +out_inflate_end: + zlib_inflateEnd(&s); +out: + kfree(s.workspace); + return retval; +} +#elif CONFIG_MODULE_COMPRESS_XZ +#include +#define MODULE_COMPRESSION xz +#define MODULE_DECOMPRESS_FN module_xz_decompress + +static ssize_t module_xz_decompress(struct load_info *info, + const void *buf, size_t size) +{ + static const u8 signature[] = { 0xfd, '7', 'z', 'X', 'Z', 0 }; + struct xz_dec *xz_dec; + struct xz_buf xz_buf; + enum xz_ret xz_ret; + size_t new_size = 0; + ssize_t retval; + + if (size < sizeof(signature) || + memcmp(buf, signature, sizeof(signature))) { + pr_err("not an xz compressed module\n"); + return -EINVAL; + } + + xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1); + if (!xz_dec) + return -ENOMEM; + + xz_buf.in_size = size; + xz_buf.in = buf; + xz_buf.in_pos = 0; + + do { + struct page *page = module_get_next_page(info); + if (!page) { + retval = -ENOMEM; + goto out; + } + + xz_buf.out = kmap(page); + xz_buf.out_pos = 0; + xz_buf.out_size = PAGE_SIZE; + xz_ret = xz_dec_run(xz_dec, &xz_buf); + kunmap(page); + + new_size += xz_buf.out_pos; + } while (xz_buf.out_pos == PAGE_SIZE && xz_ret == XZ_OK); + + if (xz_ret != XZ_STREAM_END) { + pr_err("decompression failed with status %d\n", xz_ret); + retval = -EINVAL; + goto out; + } + + retval = new_size; + + out: + xz_dec_end(xz_dec); + return retval; +} +#else +#error "Unexpected configuration for CONFIG_MODULE_DECOMPRESS" +#endif + +int module_decompress(struct load_info *info, const void *buf, size_t size) +{ + unsigned int n_pages; + ssize_t data_size; + int error; + + /* + * Start with number of pages twice as big as needed for + * compressed data. + */ + n_pages = DIV_ROUND_UP(size, PAGE_SIZE) * 2; + error = module_extend_max_pages(info, n_pages); + + data_size = MODULE_DECOMPRESS_FN(info, buf, size); + if (data_size < 0) { + error = data_size; + goto err; + } + + info->hdr = vmap(info->pages, info->used_pages, VM_MAP, PAGE_KERNEL); + if (!info->hdr) { + error = -ENOMEM; + goto err; + } + + info->len = data_size; + return 0; + +err: + module_decompress_cleanup(info); + return error; +} + +void module_decompress_cleanup(struct load_info *info) +{ + int i; + + if (info->hdr) + vunmap(info->hdr); + + for (i = 0; i < info->used_pages; i++) + __free_page(info->pages[i]); + + kvfree(info->pages); + + info->pages = NULL; + info->max_pages = info->used_pages = 0; +} + +#ifdef CONFIG_SYSFS +static ssize_t compression_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%s\n", __stringify(MODULE_COMPRESSION)); +} +static struct kobj_attribute module_compression_attr = __ATTR_RO(compression); + +static int __init module_decompress_sysfs_init(void) +{ + int error; + + error = sysfs_create_file(&module_kset->kobj, + &module_compression_attr.attr); + if (error) + pr_warn("Failed to create 'compression' attribute"); + + return 0; +} +late_initcall(module_decompress_sysfs_init); +#endif diff --git a/kernel/module/internal.h b/kernel/module/internal.h new file mode 100644 index 000000000000..8c381c99062f --- /dev/null +++ b/kernel/module/internal.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* Module internals + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include + +struct load_info { + const char *name; + /* pointer to module in temporary copy, freed at end of load_module() */ + struct module *mod; + Elf_Ehdr *hdr; + unsigned long len; + Elf_Shdr *sechdrs; + char *secstrings, *strtab; + unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs; + struct _ddebug *debug; + unsigned int num_debug; + bool sig_ok; +#ifdef CONFIG_KALLSYMS + unsigned long mod_kallsyms_init_off; +#endif +#ifdef CONFIG_MODULE_DECOMPRESS + struct page **pages; + unsigned int max_pages; + unsigned int used_pages; +#endif + struct { + unsigned int sym, str, mod, vers, info, pcpu; + } index; +}; + +extern int mod_verify_sig(const void *mod, struct load_info *info); + +#ifdef CONFIG_MODULE_DECOMPRESS +int module_decompress(struct load_info *info, const void *buf, size_t size); +void module_decompress_cleanup(struct load_info *info); +#else +static inline int module_decompress(struct load_info *info, + const void *buf, size_t size) +{ + return -EOPNOTSUPP; +} +static inline void module_decompress_cleanup(struct load_info *info) +{ +} +#endif diff --git a/kernel/module/main.c b/kernel/module/main.c new file mode 100644 index 000000000000..1a17f02f69a0 --- /dev/null +++ b/kernel/module/main.c @@ -0,0 +1,4810 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2002 Richard Henderson + * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. + */ + +#define INCLUDE_VERMAGIC + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "internal.h" + +#define CREATE_TRACE_POINTS +#include + +#ifndef ARCH_SHF_SMALL +#define ARCH_SHF_SMALL 0 +#endif + +/* + * Modules' sections will be aligned on page boundaries + * to ensure complete separation of code and data, but + * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y + */ +#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX +# define debug_align(X) ALIGN(X, PAGE_SIZE) +#else +# define debug_align(X) (X) +#endif + +/* If this is set, the section belongs in the init part of the module */ +#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) + +/* + * Mutex protects: + * 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). + */ +static DEFINE_MUTEX(module_mutex); +static LIST_HEAD(modules); + +/* Work queue for freeing init sections in success case */ +static void do_free_init(struct work_struct *w); +static DECLARE_WORK(init_free_wq, do_free_init); +static LLIST_HEAD(init_free_list); + +#ifdef CONFIG_MODULES_TREE_LOOKUP + +/* + * Use a latched RB-tree for __module_address(); this allows us to use + * RCU-sched lookups of the address from any context. + * + * This is conditional on PERF_EVENTS || TRACING because those can really hit + * __module_address() hard by doing a lot of stack unwinding; potentially from + * NMI context. + */ + +static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) +{ + struct module_layout *layout = container_of(n, struct module_layout, mtn.node); + + return (unsigned long)layout->base; +} + +static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) +{ + struct module_layout *layout = container_of(n, struct module_layout, mtn.node); + + return (unsigned long)layout->size; +} + +static __always_inline bool +mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b) +{ + return __mod_tree_val(a) < __mod_tree_val(b); +} + +static __always_inline int +mod_tree_comp(void *key, struct latch_tree_node *n) +{ + unsigned long val = (unsigned long)key; + unsigned long start, end; + + start = __mod_tree_val(n); + if (val < start) + return -1; + + end = start + __mod_tree_size(n); + if (val >= end) + return 1; + + return 0; +} + +static const struct latch_tree_ops mod_tree_ops = { + .less = mod_tree_less, + .comp = mod_tree_comp, +}; + +static struct mod_tree_root { + struct latch_tree_root root; + unsigned long addr_min; + unsigned long addr_max; +} mod_tree __cacheline_aligned = { + .addr_min = -1UL, +}; + +#define module_addr_min mod_tree.addr_min +#define module_addr_max mod_tree.addr_max + +static noinline void __mod_tree_insert(struct mod_tree_node *node) +{ + latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops); +} + +static void __mod_tree_remove(struct mod_tree_node *node) +{ + latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops); +} + +/* + * These modifications: insert, remove_init and remove; are serialized by the + * module_mutex. + */ +static void mod_tree_insert(struct module *mod) +{ + mod->core_layout.mtn.mod = mod; + mod->init_layout.mtn.mod = mod; + + __mod_tree_insert(&mod->core_layout.mtn); + if (mod->init_layout.size) + __mod_tree_insert(&mod->init_layout.mtn); +} + +static void mod_tree_remove_init(struct module *mod) +{ + if (mod->init_layout.size) + __mod_tree_remove(&mod->init_layout.mtn); +} + +static void mod_tree_remove(struct module *mod) +{ + __mod_tree_remove(&mod->core_layout.mtn); + mod_tree_remove_init(mod); +} + +static struct module *mod_find(unsigned long addr) +{ + struct latch_tree_node *ltn; + + ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops); + if (!ltn) + return NULL; + + return container_of(ltn, struct mod_tree_node, node)->mod; +} + +#else /* MODULES_TREE_LOOKUP */ + +static unsigned long module_addr_min = -1UL, module_addr_max = 0; + +static void mod_tree_insert(struct module *mod) { } +static void mod_tree_remove_init(struct module *mod) { } +static void mod_tree_remove(struct module *mod) { } + +static struct module *mod_find(unsigned long addr) +{ + struct module *mod; + + list_for_each_entry_rcu(mod, &modules, list, + lockdep_is_held(&module_mutex)) { + if (within_module(addr, mod)) + return mod; + } + + return NULL; +} + +#endif /* MODULES_TREE_LOOKUP */ + +/* + * Bounds of module text, for speeding up __module_address. + * Protected by module_mutex. + */ +static void __mod_update_bounds(void *base, unsigned int size) +{ + unsigned long min = (unsigned long)base; + unsigned long max = min + size; + + if (min < module_addr_min) + module_addr_min = min; + if (max > module_addr_max) + module_addr_max = max; +} + +static void mod_update_bounds(struct module *mod) +{ + __mod_update_bounds(mod->core_layout.base, mod->core_layout.size); + if (mod->init_layout.size) + __mod_update_bounds(mod->init_layout.base, mod->init_layout.size); +} + +#ifdef CONFIG_KGDB_KDB +struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ +#endif /* CONFIG_KGDB_KDB */ + +static void module_assert_mutex_or_preempt(void) +{ +#ifdef CONFIG_LOCKDEP + if (unlikely(!debug_locks)) + return; + + WARN_ON_ONCE(!rcu_read_lock_sched_held() && + !lockdep_is_held(&module_mutex)); +#endif +} + +#ifdef CONFIG_MODULE_SIG +static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); +module_param(sig_enforce, bool_enable_only, 0644); + +void set_module_sig_enforced(void) +{ + sig_enforce = true; +} +#else +#define sig_enforce false +#endif + +/* + * Export sig_enforce kernel cmdline parameter to allow other subsystems rely + * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. + */ +bool is_module_sig_enforced(void) +{ + return sig_enforce; +} +EXPORT_SYMBOL(is_module_sig_enforced); + +/* Block module loading/unloading? */ +int modules_disabled = 0; +core_param(nomodule, modules_disabled, bint, 0); + +/* Waiting for a module to finish initializing? */ +static DECLARE_WAIT_QUEUE_HEAD(module_wq); + +static BLOCKING_NOTIFIER_HEAD(module_notify_list); + +int register_module_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&module_notify_list, nb); +} +EXPORT_SYMBOL(register_module_notifier); + +int unregister_module_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&module_notify_list, nb); +} +EXPORT_SYMBOL(unregister_module_notifier); + +/* + * We require a truly strong try_module_get(): 0 means success. + * Otherwise an error is returned due to ongoing or failed + * initialization etc. + */ +static inline int strong_try_module_get(struct module *mod) +{ + BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); + if (mod && mod->state == MODULE_STATE_COMING) + return -EBUSY; + if (try_module_get(mod)) + return 0; + else + return -ENOENT; +} + +static inline void add_taint_module(struct module *mod, unsigned flag, + enum lockdep_ok lockdep_ok) +{ + add_taint(flag, lockdep_ok); + set_bit(flag, &mod->taints); +} + +/* + * A thread that wants to hold a reference to a module only while it + * is running can call this to safely exit. + */ +void __noreturn __module_put_and_kthread_exit(struct module *mod, long code) +{ + module_put(mod); + kthread_exit(code); +} +EXPORT_SYMBOL(__module_put_and_kthread_exit); + +/* Find a module section: 0 means not found. */ +static unsigned int find_sec(const struct load_info *info, const char *name) +{ + unsigned int i; + + for (i = 1; i < info->hdr->e_shnum; i++) { + Elf_Shdr *shdr = &info->sechdrs[i]; + /* Alloc bit cleared means "ignore it." */ + if ((shdr->sh_flags & SHF_ALLOC) + && strcmp(info->secstrings + shdr->sh_name, name) == 0) + return i; + } + return 0; +} + +/* Find a module section, or NULL. */ +static void *section_addr(const struct load_info *info, const char *name) +{ + /* Section 0 has sh_addr 0. */ + return (void *)info->sechdrs[find_sec(info, name)].sh_addr; +} + +/* Find a module section, or NULL. Fill in number of "objects" in section. */ +static void *section_objs(const struct load_info *info, + const char *name, + size_t object_size, + unsigned int *num) +{ + unsigned int sec = find_sec(info, name); + + /* Section 0 has sh_addr 0 and sh_size 0. */ + *num = info->sechdrs[sec].sh_size / object_size; + return (void *)info->sechdrs[sec].sh_addr; +} + +/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */ +static unsigned int find_any_sec(const struct load_info *info, const char *name) +{ + unsigned int i; + + for (i = 1; i < info->hdr->e_shnum; i++) { + Elf_Shdr *shdr = &info->sechdrs[i]; + if (strcmp(info->secstrings + shdr->sh_name, name) == 0) + return i; + } + return 0; +} + +/* + * Find a module section, or NULL. Fill in number of "objects" in section. + * Ignores SHF_ALLOC flag. + */ +static __maybe_unused void *any_section_objs(const struct load_info *info, + const char *name, + size_t object_size, + unsigned int *num) +{ + unsigned int sec = find_any_sec(info, name); + + /* Section 0 has sh_addr 0 and sh_size 0. */ + *num = info->sechdrs[sec].sh_size / object_size; + return (void *)info->sechdrs[sec].sh_addr; +} + +/* Provided by the linker */ +extern const struct kernel_symbol __start___ksymtab[]; +extern const struct kernel_symbol __stop___ksymtab[]; +extern const struct kernel_symbol __start___ksymtab_gpl[]; +extern const struct kernel_symbol __stop___ksymtab_gpl[]; +extern const s32 __start___kcrctab[]; +extern const s32 __start___kcrctab_gpl[]; + +#ifndef CONFIG_MODVERSIONS +#define symversion(base, idx) NULL +#else +#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) +#endif + +struct symsearch { + const struct kernel_symbol *start, *stop; + const s32 *crcs; + enum mod_license { + NOT_GPL_ONLY, + GPL_ONLY, + } license; +}; + +struct find_symbol_arg { + /* Input */ + const char *name; + bool gplok; + bool warn; + + /* Output */ + struct module *owner; + const s32 *crc; + const struct kernel_symbol *sym; + enum mod_license license; +}; + +static bool check_exported_symbol(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data) +{ + struct find_symbol_arg *fsa = data; + + if (!fsa->gplok && syms->license == GPL_ONLY) + return false; + fsa->owner = owner; + fsa->crc = symversion(syms->crcs, symnum); + fsa->sym = &syms->start[symnum]; + fsa->license = syms->license; + return true; +} + +static unsigned long kernel_symbol_value(const struct kernel_symbol *sym) +{ +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS + return (unsigned long)offset_to_ptr(&sym->value_offset); +#else + return sym->value; +#endif +} + +static const char *kernel_symbol_name(const struct kernel_symbol *sym) +{ +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS + return offset_to_ptr(&sym->name_offset); +#else + return sym->name; +#endif +} + +static const char *kernel_symbol_namespace(const struct kernel_symbol *sym) +{ +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS + if (!sym->namespace_offset) + return NULL; + return offset_to_ptr(&sym->namespace_offset); +#else + return sym->namespace; +#endif +} + +static int cmp_name(const void *name, const void *sym) +{ + return strcmp(name, kernel_symbol_name(sym)); +} + +static bool find_exported_symbol_in_section(const struct symsearch *syms, + struct module *owner, + void *data) +{ + struct find_symbol_arg *fsa = data; + struct kernel_symbol *sym; + + sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, + sizeof(struct kernel_symbol), cmp_name); + + if (sym != NULL && check_exported_symbol(syms, owner, + sym - syms->start, data)) + return true; + + 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. + */ +static bool find_symbol(struct find_symbol_arg *fsa) +{ + static const struct symsearch arr[] = { + { __start___ksymtab, __stop___ksymtab, __start___kcrctab, + NOT_GPL_ONLY }, + { __start___ksymtab_gpl, __stop___ksymtab_gpl, + __start___kcrctab_gpl, + GPL_ONLY }, + }; + struct module *mod; + unsigned int i; + + module_assert_mutex_or_preempt(); + + for (i = 0; i < ARRAY_SIZE(arr); i++) + if (find_exported_symbol_in_section(&arr[i], NULL, fsa)) + return true; + + list_for_each_entry_rcu(mod, &modules, list, + lockdep_is_held(&module_mutex)) { + struct symsearch arr[] = { + { mod->syms, mod->syms + mod->num_syms, mod->crcs, + NOT_GPL_ONLY }, + { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, + mod->gpl_crcs, + GPL_ONLY }, + }; + + if (mod->state == MODULE_STATE_UNFORMED) + continue; + + for (i = 0; i < ARRAY_SIZE(arr); i++) + if (find_exported_symbol_in_section(&arr[i], mod, fsa)) + return true; + } + + pr_debug("Failed to find symbol %s\n", fsa->name); + return false; +} + +/* + * Search for module by name: must hold module_mutex (or preempt disabled + * for read-only access). + */ +static struct module *find_module_all(const char *name, size_t len, + bool even_unformed) +{ + struct module *mod; + + module_assert_mutex_or_preempt(); + + list_for_each_entry_rcu(mod, &modules, list, + lockdep_is_held(&module_mutex)) { + if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) + continue; + if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) + return mod; + } + return NULL; +} + +struct module *find_module(const char *name) +{ + return find_module_all(name, strlen(name), false); +} + +#ifdef CONFIG_SMP + +static inline void __percpu *mod_percpu(struct module *mod) +{ + return mod->percpu; +} + +static int percpu_modalloc(struct module *mod, struct load_info *info) +{ + Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; + unsigned long align = pcpusec->sh_addralign; + + if (!pcpusec->sh_size) + return 0; + + if (align > PAGE_SIZE) { + pr_warn("%s: per-cpu alignment %li > %li\n", + mod->name, align, PAGE_SIZE); + align = PAGE_SIZE; + } + + mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); + if (!mod->percpu) { + pr_warn("%s: Could not allocate %lu bytes percpu data\n", + mod->name, (unsigned long)pcpusec->sh_size); + return -ENOMEM; + } + mod->percpu_size = pcpusec->sh_size; + return 0; +} + +static void percpu_modfree(struct module *mod) +{ + free_percpu(mod->percpu); +} + +static unsigned int find_pcpusec(struct load_info *info) +{ + return find_sec(info, ".data..percpu"); +} + +static void percpu_modcopy(struct module *mod, + const void *from, unsigned long size) +{ + int cpu; + + for_each_possible_cpu(cpu) + memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); +} + +bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) +{ + struct module *mod; + unsigned int cpu; + + preempt_disable(); + + list_for_each_entry_rcu(mod, &modules, list) { + if (mod->state == MODULE_STATE_UNFORMED) + continue; + if (!mod->percpu_size) + continue; + for_each_possible_cpu(cpu) { + void *start = per_cpu_ptr(mod->percpu, cpu); + void *va = (void *)addr; + + if (va >= start && va < start + mod->percpu_size) { + if (can_addr) { + *can_addr = (unsigned long) (va - start); + *can_addr += (unsigned long) + per_cpu_ptr(mod->percpu, + get_boot_cpu_id()); + } + preempt_enable(); + return true; + } + } + } + + preempt_enable(); + return false; +} + +/** + * 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. + * + * Return: %true if @addr is from module static percpu area + */ +bool is_module_percpu_address(unsigned long addr) +{ + return __is_module_percpu_address(addr, NULL); +} + +#else /* ... !CONFIG_SMP */ + +static inline void __percpu *mod_percpu(struct module *mod) +{ + return NULL; +} +static int percpu_modalloc(struct module *mod, struct load_info *info) +{ + /* UP modules shouldn't have this section: ENOMEM isn't quite right */ + if (info->sechdrs[info->index.pcpu].sh_size != 0) + return -ENOMEM; + return 0; +} +static inline void percpu_modfree(struct module *mod) +{ +} +static unsigned int find_pcpusec(struct load_info *info) +{ + return 0; +} +static inline void percpu_modcopy(struct module *mod, + const void *from, unsigned long size) +{ + /* pcpusec should be 0, and size of that section should be 0. */ + BUG_ON(size != 0); +} +bool is_module_percpu_address(unsigned long addr) +{ + return false; +} + +bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) +{ + return false; +} + +#endif /* CONFIG_SMP */ + +#define MODINFO_ATTR(field) \ +static void setup_modinfo_##field(struct module *mod, const char *s) \ +{ \ + mod->field = kstrdup(s, GFP_KERNEL); \ +} \ +static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ + struct module_kobject *mk, char *buffer) \ +{ \ + return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ +} \ +static int modinfo_##field##_exists(struct module *mod) \ +{ \ + return mod->field != NULL; \ +} \ +static void free_modinfo_##field(struct module *mod) \ +{ \ + kfree(mod->field); \ + mod->field = NULL; \ +} \ +static struct module_attribute modinfo_##field = { \ + .attr = { .name = __stringify(field), .mode = 0444 }, \ + .show = show_modinfo_##field, \ + .setup = setup_modinfo_##field, \ + .test = modinfo_##field##_exists, \ + .free = free_modinfo_##field, \ +}; + +MODINFO_ATTR(version); +MODINFO_ATTR(srcversion); + +static char last_unloaded_module[MODULE_NAME_LEN+1]; + +#ifdef CONFIG_MODULE_UNLOAD + +EXPORT_TRACEPOINT_SYMBOL(module_get); + +/* MODULE_REF_BASE is the base reference count by kmodule loader. */ +#define MODULE_REF_BASE 1 + +/* Init the unload section of the module. */ +static int module_unload_init(struct module *mod) +{ + /* + * Initialize reference counter to MODULE_REF_BASE. + * refcnt == 0 means module is going. + */ + atomic_set(&mod->refcnt, MODULE_REF_BASE); + + INIT_LIST_HEAD(&mod->source_list); + INIT_LIST_HEAD(&mod->target_list); + + /* Hold reference count during initialization. */ + atomic_inc(&mod->refcnt); + + return 0; +} + +/* Does a already use b? */ +static int already_uses(struct module *a, struct module *b) +{ + struct module_use *use; + + list_for_each_entry(use, &b->source_list, source_list) { + if (use->source == a) { + pr_debug("%s uses %s!\n", a->name, b->name); + return 1; + } + } + pr_debug("%s does not use %s!\n", a->name, b->name); + return 0; +} + +/* + * Module a uses b + * - we add 'a' as a "source", 'b' as a "target" of module use + * - the module_use is added to the list of 'b' sources (so + * 'b' can walk the list to see who sourced them), and of 'a' + * targets (so 'a' can see what modules it targets). + */ +static int add_module_usage(struct module *a, struct module *b) +{ + struct module_use *use; + + pr_debug("Allocating new usage for %s.\n", a->name); + use = kmalloc(sizeof(*use), GFP_ATOMIC); + if (!use) + return -ENOMEM; + + use->source = a; + use->target = b; + list_add(&use->source_list, &b->source_list); + list_add(&use->target_list, &a->target_list); + return 0; +} + +/* Module a uses b: caller needs module_mutex() */ +static int ref_module(struct module *a, struct module *b) +{ + int err; + + if (b == NULL || already_uses(a, b)) + return 0; + + /* If module isn't available, we fail. */ + err = strong_try_module_get(b); + if (err) + return err; + + err = add_module_usage(a, b); + if (err) { + module_put(b); + return err; + } + return 0; +} + +/* Clear the unload stuff of the module. */ +static void module_unload_free(struct module *mod) +{ + struct module_use *use, *tmp; + + mutex_lock(&module_mutex); + list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { + struct module *i = use->target; + pr_debug("%s unusing %s\n", mod->name, i->name); + module_put(i); + list_del(&use->source_list); + list_del(&use->target_list); + kfree(use); + } + mutex_unlock(&module_mutex); +} + +#ifdef CONFIG_MODULE_FORCE_UNLOAD +static inline int try_force_unload(unsigned int flags) +{ + int ret = (flags & O_TRUNC); + if (ret) + add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); + return ret; +} +#else +static inline int try_force_unload(unsigned int flags) +{ + return 0; +} +#endif /* CONFIG_MODULE_FORCE_UNLOAD */ + +/* Try to release refcount of module, 0 means success. */ +static int try_release_module_ref(struct module *mod) +{ + int ret; + + /* Try to decrement refcnt which we set at loading */ + ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); + BUG_ON(ret < 0); + if (ret) + /* Someone can put this right now, recover with checking */ + ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); + + return ret; +} + +static int try_stop_module(struct module *mod, int flags, int *forced) +{ + /* If it's not unused, quit unless we're forcing. */ + if (try_release_module_ref(mod) != 0) { + *forced = try_force_unload(flags); + if (!(*forced)) + return -EWOULDBLOCK; + } + + /* Mark it as dying. */ + mod->state = MODULE_STATE_GOING; + + return 0; +} + +/** + * module_refcount() - return the refcount or -1 if unloading + * @mod: the module we're checking + * + * Return: + * -1 if the module is in the process of unloading + * otherwise the number of references in the kernel to the module + */ +int module_refcount(struct module *mod) +{ + return atomic_read(&mod->refcnt) - MODULE_REF_BASE; +} +EXPORT_SYMBOL(module_refcount); + +/* This exists whether we can unload or not */ +static void free_module(struct module *mod); + +SYSCALL_DEFINE2(delete_module, const char __user *, name_user, + unsigned int, flags) +{ + struct module *mod; + char name[MODULE_NAME_LEN]; + int ret, forced = 0; + + if (!capable(CAP_SYS_MODULE) || modules_disabled) + return -EPERM; + + if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) + return -EFAULT; + name[MODULE_NAME_LEN-1] = '\0'; + + audit_log_kern_module(name); + + if (mutex_lock_interruptible(&module_mutex) != 0) + return -EINTR; + + mod = find_module(name); + if (!mod) { + ret = -ENOENT; + goto out; + } + + if (!list_empty(&mod->source_list)) { + /* Other modules depend on us: get rid of them first. */ + ret = -EWOULDBLOCK; + goto out; + } + + /* Doing init or already dying? */ + if (mod->state != MODULE_STATE_LIVE) { + /* FIXME: if (force), slam module count damn the torpedoes */ + pr_debug("%s already dying\n", mod->name); + ret = -EBUSY; + goto out; + } + + /* If it has an init func, it must have an exit func to unload */ + if (mod->init && !mod->exit) { + forced = try_force_unload(flags); + if (!forced) { + /* This module can't be removed */ + ret = -EBUSY; + goto out; + } + } + + ret = try_stop_module(mod, flags, &forced); + if (ret != 0) + goto out; + + mutex_unlock(&module_mutex); + /* Final destruction now no one is using it. */ + if (mod->exit != NULL) + mod->exit(); + blocking_notifier_call_chain(&module_notify_list, + MODULE_STATE_GOING, mod); + klp_module_going(mod); + ftrace_release_mod(mod); + + async_synchronize_full(); + + /* Store the name of the last unloaded module for diagnostic purposes */ + strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); + + free_module(mod); + /* someone could wait for the module in add_unformed_module() */ + wake_up_all(&module_wq); + return 0; +out: + mutex_unlock(&module_mutex); + return ret; +} + +static inline void print_unload_info(struct seq_file *m, struct module *mod) +{ + struct module_use *use; + int printed_something = 0; + + seq_printf(m, " %i ", module_refcount(mod)); + + /* + * Always include a trailing , so userspace can differentiate + * between this and the old multi-field proc format. + */ + list_for_each_entry(use, &mod->source_list, source_list) { + printed_something = 1; + seq_printf(m, "%s,", use->source->name); + } + + if (mod->init != NULL && mod->exit == NULL) { + printed_something = 1; + seq_puts(m, "[permanent],"); + } + + if (!printed_something) + seq_puts(m, "-"); +} + +void __symbol_put(const char *symbol) +{ + struct find_symbol_arg fsa = { + .name = symbol, + .gplok = true, + }; + + preempt_disable(); + BUG_ON(!find_symbol(&fsa)); + module_put(fsa.owner); + preempt_enable(); +} +EXPORT_SYMBOL(__symbol_put); + +/* Note this assumes addr is a function, which it currently always is. */ +void symbol_put_addr(void *addr) +{ + struct module *modaddr; + unsigned long a = (unsigned long)dereference_function_descriptor(addr); + + if (core_kernel_text(a)) + return; + + /* + * Even though we hold a reference on the module; we still need to + * disable preemption in order to safely traverse the data structure. + */ + preempt_disable(); + modaddr = __module_text_address(a); + BUG_ON(!modaddr); + module_put(modaddr); + preempt_enable(); +} +EXPORT_SYMBOL_GPL(symbol_put_addr); + +static ssize_t show_refcnt(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + return sprintf(buffer, "%i\n", module_refcount(mk->mod)); +} + +static struct module_attribute modinfo_refcnt = + __ATTR(refcnt, 0444, show_refcnt, NULL); + +void __module_get(struct module *module) +{ + if (module) { + preempt_disable(); + atomic_inc(&module->refcnt); + trace_module_get(module, _RET_IP_); + preempt_enable(); + } +} +EXPORT_SYMBOL(__module_get); + +bool try_module_get(struct module *module) +{ + bool ret = true; + + if (module) { + preempt_disable(); + /* Note: here, we can fail to get a reference */ + if (likely(module_is_live(module) && + atomic_inc_not_zero(&module->refcnt) != 0)) + trace_module_get(module, _RET_IP_); + else + ret = false; + + preempt_enable(); + } + return ret; +} +EXPORT_SYMBOL(try_module_get); + +void module_put(struct module *module) +{ + int ret; + + if (module) { + preempt_disable(); + ret = atomic_dec_if_positive(&module->refcnt); + WARN_ON(ret < 0); /* Failed to put refcount */ + trace_module_put(module, _RET_IP_); + preempt_enable(); + } +} +EXPORT_SYMBOL(module_put); + +#else /* !CONFIG_MODULE_UNLOAD */ +static inline void print_unload_info(struct seq_file *m, struct module *mod) +{ + /* We don't know the usage count, or what modules are using. */ + seq_puts(m, " - -"); +} + +static inline void module_unload_free(struct module *mod) +{ +} + +static int ref_module(struct module *a, struct module *b) +{ + return strong_try_module_get(b); +} + +static inline int module_unload_init(struct module *mod) +{ + return 0; +} +#endif /* CONFIG_MODULE_UNLOAD */ + +static size_t module_flags_taint(struct module *mod, char *buf) +{ + size_t l = 0; + int i; + + for (i = 0; i < TAINT_FLAGS_COUNT; i++) { + if (taint_flags[i].module && test_bit(i, &mod->taints)) + buf[l++] = taint_flags[i].c_true; + } + + return l; +} + +static ssize_t show_initstate(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + const char *state = "unknown"; + + switch (mk->mod->state) { + case MODULE_STATE_LIVE: + state = "live"; + break; + case MODULE_STATE_COMING: + state = "coming"; + break; + case MODULE_STATE_GOING: + state = "going"; + break; + default: + BUG(); + } + return sprintf(buffer, "%s\n", state); +} + +static struct module_attribute modinfo_initstate = + __ATTR(initstate, 0444, show_initstate, NULL); + +static ssize_t store_uevent(struct module_attribute *mattr, + struct module_kobject *mk, + const char *buffer, size_t count) +{ + int rc; + + rc = kobject_synth_uevent(&mk->kobj, buffer, count); + return rc ? rc : count; +} + +struct module_attribute module_uevent = + __ATTR(uevent, 0200, NULL, store_uevent); + +static ssize_t show_coresize(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + return sprintf(buffer, "%u\n", mk->mod->core_layout.size); +} + +static struct module_attribute modinfo_coresize = + __ATTR(coresize, 0444, show_coresize, NULL); + +static ssize_t show_initsize(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + return sprintf(buffer, "%u\n", mk->mod->init_layout.size); +} + +static struct module_attribute modinfo_initsize = + __ATTR(initsize, 0444, show_initsize, NULL); + +static ssize_t show_taint(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + size_t l; + + l = module_flags_taint(mk->mod, buffer); + buffer[l++] = '\n'; + return l; +} + +static struct module_attribute modinfo_taint = + __ATTR(taint, 0444, show_taint, NULL); + +static struct module_attribute *modinfo_attrs[] = { + &module_uevent, + &modinfo_version, + &modinfo_srcversion, + &modinfo_initstate, + &modinfo_coresize, + &modinfo_initsize, + &modinfo_taint, +#ifdef CONFIG_MODULE_UNLOAD + &modinfo_refcnt, +#endif + NULL, +}; + +static const char vermagic[] = VERMAGIC_STRING; + +static int try_to_force_load(struct module *mod, const char *reason) +{ +#ifdef CONFIG_MODULE_FORCE_LOAD + if (!test_taint(TAINT_FORCED_MODULE)) + pr_warn("%s: %s: kernel tainted.\n", mod->name, reason); + add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); + return 0; +#else + return -ENOEXEC; +#endif +} + +#ifdef CONFIG_MODVERSIONS + +static u32 resolve_rel_crc(const s32 *crc) +{ + return *(u32 *)((void *)crc + *crc); +} + +static int check_version(const struct load_info *info, + const char *symname, + struct module *mod, + const s32 *crc) +{ + Elf_Shdr *sechdrs = info->sechdrs; + unsigned int versindex = info->index.vers; + unsigned int i, num_versions; + struct modversion_info *versions; + + /* Exporting module didn't supply crcs? OK, we're already tainted. */ + if (!crc) + return 1; + + /* No versions at all? modprobe --force does this. */ + if (versindex == 0) + return try_to_force_load(mod, symname) == 0; + + versions = (void *) sechdrs[versindex].sh_addr; + num_versions = sechdrs[versindex].sh_size + / sizeof(struct modversion_info); + + for (i = 0; i < num_versions; i++) { + u32 crcval; + + if (strcmp(versions[i].name, symname) != 0) + continue; + + if (IS_ENABLED(CONFIG_MODULE_REL_CRCS)) + crcval = resolve_rel_crc(crc); + else + crcval = *crc; + if (versions[i].crc == crcval) + return 1; + pr_debug("Found checksum %X vs module %lX\n", + crcval, versions[i].crc); + goto bad_version; + } + + /* Broken toolchain. Warn once, then let it go.. */ + pr_warn_once("%s: no symbol version for %s\n", info->name, symname); + return 1; + +bad_version: + pr_warn("%s: disagrees about version of symbol %s\n", + info->name, symname); + return 0; +} + +static inline int check_modstruct_version(const struct load_info *info, + struct module *mod) +{ + struct find_symbol_arg fsa = { + .name = "module_layout", + .gplok = true, + }; + + /* + * Since this should be found in kernel (which can't be removed), no + * locking is necessary -- use preempt_disable() to placate lockdep. + */ + preempt_disable(); + if (!find_symbol(&fsa)) { + preempt_enable(); + BUG(); + } + preempt_enable(); + return check_version(info, "module_layout", mod, fsa.crc); +} + +/* First part is kernel version, which we ignore if module has crcs. */ +static inline int same_magic(const char *amagic, const char *bmagic, + bool has_crcs) +{ + if (has_crcs) { + amagic += strcspn(amagic, " "); + bmagic += strcspn(bmagic, " "); + } + return strcmp(amagic, bmagic) == 0; +} +#else +static inline int check_version(const struct load_info *info, + const char *symname, + struct module *mod, + const s32 *crc) +{ + return 1; +} + +static inline int check_modstruct_version(const struct load_info *info, + struct module *mod) +{ + return 1; +} + +static inline int same_magic(const char *amagic, const char *bmagic, + bool has_crcs) +{ + return strcmp(amagic, bmagic) == 0; +} +#endif /* CONFIG_MODVERSIONS */ + +static char *get_modinfo(const struct load_info *info, const char *tag); +static char *get_next_modinfo(const struct load_info *info, const char *tag, + char *prev); + +static int verify_namespace_is_imported(const struct load_info *info, + const struct kernel_symbol *sym, + struct module *mod) +{ + const char *namespace; + char *imported_namespace; + + namespace = kernel_symbol_namespace(sym); + if (namespace && namespace[0]) { + imported_namespace = get_modinfo(info, "import_ns"); + while (imported_namespace) { + if (strcmp(namespace, imported_namespace) == 0) + return 0; + imported_namespace = get_next_modinfo( + info, "import_ns", imported_namespace); + } +#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS + pr_warn( +#else + pr_err( +#endif + "%s: module uses symbol (%s) from namespace %s, but does not import it.\n", + mod->name, kernel_symbol_name(sym), namespace); +#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS + return -EINVAL; +#endif + } + return 0; +} + +static bool inherit_taint(struct module *mod, struct module *owner) +{ + if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) + return true; + + if (mod->using_gplonly_symbols) { + pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n", + mod->name, owner->name); + return false; + } + + if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) { + pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n", + mod->name, owner->name); + set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints); + } + return true; +} + +/* Resolve a symbol for this module. I.e. if we find one, record usage. */ +static const struct kernel_symbol *resolve_symbol(struct module *mod, + const struct load_info *info, + const char *name, + char ownername[]) +{ + struct find_symbol_arg fsa = { + .name = name, + .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), + .warn = true, + }; + int err; + + /* + * The module_mutex should not be a heavily contended lock; + * if we get the occasional sleep here, we'll go an extra iteration + * in the wait_event_interruptible(), which is harmless. + */ + sched_annotate_sleep(); + mutex_lock(&module_mutex); + if (!find_symbol(&fsa)) + goto unlock; + + if (fsa.license == GPL_ONLY) + mod->using_gplonly_symbols = true; + + if (!inherit_taint(mod, fsa.owner)) { + fsa.sym = NULL; + goto getname; + } + + if (!check_version(info, name, mod, fsa.crc)) { + fsa.sym = ERR_PTR(-EINVAL); + goto getname; + } + + err = verify_namespace_is_imported(info, fsa.sym, mod); + if (err) { + fsa.sym = ERR_PTR(err); + goto getname; + } + + err = ref_module(mod, fsa.owner); + if (err) { + fsa.sym = ERR_PTR(err); + goto getname; + } + +getname: + /* We must make copy under the lock if we failed to get ref. */ + strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN); +unlock: + mutex_unlock(&module_mutex); + return fsa.sym; +} + +static const struct kernel_symbol * +resolve_symbol_wait(struct module *mod, + const struct load_info *info, + const char *name) +{ + const struct kernel_symbol *ksym; + char owner[MODULE_NAME_LEN]; + + if (wait_event_interruptible_timeout(module_wq, + !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) + || PTR_ERR(ksym) != -EBUSY, + 30 * HZ) <= 0) { + pr_warn("%s: gave up waiting for init of module %s.\n", + mod->name, owner); + } + return ksym; +} + +#ifdef CONFIG_KALLSYMS +static inline bool sect_empty(const Elf_Shdr *sect) +{ + return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; +} +#endif + +/* + * /sys/module/foo/sections stuff + * J. Corbet + */ +#ifdef CONFIG_SYSFS + +#ifdef CONFIG_KALLSYMS +struct module_sect_attr { + struct bin_attribute battr; + unsigned long address; +}; + +struct module_sect_attrs { + struct attribute_group grp; + unsigned int nsections; + struct module_sect_attr attrs[]; +}; + +#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4)) +static ssize_t module_sect_read(struct file *file, struct kobject *kobj, + struct bin_attribute *battr, + char *buf, loff_t pos, size_t count) +{ + struct module_sect_attr *sattr = + container_of(battr, struct module_sect_attr, battr); + char bounce[MODULE_SECT_READ_SIZE + 1]; + size_t wrote; + + if (pos != 0) + return -EINVAL; + + /* + * Since we're a binary read handler, we must account for the + * trailing NUL byte that sprintf will write: if "buf" is + * too small to hold the NUL, or the NUL is exactly the last + * byte, the read will look like it got truncated by one byte. + * Since there is no way to ask sprintf nicely to not write + * the NUL, we have to use a bounce buffer. + */ + wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n", + kallsyms_show_value(file->f_cred) + ? (void *)sattr->address : NULL); + count = min(count, wrote); + memcpy(buf, bounce, count); + + return count; +} + +static void free_sect_attrs(struct module_sect_attrs *sect_attrs) +{ + unsigned int section; + + for (section = 0; section < sect_attrs->nsections; section++) + kfree(sect_attrs->attrs[section].battr.attr.name); + kfree(sect_attrs); +} + +static void add_sect_attrs(struct module *mod, const struct load_info *info) +{ + unsigned int nloaded = 0, i, size[2]; + struct module_sect_attrs *sect_attrs; + struct module_sect_attr *sattr; + struct bin_attribute **gattr; + + /* Count loaded sections and allocate structures */ + for (i = 0; i < info->hdr->e_shnum; i++) + if (!sect_empty(&info->sechdrs[i])) + nloaded++; + size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), + sizeof(sect_attrs->grp.bin_attrs[0])); + size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]); + sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); + if (sect_attrs == NULL) + return; + + /* Setup section attributes. */ + sect_attrs->grp.name = "sections"; + sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0]; + + sect_attrs->nsections = 0; + sattr = §_attrs->attrs[0]; + gattr = §_attrs->grp.bin_attrs[0]; + for (i = 0; i < info->hdr->e_shnum; i++) { + Elf_Shdr *sec = &info->sechdrs[i]; + if (sect_empty(sec)) + continue; + sysfs_bin_attr_init(&sattr->battr); + sattr->address = sec->sh_addr; + sattr->battr.attr.name = + kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); + if (sattr->battr.attr.name == NULL) + goto out; + sect_attrs->nsections++; + sattr->battr.read = module_sect_read; + sattr->battr.size = MODULE_SECT_READ_SIZE; + sattr->battr.attr.mode = 0400; + *(gattr++) = &(sattr++)->battr; + } + *gattr = NULL; + + if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) + goto out; + + mod->sect_attrs = sect_attrs; + return; + out: + free_sect_attrs(sect_attrs); +} + +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. + */ + free_sect_attrs(mod->sect_attrs); + mod->sect_attrs = NULL; + } +} + +/* + * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. + */ + +struct module_notes_attrs { + struct kobject *dir; + unsigned int notes; + struct bin_attribute attrs[]; +}; + +static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t pos, size_t count) +{ + /* + * The caller checked the pos and count against our size. + */ + memcpy(buf, bin_attr->private + pos, count); + return count; +} + +static void free_notes_attrs(struct module_notes_attrs *notes_attrs, + unsigned int i) +{ + if (notes_attrs->dir) { + while (i-- > 0) + sysfs_remove_bin_file(notes_attrs->dir, + ¬es_attrs->attrs[i]); + kobject_put(notes_attrs->dir); + } + kfree(notes_attrs); +} + +static void add_notes_attrs(struct module *mod, const struct load_info *info) +{ + unsigned int notes, loaded, i; + struct module_notes_attrs *notes_attrs; + struct bin_attribute *nattr; + + /* failed to create section attributes, so can't create notes */ + if (!mod->sect_attrs) + return; + + /* Count notes sections and allocate structures. */ + notes = 0; + for (i = 0; i < info->hdr->e_shnum; i++) + if (!sect_empty(&info->sechdrs[i]) && + (info->sechdrs[i].sh_type == SHT_NOTE)) + ++notes; + + if (notes == 0) + return; + + notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), + GFP_KERNEL); + if (notes_attrs == NULL) + return; + + notes_attrs->notes = notes; + nattr = ¬es_attrs->attrs[0]; + for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { + if (sect_empty(&info->sechdrs[i])) + continue; + if (info->sechdrs[i].sh_type == SHT_NOTE) { + sysfs_bin_attr_init(nattr); + nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name; + nattr->attr.mode = S_IRUGO; + nattr->size = info->sechdrs[i].sh_size; + nattr->private = (void *) info->sechdrs[i].sh_addr; + nattr->read = module_notes_read; + ++nattr; + } + ++loaded; + } + + notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); + if (!notes_attrs->dir) + goto out; + + for (i = 0; i < notes; ++i) + if (sysfs_create_bin_file(notes_attrs->dir, + ¬es_attrs->attrs[i])) + goto out; + + mod->notes_attrs = notes_attrs; + return; + + out: + free_notes_attrs(notes_attrs, i); +} + +static void remove_notes_attrs(struct module *mod) +{ + if (mod->notes_attrs) + free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); +} + +#else + +static inline void add_sect_attrs(struct module *mod, + const struct load_info *info) +{ +} + +static inline void remove_sect_attrs(struct module *mod) +{ +} + +static inline void add_notes_attrs(struct module *mod, + const struct load_info *info) +{ +} + +static inline void remove_notes_attrs(struct module *mod) +{ +} +#endif /* CONFIG_KALLSYMS */ + +static void del_usage_links(struct module *mod) +{ +#ifdef CONFIG_MODULE_UNLOAD + struct module_use *use; + + mutex_lock(&module_mutex); + list_for_each_entry(use, &mod->target_list, target_list) + sysfs_remove_link(use->target->holders_dir, mod->name); + mutex_unlock(&module_mutex); +#endif +} + +static int add_usage_links(struct module *mod) +{ + int ret = 0; +#ifdef CONFIG_MODULE_UNLOAD + struct module_use *use; + + mutex_lock(&module_mutex); + list_for_each_entry(use, &mod->target_list, target_list) { + ret = sysfs_create_link(use->target->holders_dir, + &mod->mkobj.kobj, mod->name); + if (ret) + break; + } + mutex_unlock(&module_mutex); + if (ret) + del_usage_links(mod); +#endif + return ret; +} + +static void module_remove_modinfo_attrs(struct module *mod, int end); + +static int module_add_modinfo_attrs(struct module *mod) +{ + struct module_attribute *attr; + struct module_attribute *temp_attr; + int error = 0; + int i; + + mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * + (ARRAY_SIZE(modinfo_attrs) + 1)), + GFP_KERNEL); + if (!mod->modinfo_attrs) + return -ENOMEM; + + temp_attr = mod->modinfo_attrs; + for (i = 0; (attr = modinfo_attrs[i]); i++) { + if (!attr->test || attr->test(mod)) { + memcpy(temp_attr, attr, sizeof(*temp_attr)); + sysfs_attr_init(&temp_attr->attr); + error = sysfs_create_file(&mod->mkobj.kobj, + &temp_attr->attr); + if (error) + goto error_out; + ++temp_attr; + } + } + + return 0; + +error_out: + if (i > 0) + module_remove_modinfo_attrs(mod, --i); + else + kfree(mod->modinfo_attrs); + return error; +} + +static void module_remove_modinfo_attrs(struct module *mod, int end) +{ + struct module_attribute *attr; + int i; + + for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { + if (end >= 0 && i > end) + break; + /* pick a field to test for end of list */ + if (!attr->attr.name) + break; + sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); + if (attr->free) + attr->free(mod); + } + kfree(mod->modinfo_attrs); +} + +static void mod_kobject_put(struct module *mod) +{ + DECLARE_COMPLETION_ONSTACK(c); + mod->mkobj.kobj_completion = &c; + kobject_put(&mod->mkobj.kobj); + wait_for_completion(&c); +} + +static int mod_sysfs_init(struct module *mod) +{ + int err; + struct kobject *kobj; + + if (!module_sysfs_initialized) { + pr_err("%s: module sysfs not initialized\n", mod->name); + err = -EINVAL; + goto out; + } + + kobj = kset_find_obj(module_kset, mod->name); + if (kobj) { + pr_err("%s: module is already loaded\n", mod->name); + kobject_put(kobj); + err = -EINVAL; + goto out; + } + + mod->mkobj.mod = mod; + + memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); + mod->mkobj.kobj.kset = module_kset; + err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, + "%s", mod->name); + if (err) + mod_kobject_put(mod); + +out: + return err; +} + +static int mod_sysfs_setup(struct module *mod, + const struct load_info *info, + struct kernel_param *kparam, + unsigned int num_params) +{ + int err; + + err = mod_sysfs_init(mod); + if (err) + goto out; + + mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); + if (!mod->holders_dir) { + err = -ENOMEM; + goto out_unreg; + } + + err = module_param_sysfs_setup(mod, kparam, num_params); + if (err) + goto out_unreg_holders; + + err = module_add_modinfo_attrs(mod); + if (err) + goto out_unreg_param; + + err = add_usage_links(mod); + if (err) + goto out_unreg_modinfo_attrs; + + add_sect_attrs(mod, info); + add_notes_attrs(mod, info); + + return 0; + +out_unreg_modinfo_attrs: + module_remove_modinfo_attrs(mod, -1); +out_unreg_param: + module_param_sysfs_remove(mod); +out_unreg_holders: + kobject_put(mod->holders_dir); +out_unreg: + mod_kobject_put(mod); +out: + return err; +} + +static void mod_sysfs_fini(struct module *mod) +{ + remove_notes_attrs(mod); + remove_sect_attrs(mod); + mod_kobject_put(mod); +} + +static void init_param_lock(struct module *mod) +{ + mutex_init(&mod->param_lock); +} +#else /* !CONFIG_SYSFS */ + +static int mod_sysfs_setup(struct module *mod, + const struct load_info *info, + struct kernel_param *kparam, + unsigned int num_params) +{ + return 0; +} + +static void mod_sysfs_fini(struct module *mod) +{ +} + +static void module_remove_modinfo_attrs(struct module *mod, int end) +{ +} + +static void del_usage_links(struct module *mod) +{ +} + +static void init_param_lock(struct module *mod) +{ +} +#endif /* CONFIG_SYSFS */ + +static void mod_sysfs_teardown(struct module *mod) +{ + del_usage_links(mod); + module_remove_modinfo_attrs(mod, -1); + module_param_sysfs_remove(mod); + kobject_put(mod->mkobj.drivers_dir); + kobject_put(mod->holders_dir); + mod_sysfs_fini(mod); +} + +/* + * LKM RO/NX protection: protect module's text/ro-data + * from modification and any data from execution. + * + * General layout of module is: + * [text] [read-only-data] [ro-after-init] [writable data] + * text_size -----^ ^ ^ ^ + * ro_size ------------------------| | | + * ro_after_init_size -----------------------------| | + * size -----------------------------------------------------------| + * + * These values are always page-aligned (as is base) + */ + +/* + * Since some arches are moving towards PAGE_KERNEL module allocations instead + * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the + * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of + * whether we are strict. + */ +#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX +static void frob_text(const struct module_layout *layout, + int (*set_memory)(unsigned long start, int num_pages)) +{ + BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); + set_memory((unsigned long)layout->base, + layout->text_size >> PAGE_SHIFT); +} + +static void module_enable_x(const struct module *mod) +{ + frob_text(&mod->core_layout, set_memory_x); + frob_text(&mod->init_layout, set_memory_x); +} +#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ +static void module_enable_x(const struct module *mod) { } +#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ + +#ifdef CONFIG_STRICT_MODULE_RWX +static void frob_rodata(const struct module_layout *layout, + int (*set_memory)(unsigned long start, int num_pages)) +{ + BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); + set_memory((unsigned long)layout->base + layout->text_size, + (layout->ro_size - layout->text_size) >> PAGE_SHIFT); +} + +static void frob_ro_after_init(const struct module_layout *layout, + int (*set_memory)(unsigned long start, int num_pages)) +{ + BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); + set_memory((unsigned long)layout->base + layout->ro_size, + (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); +} + +static void frob_writable_data(const struct module_layout *layout, + int (*set_memory)(unsigned long start, int num_pages)) +{ + BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1)); + set_memory((unsigned long)layout->base + layout->ro_after_init_size, + (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); +} + +static void module_enable_ro(const struct module *mod, bool after_init) +{ + if (!rodata_enabled) + return; + + set_vm_flush_reset_perms(mod->core_layout.base); + set_vm_flush_reset_perms(mod->init_layout.base); + frob_text(&mod->core_layout, set_memory_ro); + + frob_rodata(&mod->core_layout, set_memory_ro); + frob_text(&mod->init_layout, set_memory_ro); + frob_rodata(&mod->init_layout, set_memory_ro); + + if (after_init) + frob_ro_after_init(&mod->core_layout, set_memory_ro); +} + +static void module_enable_nx(const struct module *mod) +{ + frob_rodata(&mod->core_layout, set_memory_nx); + frob_ro_after_init(&mod->core_layout, set_memory_nx); + frob_writable_data(&mod->core_layout, set_memory_nx); + frob_rodata(&mod->init_layout, set_memory_nx); + frob_writable_data(&mod->init_layout, set_memory_nx); +} + +static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, + char *secstrings, struct module *mod) +{ + const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR; + int i; + + for (i = 0; i < hdr->e_shnum; i++) { + if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) { + pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n", + mod->name, secstrings + sechdrs[i].sh_name, i); + return -ENOEXEC; + } + } + + return 0; +} + +#else /* !CONFIG_STRICT_MODULE_RWX */ +static void module_enable_nx(const struct module *mod) { } +static void module_enable_ro(const struct module *mod, bool after_init) {} +static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, + char *secstrings, struct module *mod) +{ + return 0; +} +#endif /* CONFIG_STRICT_MODULE_RWX */ + +#ifdef CONFIG_LIVEPATCH +/* + * Persist Elf information about a module. Copy the Elf header, + * section header table, section string table, and symtab section + * index from info to mod->klp_info. + */ +static int copy_module_elf(struct module *mod, struct load_info *info) +{ + unsigned int size, symndx; + int ret; + + size = sizeof(*mod->klp_info); + mod->klp_info = kmalloc(size, GFP_KERNEL); + if (mod->klp_info == NULL) + return -ENOMEM; + + /* Elf header */ + size = sizeof(mod->klp_info->hdr); + memcpy(&mod->klp_info->hdr, info->hdr, size); + + /* Elf section header table */ + size = sizeof(*info->sechdrs) * info->hdr->e_shnum; + mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL); + if (mod->klp_info->sechdrs == NULL) { + ret = -ENOMEM; + goto free_info; + } + + /* Elf section name string table */ + size = info->sechdrs[info->hdr->e_shstrndx].sh_size; + mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL); + if (mod->klp_info->secstrings == NULL) { + ret = -ENOMEM; + goto free_sechdrs; + } + + /* Elf symbol section index */ + symndx = info->index.sym; + mod->klp_info->symndx = symndx; + + /* + * For livepatch modules, core_kallsyms.symtab is a complete + * copy of the original symbol table. Adjust sh_addr to point + * to core_kallsyms.symtab since the copy of the symtab in module + * init memory is freed at the end of do_init_module(). + */ + mod->klp_info->sechdrs[symndx].sh_addr = \ + (unsigned long) mod->core_kallsyms.symtab; + + return 0; + +free_sechdrs: + kfree(mod->klp_info->sechdrs); +free_info: + kfree(mod->klp_info); + return ret; +} + +static void free_module_elf(struct module *mod) +{ + kfree(mod->klp_info->sechdrs); + kfree(mod->klp_info->secstrings); + kfree(mod->klp_info); +} +#else /* !CONFIG_LIVEPATCH */ +static int copy_module_elf(struct module *mod, struct load_info *info) +{ + return 0; +} + +static void free_module_elf(struct module *mod) +{ +} +#endif /* CONFIG_LIVEPATCH */ + +void __weak module_memfree(void *module_region)