diff options
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 247 |
1 files changed, 162 insertions, 85 deletions
diff --git a/kernel/module.c b/kernel/module.c index 33569a01d6e1..1c5cff34d9f2 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -4,6 +4,9 @@ Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. */ + +#define INCLUDE_VERMAGIC + #include <linux/export.h> #include <linux/extable.h> #include <linux/moduleloader.h> @@ -419,7 +422,7 @@ static bool each_symbol_in_section(const struct symsearch *arr, } /* Returns true as soon as fn returns true, otherwise false. */ -bool each_symbol_section(bool (*fn)(const struct symsearch *arr, +static bool each_symbol_section(bool (*fn)(const struct symsearch *arr, struct module *owner, void *data), void *data) @@ -481,7 +484,6 @@ bool each_symbol_section(bool (*fn)(const struct symsearch *arr, } return false; } -EXPORT_SYMBOL_GPL(each_symbol_section); struct find_symbol_arg { /* Input */ @@ -493,6 +495,7 @@ struct find_symbol_arg { struct module *owner; const s32 *crc; const struct kernel_symbol *sym; + enum mod_license license; }; static bool check_exported_symbol(const struct symsearch *syms, @@ -502,9 +505,9 @@ static bool check_exported_symbol(const struct symsearch *syms, struct find_symbol_arg *fsa = data; if (!fsa->gplok) { - if (syms->licence == GPL_ONLY) + if (syms->license == GPL_ONLY) return false; - if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { + if (syms->license == WILL_BE_GPL_ONLY && fsa->warn) { pr_warn("Symbol %s is being used by a non-GPL module, " "which will not be allowed in the future\n", fsa->name); @@ -526,6 +529,7 @@ static bool check_exported_symbol(const struct symsearch *syms, fsa->owner = owner; fsa->crc = symversion(syms->crcs, symnum); fsa->sym = &syms->start[symnum]; + fsa->license = syms->license; return true; } @@ -582,9 +586,10 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms, /* Find an exported symbol and return it, along with, (optional) crc and * (optional) module which owns it. Needs preempt disabled or module_mutex. */ -const struct kernel_symbol *find_symbol(const char *name, +static const struct kernel_symbol *find_symbol(const char *name, struct module **owner, const s32 **crc, + enum mod_license *license, bool gplok, bool warn) { @@ -599,13 +604,14 @@ const struct kernel_symbol *find_symbol(const char *name, *owner = fsa.owner; if (crc) *crc = fsa.crc; + if (license) + *license = fsa.license; return fsa.sym; } pr_debug("Failed to find symbol %s\n", name); return NULL; } -EXPORT_SYMBOL_GPL(find_symbol); /* * Search for module by name: must hold module_mutex (or preempt disabled @@ -866,7 +872,7 @@ static int add_module_usage(struct module *a, struct module *b) } /* Module a uses b: caller needs module_mutex() */ -int ref_module(struct module *a, struct module *b) +static int ref_module(struct module *a, struct module *b) { int err; @@ -885,7 +891,6 @@ int ref_module(struct module *a, struct module *b) } return 0; } -EXPORT_SYMBOL_GPL(ref_module); /* Clear the unload stuff of the module. */ static void module_unload_free(struct module *mod) @@ -1074,7 +1079,7 @@ void __symbol_put(const char *symbol) struct module *owner; preempt_disable(); - if (!find_symbol(symbol, &owner, NULL, true, false)) + if (!find_symbol(symbol, &owner, NULL, NULL, true, false)) BUG(); module_put(owner); preempt_enable(); @@ -1166,11 +1171,10 @@ static inline void module_unload_free(struct module *mod) { } -int ref_module(struct module *a, struct module *b) +static int ref_module(struct module *a, struct module *b) { return strong_try_module_get(b); } -EXPORT_SYMBOL_GPL(ref_module); static inline int module_unload_init(struct module *mod) { @@ -1353,7 +1357,7 @@ static inline int check_modstruct_version(const struct load_info *info, * locking is necessary -- use preempt_disable() to placate lockdep. */ preempt_disable(); - if (!find_symbol("module_layout", NULL, &crc, true, false)) { + if (!find_symbol("module_layout", NULL, &crc, NULL, true, false)) { preempt_enable(); BUG(); } @@ -1427,6 +1431,24 @@ static int verify_namespace_is_imported(const struct load_info *info, 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, @@ -1437,6 +1459,7 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod, struct module *owner; const struct kernel_symbol *sym; const s32 *crc; + enum mod_license license; int err; /* @@ -1446,11 +1469,19 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod, */ sched_annotate_sleep(); mutex_lock(&module_mutex); - sym = find_symbol(name, &owner, &crc, + sym = find_symbol(name, &owner, &crc, &license, !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); if (!sym) goto unlock; + if (license == GPL_ONLY) + mod->using_gplonly_symbols = true; + + if (!inherit_taint(mod, owner)) { + sym = NULL; + goto getname; + } + if (!check_version(info, name, mod, crc)) { sym = ERR_PTR(-EINVAL); goto getname; @@ -1507,24 +1538,44 @@ static inline bool sect_empty(const Elf_Shdr *sect) } struct module_sect_attr { - struct module_attribute mattr; - char *name; + struct bin_attribute battr; unsigned long address; }; struct module_sect_attrs { struct attribute_group grp; unsigned int nsections; - struct module_sect_attr attrs[0]; + struct module_sect_attr attrs[]; }; -static ssize_t module_sect_show(struct module_attribute *mattr, - struct module_kobject *mk, char *buf) +#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(mattr, struct module_sect_attr, mattr); - return sprintf(buf, "0x%px\n", kptr_restrict < 2 ? - (void *)sattr->address : NULL); + 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) @@ -1532,7 +1583,7 @@ 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].name); + kfree(sect_attrs->attrs[section].battr.attr.name); kfree(sect_attrs); } @@ -1541,42 +1592,41 @@ 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 attribute **gattr; + 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.attrs[0])); - size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]); + 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.attrs = (void *)sect_attrs + size[0]; + sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0]; sect_attrs->nsections = 0; sattr = §_attrs->attrs[0]; - gattr = §_attrs->grp.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->name = kstrdup(info->secstrings + sec->sh_name, - GFP_KERNEL); - if (sattr->name == NULL) + sattr->battr.attr.name = + kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); + if (sattr->battr.attr.name == NULL) goto out; sect_attrs->nsections++; - sysfs_attr_init(&sattr->mattr.attr); - sattr->mattr.show = module_sect_show; - sattr->mattr.store = NULL; - sattr->mattr.attr.name = sattr->name; - sattr->mattr.attr.mode = S_IRUSR; - *(gattr++) = &(sattr++)->mattr.attr; + sattr->battr.read = module_sect_read; + sattr->battr.size = MODULE_SECT_READ_SIZE; + sattr->battr.attr.mode = 0400; + *(gattr++) = &(sattr++)->battr; } *gattr = NULL; @@ -1608,7 +1658,7 @@ static void remove_sect_attrs(struct module *mod) struct module_notes_attrs { struct kobject *dir; unsigned int notes; - struct bin_attribute attrs[0]; + struct bin_attribute attrs[]; }; static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, @@ -1666,7 +1716,7 @@ static void add_notes_attrs(struct module *mod, const struct load_info *info) continue; if (info->sechdrs[i].sh_type == SHT_NOTE) { sysfs_bin_attr_init(nattr); - nattr->attr.name = mod->sect_attrs->attrs[loaded].name; + 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; @@ -1943,7 +1993,6 @@ static void mod_sysfs_teardown(struct module *mod) mod_sysfs_fini(mod); } -#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX /* * LKM RO/NX protection: protect module's text/ro-data * from modification and any data from execution. @@ -1957,6 +2006,14 @@ static void mod_sysfs_teardown(struct module *mod) * * 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)) { @@ -1966,6 +2023,15 @@ static void frob_text(const struct module_layout *layout, 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)) @@ -1997,20 +2063,7 @@ static void frob_writable_data(const struct module_layout *layout, (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); } -/* livepatching wants to disable read-only so it can frob module. */ -void module_disable_ro(const struct module *mod) -{ - if (!rodata_enabled) - return; - - frob_text(&mod->core_layout, set_memory_rw); - frob_rodata(&mod->core_layout, set_memory_rw); - frob_ro_after_init(&mod->core_layout, set_memory_rw); - frob_text(&mod->init_layout, set_memory_rw); - frob_rodata(&mod->init_layout, set_memory_rw); -} - -void module_enable_ro(const struct module *mod, bool after_init) +static void module_enable_ro(const struct module *mod, bool after_init) { if (!rodata_enabled) return; @@ -2036,19 +2089,29 @@ static void module_enable_nx(const struct module *mod) 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) + return -ENOEXEC; + } + + return 0; +} + #else /* !CONFIG_STRICT_MODULE_RWX */ static void module_enable_nx(const struct module *mod) { } -#endif /* CONFIG_STRICT_MODULE_RWX */ -static void module_enable_x(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) { - frob_text(&mod->core_layout, set_memory_x); - frob_text(&mod->init_layout, set_memory_x); + return 0; } -#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ -static void module_enable_nx(const struct module *mod) { } -static void module_enable_x(const struct module *mod) { } -#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ - +#endif /* CONFIG_STRICT_MODULE_RWX */ #ifdef CONFIG_LIVEPATCH /* @@ -2201,7 +2264,7 @@ void *__symbol_get(const char *symbol) const struct kernel_symbol *sym; preempt_disable(); - sym = find_symbol(symbol, &owner, NULL, true, true); + sym = find_symbol(symbol, &owner, NULL, NULL, true, true); if (sym && strong_try_module_get(owner)) sym = NULL; preempt_enable(); @@ -2237,7 +2300,7 @@ static int verify_exported_symbols(struct module *mod) for (i = 0; i < ARRAY_SIZE(arr); i++) { for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { if (find_symbol(kernel_symbol_name(s), &owner, NULL, - true, false)) { + NULL, true, false)) { pr_err("%s: exports duplicate symbol %s" " (owned by %s)\n", mod->name, kernel_symbol_name(s), @@ -2334,11 +2397,13 @@ static int apply_relocations(struct module *mod, const struct load_info *info) if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) continue; - /* Livepatch relocation sections are applied by livepatch */ if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) - continue; - - if (info->sechdrs[i].sh_type == SHT_REL) + err = klp_apply_section_relocs(mod, info->sechdrs, + info->secstrings, + info->strtab, + info->index.sym, i, + NULL); + else if (info->sechdrs[i].sh_type == SHT_REL) err = apply_relocate(info->sechdrs, info->strtab, info->index.sym, i, mod); else if (info->sechdrs[i].sh_type == SHT_RELA) @@ -2400,7 +2465,7 @@ static void layout_sections(struct module *mod, struct load_info *info) if ((s->sh_flags & masks[m][0]) != masks[m][0] || (s->sh_flags & masks[m][1]) || s->sh_entsize != ~0UL - || strstarts(sname, ".init")) + || module_init_section(sname)) continue; s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i); pr_debug("\t%s\n", sname); @@ -2433,7 +2498,7 @@ static void layout_sections(struct module *mod, struct load_info *info) if ((s->sh_flags & masks[m][0]) != masks[m][0] || (s->sh_flags & masks[m][1]) || s->sh_entsize != ~0UL - || !strstarts(sname, ".init")) + || !module_init_section(sname)) continue; s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i) | INIT_OFFSET_MASK); @@ -2765,7 +2830,14 @@ static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) void * __weak module_alloc(unsigned long size) { - return vmalloc_exec(size); + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, + GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, + NUMA_NO_NODE, __builtin_return_address(0)); +} + +bool __weak module_init_section(const char *name) +{ + return strstarts(name, ".init"); } bool __weak module_exit_section(const char *name) @@ -2946,8 +3018,7 @@ static int copy_module_from_user(const void __user *umod, unsigned long len, return err; /* Suck in entire file: we'll want most of it. */ - info->hdr = __vmalloc(info->len, - GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL); + info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN); if (!info->hdr) return -ENOMEM; @@ -3150,6 +3221,9 @@ static int find_module_sections(struct module *mod, struct load_info *info) } #endif + mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1, + &mod->noinstr_text_size); + #ifdef CONFIG_TRACEPOINTS mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", sizeof(*mod->tracepoints_ptrs), @@ -3194,13 +3268,20 @@ static int find_module_sections(struct module *mod, struct load_info *info) sizeof(*mod->ei_funcs), &mod->num_ei_funcs); #endif +#ifdef CONFIG_KPROBES + mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1, + &mod->kprobes_text_size); + mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist", + sizeof(unsigned long), + &mod->num_kprobe_blacklist); +#endif mod->extable = section_objs(info, "__ex_table", sizeof(*mod->extable), &mod->num_exentries); if (section_addr(info, "__obsparm")) pr_warn("%s: Ignoring obsolete parameters\n", mod->name); - info->debug = section_objs(info, "__verbose", + info->debug = section_objs(info, "__dyndbg", sizeof(*info->debug), &info->num_debug); return 0; @@ -3312,12 +3393,6 @@ static int check_module_license_and_versions(struct module *mod) static void flush_module_icache(const struct module *mod) { - mm_segment_t old_fs; - - /* flush the icache in correct context */ - old_fs = get_fs(); - set_fs(KERNEL_DS); - /* * Flush the instruction cache, since we've played with text. * Do it before processing of module parameters, so the module @@ -3329,8 +3404,6 @@ static void flush_module_icache(const struct module *mod) + mod->init_layout.size); flush_icache_range((unsigned long)mod->core_layout.base, (unsigned long)mod->core_layout.base + mod->core_layout.size); - - set_fs(old_fs); } int __weak module_frob_arch_sections(Elf_Ehdr *hdr, @@ -3378,6 +3451,11 @@ static struct module *layout_and_allocate(struct load_info *info, int flags) if (err < 0) return ERR_PTR(err); + err = module_enforce_rwx_sections(info->hdr, info->sechdrs, + info->secstrings, info->mod); + if (err < 0) + return ERR_PTR(err); + /* We will do a special allocation for per-cpu sections later. */ info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; @@ -4348,13 +4426,14 @@ static int modules_open(struct inode *inode, struct file *file) if (!err) { struct seq_file *m = file->private_data; - m->private = kallsyms_show_value() ? NULL : (void *)8ul; + m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul; } return err; } static const struct proc_ops modules_proc_ops = { + .proc_flags = PROC_ENTRY_PERMANENT, .proc_open = modules_open, .proc_read = seq_read, .proc_lseek = seq_lseek, @@ -4438,7 +4517,6 @@ struct module *__module_address(unsigned long addr) } return mod; } -EXPORT_SYMBOL_GPL(__module_address); /* * is_module_text_address - is this address inside module code? @@ -4477,7 +4555,6 @@ struct module *__module_text_address(unsigned long addr) } return mod; } -EXPORT_SYMBOL_GPL(__module_text_address); /* Don't grab lock, we're oopsing. */ void print_modules(void) |
