diff options
Diffstat (limited to 'kernel/module.c')
-rw-r--r-- | kernel/module.c | 89 |
1 files changed, 57 insertions, 32 deletions
diff --git a/kernel/module.c b/kernel/module.c index dcf2cc656e7c..9f35e1927807 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -208,7 +208,8 @@ static struct module *mod_find(unsigned long addr) { struct module *mod; - list_for_each_entry_rcu(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list, + lockdep_is_held(&module_mutex)) { if (within_module(addr, mod)) return mod; } @@ -442,7 +443,8 @@ bool each_symbol_section(bool (*fn)(const struct symsearch *arr, if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) return true; - list_for_each_entry_rcu(mod, &modules, list) { + 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, false }, @@ -602,7 +604,8 @@ static struct module *find_module_all(const char *name, size_t len, module_assert_mutex_or_preempt(); - list_for_each_entry_rcu(mod, &modules, list) { + 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)) @@ -1019,6 +1022,8 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, 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); @@ -1447,8 +1452,7 @@ 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; }; @@ -1458,13 +1462,34 @@ struct module_sect_attrs { struct module_sect_attr attrs[0]; }; -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) @@ -1472,7 +1497,7 @@ 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); } @@ -1481,7 +1506,7 @@ 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++) @@ -1489,35 +1514,34 @@ static void add_sect_attrs(struct module *mod, const struct load_info *info) nloaded++; size[0] = ALIGN(sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0]), - 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; @@ -1607,7 +1631,7 @@ 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; @@ -1725,6 +1749,8 @@ static int module_add_modinfo_attrs(struct module *mod) error_out: if (i > 0) module_remove_modinfo_attrs(mod, --i); + else + kfree(mod->modinfo_attrs); return error; } @@ -2957,9 +2983,7 @@ static int setup_load_info(struct load_info *info, int flags) /* Try to find a name early so we can log errors with a module name */ info->index.info = find_sec(info, ".modinfo"); - if (!info->index.info) - info->name = "(missing .modinfo section)"; - else + if (info->index.info) info->name = get_modinfo(info, "name"); /* Find internal symbols and strings. */ @@ -2974,14 +2998,15 @@ static int setup_load_info(struct load_info *info, int flags) } if (info->index.sym == 0) { - pr_warn("%s: module has no symbols (stripped?)\n", info->name); + pr_warn("%s: module has no symbols (stripped?)\n", + info->name ?: "(missing .modinfo section or name field)"); return -ENOEXEC; } info->index.mod = find_sec(info, ".gnu.linkonce.this_module"); if (!info->index.mod) { pr_warn("%s: No module found in object\n", - info->name ?: "(missing .modinfo name field)"); + info->name ?: "(missing .modinfo section or name field)"); return -ENOEXEC; } /* This is temporary: point mod into copy of data. */ @@ -4285,7 +4310,7 @@ 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; |