1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Module proc support 4 * 5 * Copyright (C) 2008 Alexey Dobriyan 6 */ 7 8 #include <linux/module.h> 9 #include <linux/kallsyms.h> 10 #include <linux/mutex.h> 11 #include <linux/seq_file.h> 12 #include <linux/proc_fs.h> 13 #include "internal.h" 14 15 #ifdef CONFIG_MODULE_UNLOAD 16 static inline void print_unload_info(struct seq_file *m, struct module *mod) 17 { 18 struct module_use *use; 19 int printed_something = 0; 20 21 seq_printf(m, " %i ", module_refcount(mod)); 22 23 /* 24 * Always include a trailing , so userspace can differentiate 25 * between this and the old multi-field proc format. 26 */ 27 list_for_each_entry(use, &mod->source_list, source_list) { 28 printed_something = 1; 29 seq_printf(m, "%s,", use->source->name); 30 } 31 32 if (mod->init && !mod->exit) { 33 printed_something = 1; 34 seq_puts(m, "[permanent],"); 35 } 36 37 if (!printed_something) 38 seq_puts(m, "-"); 39 } 40 #else /* !CONFIG_MODULE_UNLOAD */ 41 static inline void print_unload_info(struct seq_file *m, struct module *mod) 42 { 43 /* We don't know the usage count, or what modules are using. */ 44 seq_puts(m, " - -"); 45 } 46 #endif /* CONFIG_MODULE_UNLOAD */ 47 48 /* Called by the /proc file system to return a list of modules. */ 49 static void *m_start(struct seq_file *m, loff_t *pos) 50 { 51 mutex_lock(&module_mutex); 52 return seq_list_start(&modules, *pos); 53 } 54 55 static void *m_next(struct seq_file *m, void *p, loff_t *pos) 56 { 57 return seq_list_next(p, &modules, pos); 58 } 59 60 static void m_stop(struct seq_file *m, void *p) 61 { 62 mutex_unlock(&module_mutex); 63 } 64 65 static int m_show(struct seq_file *m, void *p) 66 { 67 struct module *mod = list_entry(p, struct module, list); 68 char buf[MODULE_FLAGS_BUF_SIZE]; 69 void *value; 70 unsigned int size; 71 72 /* We always ignore unformed modules. */ 73 if (mod->state == MODULE_STATE_UNFORMED) 74 return 0; 75 76 size = mod->init_layout.size + mod->core_layout.size; 77 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC 78 size += mod->data_layout.size; 79 #endif 80 seq_printf(m, "%s %u", mod->name, size); 81 print_unload_info(m, mod); 82 83 /* Informative for users. */ 84 seq_printf(m, " %s", 85 mod->state == MODULE_STATE_GOING ? "Unloading" : 86 mod->state == MODULE_STATE_COMING ? "Loading" : 87 "Live"); 88 /* Used by oprofile and other similar tools. */ 89 value = m->private ? NULL : mod->core_layout.base; 90 seq_printf(m, " 0x%px", value); 91 92 /* Taints info */ 93 if (mod->taints) 94 seq_printf(m, " %s", module_flags(mod, buf, true)); 95 96 seq_puts(m, "\n"); 97 return 0; 98 } 99 100 /* 101 * Format: modulename size refcount deps address 102 * 103 * Where refcount is a number or -, and deps is a comma-separated list 104 * of depends or -. 105 */ 106 static const struct seq_operations modules_op = { 107 .start = m_start, 108 .next = m_next, 109 .stop = m_stop, 110 .show = m_show 111 }; 112 113 /* 114 * This also sets the "private" pointer to non-NULL if the 115 * kernel pointers should be hidden (so you can just test 116 * "m->private" to see if you should keep the values private). 117 * 118 * We use the same logic as for /proc/kallsyms. 119 */ 120 static int modules_open(struct inode *inode, struct file *file) 121 { 122 int err = seq_open(file, &modules_op); 123 124 if (!err) { 125 struct seq_file *m = file->private_data; 126 127 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul; 128 } 129 130 return err; 131 } 132 133 static const struct proc_ops modules_proc_ops = { 134 .proc_flags = PROC_ENTRY_PERMANENT, 135 .proc_open = modules_open, 136 .proc_read = seq_read, 137 .proc_lseek = seq_lseek, 138 .proc_release = seq_release, 139 }; 140 141 static int __init proc_modules_init(void) 142 { 143 proc_create("modules", 0, NULL, &modules_proc_ops); 144 return 0; 145 } 146 module_init(proc_modules_init); 147