Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 | // SPDX-License-Identifier: GPL-2.0-only /* * srm_env.c - Access to SRM environment * variables through linux' procfs * * (C) 2001,2002,2006 by Jan-Benedict Glaw <jbglaw@lug-owl.de> * * This driver is a modified version of Erik Mouw's example proc * interface, so: thank you, Erik! He can be reached via email at * <J.A.K.Mouw@its.tudelft.nl>. It is based on an idea * provided by DEC^WCompaq^WIntel's "Jumpstart" CD. They * included a patch like this as well. Thanks for idea! */ #include <linux/kernel.h> #include <linux/gfp.h> #include <linux/module.h> #include <linux/init.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <asm/console.h> #include <linux/uaccess.h> #include <asm/machvec.h> #define BASE_DIR "srm_environment" /* Subdir in /proc/ */ #define NAMED_DIR "named_variables" /* Subdir for known variables */ #define NUMBERED_DIR "numbered_variables" /* Subdir for all variables */ #define VERSION "0.0.6" /* Module version */ #define NAME "srm_env" /* Module name */ MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>"); MODULE_DESCRIPTION("Accessing Alpha SRM environment through procfs interface"); MODULE_LICENSE("GPL"); typedef struct _srm_env { char *name; unsigned long id; } srm_env_t; static struct proc_dir_entry *base_dir; static struct proc_dir_entry *named_dir; static struct proc_dir_entry *numbered_dir; static srm_env_t srm_named_entries[] = { { "auto_action", ENV_AUTO_ACTION }, { "boot_dev", ENV_BOOT_DEV }, { "bootdef_dev", ENV_BOOTDEF_DEV }, { "booted_dev", ENV_BOOTED_DEV }, { "boot_file", ENV_BOOT_FILE }, { "booted_file", ENV_BOOTED_FILE }, { "boot_osflags", ENV_BOOT_OSFLAGS }, { "booted_osflags", ENV_BOOTED_OSFLAGS }, { "boot_reset", ENV_BOOT_RESET }, { "dump_dev", ENV_DUMP_DEV }, { "enable_audit", ENV_ENABLE_AUDIT }, { "license", ENV_LICENSE }, { "char_set", ENV_CHAR_SET }, { "language", ENV_LANGUAGE }, { "tty_dev", ENV_TTY_DEV }, { NULL, 0 }, }; static int srm_env_proc_show(struct seq_file *m, void *v) { unsigned long ret; unsigned long id = (unsigned long)m->private; char *page; page = (char *)__get_free_page(GFP_USER); if (!page) return -ENOMEM; ret = callback_getenv(id, page, PAGE_SIZE); if ((ret >> 61) == 0) { seq_write(m, page, ret); ret = 0; } else ret = -EFAULT; free_page((unsigned long)page); return ret; } static int srm_env_proc_open(struct inode *inode, struct file *file) { return single_open(file, srm_env_proc_show, pde_data(inode)); } static ssize_t srm_env_proc_write(struct file *file, const char __user *buffer, size_t count, loff_t *pos) { int res; unsigned long id = (unsigned long)pde_data(file_inode(file)); char *buf = (char *) __get_free_page(GFP_USER); unsigned long ret1, ret2; if (!buf) return -ENOMEM; res = -EINVAL; if (count >= PAGE_SIZE) goto out; res = -EFAULT; if (copy_from_user(buf, buffer, count)) goto out; buf[count] = '\0'; ret1 = callback_setenv(id, buf, count); if ((ret1 >> 61) == 0) { do ret2 = callback_save_env(); while((ret2 >> 61) == 1); res = (int) ret1; } out: free_page((unsigned long)buf); return res; } static const struct proc_ops srm_env_proc_ops = { .proc_open = srm_env_proc_open, .proc_read = seq_read, .proc_lseek = seq_lseek, .proc_release = single_release, .proc_write = srm_env_proc_write, }; static int __init srm_env_init(void) { srm_env_t *entry; unsigned long var_num; /* * Check system */ if (!alpha_using_srm) { printk(KERN_INFO "%s: This Alpha system doesn't " "know about SRM (or you've booted " "SRM->MILO->Linux, which gets " "misdetected)...\n", __func__); return -ENODEV; } /* * Create base directory */ base_dir = proc_mkdir(BASE_DIR, NULL); if (!base_dir) { printk(KERN_ERR "Couldn't create base dir /proc/%s\n", BASE_DIR); return -ENOMEM; } /* * Create per-name subdirectory */ named_dir = proc_mkdir(NAMED_DIR, base_dir); if (!named_dir) { printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n", BASE_DIR, NAMED_DIR); goto cleanup; } /* * Create per-number subdirectory */ numbered_dir = proc_mkdir(NUMBERED_DIR, base_dir); if (!numbered_dir) { printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n", BASE_DIR, NUMBERED_DIR); goto cleanup; } /* * Create all named nodes */ entry = srm_named_entries; while (entry->name && entry->id) { if (!proc_create_data(entry->name, 0644, named_dir, &srm_env_proc_ops, (void *)entry->id)) goto cleanup; entry++; } /* * Create all numbered nodes */ for (var_num = 0; var_num <= 255; var_num++) { char name[4]; sprintf(name, "%ld", var_num); if (!proc_create_data(name, 0644, numbered_dir, &srm_env_proc_ops, (void *)var_num)) goto cleanup; } printk(KERN_INFO "%s: version %s loaded successfully\n", NAME, VERSION); return 0; cleanup: remove_proc_subtree(BASE_DIR, NULL); return -ENOMEM; } static void __exit srm_env_exit(void) { remove_proc_subtree(BASE_DIR, NULL); printk(KERN_INFO "%s: unloaded successfully\n", NAME); } module_init(srm_env_init); module_exit(srm_env_exit); |