Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* -*- linux-c -*- |
| 2 | * |
| 3 | * $Id: sysrq.c,v 1.15 1998/08/23 14:56:41 mj Exp $ |
| 4 | * |
| 5 | * Linux Magic System Request Key Hacks |
| 6 | * |
| 7 | * (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> |
| 8 | * based on ideas by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz> |
| 9 | * |
| 10 | * (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com> |
| 11 | * overhauled to use key registration |
| 12 | * based upon discusions in irc://irc.openprojects.net/#kernelnewbies |
| 13 | */ |
| 14 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/sched.h> |
| 16 | #include <linux/interrupt.h> |
| 17 | #include <linux/mm.h> |
| 18 | #include <linux/fs.h> |
| 19 | #include <linux/tty.h> |
| 20 | #include <linux/mount.h> |
| 21 | #include <linux/kdev_t.h> |
| 22 | #include <linux/major.h> |
| 23 | #include <linux/reboot.h> |
| 24 | #include <linux/sysrq.h> |
| 25 | #include <linux/kbd_kern.h> |
| 26 | #include <linux/quotaops.h> |
| 27 | #include <linux/smp_lock.h> |
| 28 | #include <linux/kernel.h> |
| 29 | #include <linux/module.h> |
| 30 | #include <linux/suspend.h> |
| 31 | #include <linux/writeback.h> |
| 32 | #include <linux/buffer_head.h> /* for fsync_bdev() */ |
| 33 | #include <linux/swap.h> |
| 34 | #include <linux/spinlock.h> |
| 35 | #include <linux/vt_kern.h> |
| 36 | #include <linux/workqueue.h> |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 37 | #include <linux/kexec.h> |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 38 | #include <linux/irq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
| 40 | #include <asm/ptrace.h> |
Heiko Carstens | 2033b0c | 2006-10-06 16:38:42 +0200 | [diff] [blame] | 41 | #include <asm/irq_regs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | |
| 43 | /* Whether we react on sysrq keys or just ignore them */ |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 44 | int __read_mostly __sysrq_enabled = 1; |
| 45 | |
| 46 | static int __read_mostly sysrq_always_enabled; |
| 47 | |
| 48 | int sysrq_on(void) |
| 49 | { |
| 50 | return __sysrq_enabled || sysrq_always_enabled; |
| 51 | } |
| 52 | |
| 53 | /* |
| 54 | * A value of 1 means 'all', other nonzero values are an op mask: |
| 55 | */ |
| 56 | static inline int sysrq_on_mask(int mask) |
| 57 | { |
| 58 | return sysrq_always_enabled || __sysrq_enabled == 1 || |
| 59 | (__sysrq_enabled & mask); |
| 60 | } |
| 61 | |
| 62 | static int __init sysrq_always_enabled_setup(char *str) |
| 63 | { |
| 64 | sysrq_always_enabled = 1; |
| 65 | printk(KERN_INFO "debug: sysrq always enabled.\n"); |
| 66 | |
| 67 | return 1; |
| 68 | } |
| 69 | |
| 70 | __setup("sysrq_always_enabled", sysrq_always_enabled_setup); |
| 71 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 73 | static void sysrq_handle_loglevel(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | { |
| 75 | int i; |
| 76 | i = key - '0'; |
| 77 | console_loglevel = 7; |
| 78 | printk("Loglevel set to %d\n", i); |
| 79 | console_loglevel = i; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 80 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | static struct sysrq_key_op sysrq_loglevel_op = { |
| 82 | .handler = sysrq_handle_loglevel, |
| 83 | .help_msg = "loglevel0-8", |
| 84 | .action_msg = "Changing Loglevel", |
| 85 | .enable_mask = SYSRQ_ENABLE_LOG, |
| 86 | }; |
| 87 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | #ifdef CONFIG_VT |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 89 | static void sysrq_handle_SAK(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | { |
| 91 | if (tty) |
| 92 | do_SAK(tty); |
| 93 | reset_vc(vc_cons[fg_console].d); |
| 94 | } |
| 95 | static struct sysrq_key_op sysrq_SAK_op = { |
| 96 | .handler = sysrq_handle_SAK, |
| 97 | .help_msg = "saK", |
| 98 | .action_msg = "SAK", |
| 99 | .enable_mask = SYSRQ_ENABLE_KEYBOARD, |
| 100 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 101 | #else |
| 102 | #define sysrq_SAK_op (*(struct sysrq_key_op *)0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | #endif |
| 104 | |
| 105 | #ifdef CONFIG_VT |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 106 | static void sysrq_handle_unraw(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | { |
| 108 | struct kbd_struct *kbd = &kbd_table[fg_console]; |
| 109 | |
| 110 | if (kbd) |
| 111 | kbd->kbdmode = VC_XLATE; |
| 112 | } |
| 113 | static struct sysrq_key_op sysrq_unraw_op = { |
| 114 | .handler = sysrq_handle_unraw, |
| 115 | .help_msg = "unRaw", |
| 116 | .action_msg = "Keyboard mode set to XLATE", |
| 117 | .enable_mask = SYSRQ_ENABLE_KEYBOARD, |
| 118 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 119 | #else |
| 120 | #define sysrq_unraw_op (*(struct sysrq_key_op *)0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | #endif /* CONFIG_VT */ |
| 122 | |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 123 | #ifdef CONFIG_KEXEC |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 124 | static void sysrq_handle_crashdump(int key, struct tty_struct *tty) |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 125 | { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 126 | crash_kexec(get_irq_regs()); |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 127 | } |
| 128 | static struct sysrq_key_op sysrq_crashdump_op = { |
| 129 | .handler = sysrq_handle_crashdump, |
| 130 | .help_msg = "Crashdump", |
| 131 | .action_msg = "Trigger a crashdump", |
| 132 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 133 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 134 | #else |
| 135 | #define sysrq_crashdump_op (*(struct sysrq_key_op *)0) |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 136 | #endif |
| 137 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 138 | static void sysrq_handle_reboot(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | { |
Peter Zijlstra | b2e9c7d | 2006-09-30 23:28:02 -0700 | [diff] [blame] | 140 | lockdep_off(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | local_irq_enable(); |
Eric W. Biederman | 4de8b9b | 2005-07-26 11:51:06 -0600 | [diff] [blame] | 142 | emergency_restart(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | static struct sysrq_key_op sysrq_reboot_op = { |
| 145 | .handler = sysrq_handle_reboot, |
| 146 | .help_msg = "reBoot", |
| 147 | .action_msg = "Resetting", |
| 148 | .enable_mask = SYSRQ_ENABLE_BOOT, |
| 149 | }; |
| 150 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 151 | static void sysrq_handle_sync(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | { |
| 153 | emergency_sync(); |
| 154 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | static struct sysrq_key_op sysrq_sync_op = { |
| 156 | .handler = sysrq_handle_sync, |
| 157 | .help_msg = "Sync", |
| 158 | .action_msg = "Emergency Sync", |
| 159 | .enable_mask = SYSRQ_ENABLE_SYNC, |
| 160 | }; |
| 161 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 162 | static void sysrq_handle_mountro(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | { |
| 164 | emergency_remount(); |
| 165 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | static struct sysrq_key_op sysrq_mountro_op = { |
| 167 | .handler = sysrq_handle_mountro, |
| 168 | .help_msg = "Unmount", |
| 169 | .action_msg = "Emergency Remount R/O", |
| 170 | .enable_mask = SYSRQ_ENABLE_REMOUNT, |
| 171 | }; |
| 172 | |
Ingo Molnar | 8c64580 | 2006-07-03 00:24:56 -0700 | [diff] [blame] | 173 | #ifdef CONFIG_LOCKDEP |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 174 | static void sysrq_handle_showlocks(int key, struct tty_struct *tty) |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 175 | { |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 176 | debug_show_all_locks(); |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 177 | } |
Ingo Molnar | 8c64580 | 2006-07-03 00:24:56 -0700 | [diff] [blame] | 178 | |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 179 | static struct sysrq_key_op sysrq_showlocks_op = { |
| 180 | .handler = sysrq_handle_showlocks, |
| 181 | .help_msg = "show-all-locks(D)", |
| 182 | .action_msg = "Show Locks Held", |
| 183 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 184 | #else |
| 185 | #define sysrq_showlocks_op (*(struct sysrq_key_op *)0) |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 186 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 188 | static void sysrq_handle_showregs(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 190 | struct pt_regs *regs = get_irq_regs(); |
| 191 | if (regs) |
| 192 | show_regs(regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | } |
| 194 | static struct sysrq_key_op sysrq_showregs_op = { |
| 195 | .handler = sysrq_handle_showregs, |
| 196 | .help_msg = "showPc", |
| 197 | .action_msg = "Show Regs", |
| 198 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 199 | }; |
| 200 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 201 | static void sysrq_handle_showstate(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | { |
| 203 | show_state(); |
| 204 | } |
| 205 | static struct sysrq_key_op sysrq_showstate_op = { |
| 206 | .handler = sysrq_handle_showstate, |
| 207 | .help_msg = "showTasks", |
| 208 | .action_msg = "Show State", |
| 209 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 210 | }; |
| 211 | |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 212 | static void sysrq_handle_showstate_blocked(int key, struct tty_struct *tty) |
| 213 | { |
| 214 | show_state_filter(TASK_UNINTERRUPTIBLE); |
| 215 | } |
| 216 | static struct sysrq_key_op sysrq_showstate_blocked_op = { |
| 217 | .handler = sysrq_handle_showstate_blocked, |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame^] | 218 | .help_msg = "shoW-blocked-tasks", |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 219 | .action_msg = "Show Blocked State", |
| 220 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 221 | }; |
| 222 | |
| 223 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 224 | static void sysrq_handle_showmem(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | { |
| 226 | show_mem(); |
| 227 | } |
| 228 | static struct sysrq_key_op sysrq_showmem_op = { |
| 229 | .handler = sysrq_handle_showmem, |
| 230 | .help_msg = "showMem", |
| 231 | .action_msg = "Show Memory", |
| 232 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 233 | }; |
| 234 | |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 235 | /* |
| 236 | * Signal sysrq helper function. Sends a signal to all user processes. |
| 237 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | static void send_sig_all(int sig) |
| 239 | { |
| 240 | struct task_struct *p; |
| 241 | |
| 242 | for_each_process(p) { |
Sukadev Bhattiprolu | f400e19 | 2006-09-29 02:00:07 -0700 | [diff] [blame] | 243 | if (p->mm && !is_init(p)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | /* Not swapper, init nor kernel thread */ |
| 245 | force_sig(sig, p); |
| 246 | } |
| 247 | } |
| 248 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 249 | static void sysrq_handle_term(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | { |
| 251 | send_sig_all(SIGTERM); |
| 252 | console_loglevel = 8; |
| 253 | } |
| 254 | static struct sysrq_key_op sysrq_term_op = { |
| 255 | .handler = sysrq_handle_term, |
| 256 | .help_msg = "tErm", |
| 257 | .action_msg = "Terminate All Tasks", |
| 258 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 259 | }; |
| 260 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 261 | static void moom_callback(struct work_struct *ignored) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | { |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 263 | out_of_memory(&NODE_DATA(0)->node_zonelists[ZONE_NORMAL], |
| 264 | GFP_KERNEL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | } |
| 266 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 267 | static DECLARE_WORK(moom_work, moom_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 269 | static void sysrq_handle_moom(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | { |
| 271 | schedule_work(&moom_work); |
| 272 | } |
| 273 | static struct sysrq_key_op sysrq_moom_op = { |
| 274 | .handler = sysrq_handle_moom, |
| 275 | .help_msg = "Full", |
| 276 | .action_msg = "Manual OOM execution", |
| 277 | }; |
| 278 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 279 | static void sysrq_handle_kill(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | { |
| 281 | send_sig_all(SIGKILL); |
| 282 | console_loglevel = 8; |
| 283 | } |
| 284 | static struct sysrq_key_op sysrq_kill_op = { |
| 285 | .handler = sysrq_handle_kill, |
| 286 | .help_msg = "kIll", |
| 287 | .action_msg = "Kill All Tasks", |
| 288 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 289 | }; |
| 290 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 291 | static void sysrq_handle_unrt(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | { |
| 293 | normalize_rt_tasks(); |
| 294 | } |
| 295 | static struct sysrq_key_op sysrq_unrt_op = { |
| 296 | .handler = sysrq_handle_unrt, |
| 297 | .help_msg = "Nice", |
| 298 | .action_msg = "Nice All RT Tasks", |
| 299 | .enable_mask = SYSRQ_ENABLE_RTNICE, |
| 300 | }; |
| 301 | |
| 302 | /* Key Operations table and lock */ |
| 303 | static DEFINE_SPINLOCK(sysrq_key_table_lock); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 304 | |
| 305 | static struct sysrq_key_op *sysrq_key_table[36] = { |
| 306 | &sysrq_loglevel_op, /* 0 */ |
| 307 | &sysrq_loglevel_op, /* 1 */ |
| 308 | &sysrq_loglevel_op, /* 2 */ |
| 309 | &sysrq_loglevel_op, /* 3 */ |
| 310 | &sysrq_loglevel_op, /* 4 */ |
| 311 | &sysrq_loglevel_op, /* 5 */ |
| 312 | &sysrq_loglevel_op, /* 6 */ |
| 313 | &sysrq_loglevel_op, /* 7 */ |
| 314 | &sysrq_loglevel_op, /* 8 */ |
| 315 | &sysrq_loglevel_op, /* 9 */ |
| 316 | |
| 317 | /* |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame^] | 318 | * a: Don't use for system provided sysrqs, it is handled specially on |
| 319 | * sparc and will never arrive. |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 320 | */ |
| 321 | NULL, /* a */ |
| 322 | &sysrq_reboot_op, /* b */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame^] | 323 | &sysrq_crashdump_op, /* c & ibm_emac driver debug */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 324 | &sysrq_showlocks_op, /* d */ |
| 325 | &sysrq_term_op, /* e */ |
| 326 | &sysrq_moom_op, /* f */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame^] | 327 | /* g: May be registered by ppc for kgdb */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 328 | NULL, /* g */ |
| 329 | NULL, /* h */ |
| 330 | &sysrq_kill_op, /* i */ |
| 331 | NULL, /* j */ |
| 332 | &sysrq_SAK_op, /* k */ |
| 333 | NULL, /* l */ |
| 334 | &sysrq_showmem_op, /* m */ |
| 335 | &sysrq_unrt_op, /* n */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame^] | 336 | /* o: This will often be registered as 'Off' at init time */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 337 | NULL, /* o */ |
| 338 | &sysrq_showregs_op, /* p */ |
| 339 | NULL, /* q */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame^] | 340 | &sysrq_unraw_op, /* r */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 341 | &sysrq_sync_op, /* s */ |
| 342 | &sysrq_showstate_op, /* t */ |
| 343 | &sysrq_mountro_op, /* u */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame^] | 344 | /* v: May be registered at init time by SMP VOYAGER */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 345 | NULL, /* v */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame^] | 346 | &sysrq_showstate_blocked_op, /* w */ |
| 347 | /* x: May be registered on ppc/powerpc for xmon */ |
| 348 | NULL, /* x */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 349 | NULL, /* y */ |
| 350 | NULL /* z */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | }; |
| 352 | |
| 353 | /* key2index calculation, -1 on invalid index */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 354 | static int sysrq_key_table_key2index(int key) |
| 355 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | int retval; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 357 | |
| 358 | if ((key >= '0') && (key <= '9')) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | retval = key - '0'; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 360 | else if ((key >= 'a') && (key <= 'z')) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | retval = key + 10 - 'a'; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 362 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | retval = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | return retval; |
| 365 | } |
| 366 | |
| 367 | /* |
| 368 | * get and put functions for the table, exposed to modules. |
| 369 | */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 370 | struct sysrq_key_op *__sysrq_get_key_op(int key) |
| 371 | { |
| 372 | struct sysrq_key_op *op_p = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | int i; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 374 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | i = sysrq_key_table_key2index(key); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 376 | if (i != -1) |
| 377 | op_p = sysrq_key_table[i]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 378 | return op_p; |
| 379 | } |
| 380 | |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 381 | static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p) |
| 382 | { |
| 383 | int i = sysrq_key_table_key2index(key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | if (i != -1) |
| 386 | sysrq_key_table[i] = op_p; |
| 387 | } |
| 388 | |
| 389 | /* |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 390 | * This is the non-locking version of handle_sysrq. It must/can only be called |
| 391 | * by sysrq key handlers, as they are inside of the lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 393 | void __handle_sysrq(int key, struct tty_struct *tty, int check_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | { |
| 395 | struct sysrq_key_op *op_p; |
| 396 | int orig_log_level; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 397 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | unsigned long flags; |
| 399 | |
| 400 | spin_lock_irqsave(&sysrq_key_table_lock, flags); |
| 401 | orig_log_level = console_loglevel; |
| 402 | console_loglevel = 7; |
| 403 | printk(KERN_INFO "SysRq : "); |
| 404 | |
| 405 | op_p = __sysrq_get_key_op(key); |
| 406 | if (op_p) { |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 407 | /* |
| 408 | * Should we check for enabled operations (/proc/sysrq-trigger |
| 409 | * should not) and is the invoked operation enabled? |
| 410 | */ |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 411 | if (!check_mask || sysrq_on_mask(op_p->enable_mask)) { |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 412 | printk("%s\n", op_p->action_msg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | console_loglevel = orig_log_level; |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 414 | op_p->handler(key, tty); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 415 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | printk("This sysrq operation is disabled.\n"); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 417 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | } else { |
| 419 | printk("HELP : "); |
| 420 | /* Only print the help msg once per handler */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 421 | for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) { |
| 422 | if (sysrq_key_table[i]) { |
| 423 | int j; |
| 424 | |
| 425 | for (j = 0; sysrq_key_table[i] != |
| 426 | sysrq_key_table[j]; j++) |
| 427 | ; |
| 428 | if (j != i) |
| 429 | continue; |
| 430 | printk("%s ", sysrq_key_table[i]->help_msg); |
| 431 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 433 | printk("\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | console_loglevel = orig_log_level; |
| 435 | } |
| 436 | spin_unlock_irqrestore(&sysrq_key_table_lock, flags); |
| 437 | } |
| 438 | |
| 439 | /* |
| 440 | * This function is called by the keyboard handler when SysRq is pressed |
| 441 | * and any other keycode arrives. |
| 442 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 443 | void handle_sysrq(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | { |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 445 | if (sysrq_on()) |
| 446 | __handle_sysrq(key, tty, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 448 | EXPORT_SYMBOL(handle_sysrq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | |
Adrian Bunk | cf62ddc | 2005-11-08 21:39:47 -0800 | [diff] [blame] | 450 | static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p, |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 451 | struct sysrq_key_op *remove_op_p) |
| 452 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | |
| 454 | int retval; |
| 455 | unsigned long flags; |
| 456 | |
| 457 | spin_lock_irqsave(&sysrq_key_table_lock, flags); |
| 458 | if (__sysrq_get_key_op(key) == remove_op_p) { |
| 459 | __sysrq_put_key_op(key, insert_op_p); |
| 460 | retval = 0; |
| 461 | } else { |
| 462 | retval = -1; |
| 463 | } |
| 464 | spin_unlock_irqrestore(&sysrq_key_table_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | return retval; |
| 466 | } |
| 467 | |
| 468 | int register_sysrq_key(int key, struct sysrq_key_op *op_p) |
| 469 | { |
| 470 | return __sysrq_swap_key_ops(key, op_p, NULL); |
| 471 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 472 | EXPORT_SYMBOL(register_sysrq_key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | |
| 474 | int unregister_sysrq_key(int key, struct sysrq_key_op *op_p) |
| 475 | { |
| 476 | return __sysrq_swap_key_ops(key, NULL, op_p); |
| 477 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | EXPORT_SYMBOL(unregister_sysrq_key); |