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> |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 26 | #include <linux/proc_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <linux/quotaops.h> |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 28 | #include <linux/perf_counter.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <linux/kernel.h> |
| 30 | #include <linux/module.h> |
| 31 | #include <linux/suspend.h> |
| 32 | #include <linux/writeback.h> |
| 33 | #include <linux/buffer_head.h> /* for fsync_bdev() */ |
| 34 | #include <linux/swap.h> |
| 35 | #include <linux/spinlock.h> |
| 36 | #include <linux/vt_kern.h> |
| 37 | #include <linux/workqueue.h> |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 38 | #include <linux/kexec.h> |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 39 | #include <linux/hrtimer.h> |
David Rientjes | 5a3135c2 | 2007-10-16 23:25:53 -0700 | [diff] [blame] | 40 | #include <linux/oom.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
| 42 | #include <asm/ptrace.h> |
Heiko Carstens | 2033b0c | 2006-10-06 16:38:42 +0200 | [diff] [blame] | 43 | #include <asm/irq_regs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
| 45 | /* Whether we react on sysrq keys or just ignore them */ |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 46 | int __read_mostly __sysrq_enabled = 1; |
| 47 | |
| 48 | static int __read_mostly sysrq_always_enabled; |
| 49 | |
| 50 | int sysrq_on(void) |
| 51 | { |
| 52 | return __sysrq_enabled || sysrq_always_enabled; |
| 53 | } |
| 54 | |
| 55 | /* |
| 56 | * A value of 1 means 'all', other nonzero values are an op mask: |
| 57 | */ |
| 58 | static inline int sysrq_on_mask(int mask) |
| 59 | { |
| 60 | return sysrq_always_enabled || __sysrq_enabled == 1 || |
| 61 | (__sysrq_enabled & mask); |
| 62 | } |
| 63 | |
| 64 | static int __init sysrq_always_enabled_setup(char *str) |
| 65 | { |
| 66 | sysrq_always_enabled = 1; |
| 67 | printk(KERN_INFO "debug: sysrq always enabled.\n"); |
| 68 | |
| 69 | return 1; |
| 70 | } |
| 71 | |
| 72 | __setup("sysrq_always_enabled", sysrq_always_enabled_setup); |
| 73 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 75 | static void sysrq_handle_loglevel(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | { |
| 77 | int i; |
| 78 | i = key - '0'; |
| 79 | console_loglevel = 7; |
| 80 | printk("Loglevel set to %d\n", i); |
| 81 | console_loglevel = i; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 82 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | static struct sysrq_key_op sysrq_loglevel_op = { |
| 84 | .handler = sysrq_handle_loglevel, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 85 | .help_msg = "loglevel(0-9)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | .action_msg = "Changing Loglevel", |
| 87 | .enable_mask = SYSRQ_ENABLE_LOG, |
| 88 | }; |
| 89 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | #ifdef CONFIG_VT |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 91 | static void sysrq_handle_SAK(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | { |
Eric W. Biederman | 8b6312f | 2007-02-10 01:44:34 -0800 | [diff] [blame] | 93 | struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work; |
Eric W. Biederman | 8b6312f | 2007-02-10 01:44:34 -0800 | [diff] [blame] | 94 | schedule_work(SAK_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | } |
| 96 | static struct sysrq_key_op sysrq_SAK_op = { |
| 97 | .handler = sysrq_handle_SAK, |
| 98 | .help_msg = "saK", |
| 99 | .action_msg = "SAK", |
| 100 | .enable_mask = SYSRQ_ENABLE_KEYBOARD, |
| 101 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 102 | #else |
| 103 | #define sysrq_SAK_op (*(struct sysrq_key_op *)0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | #endif |
| 105 | |
| 106 | #ifdef CONFIG_VT |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 107 | static void sysrq_handle_unraw(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | { |
| 109 | struct kbd_struct *kbd = &kbd_table[fg_console]; |
| 110 | |
| 111 | if (kbd) |
Bill Nottingham | 2e8ecb9 | 2007-10-16 23:29:38 -0700 | [diff] [blame] | 112 | kbd->kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | } |
| 114 | static struct sysrq_key_op sysrq_unraw_op = { |
| 115 | .handler = sysrq_handle_unraw, |
| 116 | .help_msg = "unRaw", |
Bill Nottingham | 2e8ecb9 | 2007-10-16 23:29:38 -0700 | [diff] [blame] | 117 | .action_msg = "Keyboard mode set to system default", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | .enable_mask = SYSRQ_ENABLE_KEYBOARD, |
| 119 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 120 | #else |
| 121 | #define sysrq_unraw_op (*(struct sysrq_key_op *)0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | #endif /* CONFIG_VT */ |
| 123 | |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 124 | #ifdef CONFIG_KEXEC |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 125 | static void sysrq_handle_crashdump(int key, struct tty_struct *tty) |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 126 | { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 127 | crash_kexec(get_irq_regs()); |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 128 | } |
| 129 | static struct sysrq_key_op sysrq_crashdump_op = { |
| 130 | .handler = sysrq_handle_crashdump, |
| 131 | .help_msg = "Crashdump", |
| 132 | .action_msg = "Trigger a crashdump", |
| 133 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 134 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 135 | #else |
| 136 | #define sysrq_crashdump_op (*(struct sysrq_key_op *)0) |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 137 | #endif |
| 138 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 139 | static void sysrq_handle_reboot(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | { |
Peter Zijlstra | b2e9c7d | 2006-09-30 23:28:02 -0700 | [diff] [blame] | 141 | lockdep_off(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | local_irq_enable(); |
Eric W. Biederman | 4de8b9b | 2005-07-26 11:51:06 -0600 | [diff] [blame] | 143 | emergency_restart(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | static struct sysrq_key_op sysrq_reboot_op = { |
| 146 | .handler = sysrq_handle_reboot, |
| 147 | .help_msg = "reBoot", |
| 148 | .action_msg = "Resetting", |
| 149 | .enable_mask = SYSRQ_ENABLE_BOOT, |
| 150 | }; |
| 151 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 152 | static void sysrq_handle_sync(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | { |
| 154 | emergency_sync(); |
| 155 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | static struct sysrq_key_op sysrq_sync_op = { |
| 157 | .handler = sysrq_handle_sync, |
| 158 | .help_msg = "Sync", |
| 159 | .action_msg = "Emergency Sync", |
| 160 | .enable_mask = SYSRQ_ENABLE_SYNC, |
| 161 | }; |
| 162 | |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 163 | static void sysrq_handle_show_timers(int key, struct tty_struct *tty) |
| 164 | { |
| 165 | sysrq_timer_list_show(); |
| 166 | } |
| 167 | |
| 168 | static struct sysrq_key_op sysrq_show_timers_op = { |
| 169 | .handler = sysrq_handle_show_timers, |
| 170 | .help_msg = "show-all-timers(Q)", |
Thomas Gleixner | 322acf6 | 2008-10-20 12:33:14 +0200 | [diff] [blame] | 171 | .action_msg = "Show clockevent devices & pending hrtimers (no others)", |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 172 | }; |
| 173 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 174 | static void sysrq_handle_mountro(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | { |
| 176 | emergency_remount(); |
| 177 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | static struct sysrq_key_op sysrq_mountro_op = { |
| 179 | .handler = sysrq_handle_mountro, |
| 180 | .help_msg = "Unmount", |
| 181 | .action_msg = "Emergency Remount R/O", |
| 182 | .enable_mask = SYSRQ_ENABLE_REMOUNT, |
| 183 | }; |
| 184 | |
Ingo Molnar | 8c64580 | 2006-07-03 00:24:56 -0700 | [diff] [blame] | 185 | #ifdef CONFIG_LOCKDEP |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 186 | static void sysrq_handle_showlocks(int key, struct tty_struct *tty) |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 187 | { |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 188 | debug_show_all_locks(); |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 189 | } |
Ingo Molnar | 8c64580 | 2006-07-03 00:24:56 -0700 | [diff] [blame] | 190 | |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 191 | static struct sysrq_key_op sysrq_showlocks_op = { |
| 192 | .handler = sysrq_handle_showlocks, |
| 193 | .help_msg = "show-all-locks(D)", |
| 194 | .action_msg = "Show Locks Held", |
| 195 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 196 | #else |
| 197 | #define sysrq_showlocks_op (*(struct sysrq_key_op *)0) |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 198 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 200 | #ifdef CONFIG_SMP |
| 201 | static DEFINE_SPINLOCK(show_lock); |
| 202 | |
| 203 | static void showacpu(void *dummy) |
| 204 | { |
| 205 | unsigned long flags; |
| 206 | |
| 207 | /* Idle CPUs have no interesting backtrace. */ |
| 208 | if (idle_cpu(smp_processor_id())) |
| 209 | return; |
| 210 | |
| 211 | spin_lock_irqsave(&show_lock, flags); |
| 212 | printk(KERN_INFO "CPU%d:\n", smp_processor_id()); |
| 213 | show_stack(NULL, NULL); |
| 214 | spin_unlock_irqrestore(&show_lock, flags); |
| 215 | } |
| 216 | |
| 217 | static void sysrq_showregs_othercpus(struct work_struct *dummy) |
| 218 | { |
Ingo Molnar | 8b604d5 | 2008-06-27 11:52:45 +0200 | [diff] [blame] | 219 | smp_call_function(showacpu, NULL, 0); |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 220 | } |
| 221 | |
| 222 | static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus); |
| 223 | |
| 224 | static void sysrq_handle_showallcpus(int key, struct tty_struct *tty) |
| 225 | { |
| 226 | struct pt_regs *regs = get_irq_regs(); |
| 227 | if (regs) { |
| 228 | printk(KERN_INFO "CPU%d:\n", smp_processor_id()); |
| 229 | show_regs(regs); |
| 230 | } |
| 231 | schedule_work(&sysrq_showallcpus); |
| 232 | } |
| 233 | |
| 234 | static struct sysrq_key_op sysrq_showallcpus_op = { |
| 235 | .handler = sysrq_handle_showallcpus, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 236 | .help_msg = "show-backtrace-all-active-cpus(L)", |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 237 | .action_msg = "Show backtrace of all active CPUs", |
| 238 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 239 | }; |
| 240 | #endif |
| 241 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 242 | static void sysrq_handle_showregs(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 244 | struct pt_regs *regs = get_irq_regs(); |
| 245 | if (regs) |
| 246 | show_regs(regs); |
Thomas Gleixner | 0793a61 | 2008-12-04 20:12:29 +0100 | [diff] [blame] | 247 | perf_counter_print_debug(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | } |
| 249 | static struct sysrq_key_op sysrq_showregs_op = { |
| 250 | .handler = sysrq_handle_showregs, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 251 | .help_msg = "show-registers(P)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | .action_msg = "Show Regs", |
| 253 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 254 | }; |
| 255 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 256 | static void sysrq_handle_showstate(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | { |
| 258 | show_state(); |
| 259 | } |
| 260 | static struct sysrq_key_op sysrq_showstate_op = { |
| 261 | .handler = sysrq_handle_showstate, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 262 | .help_msg = "show-task-states(T)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | .action_msg = "Show State", |
| 264 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 265 | }; |
| 266 | |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 267 | static void sysrq_handle_showstate_blocked(int key, struct tty_struct *tty) |
| 268 | { |
| 269 | show_state_filter(TASK_UNINTERRUPTIBLE); |
| 270 | } |
| 271 | static struct sysrq_key_op sysrq_showstate_blocked_op = { |
| 272 | .handler = sysrq_handle_showstate_blocked, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 273 | .help_msg = "show-blocked-tasks(W)", |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 274 | .action_msg = "Show Blocked State", |
| 275 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 276 | }; |
| 277 | |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 278 | #ifdef CONFIG_TRACING |
| 279 | #include <linux/ftrace.h> |
| 280 | |
| 281 | static void sysrq_ftrace_dump(int key, struct tty_struct *tty) |
| 282 | { |
| 283 | ftrace_dump(); |
| 284 | } |
| 285 | static struct sysrq_key_op sysrq_ftrace_dump_op = { |
| 286 | .handler = sysrq_ftrace_dump, |
Randy Dunlap | 3871f2f | 2008-12-24 16:06:57 -0800 | [diff] [blame] | 287 | .help_msg = "dump-ftrace-buffer(Z)", |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 288 | .action_msg = "Dump ftrace buffer", |
| 289 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 290 | }; |
| 291 | #else |
| 292 | #define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)0) |
| 293 | #endif |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 294 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 295 | static void sysrq_handle_showmem(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | { |
| 297 | show_mem(); |
| 298 | } |
| 299 | static struct sysrq_key_op sysrq_showmem_op = { |
| 300 | .handler = sysrq_handle_showmem, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 301 | .help_msg = "show-memory-usage(M)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | .action_msg = "Show Memory", |
| 303 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 304 | }; |
| 305 | |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 306 | /* |
| 307 | * Signal sysrq helper function. Sends a signal to all user processes. |
| 308 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | static void send_sig_all(int sig) |
| 310 | { |
| 311 | struct task_struct *p; |
| 312 | |
| 313 | for_each_process(p) { |
Serge E. Hallyn | b460cbc | 2007-10-18 23:39:52 -0700 | [diff] [blame] | 314 | if (p->mm && !is_global_init(p)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | /* Not swapper, init nor kernel thread */ |
| 316 | force_sig(sig, p); |
| 317 | } |
| 318 | } |
| 319 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 320 | static void sysrq_handle_term(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | { |
| 322 | send_sig_all(SIGTERM); |
| 323 | console_loglevel = 8; |
| 324 | } |
| 325 | static struct sysrq_key_op sysrq_term_op = { |
| 326 | .handler = sysrq_handle_term, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 327 | .help_msg = "terminate-all-tasks(E)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | .action_msg = "Terminate All Tasks", |
| 329 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 330 | }; |
| 331 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 332 | static void moom_callback(struct work_struct *ignored) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | { |
Mel Gorman | 0e88460 | 2008-04-28 02:12:14 -0700 | [diff] [blame] | 334 | out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | } |
| 336 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 337 | static DECLARE_WORK(moom_work, moom_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 339 | static void sysrq_handle_moom(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | { |
| 341 | schedule_work(&moom_work); |
| 342 | } |
| 343 | static struct sysrq_key_op sysrq_moom_op = { |
| 344 | .handler = sysrq_handle_moom, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 345 | .help_msg = "memory-full-oom-kill(F)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | .action_msg = "Manual OOM execution", |
Naohiro Ooiwa | b4236f8 | 2008-10-15 22:01:43 -0700 | [diff] [blame] | 347 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | }; |
| 349 | |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 350 | #ifdef CONFIG_BLOCK |
| 351 | static void sysrq_handle_thaw(int key, struct tty_struct *tty) |
| 352 | { |
| 353 | emergency_thaw_all(); |
| 354 | } |
| 355 | static struct sysrq_key_op sysrq_thaw_op = { |
| 356 | .handler = sysrq_handle_thaw, |
| 357 | .help_msg = "thaw-filesystems(J)", |
| 358 | .action_msg = "Emergency Thaw of all frozen filesystems", |
| 359 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 360 | }; |
| 361 | #endif |
| 362 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 363 | static void sysrq_handle_kill(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | { |
| 365 | send_sig_all(SIGKILL); |
| 366 | console_loglevel = 8; |
| 367 | } |
| 368 | static struct sysrq_key_op sysrq_kill_op = { |
| 369 | .handler = sysrq_handle_kill, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 370 | .help_msg = "kill-all-tasks(I)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | .action_msg = "Kill All Tasks", |
| 372 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 373 | }; |
| 374 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 375 | static void sysrq_handle_unrt(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 376 | { |
| 377 | normalize_rt_tasks(); |
| 378 | } |
| 379 | static struct sysrq_key_op sysrq_unrt_op = { |
| 380 | .handler = sysrq_handle_unrt, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 381 | .help_msg = "nice-all-RT-tasks(N)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | .action_msg = "Nice All RT Tasks", |
| 383 | .enable_mask = SYSRQ_ENABLE_RTNICE, |
| 384 | }; |
| 385 | |
| 386 | /* Key Operations table and lock */ |
| 387 | static DEFINE_SPINLOCK(sysrq_key_table_lock); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 388 | |
| 389 | static struct sysrq_key_op *sysrq_key_table[36] = { |
| 390 | &sysrq_loglevel_op, /* 0 */ |
| 391 | &sysrq_loglevel_op, /* 1 */ |
| 392 | &sysrq_loglevel_op, /* 2 */ |
| 393 | &sysrq_loglevel_op, /* 3 */ |
| 394 | &sysrq_loglevel_op, /* 4 */ |
| 395 | &sysrq_loglevel_op, /* 5 */ |
| 396 | &sysrq_loglevel_op, /* 6 */ |
| 397 | &sysrq_loglevel_op, /* 7 */ |
| 398 | &sysrq_loglevel_op, /* 8 */ |
| 399 | &sysrq_loglevel_op, /* 9 */ |
| 400 | |
| 401 | /* |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 402 | * a: Don't use for system provided sysrqs, it is handled specially on |
| 403 | * sparc and will never arrive. |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 404 | */ |
| 405 | NULL, /* a */ |
| 406 | &sysrq_reboot_op, /* b */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 407 | &sysrq_crashdump_op, /* c & ibm_emac driver debug */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 408 | &sysrq_showlocks_op, /* d */ |
| 409 | &sysrq_term_op, /* e */ |
| 410 | &sysrq_moom_op, /* f */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 411 | /* g: May be registered by ppc for kgdb */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 412 | NULL, /* g */ |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 413 | NULL, /* h - reserved for help */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 414 | &sysrq_kill_op, /* i */ |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 415 | #ifdef CONFIG_BLOCK |
| 416 | &sysrq_thaw_op, /* j */ |
| 417 | #else |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 418 | NULL, /* j */ |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 419 | #endif |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 420 | &sysrq_SAK_op, /* k */ |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 421 | #ifdef CONFIG_SMP |
| 422 | &sysrq_showallcpus_op, /* l */ |
| 423 | #else |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 424 | NULL, /* l */ |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 425 | #endif |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 426 | &sysrq_showmem_op, /* m */ |
| 427 | &sysrq_unrt_op, /* n */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 428 | /* o: This will often be registered as 'Off' at init time */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 429 | NULL, /* o */ |
| 430 | &sysrq_showregs_op, /* p */ |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 431 | &sysrq_show_timers_op, /* q */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 432 | &sysrq_unraw_op, /* r */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 433 | &sysrq_sync_op, /* s */ |
| 434 | &sysrq_showstate_op, /* t */ |
| 435 | &sysrq_mountro_op, /* u */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 436 | /* v: May be registered at init time by SMP VOYAGER */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 437 | NULL, /* v */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 438 | &sysrq_showstate_blocked_op, /* w */ |
| 439 | /* x: May be registered on ppc/powerpc for xmon */ |
| 440 | NULL, /* x */ |
David S. Miller | 93dae5b | 2008-05-19 23:46:00 -0700 | [diff] [blame] | 441 | /* y: May be registered on sparc64 for global register dump */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 442 | NULL, /* y */ |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 443 | &sysrq_ftrace_dump_op, /* z */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | }; |
| 445 | |
| 446 | /* key2index calculation, -1 on invalid index */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 447 | static int sysrq_key_table_key2index(int key) |
| 448 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | int retval; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 450 | |
| 451 | if ((key >= '0') && (key <= '9')) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | retval = key - '0'; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 453 | else if ((key >= 'a') && (key <= 'z')) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | retval = key + 10 - 'a'; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 455 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | retval = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | return retval; |
| 458 | } |
| 459 | |
| 460 | /* |
| 461 | * get and put functions for the table, exposed to modules. |
| 462 | */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 463 | struct sysrq_key_op *__sysrq_get_key_op(int key) |
| 464 | { |
| 465 | struct sysrq_key_op *op_p = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | int i; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 467 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | i = sysrq_key_table_key2index(key); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 469 | if (i != -1) |
| 470 | op_p = sysrq_key_table[i]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | return op_p; |
| 472 | } |
| 473 | |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 474 | static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p) |
| 475 | { |
| 476 | int i = sysrq_key_table_key2index(key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | if (i != -1) |
| 479 | sysrq_key_table[i] = op_p; |
| 480 | } |
| 481 | |
| 482 | /* |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 483 | * This is the non-locking version of handle_sysrq. It must/can only be called |
| 484 | * by sysrq key handlers, as they are inside of the lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 486 | void __handle_sysrq(int key, struct tty_struct *tty, int check_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | { |
| 488 | struct sysrq_key_op *op_p; |
| 489 | int orig_log_level; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 490 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | unsigned long flags; |
| 492 | |
| 493 | spin_lock_irqsave(&sysrq_key_table_lock, flags); |
Andy Whitcroft | fb144ad | 2009-01-15 13:50:52 -0800 | [diff] [blame] | 494 | /* |
| 495 | * Raise the apparent loglevel to maximum so that the sysrq header |
| 496 | * is shown to provide the user with positive feedback. We do not |
| 497 | * simply emit this at KERN_EMERG as that would change message |
| 498 | * routing in the consumers of /proc/kmsg. |
| 499 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | orig_log_level = console_loglevel; |
| 501 | console_loglevel = 7; |
| 502 | printk(KERN_INFO "SysRq : "); |
| 503 | |
| 504 | op_p = __sysrq_get_key_op(key); |
| 505 | if (op_p) { |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 506 | /* |
| 507 | * Should we check for enabled operations (/proc/sysrq-trigger |
| 508 | * should not) and is the invoked operation enabled? |
| 509 | */ |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 510 | if (!check_mask || sysrq_on_mask(op_p->enable_mask)) { |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 511 | printk("%s\n", op_p->action_msg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | console_loglevel = orig_log_level; |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 513 | op_p->handler(key, tty); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 514 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | printk("This sysrq operation is disabled.\n"); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 516 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | } else { |
| 518 | printk("HELP : "); |
| 519 | /* Only print the help msg once per handler */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 520 | for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) { |
| 521 | if (sysrq_key_table[i]) { |
| 522 | int j; |
| 523 | |
| 524 | for (j = 0; sysrq_key_table[i] != |
| 525 | sysrq_key_table[j]; j++) |
| 526 | ; |
| 527 | if (j != i) |
| 528 | continue; |
| 529 | printk("%s ", sysrq_key_table[i]->help_msg); |
| 530 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 532 | printk("\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | console_loglevel = orig_log_level; |
| 534 | } |
| 535 | spin_unlock_irqrestore(&sysrq_key_table_lock, flags); |
| 536 | } |
| 537 | |
| 538 | /* |
| 539 | * This function is called by the keyboard handler when SysRq is pressed |
| 540 | * and any other keycode arrives. |
| 541 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 542 | void handle_sysrq(int key, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | { |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 544 | if (sysrq_on()) |
| 545 | __handle_sysrq(key, tty, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 547 | EXPORT_SYMBOL(handle_sysrq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | |
Adrian Bunk | cf62ddc | 2005-11-08 21:39:47 -0800 | [diff] [blame] | 549 | 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] | 550 | struct sysrq_key_op *remove_op_p) |
| 551 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | |
| 553 | int retval; |
| 554 | unsigned long flags; |
| 555 | |
| 556 | spin_lock_irqsave(&sysrq_key_table_lock, flags); |
| 557 | if (__sysrq_get_key_op(key) == remove_op_p) { |
| 558 | __sysrq_put_key_op(key, insert_op_p); |
| 559 | retval = 0; |
| 560 | } else { |
| 561 | retval = -1; |
| 562 | } |
| 563 | spin_unlock_irqrestore(&sysrq_key_table_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | return retval; |
| 565 | } |
| 566 | |
| 567 | int register_sysrq_key(int key, struct sysrq_key_op *op_p) |
| 568 | { |
| 569 | return __sysrq_swap_key_ops(key, op_p, NULL); |
| 570 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 571 | EXPORT_SYMBOL(register_sysrq_key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | |
| 573 | int unregister_sysrq_key(int key, struct sysrq_key_op *op_p) |
| 574 | { |
| 575 | return __sysrq_swap_key_ops(key, NULL, op_p); |
| 576 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | EXPORT_SYMBOL(unregister_sysrq_key); |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 578 | |
| 579 | #ifdef CONFIG_PROC_FS |
| 580 | /* |
| 581 | * writing 'C' to /proc/sysrq-trigger is like sysrq-C |
| 582 | */ |
| 583 | static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf, |
| 584 | size_t count, loff_t *ppos) |
| 585 | { |
| 586 | if (count) { |
| 587 | char c; |
| 588 | |
| 589 | if (get_user(c, buf)) |
| 590 | return -EFAULT; |
| 591 | __handle_sysrq(c, NULL, 0); |
| 592 | } |
| 593 | return count; |
| 594 | } |
| 595 | |
| 596 | static const struct file_operations proc_sysrq_trigger_operations = { |
| 597 | .write = write_sysrq_trigger, |
| 598 | }; |
| 599 | |
| 600 | static int __init sysrq_init(void) |
| 601 | { |
| 602 | proc_create("sysrq-trigger", S_IWUSR, NULL, &proc_sysrq_trigger_operations); |
| 603 | return 0; |
| 604 | } |
| 605 | module_init(sysrq_init); |
| 606 | #endif |