Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Linux Magic System Request Key Hacks |
| 3 | * |
| 4 | * (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> |
| 5 | * based on ideas by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz> |
| 6 | * |
| 7 | * (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com> |
| 8 | * overhauled to use key registration |
| 9 | * based upon discusions in irc://irc.openprojects.net/#kernelnewbies |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 10 | * |
| 11 | * Copyright (c) 2010 Dmitry Torokhov |
| 12 | * Input handler conversion |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | */ |
| 14 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 15 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 16 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/sched.h> |
| 18 | #include <linux/interrupt.h> |
| 19 | #include <linux/mm.h> |
| 20 | #include <linux/fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/mount.h> |
| 22 | #include <linux/kdev_t.h> |
| 23 | #include <linux/major.h> |
| 24 | #include <linux/reboot.h> |
| 25 | #include <linux/sysrq.h> |
| 26 | #include <linux/kbd_kern.h> |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 27 | #include <linux/proc_fs.h> |
Ingo Molnar | c1dc0b9 | 2009-08-02 11:28:21 +0200 | [diff] [blame] | 28 | #include <linux/nmi.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <linux/quotaops.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 30 | #include <linux/perf_event.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | #include <linux/kernel.h> |
| 32 | #include <linux/module.h> |
| 33 | #include <linux/suspend.h> |
| 34 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <linux/swap.h> |
| 36 | #include <linux/spinlock.h> |
| 37 | #include <linux/vt_kern.h> |
| 38 | #include <linux/workqueue.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> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 41 | #include <linux/slab.h> |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 42 | #include <linux/input.h> |
Al Viro | ff01bb48 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 43 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
| 45 | #include <asm/ptrace.h> |
Heiko Carstens | 2033b0c | 2006-10-06 16:38:42 +0200 | [diff] [blame] | 46 | #include <asm/irq_regs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
| 48 | /* Whether we react on sysrq keys or just ignore them */ |
Andy Whitcroft | 8c6a98b | 2011-01-24 09:31:38 -0800 | [diff] [blame] | 49 | static int __read_mostly sysrq_enabled = SYSRQ_DEFAULT_ENABLE; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 50 | static bool __read_mostly sysrq_always_enabled; |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 51 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 52 | static bool sysrq_on(void) |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 53 | { |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 54 | return sysrq_enabled || sysrq_always_enabled; |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 55 | } |
| 56 | |
| 57 | /* |
| 58 | * A value of 1 means 'all', other nonzero values are an op mask: |
| 59 | */ |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 60 | static bool sysrq_on_mask(int mask) |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 61 | { |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 62 | return sysrq_always_enabled || |
| 63 | sysrq_enabled == 1 || |
| 64 | (sysrq_enabled & mask); |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 65 | } |
| 66 | |
| 67 | static int __init sysrq_always_enabled_setup(char *str) |
| 68 | { |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 69 | sysrq_always_enabled = true; |
| 70 | pr_info("sysrq always enabled.\n"); |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 71 | |
| 72 | return 1; |
| 73 | } |
| 74 | |
| 75 | __setup("sysrq_always_enabled", sysrq_always_enabled_setup); |
| 76 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 78 | static void sysrq_handle_loglevel(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | { |
| 80 | int i; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 81 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | i = key - '0'; |
| 83 | console_loglevel = 7; |
| 84 | printk("Loglevel set to %d\n", i); |
| 85 | console_loglevel = i; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 86 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | static struct sysrq_key_op sysrq_loglevel_op = { |
| 88 | .handler = sysrq_handle_loglevel, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 89 | .help_msg = "loglevel(0-9)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | .action_msg = "Changing Loglevel", |
| 91 | .enable_mask = SYSRQ_ENABLE_LOG, |
| 92 | }; |
| 93 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | #ifdef CONFIG_VT |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 95 | static void sysrq_handle_SAK(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | { |
Eric W. Biederman | 8b6312f | 2007-02-10 01:44:34 -0800 | [diff] [blame] | 97 | struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work; |
Eric W. Biederman | 8b6312f | 2007-02-10 01:44:34 -0800 | [diff] [blame] | 98 | schedule_work(SAK_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | } |
| 100 | static struct sysrq_key_op sysrq_SAK_op = { |
| 101 | .handler = sysrq_handle_SAK, |
| 102 | .help_msg = "saK", |
| 103 | .action_msg = "SAK", |
| 104 | .enable_mask = SYSRQ_ENABLE_KEYBOARD, |
| 105 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 106 | #else |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 107 | #define sysrq_SAK_op (*(struct sysrq_key_op *)NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | #endif |
| 109 | |
| 110 | #ifdef CONFIG_VT |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 111 | static void sysrq_handle_unraw(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | { |
| 113 | struct kbd_struct *kbd = &kbd_table[fg_console]; |
| 114 | |
| 115 | if (kbd) |
Bill Nottingham | 2e8ecb9 | 2007-10-16 23:29:38 -0700 | [diff] [blame] | 116 | kbd->kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | } |
| 118 | static struct sysrq_key_op sysrq_unraw_op = { |
| 119 | .handler = sysrq_handle_unraw, |
| 120 | .help_msg = "unRaw", |
Bill Nottingham | 2e8ecb9 | 2007-10-16 23:29:38 -0700 | [diff] [blame] | 121 | .action_msg = "Keyboard mode set to system default", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | .enable_mask = SYSRQ_ENABLE_KEYBOARD, |
| 123 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 124 | #else |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 125 | #define sysrq_unraw_op (*(struct sysrq_key_op *)NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | #endif /* CONFIG_VT */ |
| 127 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 128 | static void sysrq_handle_crash(int key) |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 129 | { |
Neil Horman | d6580a9 | 2009-06-17 16:28:17 -0700 | [diff] [blame] | 130 | char *killer = NULL; |
Hidetoshi Seto | cab8bd3 | 2009-07-29 15:04:14 -0700 | [diff] [blame] | 131 | |
| 132 | panic_on_oops = 1; /* force panic */ |
| 133 | wmb(); |
Neil Horman | d6580a9 | 2009-06-17 16:28:17 -0700 | [diff] [blame] | 134 | *killer = 1; |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 135 | } |
Hidetoshi Seto | cab8bd3 | 2009-07-29 15:04:14 -0700 | [diff] [blame] | 136 | static struct sysrq_key_op sysrq_crash_op = { |
Neil Horman | d6580a9 | 2009-06-17 16:28:17 -0700 | [diff] [blame] | 137 | .handler = sysrq_handle_crash, |
| 138 | .help_msg = "Crash", |
| 139 | .action_msg = "Trigger a crash", |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 140 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 141 | }; |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 142 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 143 | static void sysrq_handle_reboot(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | { |
Peter Zijlstra | b2e9c7d | 2006-09-30 23:28:02 -0700 | [diff] [blame] | 145 | lockdep_off(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | local_irq_enable(); |
Eric W. Biederman | 4de8b9b | 2005-07-26 11:51:06 -0600 | [diff] [blame] | 147 | emergency_restart(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | static struct sysrq_key_op sysrq_reboot_op = { |
| 150 | .handler = sysrq_handle_reboot, |
| 151 | .help_msg = "reBoot", |
| 152 | .action_msg = "Resetting", |
| 153 | .enable_mask = SYSRQ_ENABLE_BOOT, |
| 154 | }; |
| 155 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 156 | static void sysrq_handle_sync(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | { |
| 158 | emergency_sync(); |
| 159 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | static struct sysrq_key_op sysrq_sync_op = { |
| 161 | .handler = sysrq_handle_sync, |
| 162 | .help_msg = "Sync", |
| 163 | .action_msg = "Emergency Sync", |
| 164 | .enable_mask = SYSRQ_ENABLE_SYNC, |
| 165 | }; |
| 166 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 167 | static void sysrq_handle_show_timers(int key) |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 168 | { |
| 169 | sysrq_timer_list_show(); |
| 170 | } |
| 171 | |
| 172 | static struct sysrq_key_op sysrq_show_timers_op = { |
| 173 | .handler = sysrq_handle_show_timers, |
| 174 | .help_msg = "show-all-timers(Q)", |
Thomas Gleixner | 322acf6 | 2008-10-20 12:33:14 +0200 | [diff] [blame] | 175 | .action_msg = "Show clockevent devices & pending hrtimers (no others)", |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 176 | }; |
| 177 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 178 | static void sysrq_handle_mountro(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | { |
| 180 | emergency_remount(); |
| 181 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | static struct sysrq_key_op sysrq_mountro_op = { |
| 183 | .handler = sysrq_handle_mountro, |
| 184 | .help_msg = "Unmount", |
| 185 | .action_msg = "Emergency Remount R/O", |
| 186 | .enable_mask = SYSRQ_ENABLE_REMOUNT, |
| 187 | }; |
| 188 | |
Ingo Molnar | 8c64580 | 2006-07-03 00:24:56 -0700 | [diff] [blame] | 189 | #ifdef CONFIG_LOCKDEP |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 190 | static void sysrq_handle_showlocks(int key) |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 191 | { |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 192 | debug_show_all_locks(); |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 193 | } |
Ingo Molnar | 8c64580 | 2006-07-03 00:24:56 -0700 | [diff] [blame] | 194 | |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 195 | static struct sysrq_key_op sysrq_showlocks_op = { |
| 196 | .handler = sysrq_handle_showlocks, |
| 197 | .help_msg = "show-all-locks(D)", |
| 198 | .action_msg = "Show Locks Held", |
| 199 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 200 | #else |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 201 | #define sysrq_showlocks_op (*(struct sysrq_key_op *)NULL) |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 202 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 204 | #ifdef CONFIG_SMP |
| 205 | static DEFINE_SPINLOCK(show_lock); |
| 206 | |
| 207 | static void showacpu(void *dummy) |
| 208 | { |
| 209 | unsigned long flags; |
| 210 | |
| 211 | /* Idle CPUs have no interesting backtrace. */ |
| 212 | if (idle_cpu(smp_processor_id())) |
| 213 | return; |
| 214 | |
| 215 | spin_lock_irqsave(&show_lock, flags); |
| 216 | printk(KERN_INFO "CPU%d:\n", smp_processor_id()); |
| 217 | show_stack(NULL, NULL); |
| 218 | spin_unlock_irqrestore(&show_lock, flags); |
| 219 | } |
| 220 | |
| 221 | static void sysrq_showregs_othercpus(struct work_struct *dummy) |
| 222 | { |
Ingo Molnar | 8b604d5 | 2008-06-27 11:52:45 +0200 | [diff] [blame] | 223 | smp_call_function(showacpu, NULL, 0); |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 224 | } |
| 225 | |
| 226 | static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus); |
| 227 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 228 | static void sysrq_handle_showallcpus(int key) |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 229 | { |
Ingo Molnar | 47cab6a | 2009-08-03 09:31:54 +0200 | [diff] [blame] | 230 | /* |
| 231 | * Fall back to the workqueue based printing if the |
| 232 | * backtrace printing did not succeed or the |
| 233 | * architecture has no support for it: |
| 234 | */ |
| 235 | if (!trigger_all_cpu_backtrace()) { |
| 236 | struct pt_regs *regs = get_irq_regs(); |
| 237 | |
| 238 | if (regs) { |
| 239 | printk(KERN_INFO "CPU%d:\n", smp_processor_id()); |
| 240 | show_regs(regs); |
| 241 | } |
| 242 | schedule_work(&sysrq_showallcpus); |
| 243 | } |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 244 | } |
| 245 | |
| 246 | static struct sysrq_key_op sysrq_showallcpus_op = { |
| 247 | .handler = sysrq_handle_showallcpus, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 248 | .help_msg = "show-backtrace-all-active-cpus(L)", |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 249 | .action_msg = "Show backtrace of all active CPUs", |
| 250 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 251 | }; |
| 252 | #endif |
| 253 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 254 | static void sysrq_handle_showregs(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 256 | struct pt_regs *regs = get_irq_regs(); |
| 257 | if (regs) |
| 258 | show_regs(regs); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 259 | perf_event_print_debug(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | } |
| 261 | static struct sysrq_key_op sysrq_showregs_op = { |
| 262 | .handler = sysrq_handle_showregs, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 263 | .help_msg = "show-registers(P)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | .action_msg = "Show Regs", |
| 265 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 266 | }; |
| 267 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 268 | static void sysrq_handle_showstate(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | { |
| 270 | show_state(); |
| 271 | } |
| 272 | static struct sysrq_key_op sysrq_showstate_op = { |
| 273 | .handler = sysrq_handle_showstate, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 274 | .help_msg = "show-task-states(T)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | .action_msg = "Show State", |
| 276 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 277 | }; |
| 278 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 279 | static void sysrq_handle_showstate_blocked(int key) |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 280 | { |
| 281 | show_state_filter(TASK_UNINTERRUPTIBLE); |
| 282 | } |
| 283 | static struct sysrq_key_op sysrq_showstate_blocked_op = { |
| 284 | .handler = sysrq_handle_showstate_blocked, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 285 | .help_msg = "show-blocked-tasks(W)", |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 286 | .action_msg = "Show Blocked State", |
| 287 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 288 | }; |
| 289 | |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 290 | #ifdef CONFIG_TRACING |
| 291 | #include <linux/ftrace.h> |
| 292 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 293 | static void sysrq_ftrace_dump(int key) |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 294 | { |
Frederic Weisbecker | cecbca9 | 2010-04-18 19:08:41 +0200 | [diff] [blame] | 295 | ftrace_dump(DUMP_ALL); |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 296 | } |
| 297 | static struct sysrq_key_op sysrq_ftrace_dump_op = { |
| 298 | .handler = sysrq_ftrace_dump, |
Randy Dunlap | 3871f2f | 2008-12-24 16:06:57 -0800 | [diff] [blame] | 299 | .help_msg = "dump-ftrace-buffer(Z)", |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 300 | .action_msg = "Dump ftrace buffer", |
| 301 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 302 | }; |
| 303 | #else |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 304 | #define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)NULL) |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 305 | #endif |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 306 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 307 | static void sysrq_handle_showmem(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | { |
David Rientjes | b2b755b | 2011-03-24 15:18:15 -0700 | [diff] [blame] | 309 | show_mem(0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | } |
| 311 | static struct sysrq_key_op sysrq_showmem_op = { |
| 312 | .handler = sysrq_handle_showmem, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 313 | .help_msg = "show-memory-usage(M)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | .action_msg = "Show Memory", |
| 315 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 316 | }; |
| 317 | |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 318 | /* |
| 319 | * Signal sysrq helper function. Sends a signal to all user processes. |
| 320 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | static void send_sig_all(int sig) |
| 322 | { |
| 323 | struct task_struct *p; |
| 324 | |
Anton Vorontsov | e502bab | 2012-02-07 10:49:39 +0400 | [diff] [blame^] | 325 | read_lock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | for_each_process(p) { |
Serge E. Hallyn | b460cbc | 2007-10-18 23:39:52 -0700 | [diff] [blame] | 327 | if (p->mm && !is_global_init(p)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | /* Not swapper, init nor kernel thread */ |
| 329 | force_sig(sig, p); |
| 330 | } |
Anton Vorontsov | e502bab | 2012-02-07 10:49:39 +0400 | [diff] [blame^] | 331 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | } |
| 333 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 334 | static void sysrq_handle_term(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | { |
| 336 | send_sig_all(SIGTERM); |
| 337 | console_loglevel = 8; |
| 338 | } |
| 339 | static struct sysrq_key_op sysrq_term_op = { |
| 340 | .handler = sysrq_handle_term, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 341 | .help_msg = "terminate-all-tasks(E)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | .action_msg = "Terminate All Tasks", |
| 343 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 344 | }; |
| 345 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 346 | static void moom_callback(struct work_struct *ignored) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | { |
KAMEZAWA Hiroyuki | 4365a56 | 2009-12-15 16:45:33 -0800 | [diff] [blame] | 348 | out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | } |
| 350 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 351 | static DECLARE_WORK(moom_work, moom_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 353 | static void sysrq_handle_moom(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | { |
| 355 | schedule_work(&moom_work); |
| 356 | } |
| 357 | static struct sysrq_key_op sysrq_moom_op = { |
| 358 | .handler = sysrq_handle_moom, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 359 | .help_msg = "memory-full-oom-kill(F)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | .action_msg = "Manual OOM execution", |
Naohiro Ooiwa | b4236f8 | 2008-10-15 22:01:43 -0700 | [diff] [blame] | 361 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | }; |
| 363 | |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 364 | #ifdef CONFIG_BLOCK |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 365 | static void sysrq_handle_thaw(int key) |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 366 | { |
| 367 | emergency_thaw_all(); |
| 368 | } |
| 369 | static struct sysrq_key_op sysrq_thaw_op = { |
| 370 | .handler = sysrq_handle_thaw, |
| 371 | .help_msg = "thaw-filesystems(J)", |
| 372 | .action_msg = "Emergency Thaw of all frozen filesystems", |
| 373 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 374 | }; |
| 375 | #endif |
| 376 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 377 | static void sysrq_handle_kill(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 378 | { |
| 379 | send_sig_all(SIGKILL); |
| 380 | console_loglevel = 8; |
| 381 | } |
| 382 | static struct sysrq_key_op sysrq_kill_op = { |
| 383 | .handler = sysrq_handle_kill, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 384 | .help_msg = "kill-all-tasks(I)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | .action_msg = "Kill All Tasks", |
| 386 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 387 | }; |
| 388 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 389 | static void sysrq_handle_unrt(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | { |
| 391 | normalize_rt_tasks(); |
| 392 | } |
| 393 | static struct sysrq_key_op sysrq_unrt_op = { |
| 394 | .handler = sysrq_handle_unrt, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 395 | .help_msg = "nice-all-RT-tasks(N)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | .action_msg = "Nice All RT Tasks", |
| 397 | .enable_mask = SYSRQ_ENABLE_RTNICE, |
| 398 | }; |
| 399 | |
| 400 | /* Key Operations table and lock */ |
| 401 | static DEFINE_SPINLOCK(sysrq_key_table_lock); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 402 | |
| 403 | static struct sysrq_key_op *sysrq_key_table[36] = { |
| 404 | &sysrq_loglevel_op, /* 0 */ |
| 405 | &sysrq_loglevel_op, /* 1 */ |
| 406 | &sysrq_loglevel_op, /* 2 */ |
| 407 | &sysrq_loglevel_op, /* 3 */ |
| 408 | &sysrq_loglevel_op, /* 4 */ |
| 409 | &sysrq_loglevel_op, /* 5 */ |
| 410 | &sysrq_loglevel_op, /* 6 */ |
| 411 | &sysrq_loglevel_op, /* 7 */ |
| 412 | &sysrq_loglevel_op, /* 8 */ |
| 413 | &sysrq_loglevel_op, /* 9 */ |
| 414 | |
| 415 | /* |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 416 | * a: Don't use for system provided sysrqs, it is handled specially on |
| 417 | * sparc and will never arrive. |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 418 | */ |
| 419 | NULL, /* a */ |
| 420 | &sysrq_reboot_op, /* b */ |
Hidetoshi Seto | cab8bd3 | 2009-07-29 15:04:14 -0700 | [diff] [blame] | 421 | &sysrq_crash_op, /* c & ibm_emac driver debug */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 422 | &sysrq_showlocks_op, /* d */ |
| 423 | &sysrq_term_op, /* e */ |
| 424 | &sysrq_moom_op, /* f */ |
Jason Wessel | 364b5b7 | 2009-05-13 21:56:59 -0500 | [diff] [blame] | 425 | /* g: May be registered for the kernel debugger */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 426 | NULL, /* g */ |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 427 | NULL, /* h - reserved for help */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 428 | &sysrq_kill_op, /* i */ |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 429 | #ifdef CONFIG_BLOCK |
| 430 | &sysrq_thaw_op, /* j */ |
| 431 | #else |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 432 | NULL, /* j */ |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 433 | #endif |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 434 | &sysrq_SAK_op, /* k */ |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 435 | #ifdef CONFIG_SMP |
| 436 | &sysrq_showallcpus_op, /* l */ |
| 437 | #else |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 438 | NULL, /* l */ |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 439 | #endif |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 440 | &sysrq_showmem_op, /* m */ |
| 441 | &sysrq_unrt_op, /* n */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 442 | /* o: This will often be registered as 'Off' at init time */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 443 | NULL, /* o */ |
| 444 | &sysrq_showregs_op, /* p */ |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 445 | &sysrq_show_timers_op, /* q */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 446 | &sysrq_unraw_op, /* r */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 447 | &sysrq_sync_op, /* s */ |
| 448 | &sysrq_showstate_op, /* t */ |
| 449 | &sysrq_mountro_op, /* u */ |
Jason Wessel | 364b5b7 | 2009-05-13 21:56:59 -0500 | [diff] [blame] | 450 | /* v: May be registered for frame buffer console restore */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 451 | NULL, /* v */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 452 | &sysrq_showstate_blocked_op, /* w */ |
| 453 | /* x: May be registered on ppc/powerpc for xmon */ |
| 454 | NULL, /* x */ |
David S. Miller | 93dae5b | 2008-05-19 23:46:00 -0700 | [diff] [blame] | 455 | /* y: May be registered on sparc64 for global register dump */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 456 | NULL, /* y */ |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 457 | &sysrq_ftrace_dump_op, /* z */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | }; |
| 459 | |
| 460 | /* key2index calculation, -1 on invalid index */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 461 | static int sysrq_key_table_key2index(int key) |
| 462 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | int retval; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 464 | |
| 465 | if ((key >= '0') && (key <= '9')) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | retval = key - '0'; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 467 | else if ((key >= 'a') && (key <= 'z')) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | retval = key + 10 - 'a'; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 469 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | retval = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | return retval; |
| 472 | } |
| 473 | |
| 474 | /* |
| 475 | * get and put functions for the table, exposed to modules. |
| 476 | */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 477 | struct sysrq_key_op *__sysrq_get_key_op(int key) |
| 478 | { |
| 479 | struct sysrq_key_op *op_p = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | int i; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 481 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | i = sysrq_key_table_key2index(key); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 483 | if (i != -1) |
| 484 | op_p = sysrq_key_table[i]; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 485 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | return op_p; |
| 487 | } |
| 488 | |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 489 | static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p) |
| 490 | { |
| 491 | int i = sysrq_key_table_key2index(key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | if (i != -1) |
| 494 | sysrq_key_table[i] = op_p; |
| 495 | } |
| 496 | |
Dmitry Torokhov | f335397 | 2010-08-17 21:15:47 -0700 | [diff] [blame] | 497 | void __handle_sysrq(int key, bool check_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | { |
| 499 | struct sysrq_key_op *op_p; |
| 500 | int orig_log_level; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 501 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | unsigned long flags; |
| 503 | |
| 504 | spin_lock_irqsave(&sysrq_key_table_lock, flags); |
Andy Whitcroft | fb144ad | 2009-01-15 13:50:52 -0800 | [diff] [blame] | 505 | /* |
| 506 | * Raise the apparent loglevel to maximum so that the sysrq header |
| 507 | * is shown to provide the user with positive feedback. We do not |
| 508 | * simply emit this at KERN_EMERG as that would change message |
| 509 | * routing in the consumers of /proc/kmsg. |
| 510 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 511 | orig_log_level = console_loglevel; |
| 512 | console_loglevel = 7; |
| 513 | printk(KERN_INFO "SysRq : "); |
| 514 | |
| 515 | op_p = __sysrq_get_key_op(key); |
| 516 | if (op_p) { |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 517 | /* |
| 518 | * Should we check for enabled operations (/proc/sysrq-trigger |
| 519 | * should not) and is the invoked operation enabled? |
| 520 | */ |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 521 | if (!check_mask || sysrq_on_mask(op_p->enable_mask)) { |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 522 | printk("%s\n", op_p->action_msg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | console_loglevel = orig_log_level; |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 524 | op_p->handler(key); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 525 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | printk("This sysrq operation is disabled.\n"); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 527 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | } else { |
| 529 | printk("HELP : "); |
| 530 | /* Only print the help msg once per handler */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 531 | for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) { |
| 532 | if (sysrq_key_table[i]) { |
| 533 | int j; |
| 534 | |
| 535 | for (j = 0; sysrq_key_table[i] != |
| 536 | sysrq_key_table[j]; j++) |
| 537 | ; |
| 538 | if (j != i) |
| 539 | continue; |
| 540 | printk("%s ", sysrq_key_table[i]->help_msg); |
| 541 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 543 | printk("\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | console_loglevel = orig_log_level; |
| 545 | } |
| 546 | spin_unlock_irqrestore(&sysrq_key_table_lock, flags); |
| 547 | } |
| 548 | |
Dmitry Torokhov | f335397 | 2010-08-17 21:15:47 -0700 | [diff] [blame] | 549 | void handle_sysrq(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | { |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 551 | if (sysrq_on()) |
Dmitry Torokhov | f335397 | 2010-08-17 21:15:47 -0700 | [diff] [blame] | 552 | __handle_sysrq(key, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 554 | EXPORT_SYMBOL(handle_sysrq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 556 | #ifdef CONFIG_INPUT |
| 557 | |
| 558 | /* Simple translation table for the SysRq keys */ |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 559 | static const unsigned char sysrq_xlate[KEY_CNT] = |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 560 | "\000\0331234567890-=\177\t" /* 0x00 - 0x0f */ |
| 561 | "qwertyuiop[]\r\000as" /* 0x10 - 0x1f */ |
| 562 | "dfghjkl;'`\000\\zxcv" /* 0x20 - 0x2f */ |
| 563 | "bnm,./\000*\000 \000\201\202\203\204\205" /* 0x30 - 0x3f */ |
| 564 | "\206\207\210\211\212\000\000789-456+1" /* 0x40 - 0x4f */ |
| 565 | "230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */ |
| 566 | "\r\000/"; /* 0x60 - 0x6f */ |
| 567 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 568 | struct sysrq_state { |
| 569 | struct input_handle handle; |
| 570 | struct work_struct reinject_work; |
| 571 | unsigned long key_down[BITS_TO_LONGS(KEY_CNT)]; |
| 572 | unsigned int alt; |
| 573 | unsigned int alt_use; |
| 574 | bool active; |
| 575 | bool need_reinject; |
Dmitry Torokhov | 7ab7b5a | 2011-02-02 22:59:54 -0800 | [diff] [blame] | 576 | bool reinjecting; |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 577 | }; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 578 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 579 | static void sysrq_reinject_alt_sysrq(struct work_struct *work) |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 580 | { |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 581 | struct sysrq_state *sysrq = |
| 582 | container_of(work, struct sysrq_state, reinject_work); |
| 583 | struct input_handle *handle = &sysrq->handle; |
| 584 | unsigned int alt_code = sysrq->alt_use; |
| 585 | |
| 586 | if (sysrq->need_reinject) { |
Dmitry Torokhov | 7ab7b5a | 2011-02-02 22:59:54 -0800 | [diff] [blame] | 587 | /* we do not want the assignment to be reordered */ |
| 588 | sysrq->reinjecting = true; |
| 589 | mb(); |
| 590 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 591 | /* Simulate press and release of Alt + SysRq */ |
| 592 | input_inject_event(handle, EV_KEY, alt_code, 1); |
| 593 | input_inject_event(handle, EV_KEY, KEY_SYSRQ, 1); |
| 594 | input_inject_event(handle, EV_SYN, SYN_REPORT, 1); |
| 595 | |
| 596 | input_inject_event(handle, EV_KEY, KEY_SYSRQ, 0); |
| 597 | input_inject_event(handle, EV_KEY, alt_code, 0); |
| 598 | input_inject_event(handle, EV_SYN, SYN_REPORT, 1); |
Dmitry Torokhov | 7ab7b5a | 2011-02-02 22:59:54 -0800 | [diff] [blame] | 599 | |
| 600 | mb(); |
| 601 | sysrq->reinjecting = false; |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 602 | } |
| 603 | } |
| 604 | |
| 605 | static bool sysrq_filter(struct input_handle *handle, |
| 606 | unsigned int type, unsigned int code, int value) |
| 607 | { |
| 608 | struct sysrq_state *sysrq = handle->private; |
| 609 | bool was_active = sysrq->active; |
Dmitry Torokhov | 1966cb2 | 2010-09-29 18:04:21 -0700 | [diff] [blame] | 610 | bool suppress; |
| 611 | |
Dmitry Torokhov | 7ab7b5a | 2011-02-02 22:59:54 -0800 | [diff] [blame] | 612 | /* |
| 613 | * Do not filter anything if we are in the process of re-injecting |
| 614 | * Alt+SysRq combination. |
| 615 | */ |
| 616 | if (sysrq->reinjecting) |
| 617 | return false; |
| 618 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 619 | switch (type) { |
Dmitry Torokhov | 1966cb2 | 2010-09-29 18:04:21 -0700 | [diff] [blame] | 620 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 621 | case EV_SYN: |
| 622 | suppress = false; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 623 | break; |
| 624 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 625 | case EV_KEY: |
| 626 | switch (code) { |
| 627 | |
| 628 | case KEY_LEFTALT: |
| 629 | case KEY_RIGHTALT: |
| 630 | if (!value) { |
| 631 | /* One of ALTs is being released */ |
| 632 | if (sysrq->active && code == sysrq->alt_use) |
| 633 | sysrq->active = false; |
| 634 | |
| 635 | sysrq->alt = KEY_RESERVED; |
| 636 | |
| 637 | } else if (value != 2) { |
| 638 | sysrq->alt = code; |
| 639 | sysrq->need_reinject = false; |
| 640 | } |
| 641 | break; |
| 642 | |
| 643 | case KEY_SYSRQ: |
| 644 | if (value == 1 && sysrq->alt != KEY_RESERVED) { |
| 645 | sysrq->active = true; |
| 646 | sysrq->alt_use = sysrq->alt; |
| 647 | /* |
| 648 | * If nothing else will be pressed we'll need |
Dmitry Torokhov | 7ab7b5a | 2011-02-02 22:59:54 -0800 | [diff] [blame] | 649 | * to re-inject Alt-SysRq keysroke. |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 650 | */ |
| 651 | sysrq->need_reinject = true; |
| 652 | } |
| 653 | |
| 654 | /* |
| 655 | * Pretend that sysrq was never pressed at all. This |
| 656 | * is needed to properly handle KGDB which will try |
| 657 | * to release all keys after exiting debugger. If we |
| 658 | * do not clear key bit it KGDB will end up sending |
| 659 | * release events for Alt and SysRq, potentially |
| 660 | * triggering print screen function. |
| 661 | */ |
| 662 | if (sysrq->active) |
| 663 | clear_bit(KEY_SYSRQ, handle->dev->key); |
| 664 | |
| 665 | break; |
| 666 | |
| 667 | default: |
| 668 | if (sysrq->active && value && value != 2) { |
| 669 | sysrq->need_reinject = false; |
| 670 | __handle_sysrq(sysrq_xlate[code], true); |
| 671 | } |
| 672 | break; |
| 673 | } |
| 674 | |
| 675 | suppress = sysrq->active; |
| 676 | |
| 677 | if (!sysrq->active) { |
| 678 | /* |
| 679 | * If we are not suppressing key presses keep track of |
| 680 | * keyboard state so we can release keys that have been |
| 681 | * pressed before entering SysRq mode. |
| 682 | */ |
| 683 | if (value) |
| 684 | set_bit(code, sysrq->key_down); |
| 685 | else |
| 686 | clear_bit(code, sysrq->key_down); |
| 687 | |
| 688 | if (was_active) |
| 689 | schedule_work(&sysrq->reinject_work); |
| 690 | |
| 691 | } else if (value == 0 && |
| 692 | test_and_clear_bit(code, sysrq->key_down)) { |
| 693 | /* |
| 694 | * Pass on release events for keys that was pressed before |
| 695 | * entering SysRq mode. |
| 696 | */ |
| 697 | suppress = false; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 698 | } |
| 699 | break; |
| 700 | |
| 701 | default: |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 702 | suppress = sysrq->active; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 703 | break; |
| 704 | } |
| 705 | |
Dmitry Torokhov | 1966cb2 | 2010-09-29 18:04:21 -0700 | [diff] [blame] | 706 | return suppress; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 707 | } |
| 708 | |
| 709 | static int sysrq_connect(struct input_handler *handler, |
| 710 | struct input_dev *dev, |
| 711 | const struct input_device_id *id) |
| 712 | { |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 713 | struct sysrq_state *sysrq; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 714 | int error; |
| 715 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 716 | sysrq = kzalloc(sizeof(struct sysrq_state), GFP_KERNEL); |
| 717 | if (!sysrq) |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 718 | return -ENOMEM; |
| 719 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 720 | INIT_WORK(&sysrq->reinject_work, sysrq_reinject_alt_sysrq); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 721 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 722 | sysrq->handle.dev = dev; |
| 723 | sysrq->handle.handler = handler; |
| 724 | sysrq->handle.name = "sysrq"; |
| 725 | sysrq->handle.private = sysrq; |
| 726 | |
| 727 | error = input_register_handle(&sysrq->handle); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 728 | if (error) { |
| 729 | pr_err("Failed to register input sysrq handler, error %d\n", |
| 730 | error); |
| 731 | goto err_free; |
| 732 | } |
| 733 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 734 | error = input_open_device(&sysrq->handle); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 735 | if (error) { |
| 736 | pr_err("Failed to open input device, error %d\n", error); |
| 737 | goto err_unregister; |
| 738 | } |
| 739 | |
| 740 | return 0; |
| 741 | |
| 742 | err_unregister: |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 743 | input_unregister_handle(&sysrq->handle); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 744 | err_free: |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 745 | kfree(sysrq); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 746 | return error; |
| 747 | } |
| 748 | |
| 749 | static void sysrq_disconnect(struct input_handle *handle) |
| 750 | { |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 751 | struct sysrq_state *sysrq = handle->private; |
| 752 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 753 | input_close_device(handle); |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 754 | cancel_work_sync(&sysrq->reinject_work); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 755 | input_unregister_handle(handle); |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 756 | kfree(sysrq); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 757 | } |
| 758 | |
| 759 | /* |
Dmitry Torokhov | 1966cb2 | 2010-09-29 18:04:21 -0700 | [diff] [blame] | 760 | * We are matching on KEY_LEFTALT instead of KEY_SYSRQ because not all |
| 761 | * keyboards have SysRq key predefined and so user may add it to keymap |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 762 | * later, but we expect all such keyboards to have left alt. |
| 763 | */ |
| 764 | static const struct input_device_id sysrq_ids[] = { |
| 765 | { |
| 766 | .flags = INPUT_DEVICE_ID_MATCH_EVBIT | |
| 767 | INPUT_DEVICE_ID_MATCH_KEYBIT, |
| 768 | .evbit = { BIT_MASK(EV_KEY) }, |
| 769 | .keybit = { BIT_MASK(KEY_LEFTALT) }, |
| 770 | }, |
| 771 | { }, |
| 772 | }; |
| 773 | |
| 774 | static struct input_handler sysrq_handler = { |
| 775 | .filter = sysrq_filter, |
| 776 | .connect = sysrq_connect, |
| 777 | .disconnect = sysrq_disconnect, |
| 778 | .name = "sysrq", |
| 779 | .id_table = sysrq_ids, |
| 780 | }; |
| 781 | |
| 782 | static bool sysrq_handler_registered; |
| 783 | |
| 784 | static inline void sysrq_register_handler(void) |
| 785 | { |
| 786 | int error; |
| 787 | |
| 788 | error = input_register_handler(&sysrq_handler); |
| 789 | if (error) |
| 790 | pr_err("Failed to register input handler, error %d", error); |
| 791 | else |
| 792 | sysrq_handler_registered = true; |
| 793 | } |
| 794 | |
| 795 | static inline void sysrq_unregister_handler(void) |
| 796 | { |
| 797 | if (sysrq_handler_registered) { |
| 798 | input_unregister_handler(&sysrq_handler); |
| 799 | sysrq_handler_registered = false; |
| 800 | } |
| 801 | } |
| 802 | |
| 803 | #else |
| 804 | |
| 805 | static inline void sysrq_register_handler(void) |
| 806 | { |
| 807 | } |
| 808 | |
| 809 | static inline void sysrq_unregister_handler(void) |
| 810 | { |
| 811 | } |
| 812 | |
| 813 | #endif /* CONFIG_INPUT */ |
| 814 | |
| 815 | int sysrq_toggle_support(int enable_mask) |
| 816 | { |
| 817 | bool was_enabled = sysrq_on(); |
| 818 | |
| 819 | sysrq_enabled = enable_mask; |
| 820 | |
| 821 | if (was_enabled != sysrq_on()) { |
| 822 | if (sysrq_on()) |
| 823 | sysrq_register_handler(); |
| 824 | else |
| 825 | sysrq_unregister_handler(); |
| 826 | } |
| 827 | |
| 828 | return 0; |
| 829 | } |
| 830 | |
Adrian Bunk | cf62ddc | 2005-11-08 21:39:47 -0800 | [diff] [blame] | 831 | 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] | 832 | struct sysrq_key_op *remove_op_p) |
| 833 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 834 | int retval; |
| 835 | unsigned long flags; |
| 836 | |
| 837 | spin_lock_irqsave(&sysrq_key_table_lock, flags); |
| 838 | if (__sysrq_get_key_op(key) == remove_op_p) { |
| 839 | __sysrq_put_key_op(key, insert_op_p); |
| 840 | retval = 0; |
| 841 | } else { |
| 842 | retval = -1; |
| 843 | } |
| 844 | spin_unlock_irqrestore(&sysrq_key_table_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | return retval; |
| 846 | } |
| 847 | |
| 848 | int register_sysrq_key(int key, struct sysrq_key_op *op_p) |
| 849 | { |
| 850 | return __sysrq_swap_key_ops(key, op_p, NULL); |
| 851 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 852 | EXPORT_SYMBOL(register_sysrq_key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | |
| 854 | int unregister_sysrq_key(int key, struct sysrq_key_op *op_p) |
| 855 | { |
| 856 | return __sysrq_swap_key_ops(key, NULL, op_p); |
| 857 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | EXPORT_SYMBOL(unregister_sysrq_key); |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 859 | |
| 860 | #ifdef CONFIG_PROC_FS |
| 861 | /* |
| 862 | * writing 'C' to /proc/sysrq-trigger is like sysrq-C |
| 863 | */ |
| 864 | static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf, |
| 865 | size_t count, loff_t *ppos) |
| 866 | { |
| 867 | if (count) { |
| 868 | char c; |
| 869 | |
| 870 | if (get_user(c, buf)) |
| 871 | return -EFAULT; |
Dmitry Torokhov | f335397 | 2010-08-17 21:15:47 -0700 | [diff] [blame] | 872 | __handle_sysrq(c, false); |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 873 | } |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 874 | |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 875 | return count; |
| 876 | } |
| 877 | |
| 878 | static const struct file_operations proc_sysrq_trigger_operations = { |
| 879 | .write = write_sysrq_trigger, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 880 | .llseek = noop_llseek, |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 881 | }; |
| 882 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 883 | static void sysrq_init_procfs(void) |
| 884 | { |
| 885 | if (!proc_create("sysrq-trigger", S_IWUSR, NULL, |
| 886 | &proc_sysrq_trigger_operations)) |
| 887 | pr_err("Failed to register proc interface\n"); |
| 888 | } |
| 889 | |
| 890 | #else |
| 891 | |
| 892 | static inline void sysrq_init_procfs(void) |
| 893 | { |
| 894 | } |
| 895 | |
| 896 | #endif /* CONFIG_PROC_FS */ |
| 897 | |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 898 | static int __init sysrq_init(void) |
| 899 | { |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 900 | sysrq_init_procfs(); |
| 901 | |
| 902 | if (sysrq_on()) |
| 903 | sysrq_register_handler(); |
| 904 | |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 905 | return 0; |
| 906 | } |
| 907 | module_init(sysrq_init); |