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 | |
Ingo Molnar | 3f07c01 | 2017-02-08 18:51:30 +0100 | [diff] [blame] | 17 | #include <linux/sched/signal.h> |
Clark Williams | 8bd75c7 | 2013-02-07 09:47:07 -0600 | [diff] [blame] | 18 | #include <linux/sched/rt.h> |
Ingo Molnar | b17b015 | 2017-02-08 18:51:35 +0100 | [diff] [blame] | 19 | #include <linux/sched/debug.h> |
Ingo Molnar | 2993002 | 2017-02-08 18:51:36 +0100 | [diff] [blame] | 20 | #include <linux/sched/task.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/interrupt.h> |
| 22 | #include <linux/mm.h> |
| 23 | #include <linux/fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/mount.h> |
| 25 | #include <linux/kdev_t.h> |
| 26 | #include <linux/major.h> |
| 27 | #include <linux/reboot.h> |
| 28 | #include <linux/sysrq.h> |
| 29 | #include <linux/kbd_kern.h> |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 30 | #include <linux/proc_fs.h> |
Ingo Molnar | c1dc0b9 | 2009-08-02 11:28:21 +0200 | [diff] [blame] | 31 | #include <linux/nmi.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <linux/quotaops.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 33 | #include <linux/perf_event.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <linux/kernel.h> |
| 35 | #include <linux/module.h> |
| 36 | #include <linux/suspend.h> |
| 37 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | #include <linux/swap.h> |
| 39 | #include <linux/spinlock.h> |
| 40 | #include <linux/vt_kern.h> |
| 41 | #include <linux/workqueue.h> |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 42 | #include <linux/hrtimer.h> |
David Rientjes | 5a3135c2 | 2007-10-16 23:25:53 -0700 | [diff] [blame] | 43 | #include <linux/oom.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 44 | #include <linux/slab.h> |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 45 | #include <linux/input.h> |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 46 | #include <linux/uaccess.h> |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 47 | #include <linux/moduleparam.h> |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 48 | #include <linux/jiffies.h> |
Mathieu J. Poirier | 3d28951 | 2013-06-05 22:51:46 -0700 | [diff] [blame] | 49 | #include <linux/syscalls.h> |
Mathieu J. Poirier | 4c076eb | 2013-08-03 17:22:08 -0700 | [diff] [blame] | 50 | #include <linux/of.h> |
Rik van Riel | 722773a | 2014-06-06 14:38:14 -0700 | [diff] [blame] | 51 | #include <linux/rcupdate.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
| 53 | #include <asm/ptrace.h> |
Heiko Carstens | 2033b0c | 2006-10-06 16:38:42 +0200 | [diff] [blame] | 54 | #include <asm/irq_regs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | |
| 56 | /* Whether we react on sysrq keys or just ignore them */ |
Ben Hutchings | 8eaede4 | 2013-10-07 01:05:46 +0100 | [diff] [blame] | 57 | static int __read_mostly sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 58 | static bool __read_mostly sysrq_always_enabled; |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 59 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 60 | static bool sysrq_on(void) |
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_enabled || sysrq_always_enabled; |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 63 | } |
| 64 | |
| 65 | /* |
| 66 | * A value of 1 means 'all', other nonzero values are an op mask: |
| 67 | */ |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 68 | static bool sysrq_on_mask(int mask) |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 69 | { |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 70 | return sysrq_always_enabled || |
| 71 | sysrq_enabled == 1 || |
| 72 | (sysrq_enabled & mask); |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 73 | } |
| 74 | |
| 75 | static int __init sysrq_always_enabled_setup(char *str) |
| 76 | { |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 77 | sysrq_always_enabled = true; |
| 78 | pr_info("sysrq always enabled.\n"); |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 79 | |
| 80 | return 1; |
| 81 | } |
| 82 | |
| 83 | __setup("sysrq_always_enabled", sysrq_always_enabled_setup); |
| 84 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 86 | static void sysrq_handle_loglevel(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | { |
| 88 | int i; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 89 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | i = key - '0'; |
Borislav Petkov | a8fe19e | 2014-06-04 16:11:46 -0700 | [diff] [blame] | 91 | console_loglevel = CONSOLE_LOGLEVEL_DEFAULT; |
Michal Hocko | 401e4a7 | 2015-02-11 15:26:21 -0800 | [diff] [blame] | 92 | pr_info("Loglevel set to %d\n", i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | console_loglevel = i; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 94 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | static struct sysrq_key_op sysrq_loglevel_op = { |
| 96 | .handler = sysrq_handle_loglevel, |
Randy Dunlap | 208b95c | 2009-01-06 14:41:13 -0800 | [diff] [blame] | 97 | .help_msg = "loglevel(0-9)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | .action_msg = "Changing Loglevel", |
| 99 | .enable_mask = SYSRQ_ENABLE_LOG, |
| 100 | }; |
| 101 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | #ifdef CONFIG_VT |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 103 | static void sysrq_handle_SAK(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | { |
Eric W. Biederman | 8b6312f | 2007-02-10 01:44:34 -0800 | [diff] [blame] | 105 | struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work; |
Eric W. Biederman | 8b6312f | 2007-02-10 01:44:34 -0800 | [diff] [blame] | 106 | schedule_work(SAK_work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | } |
| 108 | static struct sysrq_key_op sysrq_SAK_op = { |
| 109 | .handler = sysrq_handle_SAK, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 110 | .help_msg = "sak(k)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | .action_msg = "SAK", |
| 112 | .enable_mask = SYSRQ_ENABLE_KEYBOARD, |
| 113 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 114 | #else |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 115 | #define sysrq_SAK_op (*(struct sysrq_key_op *)NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | #endif |
| 117 | |
| 118 | #ifdef CONFIG_VT |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 119 | static void sysrq_handle_unraw(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | { |
Alan Cox | 079c953 | 2012-02-28 14:49:23 +0000 | [diff] [blame] | 121 | vt_reset_unicode(fg_console); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | } |
Alan Cox | 079c953 | 2012-02-28 14:49:23 +0000 | [diff] [blame] | 123 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | static struct sysrq_key_op sysrq_unraw_op = { |
| 125 | .handler = sysrq_handle_unraw, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 126 | .help_msg = "unraw(r)", |
Bill Nottingham | 2e8ecb9 | 2007-10-16 23:29:38 -0700 | [diff] [blame] | 127 | .action_msg = "Keyboard mode set to system default", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | .enable_mask = SYSRQ_ENABLE_KEYBOARD, |
| 129 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 130 | #else |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 131 | #define sysrq_unraw_op (*(struct sysrq_key_op *)NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | #endif /* CONFIG_VT */ |
| 133 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 134 | static void sysrq_handle_crash(int key) |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 135 | { |
Neil Horman | d6580a9 | 2009-06-17 16:28:17 -0700 | [diff] [blame] | 136 | char *killer = NULL; |
Hidetoshi Seto | cab8bd3 | 2009-07-29 15:04:14 -0700 | [diff] [blame] | 137 | |
Ani Sinha | 984cf35 | 2015-12-17 17:15:10 -0800 | [diff] [blame] | 138 | /* we need to release the RCU read lock here, |
| 139 | * otherwise we get an annoying |
| 140 | * 'BUG: sleeping function called from invalid context' |
| 141 | * complaint from the kernel before the panic. |
| 142 | */ |
| 143 | rcu_read_unlock(); |
Hidetoshi Seto | cab8bd3 | 2009-07-29 15:04:14 -0700 | [diff] [blame] | 144 | panic_on_oops = 1; /* force panic */ |
| 145 | wmb(); |
Neil Horman | d6580a9 | 2009-06-17 16:28:17 -0700 | [diff] [blame] | 146 | *killer = 1; |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 147 | } |
Hidetoshi Seto | cab8bd3 | 2009-07-29 15:04:14 -0700 | [diff] [blame] | 148 | static struct sysrq_key_op sysrq_crash_op = { |
Neil Horman | d6580a9 | 2009-06-17 16:28:17 -0700 | [diff] [blame] | 149 | .handler = sysrq_handle_crash, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 150 | .help_msg = "crash(c)", |
Neil Horman | d6580a9 | 2009-06-17 16:28:17 -0700 | [diff] [blame] | 151 | .action_msg = "Trigger a crash", |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 152 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 153 | }; |
Hariprasad Nellitheertha | 86b1ae3 | 2005-06-25 14:58:25 -0700 | [diff] [blame] | 154 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 155 | static void sysrq_handle_reboot(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | { |
Peter Zijlstra | b2e9c7d | 2006-09-30 23:28:02 -0700 | [diff] [blame] | 157 | lockdep_off(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | local_irq_enable(); |
Eric W. Biederman | 4de8b9b | 2005-07-26 11:51:06 -0600 | [diff] [blame] | 159 | emergency_restart(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | static struct sysrq_key_op sysrq_reboot_op = { |
| 162 | .handler = sysrq_handle_reboot, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 163 | .help_msg = "reboot(b)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | .action_msg = "Resetting", |
| 165 | .enable_mask = SYSRQ_ENABLE_BOOT, |
| 166 | }; |
| 167 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 168 | static void sysrq_handle_sync(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | { |
| 170 | emergency_sync(); |
| 171 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | static struct sysrq_key_op sysrq_sync_op = { |
| 173 | .handler = sysrq_handle_sync, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 174 | .help_msg = "sync(s)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | .action_msg = "Emergency Sync", |
| 176 | .enable_mask = SYSRQ_ENABLE_SYNC, |
| 177 | }; |
| 178 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 179 | static void sysrq_handle_show_timers(int key) |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 180 | { |
| 181 | sysrq_timer_list_show(); |
| 182 | } |
| 183 | |
| 184 | static struct sysrq_key_op sysrq_show_timers_op = { |
| 185 | .handler = sysrq_handle_show_timers, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 186 | .help_msg = "show-all-timers(q)", |
Thomas Gleixner | 322acf6 | 2008-10-20 12:33:14 +0200 | [diff] [blame] | 187 | .action_msg = "Show clockevent devices & pending hrtimers (no others)", |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 188 | }; |
| 189 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 190 | static void sysrq_handle_mountro(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | { |
| 192 | emergency_remount(); |
| 193 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | static struct sysrq_key_op sysrq_mountro_op = { |
| 195 | .handler = sysrq_handle_mountro, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 196 | .help_msg = "unmount(u)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | .action_msg = "Emergency Remount R/O", |
| 198 | .enable_mask = SYSRQ_ENABLE_REMOUNT, |
| 199 | }; |
| 200 | |
Ingo Molnar | 8c64580 | 2006-07-03 00:24:56 -0700 | [diff] [blame] | 201 | #ifdef CONFIG_LOCKDEP |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 202 | static void sysrq_handle_showlocks(int key) |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 203 | { |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 204 | debug_show_all_locks(); |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 205 | } |
Ingo Molnar | 8c64580 | 2006-07-03 00:24:56 -0700 | [diff] [blame] | 206 | |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 207 | static struct sysrq_key_op sysrq_showlocks_op = { |
| 208 | .handler = sysrq_handle_showlocks, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 209 | .help_msg = "show-all-locks(d)", |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 210 | .action_msg = "Show Locks Held", |
| 211 | }; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 212 | #else |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 213 | #define sysrq_showlocks_op (*(struct sysrq_key_op *)NULL) |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 214 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 216 | #ifdef CONFIG_SMP |
| 217 | static DEFINE_SPINLOCK(show_lock); |
| 218 | |
| 219 | static void showacpu(void *dummy) |
| 220 | { |
| 221 | unsigned long flags; |
| 222 | |
| 223 | /* Idle CPUs have no interesting backtrace. */ |
| 224 | if (idle_cpu(smp_processor_id())) |
| 225 | return; |
| 226 | |
| 227 | spin_lock_irqsave(&show_lock, flags); |
Michal Hocko | 401e4a7 | 2015-02-11 15:26:21 -0800 | [diff] [blame] | 228 | pr_info("CPU%d:\n", smp_processor_id()); |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 229 | show_stack(NULL, NULL); |
| 230 | spin_unlock_irqrestore(&show_lock, flags); |
| 231 | } |
| 232 | |
| 233 | static void sysrq_showregs_othercpus(struct work_struct *dummy) |
| 234 | { |
Ingo Molnar | 8b604d5 | 2008-06-27 11:52:45 +0200 | [diff] [blame] | 235 | smp_call_function(showacpu, NULL, 0); |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 236 | } |
| 237 | |
| 238 | static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus); |
| 239 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 240 | static void sysrq_handle_showallcpus(int key) |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 241 | { |
Ingo Molnar | 47cab6a | 2009-08-03 09:31:54 +0200 | [diff] [blame] | 242 | /* |
| 243 | * Fall back to the workqueue based printing if the |
| 244 | * backtrace printing did not succeed or the |
| 245 | * architecture has no support for it: |
| 246 | */ |
| 247 | if (!trigger_all_cpu_backtrace()) { |
| 248 | struct pt_regs *regs = get_irq_regs(); |
| 249 | |
| 250 | if (regs) { |
Michal Hocko | 401e4a7 | 2015-02-11 15:26:21 -0800 | [diff] [blame] | 251 | pr_info("CPU%d:\n", smp_processor_id()); |
Ingo Molnar | 47cab6a | 2009-08-03 09:31:54 +0200 | [diff] [blame] | 252 | show_regs(regs); |
| 253 | } |
| 254 | schedule_work(&sysrq_showallcpus); |
| 255 | } |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 256 | } |
| 257 | |
| 258 | static struct sysrq_key_op sysrq_showallcpus_op = { |
| 259 | .handler = sysrq_handle_showallcpus, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 260 | .help_msg = "show-backtrace-all-active-cpus(l)", |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 261 | .action_msg = "Show backtrace of all active CPUs", |
| 262 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 263 | }; |
| 264 | #endif |
| 265 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 266 | static void sysrq_handle_showregs(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 268 | struct pt_regs *regs = get_irq_regs(); |
| 269 | if (regs) |
| 270 | show_regs(regs); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 271 | perf_event_print_debug(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | } |
| 273 | static struct sysrq_key_op sysrq_showregs_op = { |
| 274 | .handler = sysrq_handle_showregs, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 275 | .help_msg = "show-registers(p)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | .action_msg = "Show Regs", |
| 277 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 278 | }; |
| 279 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 280 | static void sysrq_handle_showstate(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | { |
| 282 | show_state(); |
Tejun Heo | 3494fc3 | 2015-03-09 09:22:28 -0400 | [diff] [blame] | 283 | show_workqueue_state(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | } |
| 285 | static struct sysrq_key_op sysrq_showstate_op = { |
| 286 | .handler = sysrq_handle_showstate, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 287 | .help_msg = "show-task-states(t)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | .action_msg = "Show State", |
| 289 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 290 | }; |
| 291 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 292 | static void sysrq_handle_showstate_blocked(int key) |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 293 | { |
| 294 | show_state_filter(TASK_UNINTERRUPTIBLE); |
| 295 | } |
| 296 | static struct sysrq_key_op sysrq_showstate_blocked_op = { |
| 297 | .handler = sysrq_handle_showstate_blocked, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 298 | .help_msg = "show-blocked-tasks(w)", |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 299 | .action_msg = "Show Blocked State", |
| 300 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 301 | }; |
| 302 | |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 303 | #ifdef CONFIG_TRACING |
| 304 | #include <linux/ftrace.h> |
| 305 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 306 | static void sysrq_ftrace_dump(int key) |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 307 | { |
Frederic Weisbecker | cecbca9 | 2010-04-18 19:08:41 +0200 | [diff] [blame] | 308 | ftrace_dump(DUMP_ALL); |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 309 | } |
| 310 | static struct sysrq_key_op sysrq_ftrace_dump_op = { |
| 311 | .handler = sysrq_ftrace_dump, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 312 | .help_msg = "dump-ftrace-buffer(z)", |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 313 | .action_msg = "Dump ftrace buffer", |
| 314 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 315 | }; |
| 316 | #else |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 317 | #define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)NULL) |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 318 | #endif |
Ingo Molnar | e59e2ae | 2006-12-06 20:35:59 -0800 | [diff] [blame] | 319 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 320 | static void sysrq_handle_showmem(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | { |
Michal Hocko | 9af744d | 2017-02-22 15:46:16 -0800 | [diff] [blame] | 322 | show_mem(0, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | } |
| 324 | static struct sysrq_key_op sysrq_showmem_op = { |
| 325 | .handler = sysrq_handle_showmem, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 326 | .help_msg = "show-memory-usage(m)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | .action_msg = "Show Memory", |
| 328 | .enable_mask = SYSRQ_ENABLE_DUMP, |
| 329 | }; |
| 330 | |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 331 | /* |
| 332 | * Signal sysrq helper function. Sends a signal to all user processes. |
| 333 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | static void send_sig_all(int sig) |
| 335 | { |
| 336 | struct task_struct *p; |
| 337 | |
Anton Vorontsov | e502bab | 2012-02-07 10:49:39 +0400 | [diff] [blame] | 338 | read_lock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | for_each_process(p) { |
Anton Vorontsov | d3a532a | 2012-02-07 10:49:51 +0400 | [diff] [blame] | 340 | if (p->flags & PF_KTHREAD) |
| 341 | continue; |
| 342 | if (is_global_init(p)) |
| 343 | continue; |
| 344 | |
Anton Vorontsov | b82c328 | 2012-04-05 14:25:05 -0700 | [diff] [blame] | 345 | do_send_sig_info(sig, SEND_SIG_FORCED, p, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | } |
Anton Vorontsov | e502bab | 2012-02-07 10:49:39 +0400 | [diff] [blame] | 347 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | } |
| 349 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 350 | static void sysrq_handle_term(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | { |
| 352 | send_sig_all(SIGTERM); |
Borislav Petkov | a8fe19e | 2014-06-04 16:11:46 -0700 | [diff] [blame] | 353 | console_loglevel = CONSOLE_LOGLEVEL_DEBUG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | } |
| 355 | static struct sysrq_key_op sysrq_term_op = { |
| 356 | .handler = sysrq_handle_term, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 357 | .help_msg = "terminate-all-tasks(e)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | .action_msg = "Terminate All Tasks", |
| 359 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 360 | }; |
| 361 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 362 | static void moom_callback(struct work_struct *ignored) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | { |
David Rientjes | 6e0fc46 | 2015-09-08 15:00:36 -0700 | [diff] [blame] | 364 | const gfp_t gfp_mask = GFP_KERNEL; |
| 365 | struct oom_control oc = { |
| 366 | .zonelist = node_zonelist(first_memory_node, gfp_mask), |
| 367 | .nodemask = NULL, |
Vladimir Davydov | 2a966b7 | 2016-07-26 15:22:33 -0700 | [diff] [blame] | 368 | .memcg = NULL, |
David Rientjes | 6e0fc46 | 2015-09-08 15:00:36 -0700 | [diff] [blame] | 369 | .gfp_mask = gfp_mask, |
David Rientjes | 54e9e29 | 2015-09-08 15:00:39 -0700 | [diff] [blame] | 370 | .order = -1, |
David Rientjes | 6e0fc46 | 2015-09-08 15:00:36 -0700 | [diff] [blame] | 371 | }; |
| 372 | |
Johannes Weiner | dc56401 | 2015-06-24 16:57:19 -0700 | [diff] [blame] | 373 | mutex_lock(&oom_lock); |
David Rientjes | 6e0fc46 | 2015-09-08 15:00:36 -0700 | [diff] [blame] | 374 | if (!out_of_memory(&oc)) |
Michal Hocko | d75da00 | 2017-05-03 14:54:57 -0700 | [diff] [blame] | 375 | pr_info("OOM request ignored. No task eligible\n"); |
Johannes Weiner | dc56401 | 2015-06-24 16:57:19 -0700 | [diff] [blame] | 376 | mutex_unlock(&oom_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | } |
| 378 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 379 | static DECLARE_WORK(moom_work, moom_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 381 | static void sysrq_handle_moom(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | { |
| 383 | schedule_work(&moom_work); |
| 384 | } |
| 385 | static struct sysrq_key_op sysrq_moom_op = { |
| 386 | .handler = sysrq_handle_moom, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 387 | .help_msg = "memory-full-oom-kill(f)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | .action_msg = "Manual OOM execution", |
Naohiro Ooiwa | b4236f8 | 2008-10-15 22:01:43 -0700 | [diff] [blame] | 389 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | }; |
| 391 | |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 392 | #ifdef CONFIG_BLOCK |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 393 | static void sysrq_handle_thaw(int key) |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 394 | { |
| 395 | emergency_thaw_all(); |
| 396 | } |
| 397 | static struct sysrq_key_op sysrq_thaw_op = { |
| 398 | .handler = sysrq_handle_thaw, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 399 | .help_msg = "thaw-filesystems(j)", |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 400 | .action_msg = "Emergency Thaw of all frozen filesystems", |
| 401 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 402 | }; |
| 403 | #endif |
| 404 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 405 | static void sysrq_handle_kill(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | { |
| 407 | send_sig_all(SIGKILL); |
Borislav Petkov | a8fe19e | 2014-06-04 16:11:46 -0700 | [diff] [blame] | 408 | console_loglevel = CONSOLE_LOGLEVEL_DEBUG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | } |
| 410 | static struct sysrq_key_op sysrq_kill_op = { |
| 411 | .handler = sysrq_handle_kill, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 412 | .help_msg = "kill-all-tasks(i)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | .action_msg = "Kill All Tasks", |
| 414 | .enable_mask = SYSRQ_ENABLE_SIGNAL, |
| 415 | }; |
| 416 | |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 417 | static void sysrq_handle_unrt(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | { |
| 419 | normalize_rt_tasks(); |
| 420 | } |
| 421 | static struct sysrq_key_op sysrq_unrt_op = { |
| 422 | .handler = sysrq_handle_unrt, |
zhangwei(Jovi) | afa80cc | 2013-03-07 17:00:02 +0800 | [diff] [blame] | 423 | .help_msg = "nice-all-RT-tasks(n)", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | .action_msg = "Nice All RT Tasks", |
| 425 | .enable_mask = SYSRQ_ENABLE_RTNICE, |
| 426 | }; |
| 427 | |
| 428 | /* Key Operations table and lock */ |
| 429 | static DEFINE_SPINLOCK(sysrq_key_table_lock); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 430 | |
| 431 | static struct sysrq_key_op *sysrq_key_table[36] = { |
| 432 | &sysrq_loglevel_op, /* 0 */ |
| 433 | &sysrq_loglevel_op, /* 1 */ |
| 434 | &sysrq_loglevel_op, /* 2 */ |
| 435 | &sysrq_loglevel_op, /* 3 */ |
| 436 | &sysrq_loglevel_op, /* 4 */ |
| 437 | &sysrq_loglevel_op, /* 5 */ |
| 438 | &sysrq_loglevel_op, /* 6 */ |
| 439 | &sysrq_loglevel_op, /* 7 */ |
| 440 | &sysrq_loglevel_op, /* 8 */ |
| 441 | &sysrq_loglevel_op, /* 9 */ |
| 442 | |
| 443 | /* |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 444 | * a: Don't use for system provided sysrqs, it is handled specially on |
| 445 | * sparc and will never arrive. |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 446 | */ |
| 447 | NULL, /* a */ |
| 448 | &sysrq_reboot_op, /* b */ |
Eric Biggers | 5e35141 | 2017-04-03 22:50:20 -0700 | [diff] [blame] | 449 | &sysrq_crash_op, /* c */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 450 | &sysrq_showlocks_op, /* d */ |
| 451 | &sysrq_term_op, /* e */ |
| 452 | &sysrq_moom_op, /* f */ |
Jason Wessel | 364b5b7 | 2009-05-13 21:56:59 -0500 | [diff] [blame] | 453 | /* g: May be registered for the kernel debugger */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 454 | NULL, /* g */ |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 455 | NULL, /* h - reserved for help */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 456 | &sysrq_kill_op, /* i */ |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 457 | #ifdef CONFIG_BLOCK |
| 458 | &sysrq_thaw_op, /* j */ |
| 459 | #else |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 460 | NULL, /* j */ |
Eric Sandeen | c2d7543 | 2009-03-31 15:23:46 -0700 | [diff] [blame] | 461 | #endif |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 462 | &sysrq_SAK_op, /* k */ |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 463 | #ifdef CONFIG_SMP |
| 464 | &sysrq_showallcpus_op, /* l */ |
| 465 | #else |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 466 | NULL, /* l */ |
Rik van Riel | 5045bca | 2008-04-29 00:59:21 -0700 | [diff] [blame] | 467 | #endif |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 468 | &sysrq_showmem_op, /* m */ |
| 469 | &sysrq_unrt_op, /* n */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 470 | /* o: This will often be registered as 'Off' at init time */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 471 | NULL, /* o */ |
| 472 | &sysrq_showregs_op, /* p */ |
Ingo Molnar | 88ad0bf6 | 2007-02-16 01:28:16 -0800 | [diff] [blame] | 473 | &sysrq_show_timers_op, /* q */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 474 | &sysrq_unraw_op, /* r */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 475 | &sysrq_sync_op, /* s */ |
| 476 | &sysrq_showstate_op, /* t */ |
| 477 | &sysrq_mountro_op, /* u */ |
Jason Wessel | 364b5b7 | 2009-05-13 21:56:59 -0500 | [diff] [blame] | 478 | /* v: May be registered for frame buffer console restore */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 479 | NULL, /* v */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 480 | &sysrq_showstate_blocked_op, /* w */ |
James Hogan | d1e9a4f | 2015-05-19 09:50:29 +0100 | [diff] [blame] | 481 | /* x: May be registered on mips for TLB dump */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 482 | /* x: May be registered on ppc/powerpc for xmon */ |
David S. Miller | 916ca14 | 2012-10-16 09:34:01 -0700 | [diff] [blame] | 483 | /* x: May be registered on sparc64 for global PMU dump */ |
Randy Dunlap | d346cce | 2007-01-31 23:48:17 -0800 | [diff] [blame] | 484 | NULL, /* x */ |
David S. Miller | 93dae5b | 2008-05-19 23:46:00 -0700 | [diff] [blame] | 485 | /* y: May be registered on sparc64 for global register dump */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 486 | NULL, /* y */ |
Peter Zijlstra | 69f698a | 2008-11-01 19:53:34 +0100 | [diff] [blame] | 487 | &sysrq_ftrace_dump_op, /* z */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | }; |
| 489 | |
| 490 | /* key2index calculation, -1 on invalid index */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 491 | static int sysrq_key_table_key2index(int key) |
| 492 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | int retval; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 494 | |
| 495 | if ((key >= '0') && (key <= '9')) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | retval = key - '0'; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 497 | else if ((key >= 'a') && (key <= 'z')) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | retval = key + 10 - 'a'; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 499 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | retval = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | return retval; |
| 502 | } |
| 503 | |
| 504 | /* |
| 505 | * get and put functions for the table, exposed to modules. |
| 506 | */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 507 | struct sysrq_key_op *__sysrq_get_key_op(int key) |
| 508 | { |
| 509 | struct sysrq_key_op *op_p = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | int i; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 511 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | i = sysrq_key_table_key2index(key); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 513 | if (i != -1) |
| 514 | op_p = sysrq_key_table[i]; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 515 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | return op_p; |
| 517 | } |
| 518 | |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 519 | static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p) |
| 520 | { |
| 521 | int i = sysrq_key_table_key2index(key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | if (i != -1) |
| 524 | sysrq_key_table[i] = op_p; |
| 525 | } |
| 526 | |
Dmitry Torokhov | f335397 | 2010-08-17 21:15:47 -0700 | [diff] [blame] | 527 | void __handle_sysrq(int key, bool check_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | { |
| 529 | struct sysrq_key_op *op_p; |
| 530 | int orig_log_level; |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 531 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | |
Rik van Riel | 722773a | 2014-06-06 14:38:14 -0700 | [diff] [blame] | 533 | rcu_sysrq_start(); |
Rik van Riel | 984d74a | 2014-06-06 14:38:13 -0700 | [diff] [blame] | 534 | rcu_read_lock(); |
Andy Whitcroft | fb144ad | 2009-01-15 13:50:52 -0800 | [diff] [blame] | 535 | /* |
| 536 | * Raise the apparent loglevel to maximum so that the sysrq header |
| 537 | * is shown to provide the user with positive feedback. We do not |
| 538 | * simply emit this at KERN_EMERG as that would change message |
| 539 | * routing in the consumers of /proc/kmsg. |
| 540 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | orig_log_level = console_loglevel; |
Borislav Petkov | a8fe19e | 2014-06-04 16:11:46 -0700 | [diff] [blame] | 542 | console_loglevel = CONSOLE_LOGLEVEL_DEFAULT; |
Michal Hocko | 401e4a7 | 2015-02-11 15:26:21 -0800 | [diff] [blame] | 543 | pr_info("SysRq : "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | |
| 545 | op_p = __sysrq_get_key_op(key); |
| 546 | if (op_p) { |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 547 | /* |
| 548 | * Should we check for enabled operations (/proc/sysrq-trigger |
| 549 | * should not) and is the invoked operation enabled? |
| 550 | */ |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 551 | if (!check_mask || sysrq_on_mask(op_p->enable_mask)) { |
Michal Hocko | 401e4a7 | 2015-02-11 15:26:21 -0800 | [diff] [blame] | 552 | pr_cont("%s\n", op_p->action_msg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | console_loglevel = orig_log_level; |
Dmitry Torokhov | 1495cc9 | 2010-08-17 21:15:46 -0700 | [diff] [blame] | 554 | op_p->handler(key); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 555 | } else { |
Michal Hocko | 401e4a7 | 2015-02-11 15:26:21 -0800 | [diff] [blame] | 556 | pr_cont("This sysrq operation is disabled.\n"); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 557 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | } else { |
Michal Hocko | 401e4a7 | 2015-02-11 15:26:21 -0800 | [diff] [blame] | 559 | pr_cont("HELP : "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 560 | /* Only print the help msg once per handler */ |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 561 | for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) { |
| 562 | if (sysrq_key_table[i]) { |
| 563 | int j; |
| 564 | |
| 565 | for (j = 0; sysrq_key_table[i] != |
| 566 | sysrq_key_table[j]; j++) |
| 567 | ; |
| 568 | if (j != i) |
| 569 | continue; |
Michal Hocko | 401e4a7 | 2015-02-11 15:26:21 -0800 | [diff] [blame] | 570 | pr_cont("%s ", sysrq_key_table[i]->help_msg); |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 571 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | } |
Michal Hocko | 401e4a7 | 2015-02-11 15:26:21 -0800 | [diff] [blame] | 573 | pr_cont("\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | console_loglevel = orig_log_level; |
| 575 | } |
Rik van Riel | 984d74a | 2014-06-06 14:38:13 -0700 | [diff] [blame] | 576 | rcu_read_unlock(); |
Rik van Riel | 722773a | 2014-06-06 14:38:14 -0700 | [diff] [blame] | 577 | rcu_sysrq_end(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | } |
| 579 | |
Dmitry Torokhov | f335397 | 2010-08-17 21:15:47 -0700 | [diff] [blame] | 580 | void handle_sysrq(int key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | { |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 582 | if (sysrq_on()) |
Dmitry Torokhov | f335397 | 2010-08-17 21:15:47 -0700 | [diff] [blame] | 583 | __handle_sysrq(key, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 585 | EXPORT_SYMBOL(handle_sysrq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 587 | #ifdef CONFIG_INPUT |
Arnd Bergmann | ffb6e0c | 2015-05-26 14:45:29 -0700 | [diff] [blame] | 588 | static int sysrq_reset_downtime_ms; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 589 | |
| 590 | /* Simple translation table for the SysRq keys */ |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 591 | static const unsigned char sysrq_xlate[KEY_CNT] = |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 592 | "\000\0331234567890-=\177\t" /* 0x00 - 0x0f */ |
| 593 | "qwertyuiop[]\r\000as" /* 0x10 - 0x1f */ |
| 594 | "dfghjkl;'`\000\\zxcv" /* 0x20 - 0x2f */ |
| 595 | "bnm,./\000*\000 \000\201\202\203\204\205" /* 0x30 - 0x3f */ |
| 596 | "\206\207\210\211\212\000\000789-456+1" /* 0x40 - 0x4f */ |
| 597 | "230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */ |
| 598 | "\r\000/"; /* 0x60 - 0x6f */ |
| 599 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 600 | struct sysrq_state { |
| 601 | struct input_handle handle; |
| 602 | struct work_struct reinject_work; |
| 603 | unsigned long key_down[BITS_TO_LONGS(KEY_CNT)]; |
| 604 | unsigned int alt; |
| 605 | unsigned int alt_use; |
| 606 | bool active; |
| 607 | bool need_reinject; |
Dmitry Torokhov | 7ab7b5a | 2011-02-02 22:59:54 -0800 | [diff] [blame] | 608 | bool reinjecting; |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 609 | |
| 610 | /* reset sequence handling */ |
| 611 | bool reset_canceled; |
Mathieu J. Poirier | 3d28951 | 2013-06-05 22:51:46 -0700 | [diff] [blame] | 612 | bool reset_requested; |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 613 | unsigned long reset_keybit[BITS_TO_LONGS(KEY_CNT)]; |
| 614 | int reset_seq_len; |
| 615 | int reset_seq_cnt; |
| 616 | int reset_seq_version; |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 617 | struct timer_list keyreset_timer; |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 618 | }; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 619 | |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 620 | #define SYSRQ_KEY_RESET_MAX 20 /* Should be plenty */ |
| 621 | static unsigned short sysrq_reset_seq[SYSRQ_KEY_RESET_MAX]; |
| 622 | static unsigned int sysrq_reset_seq_len; |
| 623 | static unsigned int sysrq_reset_seq_version = 1; |
| 624 | |
| 625 | static void sysrq_parse_reset_sequence(struct sysrq_state *state) |
| 626 | { |
| 627 | int i; |
| 628 | unsigned short key; |
| 629 | |
| 630 | state->reset_seq_cnt = 0; |
| 631 | |
| 632 | for (i = 0; i < sysrq_reset_seq_len; i++) { |
| 633 | key = sysrq_reset_seq[i]; |
| 634 | |
| 635 | if (key == KEY_RESERVED || key > KEY_MAX) |
| 636 | break; |
| 637 | |
| 638 | __set_bit(key, state->reset_keybit); |
| 639 | state->reset_seq_len++; |
| 640 | |
| 641 | if (test_bit(key, state->key_down)) |
| 642 | state->reset_seq_cnt++; |
| 643 | } |
| 644 | |
| 645 | /* Disable reset until old keys are not released */ |
| 646 | state->reset_canceled = state->reset_seq_cnt != 0; |
| 647 | |
| 648 | state->reset_seq_version = sysrq_reset_seq_version; |
| 649 | } |
| 650 | |
Mathieu J. Poirier | 3d28951 | 2013-06-05 22:51:46 -0700 | [diff] [blame] | 651 | static void sysrq_do_reset(unsigned long _state) |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 652 | { |
Mathieu J. Poirier | 3d28951 | 2013-06-05 22:51:46 -0700 | [diff] [blame] | 653 | struct sysrq_state *state = (struct sysrq_state *) _state; |
| 654 | |
| 655 | state->reset_requested = true; |
| 656 | |
| 657 | sys_sync(); |
| 658 | kernel_restart(NULL); |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 659 | } |
| 660 | |
| 661 | static void sysrq_handle_reset_request(struct sysrq_state *state) |
| 662 | { |
Mathieu J. Poirier | 3d28951 | 2013-06-05 22:51:46 -0700 | [diff] [blame] | 663 | if (state->reset_requested) |
| 664 | __handle_sysrq(sysrq_xlate[KEY_B], false); |
| 665 | |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 666 | if (sysrq_reset_downtime_ms) |
| 667 | mod_timer(&state->keyreset_timer, |
| 668 | jiffies + msecs_to_jiffies(sysrq_reset_downtime_ms)); |
| 669 | else |
Mathieu J. Poirier | 3d28951 | 2013-06-05 22:51:46 -0700 | [diff] [blame] | 670 | sysrq_do_reset((unsigned long)state); |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 671 | } |
| 672 | |
| 673 | static void sysrq_detect_reset_sequence(struct sysrq_state *state, |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 674 | unsigned int code, int value) |
| 675 | { |
| 676 | if (!test_bit(code, state->reset_keybit)) { |
| 677 | /* |
| 678 | * Pressing any key _not_ in reset sequence cancels |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 679 | * the reset sequence. Also cancelling the timer in |
| 680 | * case additional keys were pressed after a reset |
| 681 | * has been requested. |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 682 | */ |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 683 | if (value && state->reset_seq_cnt) { |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 684 | state->reset_canceled = true; |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 685 | del_timer(&state->keyreset_timer); |
| 686 | } |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 687 | } else if (value == 0) { |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 688 | /* |
| 689 | * Key release - all keys in the reset sequence need |
| 690 | * to be pressed and held for the reset timeout |
| 691 | * to hold. |
| 692 | */ |
| 693 | del_timer(&state->keyreset_timer); |
| 694 | |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 695 | if (--state->reset_seq_cnt == 0) |
| 696 | state->reset_canceled = false; |
| 697 | } else if (value == 1) { |
| 698 | /* key press, not autorepeat */ |
| 699 | if (++state->reset_seq_cnt == state->reset_seq_len && |
| 700 | !state->reset_canceled) { |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 701 | sysrq_handle_reset_request(state); |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 702 | } |
| 703 | } |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 704 | } |
| 705 | |
Mathieu J. Poirier | 4c076eb | 2013-08-03 17:22:08 -0700 | [diff] [blame] | 706 | #ifdef CONFIG_OF |
| 707 | static void sysrq_of_get_keyreset_config(void) |
| 708 | { |
| 709 | u32 key; |
| 710 | struct device_node *np; |
| 711 | struct property *prop; |
| 712 | const __be32 *p; |
| 713 | |
| 714 | np = of_find_node_by_path("/chosen/linux,sysrq-reset-seq"); |
| 715 | if (!np) { |
| 716 | pr_debug("No sysrq node found"); |
| 717 | return; |
| 718 | } |
| 719 | |
| 720 | /* Reset in case a __weak definition was present */ |
| 721 | sysrq_reset_seq_len = 0; |
| 722 | |
| 723 | of_property_for_each_u32(np, "keyset", prop, p, key) { |
| 724 | if (key == KEY_RESERVED || key > KEY_MAX || |
| 725 | sysrq_reset_seq_len == SYSRQ_KEY_RESET_MAX) |
| 726 | break; |
| 727 | |
| 728 | sysrq_reset_seq[sysrq_reset_seq_len++] = (unsigned short)key; |
| 729 | } |
| 730 | |
| 731 | /* Get reset timeout if any. */ |
| 732 | of_property_read_u32(np, "timeout-ms", &sysrq_reset_downtime_ms); |
| 733 | } |
| 734 | #else |
| 735 | static void sysrq_of_get_keyreset_config(void) |
| 736 | { |
| 737 | } |
| 738 | #endif |
| 739 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 740 | static void sysrq_reinject_alt_sysrq(struct work_struct *work) |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 741 | { |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 742 | struct sysrq_state *sysrq = |
| 743 | container_of(work, struct sysrq_state, reinject_work); |
| 744 | struct input_handle *handle = &sysrq->handle; |
| 745 | unsigned int alt_code = sysrq->alt_use; |
| 746 | |
| 747 | if (sysrq->need_reinject) { |
Dmitry Torokhov | 7ab7b5a | 2011-02-02 22:59:54 -0800 | [diff] [blame] | 748 | /* we do not want the assignment to be reordered */ |
| 749 | sysrq->reinjecting = true; |
| 750 | mb(); |
| 751 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 752 | /* Simulate press and release of Alt + SysRq */ |
| 753 | input_inject_event(handle, EV_KEY, alt_code, 1); |
| 754 | input_inject_event(handle, EV_KEY, KEY_SYSRQ, 1); |
| 755 | input_inject_event(handle, EV_SYN, SYN_REPORT, 1); |
| 756 | |
| 757 | input_inject_event(handle, EV_KEY, KEY_SYSRQ, 0); |
| 758 | input_inject_event(handle, EV_KEY, alt_code, 0); |
| 759 | input_inject_event(handle, EV_SYN, SYN_REPORT, 1); |
Dmitry Torokhov | 7ab7b5a | 2011-02-02 22:59:54 -0800 | [diff] [blame] | 760 | |
| 761 | mb(); |
| 762 | sysrq->reinjecting = false; |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 763 | } |
| 764 | } |
| 765 | |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 766 | static bool sysrq_handle_keypress(struct sysrq_state *sysrq, |
| 767 | unsigned int code, int value) |
| 768 | { |
| 769 | bool was_active = sysrq->active; |
| 770 | bool suppress; |
| 771 | |
| 772 | switch (code) { |
| 773 | |
| 774 | case KEY_LEFTALT: |
| 775 | case KEY_RIGHTALT: |
| 776 | if (!value) { |
| 777 | /* One of ALTs is being released */ |
| 778 | if (sysrq->active && code == sysrq->alt_use) |
| 779 | sysrq->active = false; |
| 780 | |
| 781 | sysrq->alt = KEY_RESERVED; |
| 782 | |
| 783 | } else if (value != 2) { |
| 784 | sysrq->alt = code; |
| 785 | sysrq->need_reinject = false; |
| 786 | } |
| 787 | break; |
| 788 | |
| 789 | case KEY_SYSRQ: |
| 790 | if (value == 1 && sysrq->alt != KEY_RESERVED) { |
| 791 | sysrq->active = true; |
| 792 | sysrq->alt_use = sysrq->alt; |
| 793 | /* |
| 794 | * If nothing else will be pressed we'll need |
| 795 | * to re-inject Alt-SysRq keysroke. |
| 796 | */ |
| 797 | sysrq->need_reinject = true; |
| 798 | } |
| 799 | |
| 800 | /* |
| 801 | * Pretend that sysrq was never pressed at all. This |
| 802 | * is needed to properly handle KGDB which will try |
| 803 | * to release all keys after exiting debugger. If we |
| 804 | * do not clear key bit it KGDB will end up sending |
| 805 | * release events for Alt and SysRq, potentially |
| 806 | * triggering print screen function. |
| 807 | */ |
| 808 | if (sysrq->active) |
| 809 | clear_bit(KEY_SYSRQ, sysrq->handle.dev->key); |
| 810 | |
| 811 | break; |
| 812 | |
| 813 | default: |
| 814 | if (sysrq->active && value && value != 2) { |
| 815 | sysrq->need_reinject = false; |
| 816 | __handle_sysrq(sysrq_xlate[code], true); |
| 817 | } |
| 818 | break; |
| 819 | } |
| 820 | |
| 821 | suppress = sysrq->active; |
| 822 | |
| 823 | if (!sysrq->active) { |
| 824 | |
| 825 | /* |
| 826 | * See if reset sequence has changed since the last time. |
| 827 | */ |
| 828 | if (sysrq->reset_seq_version != sysrq_reset_seq_version) |
| 829 | sysrq_parse_reset_sequence(sysrq); |
| 830 | |
| 831 | /* |
| 832 | * If we are not suppressing key presses keep track of |
| 833 | * keyboard state so we can release keys that have been |
| 834 | * pressed before entering SysRq mode. |
| 835 | */ |
| 836 | if (value) |
| 837 | set_bit(code, sysrq->key_down); |
| 838 | else |
| 839 | clear_bit(code, sysrq->key_down); |
| 840 | |
| 841 | if (was_active) |
| 842 | schedule_work(&sysrq->reinject_work); |
| 843 | |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 844 | /* Check for reset sequence */ |
| 845 | sysrq_detect_reset_sequence(sysrq, code, value); |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 846 | |
| 847 | } else if (value == 0 && test_and_clear_bit(code, sysrq->key_down)) { |
| 848 | /* |
| 849 | * Pass on release events for keys that was pressed before |
| 850 | * entering SysRq mode. |
| 851 | */ |
| 852 | suppress = false; |
| 853 | } |
| 854 | |
| 855 | return suppress; |
| 856 | } |
| 857 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 858 | static bool sysrq_filter(struct input_handle *handle, |
| 859 | unsigned int type, unsigned int code, int value) |
| 860 | { |
| 861 | struct sysrq_state *sysrq = handle->private; |
Dmitry Torokhov | 1966cb2 | 2010-09-29 18:04:21 -0700 | [diff] [blame] | 862 | bool suppress; |
| 863 | |
Dmitry Torokhov | 7ab7b5a | 2011-02-02 22:59:54 -0800 | [diff] [blame] | 864 | /* |
| 865 | * Do not filter anything if we are in the process of re-injecting |
| 866 | * Alt+SysRq combination. |
| 867 | */ |
| 868 | if (sysrq->reinjecting) |
| 869 | return false; |
| 870 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 871 | switch (type) { |
Dmitry Torokhov | 1966cb2 | 2010-09-29 18:04:21 -0700 | [diff] [blame] | 872 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 873 | case EV_SYN: |
| 874 | suppress = false; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 875 | break; |
| 876 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 877 | case EV_KEY: |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 878 | suppress = sysrq_handle_keypress(sysrq, code, value); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 879 | break; |
| 880 | |
| 881 | default: |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 882 | suppress = sysrq->active; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 883 | break; |
| 884 | } |
| 885 | |
Dmitry Torokhov | 1966cb2 | 2010-09-29 18:04:21 -0700 | [diff] [blame] | 886 | return suppress; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 887 | } |
| 888 | |
| 889 | static int sysrq_connect(struct input_handler *handler, |
| 890 | struct input_dev *dev, |
| 891 | const struct input_device_id *id) |
| 892 | { |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 893 | struct sysrq_state *sysrq; |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 894 | int error; |
| 895 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 896 | sysrq = kzalloc(sizeof(struct sysrq_state), GFP_KERNEL); |
| 897 | if (!sysrq) |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 898 | return -ENOMEM; |
| 899 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 900 | INIT_WORK(&sysrq->reinject_work, sysrq_reinject_alt_sysrq); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 901 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 902 | sysrq->handle.dev = dev; |
| 903 | sysrq->handle.handler = handler; |
| 904 | sysrq->handle.name = "sysrq"; |
| 905 | sysrq->handle.private = sysrq; |
Mathieu J. Poirier | 3d28951 | 2013-06-05 22:51:46 -0700 | [diff] [blame] | 906 | setup_timer(&sysrq->keyreset_timer, |
| 907 | sysrq_do_reset, (unsigned long)sysrq); |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 908 | |
| 909 | error = input_register_handle(&sysrq->handle); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 910 | if (error) { |
| 911 | pr_err("Failed to register input sysrq handler, error %d\n", |
| 912 | error); |
| 913 | goto err_free; |
| 914 | } |
| 915 | |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 916 | error = input_open_device(&sysrq->handle); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 917 | if (error) { |
| 918 | pr_err("Failed to open input device, error %d\n", error); |
| 919 | goto err_unregister; |
| 920 | } |
| 921 | |
| 922 | return 0; |
| 923 | |
| 924 | err_unregister: |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 925 | input_unregister_handle(&sysrq->handle); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 926 | err_free: |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 927 | kfree(sysrq); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 928 | return error; |
| 929 | } |
| 930 | |
| 931 | static void sysrq_disconnect(struct input_handle *handle) |
| 932 | { |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 933 | struct sysrq_state *sysrq = handle->private; |
| 934 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 935 | input_close_device(handle); |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 936 | cancel_work_sync(&sysrq->reinject_work); |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 937 | del_timer_sync(&sysrq->keyreset_timer); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 938 | input_unregister_handle(handle); |
Dmitry Torokhov | fcb7193 | 2010-11-15 00:23:42 -0800 | [diff] [blame] | 939 | kfree(sysrq); |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 940 | } |
| 941 | |
| 942 | /* |
Dmitry Torokhov | 1966cb2 | 2010-09-29 18:04:21 -0700 | [diff] [blame] | 943 | * We are matching on KEY_LEFTALT instead of KEY_SYSRQ because not all |
| 944 | * 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] | 945 | * later, but we expect all such keyboards to have left alt. |
| 946 | */ |
| 947 | static const struct input_device_id sysrq_ids[] = { |
| 948 | { |
| 949 | .flags = INPUT_DEVICE_ID_MATCH_EVBIT | |
| 950 | INPUT_DEVICE_ID_MATCH_KEYBIT, |
Akinobu Mita | 802c038 | 2017-01-06 02:14:16 +0900 | [diff] [blame] | 951 | .evbit = { [BIT_WORD(EV_KEY)] = BIT_MASK(EV_KEY) }, |
| 952 | .keybit = { [BIT_WORD(KEY_LEFTALT)] = BIT_MASK(KEY_LEFTALT) }, |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 953 | }, |
| 954 | { }, |
| 955 | }; |
| 956 | |
| 957 | static struct input_handler sysrq_handler = { |
| 958 | .filter = sysrq_filter, |
| 959 | .connect = sysrq_connect, |
| 960 | .disconnect = sysrq_disconnect, |
| 961 | .name = "sysrq", |
| 962 | .id_table = sysrq_ids, |
| 963 | }; |
| 964 | |
| 965 | static bool sysrq_handler_registered; |
| 966 | |
| 967 | static inline void sysrq_register_handler(void) |
| 968 | { |
| 969 | int error; |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 970 | |
Mathieu J. Poirier | 4c076eb | 2013-08-03 17:22:08 -0700 | [diff] [blame] | 971 | sysrq_of_get_keyreset_config(); |
| 972 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 973 | error = input_register_handler(&sysrq_handler); |
| 974 | if (error) |
| 975 | pr_err("Failed to register input handler, error %d", error); |
| 976 | else |
| 977 | sysrq_handler_registered = true; |
| 978 | } |
| 979 | |
| 980 | static inline void sysrq_unregister_handler(void) |
| 981 | { |
| 982 | if (sysrq_handler_registered) { |
| 983 | input_unregister_handler(&sysrq_handler); |
| 984 | sysrq_handler_registered = false; |
| 985 | } |
| 986 | } |
| 987 | |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 988 | static int sysrq_reset_seq_param_set(const char *buffer, |
| 989 | const struct kernel_param *kp) |
| 990 | { |
| 991 | unsigned long val; |
| 992 | int error; |
| 993 | |
Jingoo Han | 86b4056 | 2013-06-01 16:30:06 +0900 | [diff] [blame] | 994 | error = kstrtoul(buffer, 0, &val); |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 995 | if (error < 0) |
| 996 | return error; |
| 997 | |
| 998 | if (val > KEY_MAX) |
| 999 | return -EINVAL; |
| 1000 | |
| 1001 | *((unsigned short *)kp->arg) = val; |
| 1002 | sysrq_reset_seq_version++; |
| 1003 | |
| 1004 | return 0; |
| 1005 | } |
| 1006 | |
Luis R. Rodriguez | 9c27847 | 2015-05-27 11:09:38 +0930 | [diff] [blame] | 1007 | static const struct kernel_param_ops param_ops_sysrq_reset_seq = { |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 1008 | .get = param_get_ushort, |
| 1009 | .set = sysrq_reset_seq_param_set, |
| 1010 | }; |
| 1011 | |
| 1012 | #define param_check_sysrq_reset_seq(name, p) \ |
| 1013 | __param_check(name, p, unsigned short) |
| 1014 | |
Paul Gortmaker | 3bce6f6 | 2015-08-19 17:48:06 -0400 | [diff] [blame] | 1015 | /* |
| 1016 | * not really modular, but the easiest way to keep compat with existing |
| 1017 | * bootargs behaviour is to continue using module_param here. |
| 1018 | */ |
Mathieu Poirier | 154b7a4 | 2013-01-06 23:23:33 -0800 | [diff] [blame] | 1019 | module_param_array_named(reset_seq, sysrq_reset_seq, sysrq_reset_seq, |
| 1020 | &sysrq_reset_seq_len, 0644); |
| 1021 | |
Mathieu J. Poirier | 3903078 | 2013-04-01 22:14:19 -0700 | [diff] [blame] | 1022 | module_param_named(sysrq_downtime_ms, sysrq_reset_downtime_ms, int, 0644); |
| 1023 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 1024 | #else |
| 1025 | |
| 1026 | static inline void sysrq_register_handler(void) |
| 1027 | { |
| 1028 | } |
| 1029 | |
| 1030 | static inline void sysrq_unregister_handler(void) |
| 1031 | { |
| 1032 | } |
| 1033 | |
| 1034 | #endif /* CONFIG_INPUT */ |
| 1035 | |
| 1036 | int sysrq_toggle_support(int enable_mask) |
| 1037 | { |
| 1038 | bool was_enabled = sysrq_on(); |
| 1039 | |
| 1040 | sysrq_enabled = enable_mask; |
| 1041 | |
| 1042 | if (was_enabled != sysrq_on()) { |
| 1043 | if (sysrq_on()) |
| 1044 | sysrq_register_handler(); |
| 1045 | else |
| 1046 | sysrq_unregister_handler(); |
| 1047 | } |
| 1048 | |
| 1049 | return 0; |
| 1050 | } |
| 1051 | |
Adrian Bunk | cf62ddc | 2005-11-08 21:39:47 -0800 | [diff] [blame] | 1052 | 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] | 1053 | struct sysrq_key_op *remove_op_p) |
| 1054 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1055 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1056 | |
Rik van Riel | 984d74a | 2014-06-06 14:38:13 -0700 | [diff] [blame] | 1057 | spin_lock(&sysrq_key_table_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1058 | if (__sysrq_get_key_op(key) == remove_op_p) { |
| 1059 | __sysrq_put_key_op(key, insert_op_p); |
| 1060 | retval = 0; |
| 1061 | } else { |
| 1062 | retval = -1; |
| 1063 | } |
Rik van Riel | 984d74a | 2014-06-06 14:38:13 -0700 | [diff] [blame] | 1064 | spin_unlock(&sysrq_key_table_lock); |
| 1065 | |
| 1066 | /* |
| 1067 | * A concurrent __handle_sysrq either got the old op or the new op. |
| 1068 | * Wait for it to go away before returning, so the code for an old |
| 1069 | * op is not freed (eg. on module unload) while it is in use. |
| 1070 | */ |
| 1071 | synchronize_rcu(); |
| 1072 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1073 | return retval; |
| 1074 | } |
| 1075 | |
| 1076 | int register_sysrq_key(int key, struct sysrq_key_op *op_p) |
| 1077 | { |
| 1078 | return __sysrq_swap_key_ops(key, op_p, NULL); |
| 1079 | } |
Andrew Morton | bf36b90 | 2006-03-25 03:07:08 -0800 | [diff] [blame] | 1080 | EXPORT_SYMBOL(register_sysrq_key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1081 | |
| 1082 | int unregister_sysrq_key(int key, struct sysrq_key_op *op_p) |
| 1083 | { |
| 1084 | return __sysrq_swap_key_ops(key, NULL, op_p); |
| 1085 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | EXPORT_SYMBOL(unregister_sysrq_key); |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 1087 | |
| 1088 | #ifdef CONFIG_PROC_FS |
| 1089 | /* |
| 1090 | * writing 'C' to /proc/sysrq-trigger is like sysrq-C |
| 1091 | */ |
| 1092 | static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf, |
| 1093 | size_t count, loff_t *ppos) |
| 1094 | { |
| 1095 | if (count) { |
| 1096 | char c; |
| 1097 | |
| 1098 | if (get_user(c, buf)) |
| 1099 | return -EFAULT; |
Dmitry Torokhov | f335397 | 2010-08-17 21:15:47 -0700 | [diff] [blame] | 1100 | __handle_sysrq(c, false); |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 1101 | } |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 1102 | |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 1103 | return count; |
| 1104 | } |
| 1105 | |
| 1106 | static const struct file_operations proc_sysrq_trigger_operations = { |
| 1107 | .write = write_sysrq_trigger, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 1108 | .llseek = noop_llseek, |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 1109 | }; |
| 1110 | |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 1111 | static void sysrq_init_procfs(void) |
| 1112 | { |
| 1113 | if (!proc_create("sysrq-trigger", S_IWUSR, NULL, |
| 1114 | &proc_sysrq_trigger_operations)) |
| 1115 | pr_err("Failed to register proc interface\n"); |
| 1116 | } |
| 1117 | |
| 1118 | #else |
| 1119 | |
| 1120 | static inline void sysrq_init_procfs(void) |
| 1121 | { |
| 1122 | } |
| 1123 | |
| 1124 | #endif /* CONFIG_PROC_FS */ |
| 1125 | |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 1126 | static int __init sysrq_init(void) |
| 1127 | { |
Dmitry Torokhov | 97f5f0c | 2010-03-21 22:31:26 -0700 | [diff] [blame] | 1128 | sysrq_init_procfs(); |
| 1129 | |
| 1130 | if (sysrq_on()) |
| 1131 | sysrq_register_handler(); |
| 1132 | |
Alexey Dobriyan | f40cbaa | 2008-10-15 22:04:23 -0700 | [diff] [blame] | 1133 | return 0; |
| 1134 | } |
Paul Gortmaker | 3bce6f6 | 2015-08-19 17:48:06 -0400 | [diff] [blame] | 1135 | device_initcall(sysrq_init); |