hc
2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c
kernel/drivers/tty/sysrq.c
....@@ -19,6 +19,7 @@
1919 #include <linux/sched/rt.h>
2020 #include <linux/sched/debug.h>
2121 #include <linux/sched/task.h>
22
+#include <linux/ctype.h>
2223 #include <linux/interrupt.h>
2324 #include <linux/mm.h>
2425 #include <linux/fs.h>
....@@ -63,6 +64,19 @@
6364 return sysrq_enabled || sysrq_always_enabled;
6465 }
6566
67
+/**
68
+ * sysrq_mask - Getter for sysrq_enabled mask.
69
+ *
70
+ * Return: 1 if sysrq is always enabled, enabled sysrq_key_op mask otherwise.
71
+ */
72
+int sysrq_mask(void)
73
+{
74
+ if (sysrq_always_enabled)
75
+ return 1;
76
+ return sysrq_enabled;
77
+}
78
+EXPORT_SYMBOL_GPL(sysrq_mask);
79
+
6680 /*
6781 * A value of 1 means 'all', other nonzero values are an op mask:
6882 */
....@@ -93,7 +107,7 @@
93107 pr_info("Loglevel set to %d\n", i);
94108 console_loglevel = i;
95109 }
96
-static struct sysrq_key_op sysrq_loglevel_op = {
110
+static const struct sysrq_key_op sysrq_loglevel_op = {
97111 .handler = sysrq_handle_loglevel,
98112 .help_msg = "loglevel(0-9)",
99113 .action_msg = "Changing Loglevel",
....@@ -106,14 +120,14 @@
106120 struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
107121 schedule_work(SAK_work);
108122 }
109
-static struct sysrq_key_op sysrq_SAK_op = {
123
+static const struct sysrq_key_op sysrq_SAK_op = {
110124 .handler = sysrq_handle_SAK,
111125 .help_msg = "sak(k)",
112126 .action_msg = "SAK",
113127 .enable_mask = SYSRQ_ENABLE_KEYBOARD,
114128 };
115129 #else
116
-#define sysrq_SAK_op (*(struct sysrq_key_op *)NULL)
130
+#define sysrq_SAK_op (*(const struct sysrq_key_op *)NULL)
117131 #endif
118132
119133 #ifdef CONFIG_VT
....@@ -122,14 +136,14 @@
122136 vt_reset_unicode(fg_console);
123137 }
124138
125
-static struct sysrq_key_op sysrq_unraw_op = {
139
+static const struct sysrq_key_op sysrq_unraw_op = {
126140 .handler = sysrq_handle_unraw,
127141 .help_msg = "unraw(r)",
128142 .action_msg = "Keyboard mode set to system default",
129143 .enable_mask = SYSRQ_ENABLE_KEYBOARD,
130144 };
131145 #else
132
-#define sysrq_unraw_op (*(struct sysrq_key_op *)NULL)
146
+#define sysrq_unraw_op (*(const struct sysrq_key_op *)NULL)
133147 #endif /* CONFIG_VT */
134148
135149 static void sysrq_handle_crash(int key)
....@@ -139,7 +153,7 @@
139153
140154 panic("sysrq triggered crash\n");
141155 }
142
-static struct sysrq_key_op sysrq_crash_op = {
156
+static const struct sysrq_key_op sysrq_crash_op = {
143157 .handler = sysrq_handle_crash,
144158 .help_msg = "crash(c)",
145159 .action_msg = "Trigger a crash",
....@@ -152,18 +166,20 @@
152166 local_irq_enable();
153167 emergency_restart();
154168 }
155
-static struct sysrq_key_op sysrq_reboot_op = {
169
+static const struct sysrq_key_op sysrq_reboot_op = {
156170 .handler = sysrq_handle_reboot,
157171 .help_msg = "reboot(b)",
158172 .action_msg = "Resetting",
159173 .enable_mask = SYSRQ_ENABLE_BOOT,
160174 };
161175
176
+const struct sysrq_key_op *__sysrq_reboot_op = &sysrq_reboot_op;
177
+
162178 static void sysrq_handle_sync(int key)
163179 {
164180 emergency_sync();
165181 }
166
-static struct sysrq_key_op sysrq_sync_op = {
182
+static const struct sysrq_key_op sysrq_sync_op = {
167183 .handler = sysrq_handle_sync,
168184 .help_msg = "sync(s)",
169185 .action_msg = "Emergency Sync",
....@@ -175,7 +191,7 @@
175191 sysrq_timer_list_show();
176192 }
177193
178
-static struct sysrq_key_op sysrq_show_timers_op = {
194
+static const struct sysrq_key_op sysrq_show_timers_op = {
179195 .handler = sysrq_handle_show_timers,
180196 .help_msg = "show-all-timers(q)",
181197 .action_msg = "Show clockevent devices & pending hrtimers (no others)",
....@@ -185,7 +201,7 @@
185201 {
186202 emergency_remount();
187203 }
188
-static struct sysrq_key_op sysrq_mountro_op = {
204
+static const struct sysrq_key_op sysrq_mountro_op = {
189205 .handler = sysrq_handle_mountro,
190206 .help_msg = "unmount(u)",
191207 .action_msg = "Emergency Remount R/O",
....@@ -198,30 +214,32 @@
198214 debug_show_all_locks();
199215 }
200216
201
-static struct sysrq_key_op sysrq_showlocks_op = {
217
+static const struct sysrq_key_op sysrq_showlocks_op = {
202218 .handler = sysrq_handle_showlocks,
203219 .help_msg = "show-all-locks(d)",
204220 .action_msg = "Show Locks Held",
205221 };
206222 #else
207
-#define sysrq_showlocks_op (*(struct sysrq_key_op *)NULL)
223
+#define sysrq_showlocks_op (*(const struct sysrq_key_op *)NULL)
208224 #endif
209225
210226 #ifdef CONFIG_SMP
211
-static DEFINE_SPINLOCK(show_lock);
227
+static DEFINE_RAW_SPINLOCK(show_lock);
212228
213229 static void showacpu(void *dummy)
214230 {
215231 unsigned long flags;
216232
217233 /* Idle CPUs have no interesting backtrace. */
218
- if (idle_cpu(smp_processor_id()))
234
+ if (idle_cpu(smp_processor_id())) {
235
+ pr_info("CPU%d: backtrace skipped as idling\n", smp_processor_id());
219236 return;
237
+ }
220238
221
- spin_lock_irqsave(&show_lock, flags);
239
+ raw_spin_lock_irqsave(&show_lock, flags);
222240 pr_info("CPU%d:\n", smp_processor_id());
223
- show_stack(NULL, NULL);
224
- spin_unlock_irqrestore(&show_lock, flags);
241
+ show_stack(NULL, NULL, KERN_INFO);
242
+ raw_spin_unlock_irqrestore(&show_lock, flags);
225243 }
226244
227245 static void sysrq_showregs_othercpus(struct work_struct *dummy)
....@@ -243,15 +261,18 @@
243261
244262 if (in_irq())
245263 regs = get_irq_regs();
246
- if (regs) {
247
- pr_info("CPU%d:\n", smp_processor_id());
264
+
265
+ pr_info("CPU%d:\n", smp_processor_id());
266
+ if (regs)
248267 show_regs(regs);
249
- }
268
+ else
269
+ show_stack(NULL, NULL, KERN_INFO);
270
+
250271 schedule_work(&sysrq_showallcpus);
251272 }
252273 }
253274
254
-static struct sysrq_key_op sysrq_showallcpus_op = {
275
+static const struct sysrq_key_op sysrq_showallcpus_op = {
255276 .handler = sysrq_handle_showallcpus,
256277 .help_msg = "show-backtrace-all-active-cpus(l)",
257278 .action_msg = "Show backtrace of all active CPUs",
....@@ -269,7 +290,7 @@
269290 show_regs(regs);
270291 perf_event_print_debug();
271292 }
272
-static struct sysrq_key_op sysrq_showregs_op = {
293
+static const struct sysrq_key_op sysrq_showregs_op = {
273294 .handler = sysrq_handle_showregs,
274295 .help_msg = "show-registers(p)",
275296 .action_msg = "Show Regs",
....@@ -281,7 +302,7 @@
281302 show_state();
282303 show_workqueue_state();
283304 }
284
-static struct sysrq_key_op sysrq_showstate_op = {
305
+static const struct sysrq_key_op sysrq_showstate_op = {
285306 .handler = sysrq_handle_showstate,
286307 .help_msg = "show-task-states(t)",
287308 .action_msg = "Show State",
....@@ -292,7 +313,7 @@
292313 {
293314 show_state_filter(TASK_UNINTERRUPTIBLE);
294315 }
295
-static struct sysrq_key_op sysrq_showstate_blocked_op = {
316
+static const struct sysrq_key_op sysrq_showstate_blocked_op = {
296317 .handler = sysrq_handle_showstate_blocked,
297318 .help_msg = "show-blocked-tasks(w)",
298319 .action_msg = "Show Blocked State",
....@@ -306,21 +327,21 @@
306327 {
307328 ftrace_dump(DUMP_ALL);
308329 }
309
-static struct sysrq_key_op sysrq_ftrace_dump_op = {
330
+static const struct sysrq_key_op sysrq_ftrace_dump_op = {
310331 .handler = sysrq_ftrace_dump,
311332 .help_msg = "dump-ftrace-buffer(z)",
312333 .action_msg = "Dump ftrace buffer",
313334 .enable_mask = SYSRQ_ENABLE_DUMP,
314335 };
315336 #else
316
-#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)NULL)
337
+#define sysrq_ftrace_dump_op (*(const struct sysrq_key_op *)NULL)
317338 #endif
318339
319340 static void sysrq_handle_showmem(int key)
320341 {
321342 show_mem(0, NULL);
322343 }
323
-static struct sysrq_key_op sysrq_showmem_op = {
344
+static const struct sysrq_key_op sysrq_showmem_op = {
324345 .handler = sysrq_handle_showmem,
325346 .help_msg = "show-memory-usage(m)",
326347 .action_msg = "Show Memory",
....@@ -341,7 +362,7 @@
341362 if (is_global_init(p))
342363 continue;
343364
344
- do_send_sig_info(sig, SEND_SIG_FORCED, p, PIDTYPE_MAX);
365
+ do_send_sig_info(sig, SEND_SIG_PRIV, p, PIDTYPE_MAX);
345366 }
346367 read_unlock(&tasklist_lock);
347368 }
....@@ -351,7 +372,7 @@
351372 send_sig_all(SIGTERM);
352373 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
353374 }
354
-static struct sysrq_key_op sysrq_term_op = {
375
+static const struct sysrq_key_op sysrq_term_op = {
355376 .handler = sysrq_handle_term,
356377 .help_msg = "terminate-all-tasks(e)",
357378 .action_msg = "Terminate All Tasks",
....@@ -381,32 +402,30 @@
381402 {
382403 schedule_work(&moom_work);
383404 }
384
-static struct sysrq_key_op sysrq_moom_op = {
405
+static const struct sysrq_key_op sysrq_moom_op = {
385406 .handler = sysrq_handle_moom,
386407 .help_msg = "memory-full-oom-kill(f)",
387408 .action_msg = "Manual OOM execution",
388409 .enable_mask = SYSRQ_ENABLE_SIGNAL,
389410 };
390411
391
-#ifdef CONFIG_BLOCK
392412 static void sysrq_handle_thaw(int key)
393413 {
394414 emergency_thaw_all();
395415 }
396
-static struct sysrq_key_op sysrq_thaw_op = {
416
+static const struct sysrq_key_op sysrq_thaw_op = {
397417 .handler = sysrq_handle_thaw,
398418 .help_msg = "thaw-filesystems(j)",
399419 .action_msg = "Emergency Thaw of all frozen filesystems",
400420 .enable_mask = SYSRQ_ENABLE_SIGNAL,
401421 };
402
-#endif
403422
404423 static void sysrq_handle_kill(int key)
405424 {
406425 send_sig_all(SIGKILL);
407426 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
408427 }
409
-static struct sysrq_key_op sysrq_kill_op = {
428
+static const struct sysrq_key_op sysrq_kill_op = {
410429 .handler = sysrq_handle_kill,
411430 .help_msg = "kill-all-tasks(i)",
412431 .action_msg = "Kill All Tasks",
....@@ -417,7 +436,7 @@
417436 {
418437 normalize_rt_tasks();
419438 }
420
-static struct sysrq_key_op sysrq_unrt_op = {
439
+static const struct sysrq_key_op sysrq_unrt_op = {
421440 .handler = sysrq_handle_unrt,
422441 .help_msg = "nice-all-RT-tasks(n)",
423442 .action_msg = "Nice All RT Tasks",
....@@ -427,7 +446,7 @@
427446 /* Key Operations table and lock */
428447 static DEFINE_SPINLOCK(sysrq_key_table_lock);
429448
430
-static struct sysrq_key_op *sysrq_key_table[36] = {
449
+static const struct sysrq_key_op *sysrq_key_table[62] = {
431450 &sysrq_loglevel_op, /* 0 */
432451 &sysrq_loglevel_op, /* 1 */
433452 &sysrq_loglevel_op, /* 2 */
....@@ -484,6 +503,32 @@
484503 /* y: May be registered on sparc64 for global register dump */
485504 NULL, /* y */
486505 &sysrq_ftrace_dump_op, /* z */
506
+ NULL, /* A */
507
+ NULL, /* B */
508
+ NULL, /* C */
509
+ NULL, /* D */
510
+ NULL, /* E */
511
+ NULL, /* F */
512
+ NULL, /* G */
513
+ NULL, /* H */
514
+ NULL, /* I */
515
+ NULL, /* J */
516
+ NULL, /* K */
517
+ NULL, /* L */
518
+ NULL, /* M */
519
+ NULL, /* N */
520
+ NULL, /* O */
521
+ NULL, /* P */
522
+ NULL, /* Q */
523
+ NULL, /* R */
524
+ NULL, /* S */
525
+ NULL, /* T */
526
+ NULL, /* U */
527
+ NULL, /* V */
528
+ NULL, /* W */
529
+ NULL, /* X */
530
+ NULL, /* Y */
531
+ NULL, /* Z */
487532 };
488533
489534 /* key2index calculation, -1 on invalid index */
....@@ -495,6 +540,8 @@
495540 retval = key - '0';
496541 else if ((key >= 'a') && (key <= 'z'))
497542 retval = key + 10 - 'a';
543
+ else if ((key >= 'A') && (key <= 'Z'))
544
+ retval = key + 36 - 'A';
498545 else
499546 retval = -1;
500547 return retval;
....@@ -503,9 +550,9 @@
503550 /*
504551 * get and put functions for the table, exposed to modules.
505552 */
506
-struct sysrq_key_op *__sysrq_get_key_op(int key)
553
+static const struct sysrq_key_op *__sysrq_get_key_op(int key)
507554 {
508
- struct sysrq_key_op *op_p = NULL;
555
+ const struct sysrq_key_op *op_p = NULL;
509556 int i;
510557
511558 i = sysrq_key_table_key2index(key);
....@@ -515,7 +562,7 @@
515562 return op_p;
516563 }
517564
518
-static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
565
+static void __sysrq_put_key_op(int key, const struct sysrq_key_op *op_p)
519566 {
520567 int i = sysrq_key_table_key2index(key);
521568
....@@ -525,9 +572,13 @@
525572
526573 void __handle_sysrq(int key, bool check_mask)
527574 {
528
- struct sysrq_key_op *op_p;
575
+ const struct sysrq_key_op *op_p;
529576 int orig_log_level;
577
+ int orig_suppress_printk;
530578 int i;
579
+
580
+ orig_suppress_printk = suppress_printk;
581
+ suppress_printk = 0;
531582
532583 rcu_sysrq_start();
533584 rcu_read_lock();
....@@ -574,6 +625,8 @@
574625 }
575626 rcu_read_unlock();
576627 rcu_sysrq_end();
628
+
629
+ suppress_printk = orig_suppress_printk;
577630 }
578631
579632 void handle_sysrq(int key)
....@@ -602,6 +655,8 @@
602655 unsigned long key_down[BITS_TO_LONGS(KEY_CNT)];
603656 unsigned int alt;
604657 unsigned int alt_use;
658
+ unsigned int shift;
659
+ unsigned int shift_use;
605660 bool active;
606661 bool need_reinject;
607662 bool reinjecting;
....@@ -653,8 +708,7 @@
653708
654709 state->reset_requested = true;
655710
656
- ksys_sync();
657
- kernel_restart(NULL);
711
+ orderly_reboot();
658712 }
659713
660714 static void sysrq_handle_reset_request(struct sysrq_state *state)
....@@ -729,6 +783,8 @@
729783
730784 /* Get reset timeout if any. */
731785 of_property_read_u32(np, "timeout-ms", &sysrq_reset_downtime_ms);
786
+
787
+ of_node_put(np);
732788 }
733789 #else
734790 static void sysrq_of_get_keyreset_config(void)
....@@ -785,10 +841,20 @@
785841 }
786842 break;
787843
844
+ case KEY_LEFTSHIFT:
845
+ case KEY_RIGHTSHIFT:
846
+ if (!value)
847
+ sysrq->shift = KEY_RESERVED;
848
+ else if (value != 2)
849
+ sysrq->shift = code;
850
+ break;
851
+
788852 case KEY_SYSRQ:
789853 if (value == 1 && sysrq->alt != KEY_RESERVED) {
790854 sysrq->active = true;
791855 sysrq->alt_use = sysrq->alt;
856
+ /* either RESERVED (for released) or actual code */
857
+ sysrq->shift_use = sysrq->shift;
792858 /*
793859 * If nothing else will be pressed we'll need
794860 * to re-inject Alt-SysRq keysroke.
....@@ -811,8 +877,12 @@
811877
812878 default:
813879 if (sysrq->active && value && value != 2) {
880
+ unsigned char c = sysrq_xlate[code];
881
+
814882 sysrq->need_reinject = false;
815
- __handle_sysrq(sysrq_xlate[code], true);
883
+ if (sysrq->shift_use != KEY_RESERVED)
884
+ c = toupper(c);
885
+ __handle_sysrq(c, true);
816886 }
817887 break;
818888 }
....@@ -960,8 +1030,6 @@
9601030 .id_table = sysrq_ids,
9611031 };
9621032
963
-static bool sysrq_handler_registered;
964
-
9651033 static inline void sysrq_register_handler(void)
9661034 {
9671035 int error;
....@@ -971,16 +1039,11 @@
9711039 error = input_register_handler(&sysrq_handler);
9721040 if (error)
9731041 pr_err("Failed to register input handler, error %d", error);
974
- else
975
- sysrq_handler_registered = true;
9761042 }
9771043
9781044 static inline void sysrq_unregister_handler(void)
9791045 {
980
- if (sysrq_handler_registered) {
981
- input_unregister_handler(&sysrq_handler);
982
- sysrq_handler_registered = false;
983
- }
1046
+ input_unregister_handler(&sysrq_handler);
9841047 }
9851048
9861049 static int sysrq_reset_seq_param_set(const char *buffer,
....@@ -1046,9 +1109,10 @@
10461109
10471110 return 0;
10481111 }
1112
+EXPORT_SYMBOL_GPL(sysrq_toggle_support);
10491113
1050
-static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
1051
- struct sysrq_key_op *remove_op_p)
1114
+static int __sysrq_swap_key_ops(int key, const struct sysrq_key_op *insert_op_p,
1115
+ const struct sysrq_key_op *remove_op_p)
10521116 {
10531117 int retval;
10541118
....@@ -1071,13 +1135,13 @@
10711135 return retval;
10721136 }
10731137
1074
-int register_sysrq_key(int key, struct sysrq_key_op *op_p)
1138
+int register_sysrq_key(int key, const struct sysrq_key_op *op_p)
10751139 {
10761140 return __sysrq_swap_key_ops(key, op_p, NULL);
10771141 }
10781142 EXPORT_SYMBOL(register_sysrq_key);
10791143
1080
-int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
1144
+int unregister_sysrq_key(int key, const struct sysrq_key_op *op_p)
10811145 {
10821146 return __sysrq_swap_key_ops(key, NULL, op_p);
10831147 }
....@@ -1101,15 +1165,15 @@
11011165 return count;
11021166 }
11031167
1104
-static const struct file_operations proc_sysrq_trigger_operations = {
1105
- .write = write_sysrq_trigger,
1106
- .llseek = noop_llseek,
1168
+static const struct proc_ops sysrq_trigger_proc_ops = {
1169
+ .proc_write = write_sysrq_trigger,
1170
+ .proc_lseek = noop_llseek,
11071171 };
11081172
11091173 static void sysrq_init_procfs(void)
11101174 {
11111175 if (!proc_create("sysrq-trigger", S_IWUSR, NULL,
1112
- &proc_sysrq_trigger_operations))
1176
+ &sysrq_trigger_proc_ops))
11131177 pr_err("Failed to register proc interface\n");
11141178 }
11151179