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1/*
2 * arch/s390/kernel/traps.c
3 *
4 * S390 version
5 * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
8 *
9 * Derived from "arch/i386/kernel/traps.c"
10 * Copyright (C) 1991, 1992 Linus Torvalds
11 */
12
13/*
14 * 'Traps.c' handles hardware traps and faults after we have saved some
15 * state in 'asm.s'.
16 */
17#include <linux/sched.h>
18#include <linux/kernel.h>
19#include <linux/string.h>
20#include <linux/errno.h>
21#include <linux/ptrace.h>
22#include <linux/timer.h>
23#include <linux/mm.h>
24#include <linux/smp.h>
25#include <linux/init.h>
26#include <linux/interrupt.h>
27#include <linux/seq_file.h>
28#include <linux/delay.h>
29#include <linux/module.h>
30#include <linux/kdebug.h>
31#include <linux/kallsyms.h>
32#include <linux/reboot.h>
33#include <linux/kprobes.h>
34#include <linux/bug.h>
35#include <linux/utsname.h>
36#include <asm/system.h>
37#include <asm/uaccess.h>
38#include <asm/io.h>
39#include <linux/atomic.h>
40#include <asm/mathemu.h>
41#include <asm/cpcmd.h>
42#include <asm/lowcore.h>
43#include <asm/debug.h>
44#include "entry.h"
45
46void (*pgm_check_table[128])(struct pt_regs *, long, unsigned long);
47
48int show_unhandled_signals;
49
50#define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
51
52#ifndef CONFIG_64BIT
53#define LONG "%08lx "
54#define FOURLONG "%08lx %08lx %08lx %08lx\n"
55static int kstack_depth_to_print = 12;
56#else /* CONFIG_64BIT */
57#define LONG "%016lx "
58#define FOURLONG "%016lx %016lx %016lx %016lx\n"
59static int kstack_depth_to_print = 20;
60#endif /* CONFIG_64BIT */
61
62/*
63 * For show_trace we have tree different stack to consider:
64 * - the panic stack which is used if the kernel stack has overflown
65 * - the asynchronous interrupt stack (cpu related)
66 * - the synchronous kernel stack (process related)
67 * The stack trace can start at any of the three stack and can potentially
68 * touch all of them. The order is: panic stack, async stack, sync stack.
69 */
70static unsigned long
71__show_trace(unsigned long sp, unsigned long low, unsigned long high)
72{
73 struct stack_frame *sf;
74 struct pt_regs *regs;
75
76 while (1) {
77 sp = sp & PSW_ADDR_INSN;
78 if (sp < low || sp > high - sizeof(*sf))
79 return sp;
80 sf = (struct stack_frame *) sp;
81 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
82 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
83 /* Follow the backchain. */
84 while (1) {
85 low = sp;
86 sp = sf->back_chain & PSW_ADDR_INSN;
87 if (!sp)
88 break;
89 if (sp <= low || sp > high - sizeof(*sf))
90 return sp;
91 sf = (struct stack_frame *) sp;
92 printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
93 print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
94 }
95 /* Zero backchain detected, check for interrupt frame. */
96 sp = (unsigned long) (sf + 1);
97 if (sp <= low || sp > high - sizeof(*regs))
98 return sp;
99 regs = (struct pt_regs *) sp;
100 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
101 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
102 low = sp;
103 sp = regs->gprs[15];
104 }
105}
106
107static void show_trace(struct task_struct *task, unsigned long *stack)
108{
109 register unsigned long __r15 asm ("15");
110 unsigned long sp;
111
112 sp = (unsigned long) stack;
113 if (!sp)
114 sp = task ? task->thread.ksp : __r15;
115 printk("Call Trace:\n");
116#ifdef CONFIG_CHECK_STACK
117 sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
118 S390_lowcore.panic_stack);
119#endif
120 sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
121 S390_lowcore.async_stack);
122 if (task)
123 __show_trace(sp, (unsigned long) task_stack_page(task),
124 (unsigned long) task_stack_page(task) + THREAD_SIZE);
125 else
126 __show_trace(sp, S390_lowcore.thread_info,
127 S390_lowcore.thread_info + THREAD_SIZE);
128 if (!task)
129 task = current;
130 debug_show_held_locks(task);
131}
132
133void show_stack(struct task_struct *task, unsigned long *sp)
134{
135 register unsigned long * __r15 asm ("15");
136 unsigned long *stack;
137 int i;
138
139 if (!sp)
140 stack = task ? (unsigned long *) task->thread.ksp : __r15;
141 else
142 stack = sp;
143
144 for (i = 0; i < kstack_depth_to_print; i++) {
145 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
146 break;
147 if (i && ((i * sizeof (long) % 32) == 0))
148 printk("\n ");
149 printk(LONG, *stack++);
150 }
151 printk("\n");
152 show_trace(task, sp);
153}
154
155static void show_last_breaking_event(struct pt_regs *regs)
156{
157#ifdef CONFIG_64BIT
158 printk("Last Breaking-Event-Address:\n");
159 printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
160 print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
161#endif
162}
163
164/*
165 * The architecture-independent dump_stack generator
166 */
167void dump_stack(void)
168{
169 printk("CPU: %d %s %s %.*s\n",
170 task_thread_info(current)->cpu, print_tainted(),
171 init_utsname()->release,
172 (int)strcspn(init_utsname()->version, " "),
173 init_utsname()->version);
174 printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
175 current->comm, current->pid, current,
176 (void *) current->thread.ksp);
177 show_stack(NULL, NULL);
178}
179EXPORT_SYMBOL(dump_stack);
180
181static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
182{
183 return (regs->psw.mask & bits) / ((~bits + 1) & bits);
184}
185
186void show_registers(struct pt_regs *regs)
187{
188 char *mode;
189
190 mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
191 printk("%s PSW : %p %p",
192 mode, (void *) regs->psw.mask,
193 (void *) regs->psw.addr);
194 print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
195 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
196 "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
197 mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
198 mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
199 mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
200 mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
201 mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
202#ifdef CONFIG_64BIT
203 printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
204#endif
205 printk("\n%s GPRS: " FOURLONG, mode,
206 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
207 printk(" " FOURLONG,
208 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
209 printk(" " FOURLONG,
210 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
211 printk(" " FOURLONG,
212 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
213
214 show_code(regs);
215}
216
217void show_regs(struct pt_regs *regs)
218{
219 print_modules();
220 printk("CPU: %d %s %s %.*s\n",
221 task_thread_info(current)->cpu, print_tainted(),
222 init_utsname()->release,
223 (int)strcspn(init_utsname()->version, " "),
224 init_utsname()->version);
225 printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
226 current->comm, current->pid, current,
227 (void *) current->thread.ksp);
228 show_registers(regs);
229 /* Show stack backtrace if pt_regs is from kernel mode */
230 if (!(regs->psw.mask & PSW_MASK_PSTATE))
231 show_trace(NULL, (unsigned long *) regs->gprs[15]);
232 show_last_breaking_event(regs);
233}
234
235static DEFINE_SPINLOCK(die_lock);
236
237void die(const char * str, struct pt_regs * regs, long err)
238{
239 static int die_counter;
240
241 oops_enter();
242 debug_stop_all();
243 console_verbose();
244 spin_lock_irq(&die_lock);
245 bust_spinlocks(1);
246 printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
247#ifdef CONFIG_PREEMPT
248 printk("PREEMPT ");
249#endif
250#ifdef CONFIG_SMP
251 printk("SMP ");
252#endif
253#ifdef CONFIG_DEBUG_PAGEALLOC
254 printk("DEBUG_PAGEALLOC");
255#endif
256 printk("\n");
257 notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
258 show_regs(regs);
259 bust_spinlocks(0);
260 add_taint(TAINT_DIE);
261 spin_unlock_irq(&die_lock);
262 if (in_interrupt())
263 panic("Fatal exception in interrupt");
264 if (panic_on_oops)
265 panic("Fatal exception: panic_on_oops");
266 oops_exit();
267 do_exit(SIGSEGV);
268}
269
270static void inline report_user_fault(struct pt_regs *regs, long int_code,
271 int signr)
272{
273 if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
274 return;
275 if (!unhandled_signal(current, signr))
276 return;
277 if (!printk_ratelimit())
278 return;
279 printk("User process fault: interruption code 0x%lX ", int_code);
280 print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
281 printk("\n");
282 show_regs(regs);
283}
284
285int is_valid_bugaddr(unsigned long addr)
286{
287 return 1;
288}
289
290static inline void __kprobes do_trap(long pgm_int_code, int signr, char *str,
291 struct pt_regs *regs, siginfo_t *info)
292{
293 if (notify_die(DIE_TRAP, str, regs, pgm_int_code,
294 pgm_int_code, signr) == NOTIFY_STOP)
295 return;
296
297 if (regs->psw.mask & PSW_MASK_PSTATE) {
298 struct task_struct *tsk = current;
299
300 tsk->thread.trap_no = pgm_int_code & 0xffff;
301 force_sig_info(signr, info, tsk);
302 report_user_fault(regs, pgm_int_code, signr);
303 } else {
304 const struct exception_table_entry *fixup;
305 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
306 if (fixup)
307 regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
308 else {
309 enum bug_trap_type btt;
310
311 btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
312 if (btt == BUG_TRAP_TYPE_WARN)
313 return;
314 die(str, regs, pgm_int_code);
315 }
316 }
317}
318
319static inline void __user *get_psw_address(struct pt_regs *regs,
320 long pgm_int_code)
321{
322 return (void __user *)
323 ((regs->psw.addr - (pgm_int_code >> 16)) & PSW_ADDR_INSN);
324}
325
326void __kprobes do_per_trap(struct pt_regs *regs)
327{
328 siginfo_t info;
329
330 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
331 return;
332 if (!current->ptrace)
333 return;
334 info.si_signo = SIGTRAP;
335 info.si_errno = 0;
336 info.si_code = TRAP_HWBKPT;
337 info.si_addr = (void *) current->thread.per_event.address;
338 force_sig_info(SIGTRAP, &info, current);
339}
340
341static void default_trap_handler(struct pt_regs *regs, long pgm_int_code,
342 unsigned long trans_exc_code)
343{
344 if (regs->psw.mask & PSW_MASK_PSTATE) {
345 report_user_fault(regs, pgm_int_code, SIGSEGV);
346 do_exit(SIGSEGV);
347 } else
348 die("Unknown program exception", regs, pgm_int_code);
349}
350
351#define DO_ERROR_INFO(name, signr, sicode, str) \
352static void name(struct pt_regs *regs, long pgm_int_code, \
353 unsigned long trans_exc_code) \
354{ \
355 siginfo_t info; \
356 info.si_signo = signr; \
357 info.si_errno = 0; \
358 info.si_code = sicode; \
359 info.si_addr = get_psw_address(regs, pgm_int_code); \
360 do_trap(pgm_int_code, signr, str, regs, &info); \
361}
362
363DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
364 "addressing exception")
365DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
366 "execute exception")
367DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
368 "fixpoint divide exception")
369DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
370 "fixpoint overflow exception")
371DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
372 "HFP overflow exception")
373DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
374 "HFP underflow exception")
375DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
376 "HFP significance exception")
377DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
378 "HFP divide exception")
379DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
380 "HFP square root exception")
381DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
382 "operand exception")
383DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
384 "privileged operation")
385DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
386 "special operation exception")
387DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
388 "translation exception")
389
390static inline void do_fp_trap(struct pt_regs *regs, void __user *location,
391 int fpc, long pgm_int_code)
392{
393 siginfo_t si;
394
395 si.si_signo = SIGFPE;
396 si.si_errno = 0;
397 si.si_addr = location;
398 si.si_code = 0;
399 /* FPC[2] is Data Exception Code */
400 if ((fpc & 0x00000300) == 0) {
401 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
402 if (fpc & 0x8000) /* invalid fp operation */
403 si.si_code = FPE_FLTINV;
404 else if (fpc & 0x4000) /* div by 0 */
405 si.si_code = FPE_FLTDIV;
406 else if (fpc & 0x2000) /* overflow */
407 si.si_code = FPE_FLTOVF;
408 else if (fpc & 0x1000) /* underflow */
409 si.si_code = FPE_FLTUND;
410 else if (fpc & 0x0800) /* inexact */
411 si.si_code = FPE_FLTRES;
412 }
413 do_trap(pgm_int_code, SIGFPE,
414 "floating point exception", regs, &si);
415}
416
417static void __kprobes illegal_op(struct pt_regs *regs, long pgm_int_code,
418 unsigned long trans_exc_code)
419{
420 siginfo_t info;
421 __u8 opcode[6];
422 __u16 __user *location;
423 int signal = 0;
424
425 location = get_psw_address(regs, pgm_int_code);
426
427 if (regs->psw.mask & PSW_MASK_PSTATE) {
428 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
429 return;
430 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
431 if (current->ptrace) {
432 info.si_signo = SIGTRAP;
433 info.si_errno = 0;
434 info.si_code = TRAP_BRKPT;
435 info.si_addr = location;
436 force_sig_info(SIGTRAP, &info, current);
437 } else
438 signal = SIGILL;
439#ifdef CONFIG_MATHEMU
440 } else if (opcode[0] == 0xb3) {
441 if (get_user(*((__u16 *) (opcode+2)), location+1))
442 return;
443 signal = math_emu_b3(opcode, regs);
444 } else if (opcode[0] == 0xed) {
445 if (get_user(*((__u32 *) (opcode+2)),
446 (__u32 __user *)(location+1)))
447 return;
448 signal = math_emu_ed(opcode, regs);
449 } else if (*((__u16 *) opcode) == 0xb299) {
450 if (get_user(*((__u16 *) (opcode+2)), location+1))
451 return;
452 signal = math_emu_srnm(opcode, regs);
453 } else if (*((__u16 *) opcode) == 0xb29c) {
454 if (get_user(*((__u16 *) (opcode+2)), location+1))
455 return;
456 signal = math_emu_stfpc(opcode, regs);
457 } else if (*((__u16 *) opcode) == 0xb29d) {
458 if (get_user(*((__u16 *) (opcode+2)), location+1))
459 return;
460 signal = math_emu_lfpc(opcode, regs);
461#endif
462 } else
463 signal = SIGILL;
464 } else {
465 /*
466 * If we get an illegal op in kernel mode, send it through the
467 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
468 */
469 if (notify_die(DIE_BPT, "bpt", regs, pgm_int_code,
470 3, SIGTRAP) != NOTIFY_STOP)
471 signal = SIGILL;
472 }
473
474#ifdef CONFIG_MATHEMU
475 if (signal == SIGFPE)
476 do_fp_trap(regs, location,
477 current->thread.fp_regs.fpc, pgm_int_code);
478 else if (signal == SIGSEGV) {
479 info.si_signo = signal;
480 info.si_errno = 0;
481 info.si_code = SEGV_MAPERR;
482 info.si_addr = (void __user *) location;
483 do_trap(pgm_int_code, signal,
484 "user address fault", regs, &info);
485 } else
486#endif
487 if (signal) {
488 info.si_signo = signal;
489 info.si_errno = 0;
490 info.si_code = ILL_ILLOPC;
491 info.si_addr = (void __user *) location;
492 do_trap(pgm_int_code, signal,
493 "illegal operation", regs, &info);
494 }
495}
496
497
498#ifdef CONFIG_MATHEMU
499void specification_exception(struct pt_regs *regs, long pgm_int_code,
500 unsigned long trans_exc_code)
501{
502 __u8 opcode[6];
503 __u16 __user *location = NULL;
504 int signal = 0;
505
506 location = (__u16 __user *) get_psw_address(regs, pgm_int_code);
507
508 if (regs->psw.mask & PSW_MASK_PSTATE) {
509 get_user(*((__u16 *) opcode), location);
510 switch (opcode[0]) {
511 case 0x28: /* LDR Rx,Ry */
512 signal = math_emu_ldr(opcode);
513 break;
514 case 0x38: /* LER Rx,Ry */
515 signal = math_emu_ler(opcode);
516 break;
517 case 0x60: /* STD R,D(X,B) */
518 get_user(*((__u16 *) (opcode+2)), location+1);
519 signal = math_emu_std(opcode, regs);
520 break;
521 case 0x68: /* LD R,D(X,B) */
522 get_user(*((__u16 *) (opcode+2)), location+1);
523 signal = math_emu_ld(opcode, regs);
524 break;
525 case 0x70: /* STE R,D(X,B) */
526 get_user(*((__u16 *) (opcode+2)), location+1);
527 signal = math_emu_ste(opcode, regs);
528 break;
529 case 0x78: /* LE R,D(X,B) */
530 get_user(*((__u16 *) (opcode+2)), location+1);
531 signal = math_emu_le(opcode, regs);
532 break;
533 default:
534 signal = SIGILL;
535 break;
536 }
537 } else
538 signal = SIGILL;
539
540 if (signal == SIGFPE)
541 do_fp_trap(regs, location,
542 current->thread.fp_regs.fpc, pgm_int_code);
543 else if (signal) {
544 siginfo_t info;
545 info.si_signo = signal;
546 info.si_errno = 0;
547 info.si_code = ILL_ILLOPN;
548 info.si_addr = location;
549 do_trap(pgm_int_code, signal,
550 "specification exception", regs, &info);
551 }
552}
553#else
554DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
555 "specification exception");
556#endif
557
558static void data_exception(struct pt_regs *regs, long pgm_int_code,
559 unsigned long trans_exc_code)
560{
561 __u16 __user *location;
562 int signal = 0;
563
564 location = get_psw_address(regs, pgm_int_code);
565
566 if (MACHINE_HAS_IEEE)
567 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
568
569#ifdef CONFIG_MATHEMU
570 else if (regs->psw.mask & PSW_MASK_PSTATE) {
571 __u8 opcode[6];
572 get_user(*((__u16 *) opcode), location);
573 switch (opcode[0]) {
574 case 0x28: /* LDR Rx,Ry */
575 signal = math_emu_ldr(opcode);
576 break;
577 case 0x38: /* LER Rx,Ry */
578 signal = math_emu_ler(opcode);
579 break;
580 case 0x60: /* STD R,D(X,B) */
581 get_user(*((__u16 *) (opcode+2)), location+1);
582 signal = math_emu_std(opcode, regs);
583 break;
584 case 0x68: /* LD R,D(X,B) */
585 get_user(*((__u16 *) (opcode+2)), location+1);
586 signal = math_emu_ld(opcode, regs);
587 break;
588 case 0x70: /* STE R,D(X,B) */
589 get_user(*((__u16 *) (opcode+2)), location+1);
590 signal = math_emu_ste(opcode, regs);
591 break;
592 case 0x78: /* LE R,D(X,B) */
593 get_user(*((__u16 *) (opcode+2)), location+1);
594 signal = math_emu_le(opcode, regs);
595 break;
596 case 0xb3:
597 get_user(*((__u16 *) (opcode+2)), location+1);
598 signal = math_emu_b3(opcode, regs);
599 break;
600 case 0xed:
601 get_user(*((__u32 *) (opcode+2)),
602 (__u32 __user *)(location+1));
603 signal = math_emu_ed(opcode, regs);
604 break;
605 case 0xb2:
606 if (opcode[1] == 0x99) {
607 get_user(*((__u16 *) (opcode+2)), location+1);
608 signal = math_emu_srnm(opcode, regs);
609 } else if (opcode[1] == 0x9c) {
610 get_user(*((__u16 *) (opcode+2)), location+1);
611 signal = math_emu_stfpc(opcode, regs);
612 } else if (opcode[1] == 0x9d) {
613 get_user(*((__u16 *) (opcode+2)), location+1);
614 signal = math_emu_lfpc(opcode, regs);
615 } else
616 signal = SIGILL;
617 break;
618 default:
619 signal = SIGILL;
620 break;
621 }
622 }
623#endif
624 if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
625 signal = SIGFPE;
626 else
627 signal = SIGILL;
628 if (signal == SIGFPE)
629 do_fp_trap(regs, location,
630 current->thread.fp_regs.fpc, pgm_int_code);
631 else if (signal) {
632 siginfo_t info;
633 info.si_signo = signal;
634 info.si_errno = 0;
635 info.si_code = ILL_ILLOPN;
636 info.si_addr = location;
637 do_trap(pgm_int_code, signal, "data exception", regs, &info);
638 }
639}
640
641static void space_switch_exception(struct pt_regs *regs, long pgm_int_code,
642 unsigned long trans_exc_code)
643{
644 siginfo_t info;
645
646 /* Set user psw back to home space mode. */
647 if (regs->psw.mask & PSW_MASK_PSTATE)
648 regs->psw.mask |= PSW_ASC_HOME;
649 /* Send SIGILL. */
650 info.si_signo = SIGILL;
651 info.si_errno = 0;
652 info.si_code = ILL_PRVOPC;
653 info.si_addr = get_psw_address(regs, pgm_int_code);
654 do_trap(pgm_int_code, SIGILL, "space switch event", regs, &info);
655}
656
657void __kprobes kernel_stack_overflow(struct pt_regs * regs)
658{
659 bust_spinlocks(1);
660 printk("Kernel stack overflow.\n");
661 show_regs(regs);
662 bust_spinlocks(0);
663 panic("Corrupt kernel stack, can't continue.");
664}
665
666/* init is done in lowcore.S and head.S */
667
668void __init trap_init(void)
669{
670 int i;
671
672 for (i = 0; i < 128; i++)
673 pgm_check_table[i] = &default_trap_handler;
674 pgm_check_table[1] = &illegal_op;
675 pgm_check_table[2] = &privileged_op;
676 pgm_check_table[3] = &execute_exception;
677 pgm_check_table[4] = &do_protection_exception;
678 pgm_check_table[5] = &addressing_exception;
679 pgm_check_table[6] = &specification_exception;
680 pgm_check_table[7] = &data_exception;
681 pgm_check_table[8] = &overflow_exception;
682 pgm_check_table[9] = ÷_exception;
683 pgm_check_table[0x0A] = &overflow_exception;
684 pgm_check_table[0x0B] = ÷_exception;
685 pgm_check_table[0x0C] = &hfp_overflow_exception;
686 pgm_check_table[0x0D] = &hfp_underflow_exception;
687 pgm_check_table[0x0E] = &hfp_significance_exception;
688 pgm_check_table[0x0F] = &hfp_divide_exception;
689 pgm_check_table[0x10] = &do_dat_exception;
690 pgm_check_table[0x11] = &do_dat_exception;
691 pgm_check_table[0x12] = &translation_exception;
692 pgm_check_table[0x13] = &special_op_exception;
693#ifdef CONFIG_64BIT
694 pgm_check_table[0x38] = &do_asce_exception;
695 pgm_check_table[0x39] = &do_dat_exception;
696 pgm_check_table[0x3A] = &do_dat_exception;
697 pgm_check_table[0x3B] = &do_dat_exception;
698#endif /* CONFIG_64BIT */
699 pgm_check_table[0x15] = &operand_exception;
700 pgm_check_table[0x1C] = &space_switch_exception;
701 pgm_check_table[0x1D] = &hfp_sqrt_exception;
702 /* Enable machine checks early. */
703 local_mcck_enable();
704}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * S390 version
4 * Copyright IBM Corp. 1999, 2000
5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
6 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
7 *
8 * Derived from "arch/i386/kernel/traps.c"
9 * Copyright (C) 1991, 1992 Linus Torvalds
10 */
11
12/*
13 * 'Traps.c' handles hardware traps and faults after we have saved some
14 * state in 'asm.s'.
15 */
16#include <linux/kprobes.h>
17#include <linux/kdebug.h>
18#include <linux/extable.h>
19#include <linux/ptrace.h>
20#include <linux/sched.h>
21#include <linux/sched/debug.h>
22#include <linux/mm.h>
23#include <linux/slab.h>
24#include <linux/uaccess.h>
25#include <linux/cpu.h>
26#include <asm/fpu/api.h>
27#include "entry.h"
28
29static inline void __user *get_trap_ip(struct pt_regs *regs)
30{
31 unsigned long address;
32
33 if (regs->int_code & 0x200)
34 address = *(unsigned long *)(current->thread.trap_tdb + 24);
35 else
36 address = regs->psw.addr;
37 return (void __user *) (address - (regs->int_code >> 16));
38}
39
40int is_valid_bugaddr(unsigned long addr)
41{
42 return 1;
43}
44
45void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
46{
47 siginfo_t info;
48
49 if (user_mode(regs)) {
50 info.si_signo = si_signo;
51 info.si_errno = 0;
52 info.si_code = si_code;
53 info.si_addr = get_trap_ip(regs);
54 force_sig_info(si_signo, &info, current);
55 report_user_fault(regs, si_signo, 0);
56 } else {
57 const struct exception_table_entry *fixup;
58 fixup = search_exception_tables(regs->psw.addr);
59 if (fixup)
60 regs->psw.addr = extable_fixup(fixup);
61 else {
62 enum bug_trap_type btt;
63
64 btt = report_bug(regs->psw.addr, regs);
65 if (btt == BUG_TRAP_TYPE_WARN)
66 return;
67 die(regs, str);
68 }
69 }
70}
71
72static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
73{
74 if (notify_die(DIE_TRAP, str, regs, 0,
75 regs->int_code, si_signo) == NOTIFY_STOP)
76 return;
77 do_report_trap(regs, si_signo, si_code, str);
78}
79NOKPROBE_SYMBOL(do_trap);
80
81void do_per_trap(struct pt_regs *regs)
82{
83 siginfo_t info;
84
85 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
86 return;
87 if (!current->ptrace)
88 return;
89 info.si_signo = SIGTRAP;
90 info.si_errno = 0;
91 info.si_code = TRAP_HWBKPT;
92 info.si_addr =
93 (void __force __user *) current->thread.per_event.address;
94 force_sig_info(SIGTRAP, &info, current);
95}
96NOKPROBE_SYMBOL(do_per_trap);
97
98void default_trap_handler(struct pt_regs *regs)
99{
100 if (user_mode(regs)) {
101 report_user_fault(regs, SIGSEGV, 0);
102 do_exit(SIGSEGV);
103 } else
104 die(regs, "Unknown program exception");
105}
106
107#define DO_ERROR_INFO(name, signr, sicode, str) \
108void name(struct pt_regs *regs) \
109{ \
110 do_trap(regs, signr, sicode, str); \
111}
112
113DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
114 "addressing exception")
115DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
116 "execute exception")
117DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
118 "fixpoint divide exception")
119DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
120 "fixpoint overflow exception")
121DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
122 "HFP overflow exception")
123DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
124 "HFP underflow exception")
125DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
126 "HFP significance exception")
127DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
128 "HFP divide exception")
129DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
130 "HFP square root exception")
131DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
132 "operand exception")
133DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
134 "privileged operation")
135DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
136 "special operation exception")
137DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
138 "transaction constraint exception")
139
140static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
141{
142 int si_code = 0;
143 /* FPC[2] is Data Exception Code */
144 if ((fpc & 0x00000300) == 0) {
145 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
146 if (fpc & 0x8000) /* invalid fp operation */
147 si_code = FPE_FLTINV;
148 else if (fpc & 0x4000) /* div by 0 */
149 si_code = FPE_FLTDIV;
150 else if (fpc & 0x2000) /* overflow */
151 si_code = FPE_FLTOVF;
152 else if (fpc & 0x1000) /* underflow */
153 si_code = FPE_FLTUND;
154 else if (fpc & 0x0800) /* inexact */
155 si_code = FPE_FLTRES;
156 }
157 do_trap(regs, SIGFPE, si_code, "floating point exception");
158}
159
160void translation_exception(struct pt_regs *regs)
161{
162 /* May never happen. */
163 panic("Translation exception");
164}
165
166void illegal_op(struct pt_regs *regs)
167{
168 siginfo_t info;
169 __u8 opcode[6];
170 __u16 __user *location;
171 int is_uprobe_insn = 0;
172 int signal = 0;
173
174 location = get_trap_ip(regs);
175
176 if (user_mode(regs)) {
177 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
178 return;
179 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
180 if (current->ptrace) {
181 info.si_signo = SIGTRAP;
182 info.si_errno = 0;
183 info.si_code = TRAP_BRKPT;
184 info.si_addr = location;
185 force_sig_info(SIGTRAP, &info, current);
186 } else
187 signal = SIGILL;
188#ifdef CONFIG_UPROBES
189 } else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
190 is_uprobe_insn = 1;
191#endif
192 } else
193 signal = SIGILL;
194 }
195 /*
196 * We got either an illegal op in kernel mode, or user space trapped
197 * on a uprobes illegal instruction. See if kprobes or uprobes picks
198 * it up. If not, SIGILL.
199 */
200 if (is_uprobe_insn || !user_mode(regs)) {
201 if (notify_die(DIE_BPT, "bpt", regs, 0,
202 3, SIGTRAP) != NOTIFY_STOP)
203 signal = SIGILL;
204 }
205 if (signal)
206 do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
207}
208NOKPROBE_SYMBOL(illegal_op);
209
210DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
211 "specification exception");
212
213void vector_exception(struct pt_regs *regs)
214{
215 int si_code, vic;
216
217 if (!MACHINE_HAS_VX) {
218 do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
219 return;
220 }
221
222 /* get vector interrupt code from fpc */
223 save_fpu_regs();
224 vic = (current->thread.fpu.fpc & 0xf00) >> 8;
225 switch (vic) {
226 case 1: /* invalid vector operation */
227 si_code = FPE_FLTINV;
228 break;
229 case 2: /* division by zero */
230 si_code = FPE_FLTDIV;
231 break;
232 case 3: /* overflow */
233 si_code = FPE_FLTOVF;
234 break;
235 case 4: /* underflow */
236 si_code = FPE_FLTUND;
237 break;
238 case 5: /* inexact */
239 si_code = FPE_FLTRES;
240 break;
241 default: /* unknown cause */
242 si_code = 0;
243 }
244 do_trap(regs, SIGFPE, si_code, "vector exception");
245}
246
247void data_exception(struct pt_regs *regs)
248{
249 int signal = 0;
250
251 save_fpu_regs();
252 if (current->thread.fpu.fpc & FPC_DXC_MASK)
253 signal = SIGFPE;
254 else
255 signal = SIGILL;
256 if (signal == SIGFPE)
257 do_fp_trap(regs, current->thread.fpu.fpc);
258 else if (signal)
259 do_trap(regs, signal, ILL_ILLOPN, "data exception");
260}
261
262void space_switch_exception(struct pt_regs *regs)
263{
264 /* Set user psw back to home space mode. */
265 if (user_mode(regs))
266 regs->psw.mask |= PSW_ASC_HOME;
267 /* Send SIGILL. */
268 do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
269}
270
271void kernel_stack_overflow(struct pt_regs *regs)
272{
273 bust_spinlocks(1);
274 printk("Kernel stack overflow.\n");
275 show_regs(regs);
276 bust_spinlocks(0);
277 panic("Corrupt kernel stack, can't continue.");
278}
279NOKPROBE_SYMBOL(kernel_stack_overflow);
280
281void __init trap_init(void)
282{
283 local_mcck_enable();
284}