2 * arch/s390/kernel/traps.c
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),
9 * Derived from "arch/i386/kernel/traps.c"
10 * Copyright (C) 1991, 1992 Linus Torvalds
14 * 'Traps.c' handles hardware traps and faults after we have saved some
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>
24 #include <linux/smp.h>
25 #include <linux/smp_lock.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 #include <linux/module.h>
30 #include <linux/kallsyms.h>
31 #include <linux/reboot.h>
32 #include <linux/kprobes.h>
34 #include <asm/system.h>
35 #include <asm/uaccess.h>
37 #include <asm/atomic.h>
38 #include <asm/mathemu.h>
39 #include <asm/cpcmd.h>
40 #include <asm/s390_ext.h>
41 #include <asm/lowcore.h>
42 #include <asm/debug.h>
43 #include <asm/kdebug.h>
45 /* Called from entry.S only */
46 extern void handle_per_exception(struct pt_regs *regs);
48 typedef void pgm_check_handler_t(struct pt_regs *, long);
49 pgm_check_handler_t *pgm_check_table[128];
52 #ifdef CONFIG_PROCESS_DEBUG
53 int sysctl_userprocess_debug = 1;
55 int sysctl_userprocess_debug = 0;
59 extern pgm_check_handler_t do_protection_exception;
60 extern pgm_check_handler_t do_dat_exception;
61 extern pgm_check_handler_t do_monitor_call;
63 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
66 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
67 static int kstack_depth_to_print = 12;
68 #else /* CONFIG_64BIT */
69 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
70 static int kstack_depth_to_print = 20;
71 #endif /* CONFIG_64BIT */
73 ATOMIC_NOTIFIER_HEAD(s390die_chain);
75 int register_die_notifier(struct notifier_block *nb)
77 return atomic_notifier_chain_register(&s390die_chain, nb);
79 EXPORT_SYMBOL(register_die_notifier);
81 int unregister_die_notifier(struct notifier_block *nb)
83 return atomic_notifier_chain_unregister(&s390die_chain, nb);
85 EXPORT_SYMBOL(unregister_die_notifier);
88 * For show_trace we have tree different stack to consider:
89 * - the panic stack which is used if the kernel stack has overflown
90 * - the asynchronous interrupt stack (cpu related)
91 * - the synchronous kernel stack (process related)
92 * The stack trace can start at any of the three stack and can potentially
93 * touch all of them. The order is: panic stack, async stack, sync stack.
96 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
98 struct stack_frame *sf;
102 sp = sp & PSW_ADDR_INSN;
103 if (sp < low || sp > high - sizeof(*sf))
105 sf = (struct stack_frame *) sp;
106 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
107 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
108 /* Follow the backchain. */
111 sp = sf->back_chain & PSW_ADDR_INSN;
114 if (sp <= low || sp > high - sizeof(*sf))
116 sf = (struct stack_frame *) sp;
117 printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
118 print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
120 /* Zero backchain detected, check for interrupt frame. */
121 sp = (unsigned long) (sf + 1);
122 if (sp <= low || sp > high - sizeof(*regs))
124 regs = (struct pt_regs *) sp;
125 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
126 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
132 void show_trace(struct task_struct *task, unsigned long *stack)
134 register unsigned long __r15 asm ("15");
137 sp = (unsigned long) stack;
139 sp = task ? task->thread.ksp : __r15;
140 printk("Call Trace:\n");
141 #ifdef CONFIG_CHECK_STACK
142 sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
143 S390_lowcore.panic_stack);
145 sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
146 S390_lowcore.async_stack);
148 __show_trace(sp, (unsigned long) task_stack_page(task),
149 (unsigned long) task_stack_page(task) + THREAD_SIZE);
151 __show_trace(sp, S390_lowcore.thread_info,
152 S390_lowcore.thread_info + THREAD_SIZE);
156 debug_show_held_locks(task);
159 void show_stack(struct task_struct *task, unsigned long *sp)
161 register unsigned long * __r15 asm ("15");
162 unsigned long *stack;
166 stack = task ? (unsigned long *) task->thread.ksp : __r15;
170 for (i = 0; i < kstack_depth_to_print; i++) {
171 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
173 if (i && ((i * sizeof (long) % 32) == 0))
175 printk("%p ", (void *)*stack++);
178 show_trace(task, sp);
182 * The architecture-independent dump_stack generator
184 void dump_stack(void)
186 show_stack(NULL, NULL);
189 EXPORT_SYMBOL(dump_stack);
191 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
193 return (regs->psw.mask & bits) / ((~bits + 1) & bits);
196 void show_registers(struct pt_regs *regs)
200 mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
201 printk("%s PSW : %p %p",
202 mode, (void *) regs->psw.mask,
203 (void *) regs->psw.addr);
204 print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
205 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
206 "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
207 mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
208 mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
209 mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
210 mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
211 mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
213 printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
215 printk("\n%s GPRS: " FOURLONG, mode,
216 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
218 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
220 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
222 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
227 /* This is called from fs/proc/array.c */
228 char *task_show_regs(struct task_struct *task, char *buffer)
230 struct pt_regs *regs;
232 regs = task_pt_regs(task);
233 buffer += sprintf(buffer, "task: %p, ksp: %p\n",
234 task, (void *)task->thread.ksp);
235 buffer += sprintf(buffer, "User PSW : %p %p\n",
236 (void *) regs->psw.mask, (void *)regs->psw.addr);
238 buffer += sprintf(buffer, "User GPRS: " FOURLONG,
239 regs->gprs[0], regs->gprs[1],
240 regs->gprs[2], regs->gprs[3]);
241 buffer += sprintf(buffer, " " FOURLONG,
242 regs->gprs[4], regs->gprs[5],
243 regs->gprs[6], regs->gprs[7]);
244 buffer += sprintf(buffer, " " FOURLONG,
245 regs->gprs[8], regs->gprs[9],
246 regs->gprs[10], regs->gprs[11]);
247 buffer += sprintf(buffer, " " FOURLONG,
248 regs->gprs[12], regs->gprs[13],
249 regs->gprs[14], regs->gprs[15]);
250 buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
251 task->thread.acrs[0], task->thread.acrs[1],
252 task->thread.acrs[2], task->thread.acrs[3]);
253 buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
254 task->thread.acrs[4], task->thread.acrs[5],
255 task->thread.acrs[6], task->thread.acrs[7]);
256 buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
257 task->thread.acrs[8], task->thread.acrs[9],
258 task->thread.acrs[10], task->thread.acrs[11]);
259 buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
260 task->thread.acrs[12], task->thread.acrs[13],
261 task->thread.acrs[14], task->thread.acrs[15]);
265 static DEFINE_SPINLOCK(die_lock);
267 void die(const char * str, struct pt_regs * regs, long err)
269 static int die_counter;
273 spin_lock_irq(&die_lock);
275 printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
278 spin_unlock_irq(&die_lock);
280 panic("Fatal exception in interrupt");
282 panic("Fatal exception: panic_on_oops");
287 report_user_fault(long interruption_code, struct pt_regs *regs)
289 #if defined(CONFIG_SYSCTL)
290 if (!sysctl_userprocess_debug)
293 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
294 printk("User process fault: interruption code 0x%lX\n",
300 static void __kprobes inline do_trap(long interruption_code, int signr,
301 char *str, struct pt_regs *regs,
305 * We got all needed information from the lowcore and can
306 * now safely switch on interrupts.
308 if (regs->psw.mask & PSW_MASK_PSTATE)
311 if (notify_die(DIE_TRAP, str, regs, interruption_code,
312 interruption_code, signr) == NOTIFY_STOP)
315 if (regs->psw.mask & PSW_MASK_PSTATE) {
316 struct task_struct *tsk = current;
318 tsk->thread.trap_no = interruption_code & 0xffff;
319 force_sig_info(signr, info, tsk);
320 report_user_fault(interruption_code, regs);
322 const struct exception_table_entry *fixup;
323 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
325 regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
327 die(str, regs, interruption_code);
331 static inline void __user *get_check_address(struct pt_regs *regs)
333 return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
336 void __kprobes do_single_step(struct pt_regs *regs)
338 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
339 SIGTRAP) == NOTIFY_STOP){
342 if ((current->ptrace & PT_PTRACED) != 0)
343 force_sig(SIGTRAP, current);
346 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
348 if (regs->psw.mask & PSW_MASK_PSTATE) {
351 report_user_fault(interruption_code, regs);
353 die("Unknown program exception", regs, interruption_code);
356 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
357 static void name(struct pt_regs * regs, long interruption_code) \
360 info.si_signo = signr; \
362 info.si_code = sicode; \
363 info.si_addr = siaddr; \
364 do_trap(interruption_code, signr, str, regs, &info); \
367 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
368 ILL_ILLADR, get_check_address(regs))
369 DO_ERROR_INFO(SIGILL, "execute exception", execute_exception,
370 ILL_ILLOPN, get_check_address(regs))
371 DO_ERROR_INFO(SIGFPE, "fixpoint divide exception", divide_exception,
372 FPE_INTDIV, get_check_address(regs))
373 DO_ERROR_INFO(SIGFPE, "fixpoint overflow exception", overflow_exception,
374 FPE_INTOVF, get_check_address(regs))
375 DO_ERROR_INFO(SIGFPE, "HFP overflow exception", hfp_overflow_exception,
376 FPE_FLTOVF, get_check_address(regs))
377 DO_ERROR_INFO(SIGFPE, "HFP underflow exception", hfp_underflow_exception,
378 FPE_FLTUND, get_check_address(regs))
379 DO_ERROR_INFO(SIGFPE, "HFP significance exception", hfp_significance_exception,
380 FPE_FLTRES, get_check_address(regs))
381 DO_ERROR_INFO(SIGFPE, "HFP divide exception", hfp_divide_exception,
382 FPE_FLTDIV, get_check_address(regs))
383 DO_ERROR_INFO(SIGFPE, "HFP square root exception", hfp_sqrt_exception,
384 FPE_FLTINV, get_check_address(regs))
385 DO_ERROR_INFO(SIGILL, "operand exception", operand_exception,
386 ILL_ILLOPN, get_check_address(regs))
387 DO_ERROR_INFO(SIGILL, "privileged operation", privileged_op,
388 ILL_PRVOPC, get_check_address(regs))
389 DO_ERROR_INFO(SIGILL, "special operation exception", special_op_exception,
390 ILL_ILLOPN, get_check_address(regs))
391 DO_ERROR_INFO(SIGILL, "translation exception", translation_exception,
392 ILL_ILLOPN, get_check_address(regs))
395 do_fp_trap(struct pt_regs *regs, void __user *location,
396 int fpc, long interruption_code)
400 si.si_signo = SIGFPE;
402 si.si_addr = location;
404 /* FPC[2] is Data Exception Code */
405 if ((fpc & 0x00000300) == 0) {
406 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
407 if (fpc & 0x8000) /* invalid fp operation */
408 si.si_code = FPE_FLTINV;
409 else if (fpc & 0x4000) /* div by 0 */
410 si.si_code = FPE_FLTDIV;
411 else if (fpc & 0x2000) /* overflow */
412 si.si_code = FPE_FLTOVF;
413 else if (fpc & 0x1000) /* underflow */
414 si.si_code = FPE_FLTUND;
415 else if (fpc & 0x0800) /* inexact */
416 si.si_code = FPE_FLTRES;
418 current->thread.ieee_instruction_pointer = (addr_t) location;
419 do_trap(interruption_code, SIGFPE,
420 "floating point exception", regs, &si);
423 static void illegal_op(struct pt_regs * regs, long interruption_code)
427 __u16 __user *location;
430 location = get_check_address(regs);
433 * We got all needed information from the lowcore and can
434 * now safely switch on interrupts.
436 if (regs->psw.mask & PSW_MASK_PSTATE)
439 if (regs->psw.mask & PSW_MASK_PSTATE) {
440 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
442 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
443 if (current->ptrace & PT_PTRACED)
444 force_sig(SIGTRAP, current);
447 #ifdef CONFIG_MATHEMU
448 } else if (opcode[0] == 0xb3) {
449 if (get_user(*((__u16 *) (opcode+2)), location+1))
451 signal = math_emu_b3(opcode, regs);
452 } else if (opcode[0] == 0xed) {
453 if (get_user(*((__u32 *) (opcode+2)),
454 (__u32 __user *)(location+1)))
456 signal = math_emu_ed(opcode, regs);
457 } else if (*((__u16 *) opcode) == 0xb299) {
458 if (get_user(*((__u16 *) (opcode+2)), location+1))
460 signal = math_emu_srnm(opcode, regs);
461 } else if (*((__u16 *) opcode) == 0xb29c) {
462 if (get_user(*((__u16 *) (opcode+2)), location+1))
464 signal = math_emu_stfpc(opcode, regs);
465 } else if (*((__u16 *) opcode) == 0xb29d) {
466 if (get_user(*((__u16 *) (opcode+2)), location+1))
468 signal = math_emu_lfpc(opcode, regs);
474 * If we get an illegal op in kernel mode, send it through the
475 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
477 if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
478 3, SIGTRAP) != NOTIFY_STOP)
482 #ifdef CONFIG_MATHEMU
483 if (signal == SIGFPE)
484 do_fp_trap(regs, location,
485 current->thread.fp_regs.fpc, interruption_code);
486 else if (signal == SIGSEGV) {
487 info.si_signo = signal;
489 info.si_code = SEGV_MAPERR;
490 info.si_addr = (void __user *) location;
491 do_trap(interruption_code, signal,
492 "user address fault", regs, &info);
496 info.si_signo = signal;
498 info.si_code = ILL_ILLOPC;
499 info.si_addr = (void __user *) location;
500 do_trap(interruption_code, signal,
501 "illegal operation", regs, &info);
506 #ifdef CONFIG_MATHEMU
508 specification_exception(struct pt_regs * regs, long interruption_code)
511 __u16 __user *location = NULL;
514 location = (__u16 __user *) get_check_address(regs);
517 * We got all needed information from the lowcore and can
518 * now safely switch on interrupts.
520 if (regs->psw.mask & PSW_MASK_PSTATE)
523 if (regs->psw.mask & PSW_MASK_PSTATE) {
524 get_user(*((__u16 *) opcode), location);
526 case 0x28: /* LDR Rx,Ry */
527 signal = math_emu_ldr(opcode);
529 case 0x38: /* LER Rx,Ry */
530 signal = math_emu_ler(opcode);
532 case 0x60: /* STD R,D(X,B) */
533 get_user(*((__u16 *) (opcode+2)), location+1);
534 signal = math_emu_std(opcode, regs);
536 case 0x68: /* LD R,D(X,B) */
537 get_user(*((__u16 *) (opcode+2)), location+1);
538 signal = math_emu_ld(opcode, regs);
540 case 0x70: /* STE R,D(X,B) */
541 get_user(*((__u16 *) (opcode+2)), location+1);
542 signal = math_emu_ste(opcode, regs);
544 case 0x78: /* LE R,D(X,B) */
545 get_user(*((__u16 *) (opcode+2)), location+1);
546 signal = math_emu_le(opcode, regs);
555 if (signal == SIGFPE)
556 do_fp_trap(regs, location,
557 current->thread.fp_regs.fpc, interruption_code);
560 info.si_signo = signal;
562 info.si_code = ILL_ILLOPN;
563 info.si_addr = location;
564 do_trap(interruption_code, signal,
565 "specification exception", regs, &info);
569 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
570 ILL_ILLOPN, get_check_address(regs));
573 static void data_exception(struct pt_regs * regs, long interruption_code)
575 __u16 __user *location;
578 location = get_check_address(regs);
581 * We got all needed information from the lowcore and can
582 * now safely switch on interrupts.
584 if (regs->psw.mask & PSW_MASK_PSTATE)
587 if (MACHINE_HAS_IEEE)
588 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
590 #ifdef CONFIG_MATHEMU
591 else if (regs->psw.mask & PSW_MASK_PSTATE) {
593 get_user(*((__u16 *) opcode), location);
595 case 0x28: /* LDR Rx,Ry */
596 signal = math_emu_ldr(opcode);
598 case 0x38: /* LER Rx,Ry */
599 signal = math_emu_ler(opcode);
601 case 0x60: /* STD R,D(X,B) */
602 get_user(*((__u16 *) (opcode+2)), location+1);
603 signal = math_emu_std(opcode, regs);
605 case 0x68: /* LD R,D(X,B) */
606 get_user(*((__u16 *) (opcode+2)), location+1);
607 signal = math_emu_ld(opcode, regs);
609 case 0x70: /* STE R,D(X,B) */
610 get_user(*((__u16 *) (opcode+2)), location+1);
611 signal = math_emu_ste(opcode, regs);
613 case 0x78: /* LE R,D(X,B) */
614 get_user(*((__u16 *) (opcode+2)), location+1);
615 signal = math_emu_le(opcode, regs);
618 get_user(*((__u16 *) (opcode+2)), location+1);
619 signal = math_emu_b3(opcode, regs);
622 get_user(*((__u32 *) (opcode+2)),
623 (__u32 __user *)(location+1));
624 signal = math_emu_ed(opcode, regs);
627 if (opcode[1] == 0x99) {
628 get_user(*((__u16 *) (opcode+2)), location+1);
629 signal = math_emu_srnm(opcode, regs);
630 } else if (opcode[1] == 0x9c) {
631 get_user(*((__u16 *) (opcode+2)), location+1);
632 signal = math_emu_stfpc(opcode, regs);
633 } else if (opcode[1] == 0x9d) {
634 get_user(*((__u16 *) (opcode+2)), location+1);
635 signal = math_emu_lfpc(opcode, regs);
645 if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
649 if (signal == SIGFPE)
650 do_fp_trap(regs, location,
651 current->thread.fp_regs.fpc, interruption_code);
654 info.si_signo = signal;
656 info.si_code = ILL_ILLOPN;
657 info.si_addr = location;
658 do_trap(interruption_code, signal,
659 "data exception", regs, &info);
663 static void space_switch_exception(struct pt_regs * regs, long int_code)
667 /* Set user psw back to home space mode. */
668 if (regs->psw.mask & PSW_MASK_PSTATE)
669 regs->psw.mask |= PSW_ASC_HOME;
671 info.si_signo = SIGILL;
673 info.si_code = ILL_PRVOPC;
674 info.si_addr = get_check_address(regs);
675 do_trap(int_code, SIGILL, "space switch event", regs, &info);
678 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
681 printk("Kernel stack overflow.\n");
684 panic("Corrupt kernel stack, can't continue.");
687 /* init is done in lowcore.S and head.S */
689 void __init trap_init(void)
693 for (i = 0; i < 128; i++)
694 pgm_check_table[i] = &default_trap_handler;
695 pgm_check_table[1] = &illegal_op;
696 pgm_check_table[2] = &privileged_op;
697 pgm_check_table[3] = &execute_exception;
698 pgm_check_table[4] = &do_protection_exception;
699 pgm_check_table[5] = &addressing_exception;
700 pgm_check_table[6] = &specification_exception;
701 pgm_check_table[7] = &data_exception;
702 pgm_check_table[8] = &overflow_exception;
703 pgm_check_table[9] = ÷_exception;
704 pgm_check_table[0x0A] = &overflow_exception;
705 pgm_check_table[0x0B] = ÷_exception;
706 pgm_check_table[0x0C] = &hfp_overflow_exception;
707 pgm_check_table[0x0D] = &hfp_underflow_exception;
708 pgm_check_table[0x0E] = &hfp_significance_exception;
709 pgm_check_table[0x0F] = &hfp_divide_exception;
710 pgm_check_table[0x10] = &do_dat_exception;
711 pgm_check_table[0x11] = &do_dat_exception;
712 pgm_check_table[0x12] = &translation_exception;
713 pgm_check_table[0x13] = &special_op_exception;
715 pgm_check_table[0x38] = &do_dat_exception;
716 pgm_check_table[0x39] = &do_dat_exception;
717 pgm_check_table[0x3A] = &do_dat_exception;
718 pgm_check_table[0x3B] = &do_dat_exception;
719 #endif /* CONFIG_64BIT */
720 pgm_check_table[0x15] = &operand_exception;
721 pgm_check_table[0x1C] = &space_switch_exception;
722 pgm_check_table[0x1D] = &hfp_sqrt_exception;
723 pgm_check_table[0x40] = &do_monitor_call;