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/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/delay.h>
28 #include <linux/module.h>
29 #include <linux/kdebug.h>
30 #include <linux/kallsyms.h>
31 #include <linux/reboot.h>
32 #include <linux/kprobes.h>
33 #include <linux/bug.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>
44 /* Called from entry.S only */
45 extern void handle_per_exception(struct pt_regs *regs);
47 typedef void pgm_check_handler_t(struct pt_regs *, long);
48 pgm_check_handler_t *pgm_check_table[128];
51 #ifdef CONFIG_PROCESS_DEBUG
52 int sysctl_userprocess_debug = 1;
54 int sysctl_userprocess_debug = 0;
58 extern pgm_check_handler_t do_protection_exception;
59 extern pgm_check_handler_t do_dat_exception;
60 extern pgm_check_handler_t do_monitor_call;
62 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
65 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
66 static int kstack_depth_to_print = 12;
67 #else /* CONFIG_64BIT */
68 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
69 static int kstack_depth_to_print = 20;
70 #endif /* CONFIG_64BIT */
73 * For show_trace we have tree different stack to consider:
74 * - the panic stack which is used if the kernel stack has overflown
75 * - the asynchronous interrupt stack (cpu related)
76 * - the synchronous kernel stack (process related)
77 * The stack trace can start at any of the three stack and can potentially
78 * touch all of them. The order is: panic stack, async stack, sync stack.
81 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
83 struct stack_frame *sf;
87 sp = sp & PSW_ADDR_INSN;
88 if (sp < low || sp > high - sizeof(*sf))
90 sf = (struct stack_frame *) sp;
91 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
92 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
93 /* Follow the backchain. */
96 sp = sf->back_chain & PSW_ADDR_INSN;
99 if (sp <= low || sp > high - sizeof(*sf))
101 sf = (struct stack_frame *) sp;
102 printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
103 print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
105 /* Zero backchain detected, check for interrupt frame. */
106 sp = (unsigned long) (sf + 1);
107 if (sp <= low || sp > high - sizeof(*regs))
109 regs = (struct pt_regs *) sp;
110 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
111 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
117 void show_trace(struct task_struct *task, unsigned long *stack)
119 register unsigned long __r15 asm ("15");
122 sp = (unsigned long) stack;
124 sp = task ? task->thread.ksp : __r15;
125 printk("Call Trace:\n");
126 #ifdef CONFIG_CHECK_STACK
127 sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
128 S390_lowcore.panic_stack);
130 sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
131 S390_lowcore.async_stack);
133 __show_trace(sp, (unsigned long) task_stack_page(task),
134 (unsigned long) task_stack_page(task) + THREAD_SIZE);
136 __show_trace(sp, S390_lowcore.thread_info,
137 S390_lowcore.thread_info + THREAD_SIZE);
141 debug_show_held_locks(task);
144 void show_stack(struct task_struct *task, unsigned long *sp)
146 register unsigned long * __r15 asm ("15");
147 unsigned long *stack;
151 stack = task ? (unsigned long *) task->thread.ksp : __r15;
155 for (i = 0; i < kstack_depth_to_print; i++) {
156 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
158 if (i && ((i * sizeof (long) % 32) == 0))
160 printk("%p ", (void *)*stack++);
163 show_trace(task, sp);
167 * The architecture-independent dump_stack generator
169 void dump_stack(void)
171 show_stack(NULL, NULL);
174 EXPORT_SYMBOL(dump_stack);
176 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
178 return (regs->psw.mask & bits) / ((~bits + 1) & bits);
181 void show_registers(struct pt_regs *regs)
185 mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
186 printk("%s PSW : %p %p",
187 mode, (void *) regs->psw.mask,
188 (void *) regs->psw.addr);
189 print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
190 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
191 "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
192 mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
193 mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
194 mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
195 mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
196 mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
198 printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
200 printk("\n%s GPRS: " FOURLONG, mode,
201 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
203 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
205 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
207 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
212 /* This is called from fs/proc/array.c */
213 char *task_show_regs(struct task_struct *task, char *buffer)
215 struct pt_regs *regs;
217 regs = task_pt_regs(task);
218 buffer += sprintf(buffer, "task: %p, ksp: %p\n",
219 task, (void *)task->thread.ksp);
220 buffer += sprintf(buffer, "User PSW : %p %p\n",
221 (void *) regs->psw.mask, (void *)regs->psw.addr);
223 buffer += sprintf(buffer, "User GPRS: " FOURLONG,
224 regs->gprs[0], regs->gprs[1],
225 regs->gprs[2], regs->gprs[3]);
226 buffer += sprintf(buffer, " " FOURLONG,
227 regs->gprs[4], regs->gprs[5],
228 regs->gprs[6], regs->gprs[7]);
229 buffer += sprintf(buffer, " " FOURLONG,
230 regs->gprs[8], regs->gprs[9],
231 regs->gprs[10], regs->gprs[11]);
232 buffer += sprintf(buffer, " " FOURLONG,
233 regs->gprs[12], regs->gprs[13],
234 regs->gprs[14], regs->gprs[15]);
235 buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
236 task->thread.acrs[0], task->thread.acrs[1],
237 task->thread.acrs[2], task->thread.acrs[3]);
238 buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
239 task->thread.acrs[4], task->thread.acrs[5],
240 task->thread.acrs[6], task->thread.acrs[7]);
241 buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
242 task->thread.acrs[8], task->thread.acrs[9],
243 task->thread.acrs[10], task->thread.acrs[11]);
244 buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
245 task->thread.acrs[12], task->thread.acrs[13],
246 task->thread.acrs[14], task->thread.acrs[15]);
250 static DEFINE_SPINLOCK(die_lock);
252 void die(const char * str, struct pt_regs * regs, long err)
254 static int die_counter;
259 spin_lock_irq(&die_lock);
261 printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
265 spin_unlock_irq(&die_lock);
267 panic("Fatal exception in interrupt");
269 panic("Fatal exception: panic_on_oops");
275 report_user_fault(long interruption_code, struct pt_regs *regs)
277 #if defined(CONFIG_SYSCTL)
278 if (!sysctl_userprocess_debug)
281 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
282 printk("User process fault: interruption code 0x%lX\n",
288 int is_valid_bugaddr(unsigned long addr)
293 static void __kprobes inline do_trap(long interruption_code, int signr,
294 char *str, struct pt_regs *regs,
298 * We got all needed information from the lowcore and can
299 * now safely switch on interrupts.
301 if (regs->psw.mask & PSW_MASK_PSTATE)
304 if (notify_die(DIE_TRAP, str, regs, interruption_code,
305 interruption_code, signr) == NOTIFY_STOP)
308 if (regs->psw.mask & PSW_MASK_PSTATE) {
309 struct task_struct *tsk = current;
311 tsk->thread.trap_no = interruption_code & 0xffff;
312 force_sig_info(signr, info, tsk);
313 report_user_fault(interruption_code, regs);
315 const struct exception_table_entry *fixup;
316 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
318 regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
320 enum bug_trap_type btt;
322 btt = report_bug(regs->psw.addr & PSW_ADDR_INSN);
323 if (btt == BUG_TRAP_TYPE_WARN)
325 die(str, regs, interruption_code);
330 static inline void __user *get_check_address(struct pt_regs *regs)
332 return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
335 void __kprobes do_single_step(struct pt_regs *regs)
337 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
338 SIGTRAP) == NOTIFY_STOP){
341 if ((current->ptrace & PT_PTRACED) != 0)
342 force_sig(SIGTRAP, current);
345 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
347 if (regs->psw.mask & PSW_MASK_PSTATE) {
350 report_user_fault(interruption_code, regs);
352 die("Unknown program exception", regs, interruption_code);
355 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
356 static void name(struct pt_regs * regs, long interruption_code) \
359 info.si_signo = signr; \
361 info.si_code = sicode; \
362 info.si_addr = siaddr; \
363 do_trap(interruption_code, signr, str, regs, &info); \
366 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
367 ILL_ILLADR, get_check_address(regs))
368 DO_ERROR_INFO(SIGILL, "execute exception", execute_exception,
369 ILL_ILLOPN, get_check_address(regs))
370 DO_ERROR_INFO(SIGFPE, "fixpoint divide exception", divide_exception,
371 FPE_INTDIV, get_check_address(regs))
372 DO_ERROR_INFO(SIGFPE, "fixpoint overflow exception", overflow_exception,
373 FPE_INTOVF, get_check_address(regs))
374 DO_ERROR_INFO(SIGFPE, "HFP overflow exception", hfp_overflow_exception,
375 FPE_FLTOVF, get_check_address(regs))
376 DO_ERROR_INFO(SIGFPE, "HFP underflow exception", hfp_underflow_exception,
377 FPE_FLTUND, get_check_address(regs))
378 DO_ERROR_INFO(SIGFPE, "HFP significance exception", hfp_significance_exception,
379 FPE_FLTRES, get_check_address(regs))
380 DO_ERROR_INFO(SIGFPE, "HFP divide exception", hfp_divide_exception,
381 FPE_FLTDIV, get_check_address(regs))
382 DO_ERROR_INFO(SIGFPE, "HFP square root exception", hfp_sqrt_exception,
383 FPE_FLTINV, get_check_address(regs))
384 DO_ERROR_INFO(SIGILL, "operand exception", operand_exception,
385 ILL_ILLOPN, get_check_address(regs))
386 DO_ERROR_INFO(SIGILL, "privileged operation", privileged_op,
387 ILL_PRVOPC, get_check_address(regs))
388 DO_ERROR_INFO(SIGILL, "special operation exception", special_op_exception,
389 ILL_ILLOPN, get_check_address(regs))
390 DO_ERROR_INFO(SIGILL, "translation exception", translation_exception,
391 ILL_ILLOPN, get_check_address(regs))
394 do_fp_trap(struct pt_regs *regs, void __user *location,
395 int fpc, long interruption_code)
399 si.si_signo = SIGFPE;
401 si.si_addr = location;
403 /* FPC[2] is Data Exception Code */
404 if ((fpc & 0x00000300) == 0) {
405 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
406 if (fpc & 0x8000) /* invalid fp operation */
407 si.si_code = FPE_FLTINV;
408 else if (fpc & 0x4000) /* div by 0 */
409 si.si_code = FPE_FLTDIV;
410 else if (fpc & 0x2000) /* overflow */
411 si.si_code = FPE_FLTOVF;
412 else if (fpc & 0x1000) /* underflow */
413 si.si_code = FPE_FLTUND;
414 else if (fpc & 0x0800) /* inexact */
415 si.si_code = FPE_FLTRES;
417 current->thread.ieee_instruction_pointer = (addr_t) location;
418 do_trap(interruption_code, SIGFPE,
419 "floating point exception", regs, &si);
422 static void illegal_op(struct pt_regs * regs, long interruption_code)
426 __u16 __user *location;
429 location = get_check_address(regs);
432 * We got all needed information from the lowcore and can
433 * now safely switch on interrupts.
435 if (regs->psw.mask & PSW_MASK_PSTATE)
438 if (regs->psw.mask & PSW_MASK_PSTATE) {
439 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
441 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
442 if (current->ptrace & PT_PTRACED)
443 force_sig(SIGTRAP, current);
446 #ifdef CONFIG_MATHEMU
447 } else if (opcode[0] == 0xb3) {
448 if (get_user(*((__u16 *) (opcode+2)), location+1))
450 signal = math_emu_b3(opcode, regs);
451 } else if (opcode[0] == 0xed) {
452 if (get_user(*((__u32 *) (opcode+2)),
453 (__u32 __user *)(location+1)))
455 signal = math_emu_ed(opcode, regs);
456 } else if (*((__u16 *) opcode) == 0xb299) {
457 if (get_user(*((__u16 *) (opcode+2)), location+1))
459 signal = math_emu_srnm(opcode, regs);
460 } else if (*((__u16 *) opcode) == 0xb29c) {
461 if (get_user(*((__u16 *) (opcode+2)), location+1))
463 signal = math_emu_stfpc(opcode, regs);
464 } else if (*((__u16 *) opcode) == 0xb29d) {
465 if (get_user(*((__u16 *) (opcode+2)), location+1))
467 signal = math_emu_lfpc(opcode, regs);
473 * If we get an illegal op in kernel mode, send it through the
474 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
476 if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
477 3, SIGTRAP) != NOTIFY_STOP)
481 #ifdef CONFIG_MATHEMU
482 if (signal == SIGFPE)
483 do_fp_trap(regs, location,
484 current->thread.fp_regs.fpc, interruption_code);
485 else if (signal == SIGSEGV) {
486 info.si_signo = signal;
488 info.si_code = SEGV_MAPERR;
489 info.si_addr = (void __user *) location;
490 do_trap(interruption_code, signal,
491 "user address fault", regs, &info);
495 info.si_signo = signal;
497 info.si_code = ILL_ILLOPC;
498 info.si_addr = (void __user *) location;
499 do_trap(interruption_code, signal,
500 "illegal operation", regs, &info);
505 #ifdef CONFIG_MATHEMU
507 specification_exception(struct pt_regs * regs, long interruption_code)
510 __u16 __user *location = NULL;
513 location = (__u16 __user *) get_check_address(regs);
516 * We got all needed information from the lowcore and can
517 * now safely switch on interrupts.
519 if (regs->psw.mask & PSW_MASK_PSTATE)
522 if (regs->psw.mask & PSW_MASK_PSTATE) {
523 get_user(*((__u16 *) opcode), location);
525 case 0x28: /* LDR Rx,Ry */
526 signal = math_emu_ldr(opcode);
528 case 0x38: /* LER Rx,Ry */
529 signal = math_emu_ler(opcode);
531 case 0x60: /* STD R,D(X,B) */
532 get_user(*((__u16 *) (opcode+2)), location+1);
533 signal = math_emu_std(opcode, regs);
535 case 0x68: /* LD R,D(X,B) */
536 get_user(*((__u16 *) (opcode+2)), location+1);
537 signal = math_emu_ld(opcode, regs);
539 case 0x70: /* STE R,D(X,B) */
540 get_user(*((__u16 *) (opcode+2)), location+1);
541 signal = math_emu_ste(opcode, regs);
543 case 0x78: /* LE R,D(X,B) */
544 get_user(*((__u16 *) (opcode+2)), location+1);
545 signal = math_emu_le(opcode, regs);
554 if (signal == SIGFPE)
555 do_fp_trap(regs, location,
556 current->thread.fp_regs.fpc, interruption_code);
559 info.si_signo = signal;
561 info.si_code = ILL_ILLOPN;
562 info.si_addr = location;
563 do_trap(interruption_code, signal,
564 "specification exception", regs, &info);
568 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
569 ILL_ILLOPN, get_check_address(regs));
572 static void data_exception(struct pt_regs * regs, long interruption_code)
574 __u16 __user *location;
577 location = get_check_address(regs);
580 * We got all needed information from the lowcore and can
581 * now safely switch on interrupts.
583 if (regs->psw.mask & PSW_MASK_PSTATE)
586 if (MACHINE_HAS_IEEE)
587 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
589 #ifdef CONFIG_MATHEMU
590 else if (regs->psw.mask & PSW_MASK_PSTATE) {
592 get_user(*((__u16 *) opcode), location);
594 case 0x28: /* LDR Rx,Ry */
595 signal = math_emu_ldr(opcode);
597 case 0x38: /* LER Rx,Ry */
598 signal = math_emu_ler(opcode);
600 case 0x60: /* STD R,D(X,B) */
601 get_user(*((__u16 *) (opcode+2)), location+1);
602 signal = math_emu_std(opcode, regs);
604 case 0x68: /* LD R,D(X,B) */
605 get_user(*((__u16 *) (opcode+2)), location+1);
606 signal = math_emu_ld(opcode, regs);
608 case 0x70: /* STE R,D(X,B) */
609 get_user(*((__u16 *) (opcode+2)), location+1);
610 signal = math_emu_ste(opcode, regs);
612 case 0x78: /* LE R,D(X,B) */
613 get_user(*((__u16 *) (opcode+2)), location+1);
614 signal = math_emu_le(opcode, regs);
617 get_user(*((__u16 *) (opcode+2)), location+1);
618 signal = math_emu_b3(opcode, regs);
621 get_user(*((__u32 *) (opcode+2)),
622 (__u32 __user *)(location+1));
623 signal = math_emu_ed(opcode, regs);
626 if (opcode[1] == 0x99) {
627 get_user(*((__u16 *) (opcode+2)), location+1);
628 signal = math_emu_srnm(opcode, regs);
629 } else if (opcode[1] == 0x9c) {
630 get_user(*((__u16 *) (opcode+2)), location+1);
631 signal = math_emu_stfpc(opcode, regs);
632 } else if (opcode[1] == 0x9d) {
633 get_user(*((__u16 *) (opcode+2)), location+1);
634 signal = math_emu_lfpc(opcode, regs);
644 if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
648 if (signal == SIGFPE)
649 do_fp_trap(regs, location,
650 current->thread.fp_regs.fpc, interruption_code);
653 info.si_signo = signal;
655 info.si_code = ILL_ILLOPN;
656 info.si_addr = location;
657 do_trap(interruption_code, signal,
658 "data exception", regs, &info);
662 static void space_switch_exception(struct pt_regs * regs, long int_code)
666 /* Set user psw back to home space mode. */
667 if (regs->psw.mask & PSW_MASK_PSTATE)
668 regs->psw.mask |= PSW_ASC_HOME;
670 info.si_signo = SIGILL;
672 info.si_code = ILL_PRVOPC;
673 info.si_addr = get_check_address(regs);
674 do_trap(int_code, SIGILL, "space switch event", regs, &info);
677 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
680 printk("Kernel stack overflow.\n");
683 panic("Corrupt kernel stack, can't continue.");
686 /* init is done in lowcore.S and head.S */
688 void __init trap_init(void)
692 for (i = 0; i < 128; i++)
693 pgm_check_table[i] = &default_trap_handler;
694 pgm_check_table[1] = &illegal_op;
695 pgm_check_table[2] = &privileged_op;
696 pgm_check_table[3] = &execute_exception;
697 pgm_check_table[4] = &do_protection_exception;
698 pgm_check_table[5] = &addressing_exception;
699 pgm_check_table[6] = &specification_exception;
700 pgm_check_table[7] = &data_exception;
701 pgm_check_table[8] = &overflow_exception;
702 pgm_check_table[9] = ÷_exception;
703 pgm_check_table[0x0A] = &overflow_exception;
704 pgm_check_table[0x0B] = ÷_exception;
705 pgm_check_table[0x0C] = &hfp_overflow_exception;
706 pgm_check_table[0x0D] = &hfp_underflow_exception;
707 pgm_check_table[0x0E] = &hfp_significance_exception;
708 pgm_check_table[0x0F] = &hfp_divide_exception;
709 pgm_check_table[0x10] = &do_dat_exception;
710 pgm_check_table[0x11] = &do_dat_exception;
711 pgm_check_table[0x12] = &translation_exception;
712 pgm_check_table[0x13] = &special_op_exception;
714 pgm_check_table[0x38] = &do_dat_exception;
715 pgm_check_table[0x39] = &do_dat_exception;
716 pgm_check_table[0x3A] = &do_dat_exception;
717 pgm_check_table[0x3B] = &do_dat_exception;
718 #endif /* CONFIG_64BIT */
719 pgm_check_table[0x15] = &operand_exception;
720 pgm_check_table[0x1C] = &space_switch_exception;
721 pgm_check_table[0x1D] = &hfp_sqrt_exception;
722 pgm_check_table[0x40] = &do_monitor_call;