Linux Audio

Check our new training course

Loading...
v6.8
  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 "asm/irqflags.h"
 17#include "asm/ptrace.h"
 18#include <linux/kprobes.h>
 19#include <linux/kdebug.h>
 20#include <linux/randomize_kstack.h>
 21#include <linux/extable.h>
 22#include <linux/ptrace.h>
 23#include <linux/sched.h>
 24#include <linux/sched/debug.h>
 25#include <linux/mm.h>
 26#include <linux/slab.h>
 27#include <linux/uaccess.h>
 28#include <linux/cpu.h>
 29#include <linux/entry-common.h>
 30#include <asm/asm-extable.h>
 31#include <asm/fpu/api.h>
 32#include <asm/vtime.h>
 33#include "entry.h"
 34
 35static inline void __user *get_trap_ip(struct pt_regs *regs)
 36{
 37	unsigned long address;
 38
 39	if (regs->int_code & 0x200)
 40		address = current->thread.trap_tdb.data[3];
 41	else
 42		address = regs->psw.addr;
 43	return (void __user *) (address - (regs->int_code >> 16));
 44}
 45
 46#ifdef CONFIG_GENERIC_BUG
 47int is_valid_bugaddr(unsigned long addr)
 48{
 49	return 1;
 50}
 51#endif
 52
 53void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
 54{
 
 
 55	if (user_mode(regs)) {
 56		force_sig_fault(si_signo, si_code, get_trap_ip(regs));
 
 
 
 
 57		report_user_fault(regs, si_signo, 0);
 58        } else {
 59		if (!fixup_exception(regs))
 
 
 
 
 
 
 
 
 
 60			die(regs, str);
 
 61        }
 62}
 63
 64static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
 65{
 66	if (notify_die(DIE_TRAP, str, regs, 0,
 67		       regs->int_code, si_signo) == NOTIFY_STOP)
 68		return;
 69	do_report_trap(regs, si_signo, si_code, str);
 70}
 71NOKPROBE_SYMBOL(do_trap);
 72
 73void do_per_trap(struct pt_regs *regs)
 74{
 
 
 75	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
 76		return;
 77	if (!current->ptrace)
 78		return;
 79	force_sig_fault(SIGTRAP, TRAP_HWBKPT,
 80		(void __force __user *) current->thread.per_event.address);
 
 
 
 
 81}
 82NOKPROBE_SYMBOL(do_per_trap);
 83
 84static void default_trap_handler(struct pt_regs *regs)
 85{
 86	if (user_mode(regs)) {
 87		report_user_fault(regs, SIGSEGV, 0);
 88		force_exit_sig(SIGSEGV);
 89	} else
 90		die(regs, "Unknown program exception");
 91}
 92
 93#define DO_ERROR_INFO(name, signr, sicode, str) \
 94static void name(struct pt_regs *regs)		\
 95{						\
 96	do_trap(regs, signr, sicode, str);	\
 97}
 98
 99DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
100	      "addressing exception")
101DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
102	      "execute exception")
103DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
104	      "fixpoint divide exception")
105DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
106	      "fixpoint overflow exception")
107DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
108	      "HFP overflow exception")
109DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
110	      "HFP underflow exception")
111DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
112	      "HFP significance exception")
113DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
114	      "HFP divide exception")
115DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
116	      "HFP square root exception")
117DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
118	      "operand exception")
119DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
120	      "privileged operation")
121DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
122	      "special operation exception")
123DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
124	      "transaction constraint exception")
125
126static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
127{
128	int si_code = 0;
129	/* FPC[2] is Data Exception Code */
130	if ((fpc & 0x00000300) == 0) {
131		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
132		if (fpc & 0x8000) /* invalid fp operation */
133			si_code = FPE_FLTINV;
134		else if (fpc & 0x4000) /* div by 0 */
135			si_code = FPE_FLTDIV;
136		else if (fpc & 0x2000) /* overflow */
137			si_code = FPE_FLTOVF;
138		else if (fpc & 0x1000) /* underflow */
139			si_code = FPE_FLTUND;
140		else if (fpc & 0x0800) /* inexact */
141			si_code = FPE_FLTRES;
142	}
143	do_trap(regs, SIGFPE, si_code, "floating point exception");
144}
145
146static void translation_specification_exception(struct pt_regs *regs)
147{
148	/* May never happen. */
149	panic("Translation-Specification Exception");
150}
151
152static void illegal_op(struct pt_regs *regs)
153{
 
154        __u8 opcode[6];
155	__u16 __user *location;
156	int is_uprobe_insn = 0;
157	int signal = 0;
158
159	location = get_trap_ip(regs);
160
161	if (user_mode(regs)) {
162		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
163			return;
164		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
165			if (current->ptrace)
166				force_sig_fault(SIGTRAP, TRAP_BRKPT, location);
167			else
 
 
 
 
168				signal = SIGILL;
169#ifdef CONFIG_UPROBES
170		} else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
171			is_uprobe_insn = 1;
172#endif
173		} else
174			signal = SIGILL;
175	}
176	/*
177	 * We got either an illegal op in kernel mode, or user space trapped
178	 * on a uprobes illegal instruction. See if kprobes or uprobes picks
179	 * it up. If not, SIGILL.
180	 */
181	if (is_uprobe_insn || !user_mode(regs)) {
182		if (notify_die(DIE_BPT, "bpt", regs, 0,
183			       3, SIGTRAP) != NOTIFY_STOP)
184			signal = SIGILL;
185	}
186	if (signal)
187		do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
188}
189NOKPROBE_SYMBOL(illegal_op);
190
191DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
192	      "specification exception");
193
194static void vector_exception(struct pt_regs *regs)
195{
196	int si_code, vic;
197
198	if (!cpu_has_vx()) {
199		do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
200		return;
201	}
202
203	/* get vector interrupt code from fpc */
204	save_fpu_regs();
205	vic = (current->thread.fpu.fpc & 0xf00) >> 8;
206	switch (vic) {
207	case 1: /* invalid vector operation */
208		si_code = FPE_FLTINV;
209		break;
210	case 2: /* division by zero */
211		si_code = FPE_FLTDIV;
212		break;
213	case 3: /* overflow */
214		si_code = FPE_FLTOVF;
215		break;
216	case 4: /* underflow */
217		si_code = FPE_FLTUND;
218		break;
219	case 5:	/* inexact */
220		si_code = FPE_FLTRES;
221		break;
222	default: /* unknown cause */
223		si_code = 0;
224	}
225	do_trap(regs, SIGFPE, si_code, "vector exception");
226}
227
228static void data_exception(struct pt_regs *regs)
229{
 
 
230	save_fpu_regs();
231	if (current->thread.fpu.fpc & FPC_DXC_MASK)
232		do_fp_trap(regs, current->thread.fpu.fpc);
233	else
234		do_trap(regs, SIGILL, ILL_ILLOPN, "data exception");
 
 
 
 
235}
236
237static void space_switch_exception(struct pt_regs *regs)
238{
239	/* Set user psw back to home space mode. */
240	if (user_mode(regs))
241		regs->psw.mask |= PSW_ASC_HOME;
242	/* Send SIGILL. */
243	do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
244}
245
246static void monitor_event_exception(struct pt_regs *regs)
247{
248	if (user_mode(regs))
249		return;
250
251	switch (report_bug(regs->psw.addr - (regs->int_code >> 16), regs)) {
252	case BUG_TRAP_TYPE_NONE:
253		fixup_exception(regs);
254		break;
255	case BUG_TRAP_TYPE_WARN:
256		break;
257	case BUG_TRAP_TYPE_BUG:
258		die(regs, "monitor event");
259		break;
260	}
261}
262
263void kernel_stack_overflow(struct pt_regs *regs)
264{
265	bust_spinlocks(1);
266	printk("Kernel stack overflow.\n");
267	show_regs(regs);
268	bust_spinlocks(0);
269	panic("Corrupt kernel stack, can't continue.");
270}
271NOKPROBE_SYMBOL(kernel_stack_overflow);
272
273static void __init test_monitor_call(void)
274{
275	int val = 1;
276
277	if (!IS_ENABLED(CONFIG_BUG))
278		return;
279	asm volatile(
280		"	mc	0,0\n"
281		"0:	xgr	%0,%0\n"
282		"1:\n"
283		EX_TABLE(0b,1b)
284		: "+d" (val));
285	if (!val)
286		panic("Monitor call doesn't work!\n");
287}
288
289void __init trap_init(void)
290{
291	unsigned long flags;
292	struct ctlreg cr0;
293
294	local_irq_save(flags);
295	cr0 = local_ctl_clear_bit(0, CR0_LOW_ADDRESS_PROTECTION_BIT);
296	psw_bits(S390_lowcore.external_new_psw).mcheck = 1;
297	psw_bits(S390_lowcore.program_new_psw).mcheck = 1;
298	psw_bits(S390_lowcore.svc_new_psw).mcheck = 1;
299	psw_bits(S390_lowcore.io_new_psw).mcheck = 1;
300	local_ctl_load(0, &cr0);
301	local_irq_restore(flags);
302	local_mcck_enable();
303	test_monitor_call();
304}
305
306static void (*pgm_check_table[128])(struct pt_regs *regs);
307
308void noinstr __do_pgm_check(struct pt_regs *regs)
309{
310	unsigned int trapnr;
311	irqentry_state_t state;
312
313	regs->int_code = S390_lowcore.pgm_int_code;
314	regs->int_parm_long = S390_lowcore.trans_exc_code;
315
316	state = irqentry_enter(regs);
317
318	if (user_mode(regs)) {
319		update_timer_sys();
320		if (!static_branch_likely(&cpu_has_bear)) {
321			if (regs->last_break < 4096)
322				regs->last_break = 1;
323		}
324		current->thread.last_break = regs->last_break;
325	}
326
327	if (S390_lowcore.pgm_code & 0x0200) {
328		/* transaction abort */
329		current->thread.trap_tdb = S390_lowcore.pgm_tdb;
330	}
331
332	if (S390_lowcore.pgm_code & PGM_INT_CODE_PER) {
333		if (user_mode(regs)) {
334			struct per_event *ev = &current->thread.per_event;
335
336			set_thread_flag(TIF_PER_TRAP);
337			ev->address = S390_lowcore.per_address;
338			ev->cause = S390_lowcore.per_code_combined;
339			ev->paid = S390_lowcore.per_access_id;
340		} else {
341			/* PER event in kernel is kprobes */
342			__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
343			do_per_trap(regs);
344			goto out;
345		}
346	}
347
348	if (!irqs_disabled_flags(regs->psw.mask))
349		trace_hardirqs_on();
350	__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
351
352	trapnr = regs->int_code & PGM_INT_CODE_MASK;
353	if (trapnr)
354		pgm_check_table[trapnr](regs);
355out:
356	local_irq_disable();
357	irqentry_exit(regs, state);
358}
359
360/*
361 * The program check table contains exactly 128 (0x00-0x7f) entries. Each
362 * line defines the function to be called corresponding to the program check
363 * interruption code.
364 */
365static void (*pgm_check_table[128])(struct pt_regs *regs) = {
366	[0x00]		= default_trap_handler,
367	[0x01]		= illegal_op,
368	[0x02]		= privileged_op,
369	[0x03]		= execute_exception,
370	[0x04]		= do_protection_exception,
371	[0x05]		= addressing_exception,
372	[0x06]		= specification_exception,
373	[0x07]		= data_exception,
374	[0x08]		= overflow_exception,
375	[0x09]		= divide_exception,
376	[0x0a]		= overflow_exception,
377	[0x0b]		= divide_exception,
378	[0x0c]		= hfp_overflow_exception,
379	[0x0d]		= hfp_underflow_exception,
380	[0x0e]		= hfp_significance_exception,
381	[0x0f]		= hfp_divide_exception,
382	[0x10]		= do_dat_exception,
383	[0x11]		= do_dat_exception,
384	[0x12]		= translation_specification_exception,
385	[0x13]		= special_op_exception,
386	[0x14]		= default_trap_handler,
387	[0x15]		= operand_exception,
388	[0x16]		= default_trap_handler,
389	[0x17]		= default_trap_handler,
390	[0x18]		= transaction_exception,
391	[0x19]		= default_trap_handler,
392	[0x1a]		= default_trap_handler,
393	[0x1b]		= vector_exception,
394	[0x1c]		= space_switch_exception,
395	[0x1d]		= hfp_sqrt_exception,
396	[0x1e ... 0x37] = default_trap_handler,
397	[0x38]		= do_dat_exception,
398	[0x39]		= do_dat_exception,
399	[0x3a]		= do_dat_exception,
400	[0x3b]		= do_dat_exception,
401	[0x3c]		= default_trap_handler,
402	[0x3d]		= do_secure_storage_access,
403	[0x3e]		= do_non_secure_storage_access,
404	[0x3f]		= do_secure_storage_violation,
405	[0x40]		= monitor_event_exception,
406	[0x41 ... 0x7f] = default_trap_handler,
407};
408
409#define COND_TRAP(x) asm(			\
410	".weak " __stringify(x) "\n\t"		\
411	".set  " __stringify(x) ","		\
412	__stringify(default_trap_handler))
413
414COND_TRAP(do_secure_storage_access);
415COND_TRAP(do_non_secure_storage_access);
416COND_TRAP(do_secure_storage_violation);
v4.6
 
  1/*
  2 *  S390 version
  3 *    Copyright IBM Corp. 1999, 2000
  4 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
  5 *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
  6 *
  7 *  Derived from "arch/i386/kernel/traps.c"
  8 *    Copyright (C) 1991, 1992 Linus Torvalds
  9 */
 10
 11/*
 12 * 'Traps.c' handles hardware traps and faults after we have saved some
 13 * state in 'asm.s'.
 14 */
 
 
 15#include <linux/kprobes.h>
 16#include <linux/kdebug.h>
 17#include <linux/module.h>
 
 18#include <linux/ptrace.h>
 19#include <linux/sched.h>
 
 20#include <linux/mm.h>
 21#include <linux/slab.h>
 
 
 
 
 22#include <asm/fpu/api.h>
 
 23#include "entry.h"
 24
 25static inline void __user *get_trap_ip(struct pt_regs *regs)
 26{
 27	unsigned long address;
 28
 29	if (regs->int_code & 0x200)
 30		address = *(unsigned long *)(current->thread.trap_tdb + 24);
 31	else
 32		address = regs->psw.addr;
 33	return (void __user *) (address - (regs->int_code >> 16));
 34}
 35
 
 36int is_valid_bugaddr(unsigned long addr)
 37{
 38	return 1;
 39}
 
 40
 41void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
 42{
 43	siginfo_t info;
 44
 45	if (user_mode(regs)) {
 46		info.si_signo = si_signo;
 47		info.si_errno = 0;
 48		info.si_code = si_code;
 49		info.si_addr = get_trap_ip(regs);
 50		force_sig_info(si_signo, &info, current);
 51		report_user_fault(regs, si_signo, 0);
 52        } else {
 53                const struct exception_table_entry *fixup;
 54		fixup = search_exception_tables(regs->psw.addr);
 55                if (fixup)
 56			regs->psw.addr = extable_fixup(fixup);
 57		else {
 58			enum bug_trap_type btt;
 59
 60			btt = report_bug(regs->psw.addr, regs);
 61			if (btt == BUG_TRAP_TYPE_WARN)
 62				return;
 63			die(regs, str);
 64		}
 65        }
 66}
 67
 68static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
 69{
 70	if (notify_die(DIE_TRAP, str, regs, 0,
 71		       regs->int_code, si_signo) == NOTIFY_STOP)
 72		return;
 73	do_report_trap(regs, si_signo, si_code, str);
 74}
 75NOKPROBE_SYMBOL(do_trap);
 76
 77void do_per_trap(struct pt_regs *regs)
 78{
 79	siginfo_t info;
 80
 81	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
 82		return;
 83	if (!current->ptrace)
 84		return;
 85	info.si_signo = SIGTRAP;
 86	info.si_errno = 0;
 87	info.si_code = TRAP_HWBKPT;
 88	info.si_addr =
 89		(void __force __user *) current->thread.per_event.address;
 90	force_sig_info(SIGTRAP, &info, current);
 91}
 92NOKPROBE_SYMBOL(do_per_trap);
 93
 94void default_trap_handler(struct pt_regs *regs)
 95{
 96	if (user_mode(regs)) {
 97		report_user_fault(regs, SIGSEGV, 0);
 98		do_exit(SIGSEGV);
 99	} else
100		die(regs, "Unknown program exception");
101}
102
103#define DO_ERROR_INFO(name, signr, sicode, str) \
104void name(struct pt_regs *regs)			\
105{						\
106	do_trap(regs, signr, sicode, str);	\
107}
108
109DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
110	      "addressing exception")
111DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
112	      "execute exception")
113DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
114	      "fixpoint divide exception")
115DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
116	      "fixpoint overflow exception")
117DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
118	      "HFP overflow exception")
119DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
120	      "HFP underflow exception")
121DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
122	      "HFP significance exception")
123DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
124	      "HFP divide exception")
125DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
126	      "HFP square root exception")
127DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
128	      "operand exception")
129DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
130	      "privileged operation")
131DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
132	      "special operation exception")
133DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
134	      "transaction constraint exception")
135
136static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
137{
138	int si_code = 0;
139	/* FPC[2] is Data Exception Code */
140	if ((fpc & 0x00000300) == 0) {
141		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
142		if (fpc & 0x8000) /* invalid fp operation */
143			si_code = FPE_FLTINV;
144		else if (fpc & 0x4000) /* div by 0 */
145			si_code = FPE_FLTDIV;
146		else if (fpc & 0x2000) /* overflow */
147			si_code = FPE_FLTOVF;
148		else if (fpc & 0x1000) /* underflow */
149			si_code = FPE_FLTUND;
150		else if (fpc & 0x0800) /* inexact */
151			si_code = FPE_FLTRES;
152	}
153	do_trap(regs, SIGFPE, si_code, "floating point exception");
154}
155
156void translation_exception(struct pt_regs *regs)
157{
158	/* May never happen. */
159	panic("Translation exception");
160}
161
162void illegal_op(struct pt_regs *regs)
163{
164	siginfo_t info;
165        __u8 opcode[6];
166	__u16 __user *location;
167	int is_uprobe_insn = 0;
168	int signal = 0;
169
170	location = get_trap_ip(regs);
171
172	if (user_mode(regs)) {
173		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
174			return;
175		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
176			if (current->ptrace) {
177				info.si_signo = SIGTRAP;
178				info.si_errno = 0;
179				info.si_code = TRAP_BRKPT;
180				info.si_addr = location;
181				force_sig_info(SIGTRAP, &info, current);
182			} else
183				signal = SIGILL;
184#ifdef CONFIG_UPROBES
185		} else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
186			is_uprobe_insn = 1;
187#endif
188		} else
189			signal = SIGILL;
190	}
191	/*
192	 * We got either an illegal op in kernel mode, or user space trapped
193	 * on a uprobes illegal instruction. See if kprobes or uprobes picks
194	 * it up. If not, SIGILL.
195	 */
196	if (is_uprobe_insn || !user_mode(regs)) {
197		if (notify_die(DIE_BPT, "bpt", regs, 0,
198			       3, SIGTRAP) != NOTIFY_STOP)
199			signal = SIGILL;
200	}
201	if (signal)
202		do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
203}
204NOKPROBE_SYMBOL(illegal_op);
205
206DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
207	      "specification exception");
208
209void vector_exception(struct pt_regs *regs)
210{
211	int si_code, vic;
212
213	if (!MACHINE_HAS_VX) {
214		do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
215		return;
216	}
217
218	/* get vector interrupt code from fpc */
219	save_fpu_regs();
220	vic = (current->thread.fpu.fpc & 0xf00) >> 8;
221	switch (vic) {
222	case 1: /* invalid vector operation */
223		si_code = FPE_FLTINV;
224		break;
225	case 2: /* division by zero */
226		si_code = FPE_FLTDIV;
227		break;
228	case 3: /* overflow */
229		si_code = FPE_FLTOVF;
230		break;
231	case 4: /* underflow */
232		si_code = FPE_FLTUND;
233		break;
234	case 5:	/* inexact */
235		si_code = FPE_FLTRES;
236		break;
237	default: /* unknown cause */
238		si_code = 0;
239	}
240	do_trap(regs, SIGFPE, si_code, "vector exception");
241}
242
243void data_exception(struct pt_regs *regs)
244{
245	int signal = 0;
246
247	save_fpu_regs();
248	if (current->thread.fpu.fpc & FPC_DXC_MASK)
249		signal = SIGFPE;
250	else
251		signal = SIGILL;
252	if (signal == SIGFPE)
253		do_fp_trap(regs, current->thread.fpu.fpc);
254	else if (signal)
255		do_trap(regs, signal, ILL_ILLOPN, "data exception");
256}
257
258void space_switch_exception(struct pt_regs *regs)
259{
260	/* Set user psw back to home space mode. */
261	if (user_mode(regs))
262		regs->psw.mask |= PSW_ASC_HOME;
263	/* Send SIGILL. */
264	do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
265}
266
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
267void kernel_stack_overflow(struct pt_regs *regs)
268{
269	bust_spinlocks(1);
270	printk("Kernel stack overflow.\n");
271	show_regs(regs);
272	bust_spinlocks(0);
273	panic("Corrupt kernel stack, can't continue.");
274}
275NOKPROBE_SYMBOL(kernel_stack_overflow);
276
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
277void __init trap_init(void)
278{
 
 
 
 
 
 
 
 
 
 
 
279	local_mcck_enable();
 
280}