[linux-2.6-block.git] / arch / s390 / kernel / traps.c

/*
 *  S390 version
 *    Copyright IBM Corp. 1999, 2000
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
 *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
 *
 *  Derived from "arch/i386/kernel/traps.c"
 *    Copyright (C) 1991, 1992 Linus Torvalds
 */

/*
 * 'Traps.c' handles hardware traps and faults after we have saved some
 * state in 'asm.s'.
 */
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/fpu/api.h>
#include "entry.h"

int show_unhandled_signals = 1;

static inline void __user *get_trap_ip(struct pt_regs *regs)
{
	unsigned long address;

	if (regs->int_code & 0x200)
		address = *(unsigned long *)(current->thread.trap_tdb + 24);
	else
		address = regs->psw.addr;
	return (void __user *)
		((address - (regs->int_code >> 16)) & PSW_ADDR_INSN);
}

static inline void report_user_fault(struct pt_regs *regs, int signr)
{
	if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
		return;
	if (!unhandled_signal(current, signr))
		return;
	if (!printk_ratelimit())
		return;
	printk("User process fault: interruption code %04x ilc:%d ",
	       regs->int_code & 0xffff, regs->int_code >> 17);
	print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
	printk("\n");
	show_regs(regs);
}

int is_valid_bugaddr(unsigned long addr)
{
	return 1;
}

void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
{
	siginfo_t info;

	if (user_mode(regs)) {
		info.si_signo = si_signo;
		info.si_errno = 0;
		info.si_code = si_code;
		info.si_addr = get_trap_ip(regs);
		force_sig_info(si_signo, &info, current);
		report_user_fault(regs, si_signo);
        } else {
                const struct exception_table_entry *fixup;
                fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
                if (fixup)
			regs->psw.addr = extable_fixup(fixup) | PSW_ADDR_AMODE;
		else {
			enum bug_trap_type btt;

			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
			if (btt == BUG_TRAP_TYPE_WARN)
				return;
			die(regs, str);
		}
        }
}

static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
{
	if (notify_die(DIE_TRAP, str, regs, 0,
		       regs->int_code, si_signo) == NOTIFY_STOP)
		return;
	do_report_trap(regs, si_signo, si_code, str);
}
NOKPROBE_SYMBOL(do_trap);

void do_per_trap(struct pt_regs *regs)
{
	siginfo_t info;

	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
		return;
	if (!current->ptrace)
		return;
	info.si_signo = SIGTRAP;
	info.si_errno = 0;
	info.si_code = TRAP_HWBKPT;
	info.si_addr =
		(void __force __user *) current->thread.per_event.address;
	force_sig_info(SIGTRAP, &info, current);
}
NOKPROBE_SYMBOL(do_per_trap);

void default_trap_handler(struct pt_regs *regs)
{
	if (user_mode(regs)) {
		report_user_fault(regs, SIGSEGV);
		do_exit(SIGSEGV);
	} else
		die(regs, "Unknown program exception");
}

#define DO_ERROR_INFO(name, signr, sicode, str) \
void name(struct pt_regs *regs)			\
{						\
	do_trap(regs, signr, sicode, str);	\
}

DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
	      "addressing exception")
DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
	      "execute exception")
DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
	      "fixpoint divide exception")
DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
	      "fixpoint overflow exception")
DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
	      "HFP overflow exception")
DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
	      "HFP underflow exception")
DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
	      "HFP significance exception")
DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
	      "HFP divide exception")
DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
	      "HFP square root exception")
DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
	      "operand exception")
DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
	      "privileged operation")
DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
	      "special operation exception")
DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
	      "transaction constraint exception")

static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
{
	int si_code = 0;
	/* FPC[2] is Data Exception Code */
	if ((fpc & 0x00000300) == 0) {
		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
		if (fpc & 0x8000) /* invalid fp operation */
			si_code = FPE_FLTINV;
		else if (fpc & 0x4000) /* div by 0 */
			si_code = FPE_FLTDIV;
		else if (fpc & 0x2000) /* overflow */
			si_code = FPE_FLTOVF;
		else if (fpc & 0x1000) /* underflow */
			si_code = FPE_FLTUND;
		else if (fpc & 0x0800) /* inexact */
			si_code = FPE_FLTRES;
	}
	do_trap(regs, SIGFPE, si_code, "floating point exception");
}

void translation_exception(struct pt_regs *regs)
{
	/* May never happen. */
	panic("Translation exception");
}

void illegal_op(struct pt_regs *regs)
{
	siginfo_t info;
        __u8 opcode[6];
	__u16 __user *location;
	int is_uprobe_insn = 0;
	int signal = 0;

	location = get_trap_ip(regs);

	if (user_mode(regs)) {
		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
			return;
		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
			if (current->ptrace) {
				info.si_signo = SIGTRAP;
				info.si_errno = 0;
				info.si_code = TRAP_BRKPT;
				info.si_addr = location;
				force_sig_info(SIGTRAP, &info, current);
			} else
				signal = SIGILL;
#ifdef CONFIG_UPROBES
		} else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
			is_uprobe_insn = 1;
#endif
		} else
			signal = SIGILL;
	}
	/*
	 * We got either an illegal op in kernel mode, or user space trapped
	 * on a uprobes illegal instruction. See if kprobes or uprobes picks
	 * it up. If not, SIGILL.
	 */
	if (is_uprobe_insn || !user_mode(regs)) {
		if (notify_die(DIE_BPT, "bpt", regs, 0,
			       3, SIGTRAP) != NOTIFY_STOP)
			signal = SIGILL;
	}
	if (signal)
		do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
}
NOKPROBE_SYMBOL(illegal_op);

DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
	      "specification exception");

void vector_exception(struct pt_regs *regs)
{
	int si_code, vic;

	if (!MACHINE_HAS_VX) {
		do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
		return;
	}

	/* get vector interrupt code from fpc */
	save_fpu_regs();
	vic = (current->thread.fpu.fpc & 0xf00) >> 8;
	switch (vic) {
	case 1: /* invalid vector operation */
		si_code = FPE_FLTINV;
		break;
	case 2: /* division by zero */
		si_code = FPE_FLTDIV;
		break;
	case 3: /* overflow */
		si_code = FPE_FLTOVF;
		break;
	case 4: /* underflow */
		si_code = FPE_FLTUND;
		break;
	case 5:	/* inexact */
		si_code = FPE_FLTRES;
		break;
	default: /* unknown cause */
		si_code = 0;
	}
	do_trap(regs, SIGFPE, si_code, "vector exception");
}

void data_exception(struct pt_regs *regs)
{
	__u16 __user *location;
	int signal = 0;

	location = get_trap_ip(regs);

	save_fpu_regs();
	if (current->thread.fpu.fpc & FPC_DXC_MASK)
		signal = SIGFPE;
	else
		signal = SIGILL;
	if (signal == SIGFPE)
		do_fp_trap(regs, current->thread.fpu.fpc);
	else if (signal)
		do_trap(regs, signal, ILL_ILLOPN, "data exception");
}

void space_switch_exception(struct pt_regs *regs)
{
	/* Set user psw back to home space mode. */
	if (user_mode(regs))
		regs->psw.mask |= PSW_ASC_HOME;
	/* Send SIGILL. */
	do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
}

void kernel_stack_overflow(struct pt_regs *regs)
{
	bust_spinlocks(1);
	printk("Kernel stack overflow.\n");
	show_regs(regs);
	bust_spinlocks(0);
	panic("Corrupt kernel stack, can't continue.");
}
NOKPROBE_SYMBOL(kernel_stack_overflow);

void __init trap_init(void)
{
	local_mcck_enable();
}
Commit	Line	Data
1da177e4	1	/*
1da177e4	2	* S390 version
a53c8fab	3	* Copyright IBM Corp. 1999, 2000
1da177e4 LT	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	*/
1bca09f7 HC	15	#include <linux/kprobes.h>
	16	#include <linux/kdebug.h>
	17	#include <linux/module.h>
73b7d40f	18	#include <linux/ptrace.h>
1bca09f7	19	#include <linux/sched.h>
1da177e4	20	#include <linux/mm.h>
80703617	21	#include <linux/slab.h>
b0753902	22	#include <asm/fpu/api.h>
a806170e	23	#include "entry.h"
1da177e4	24
02834eec	25	int show_unhandled_signals = 1;
1da177e4	26
d35339a4 MS	27	static inline void __user get_trap_ip(struct pt_regs regs)
d35339a4 MS	28	{
d35339a4 MS	29	unsigned long address;
	30
	31	if (regs->int_code & 0x200)
	32	address = (unsigned long )(current->thread.trap_tdb + 24);
	33	else
	34	address = regs->psw.addr;
	35	return (void __user *)
	36	((address - (regs->int_code >> 16)) & PSW_ADDR_INSN);
d35339a4 MS	37	}
d35339a4 MS	38
aa33c8cb	39	static inline void report_user_fault(struct pt_regs *regs, int signr)
1da177e4	40	{
ab3c68ee	41	if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
1da177e4	42	return;
ab3c68ee HC	43	if (!unhandled_signal(current, signr))
	44	return;
	45	if (!printk_ratelimit())
	46	return;
413d4047 HC	47	printk("User process fault: interruption code %04x ilc:%d ",
413d4047 HC	48	regs->int_code & 0xffff, regs->int_code >> 17);
ab3c68ee HC	49	print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
ab3c68ee HC	50	printk("\n");
1da177e4	51	show_regs(regs);
1da177e4 LT	52	}
1da177e4 LT	53
c0007f1a HC	54	int is_valid_bugaddr(unsigned long addr)
	55	{
	56	return 1;
	57	}
	58
2a0a5b22	59	void do_report_trap(struct pt_regs regs, int si_signo, int si_code, char str)
aa33c8cb MS	60	{
	61	siginfo_t info;
	62
7d256175	63	if (user_mode(regs)) {
aa33c8cb MS	64	info.si_signo = si_signo;
	65	info.si_errno = 0;
	66	info.si_code = si_code;
d35339a4	67	info.si_addr = get_trap_ip(regs);
aa33c8cb MS	68	force_sig_info(si_signo, &info, current);
aa33c8cb MS	69	report_user_fault(regs, si_signo);
1da177e4 LT	70	} else {
	71	const struct exception_table_entry *fixup;
	72	fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
	73	if (fixup)
eb608fb3	74	regs->psw.addr = extable_fixup(fixup) \| PSW_ADDR_AMODE;
c0007f1a HC	75	else {
	76	enum bug_trap_type btt;
	77
608e2619	78	btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
c0007f1a HC	79	if (btt == BUG_TRAP_TYPE_WARN)
c0007f1a HC	80	return;
aa33c8cb	81	die(regs, str);
c0007f1a	82	}
1da177e4 LT	83	}
	84	}
	85
7a5388de	86	static void do_trap(struct pt_regs regs, int si_signo, int si_code, char str)
2a0a5b22 JW	87	{
	88	if (notify_die(DIE_TRAP, str, regs, 0,
	89	regs->int_code, si_signo) == NOTIFY_STOP)
	90	return;
	91	do_report_trap(regs, si_signo, si_code, str);
	92	}
7a5388de	93	NOKPROBE_SYMBOL(do_trap);
2a0a5b22	94
7a5388de	95	void do_per_trap(struct pt_regs *regs)
1da177e4	96	{
73b7d40f MS	97	siginfo_t info;
73b7d40f MS	98
5e9a2692	99	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
4ba069b8	100	return;
73b7d40f MS	101	if (!current->ptrace)
	102	return;
	103	info.si_signo = SIGTRAP;
	104	info.si_errno = 0;
	105	info.si_code = TRAP_HWBKPT;
3c52e49d MS	106	info.si_addr =
3c52e49d MS	107	(void __force __user *) current->thread.per_event.address;
73b7d40f	108	force_sig_info(SIGTRAP, &info, current);
1da177e4	109	}
7a5388de	110	NOKPROBE_SYMBOL(do_per_trap);
1da177e4	111
b01a37a7	112	void default_trap_handler(struct pt_regs *regs)
1da177e4	113	{
7d256175	114	if (user_mode(regs)) {
aa33c8cb	115	report_user_fault(regs, SIGSEGV);
6ea50968	116	do_exit(SIGSEGV);
1da177e4	117	} else
aa33c8cb	118	die(regs, "Unknown program exception");
1da177e4 LT	119	}
1da177e4 LT	120
1e54622e	121	#define DO_ERROR_INFO(name, signr, sicode, str) \
b01a37a7 HC	122	void name(struct pt_regs *regs) \
	123	{ \
	124	do_trap(regs, signr, sicode, str); \
1da177e4 LT	125	}
1da177e4 LT	126
1e54622e MS	127	DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
	128	"addressing exception")
	129	DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
	130	"execute exception")
	131	DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
	132	"fixpoint divide exception")
	133	DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
	134	"fixpoint overflow exception")
	135	DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
	136	"HFP overflow exception")
	137	DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
	138	"HFP underflow exception")
	139	DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
	140	"HFP significance exception")
	141	DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
	142	"HFP divide exception")
	143	DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
	144	"HFP square root exception")
	145	DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
	146	"operand exception")
	147	DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
	148	"privileged operation")
	149	DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
	150	"special operation exception")
d35339a4 MS	151	DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
d35339a4 MS	152	"transaction constraint exception")
d35339a4	153
9977e886	154	static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
1da177e4	155	{
aa33c8cb	156	int si_code = 0;
1da177e4 LT	157	/* FPC[2] is Data Exception Code */
	158	if ((fpc & 0x00000300) == 0) {
	159	/* bits 6 and 7 of DXC are 0 iff IEEE exception */
	160	if (fpc & 0x8000) /* invalid fp operation */
aa33c8cb	161	si_code = FPE_FLTINV;
1da177e4	162	else if (fpc & 0x4000) /* div by 0 */
aa33c8cb	163	si_code = FPE_FLTDIV;
1da177e4	164	else if (fpc & 0x2000) /* overflow */
aa33c8cb	165	si_code = FPE_FLTOVF;
1da177e4	166	else if (fpc & 0x1000) /* underflow */
aa33c8cb	167	si_code = FPE_FLTUND;
1da177e4	168	else if (fpc & 0x0800) /* inexact */
aa33c8cb	169	si_code = FPE_FLTRES;
1da177e4	170	}
aa33c8cb	171	do_trap(regs, SIGFPE, si_code, "floating point exception");
1da177e4 LT	172	}
1da177e4 LT	173
e56da345 HC	174	void translation_exception(struct pt_regs *regs)
	175	{
	176	/* May never happen. */
e1d12d70	177	panic("Translation exception");
e56da345 HC	178	}
e56da345 HC	179
7a5388de	180	void illegal_op(struct pt_regs *regs)
1da177e4 LT	181	{
	182	siginfo_t info;
	183	__u8 opcode[6];
d2c993d8	184	__u16 __user *location;
2a0a5b22	185	int is_uprobe_insn = 0;
1da177e4 LT	186	int signal = 0;
1da177e4 LT	187
d35339a4	188	location = get_trap_ip(regs);
1da177e4	189
7d256175	190	if (user_mode(regs)) {
12bae235 HC	191	if (get_user(((__u16 ) opcode), (__u16 __user *) location))
12bae235 HC	192	return;
1da177e4	193	if (((__u16 ) opcode) == S390_BREAKPOINT_U16) {
73b7d40f MS	194	if (current->ptrace) {
	195	info.si_signo = SIGTRAP;
	196	info.si_errno = 0;
	197	info.si_code = TRAP_BRKPT;
	198	info.si_addr = location;
	199	force_sig_info(SIGTRAP, &info, current);
	200	} else
1da177e4	201	signal = SIGILL;
2a0a5b22 JW	202	#ifdef CONFIG_UPROBES
	203	} else if (((__u16 ) opcode) == UPROBE_SWBP_INSN) {
	204	is_uprobe_insn = 1;
1da177e4 LT	205	#endif
	206	} else
	207	signal = SIGILL;
2a0a5b22 JW	208	}
	209	/*
	210	* We got either an illegal op in kernel mode, or user space trapped
	211	* on a uprobes illegal instruction. See if kprobes or uprobes picks
	212	* it up. If not, SIGILL.
	213	*/
	214	if (is_uprobe_insn \|\| !user_mode(regs)) {
aa33c8cb	215	if (notify_die(DIE_BPT, "bpt", regs, 0,
35df8d53 HC	216	3, SIGTRAP) != NOTIFY_STOP)
	217	signal = SIGILL;
	218	}
aa33c8cb MS	219	if (signal)
aa33c8cb MS	220	do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
1da177e4	221	}
7a5388de	222	NOKPROBE_SYMBOL(illegal_op);
1da177e4	223
1e54622e MS	224	DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
1e54622e MS	225	"specification exception");
1da177e4	226
80703617 MS	227	void vector_exception(struct pt_regs *regs)
	228	{
	229	int si_code, vic;
	230
	231	if (!MACHINE_HAS_VX) {
	232	do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
	233	return;
	234	}
	235
	236	/* get vector interrupt code from fpc */
d0164ee2	237	save_fpu_regs();
904818e2	238	vic = (current->thread.fpu.fpc & 0xf00) >> 8;
80703617 MS	239	switch (vic) {
	240	case 1: /* invalid vector operation */
	241	si_code = FPE_FLTINV;
	242	break;
	243	case 2: /* division by zero */
	244	si_code = FPE_FLTDIV;
	245	break;
	246	case 3: /* overflow */
	247	si_code = FPE_FLTOVF;
	248	break;
	249	case 4: /* underflow */
	250	si_code = FPE_FLTUND;
	251	break;
	252	case 5: /* inexact */
	253	si_code = FPE_FLTRES;
	254	break;
	255	default: /* unknown cause */
	256	si_code = 0;
	257	}
	258	do_trap(regs, SIGFPE, si_code, "vector exception");
	259	}
	260
b01a37a7	261	void data_exception(struct pt_regs *regs)
1da177e4	262	{
d2c993d8	263	__u16 __user *location;
1da177e4 LT	264	int signal = 0;
1da177e4 LT	265
d35339a4	266	location = get_trap_ip(regs);
1da177e4	267
d0164ee2	268	save_fpu_regs();
904818e2	269	if (current->thread.fpu.fpc & FPC_DXC_MASK)
1da177e4 LT	270	signal = SIGFPE;
	271	else
	272	signal = SIGILL;
5a79859a	273	if (signal == SIGFPE)
904818e2	274	do_fp_trap(regs, current->thread.fpu.fpc);
aa33c8cb MS	275	else if (signal)
aa33c8cb MS	276	do_trap(regs, signal, ILL_ILLOPN, "data exception");
1da177e4 LT	277	}
1da177e4 LT	278
b01a37a7	279	void space_switch_exception(struct pt_regs *regs)
1da177e4	280	{
1da177e4	281	/* Set user psw back to home space mode. */
7d256175	282	if (user_mode(regs))
1da177e4 LT	283	regs->psw.mask \|= PSW_ASC_HOME;
1da177e4 LT	284	/* Send SIGILL. */
aa33c8cb	285	do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
1da177e4 LT	286	}
1da177e4 LT	287
7a5388de	288	void kernel_stack_overflow(struct pt_regs *regs)
1da177e4	289	{
77eb65cb HC	290	bust_spinlocks(1);
	291	printk("Kernel stack overflow.\n");
	292	show_regs(regs);
	293	bust_spinlocks(0);
1da177e4 LT	294	panic("Corrupt kernel stack, can't continue.");
1da177e4 LT	295	}
7a5388de	296	NOKPROBE_SYMBOL(kernel_stack_overflow);
1da177e4	297
1da177e4 LT	298	void __init trap_init(void)
1da177e4 LT	299	{
f3e1a273	300	local_mcck_enable();
1da177e4	301	}