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

// SPDX-License-Identifier: GPL-2.0
/*
 *  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 "asm/irqflags.h"
#include "asm/ptrace.h"
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <linux/randomize_kstack.h>
#include <linux/extable.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/cpu.h>
#include <linux/entry-common.h>
#include <asm/asm-extable.h>
#include <asm/fpu/api.h>
#include <asm/vtime.h>
#include "entry.h"

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

	if (regs->int_code & 0x200)
		address = current->thread.trap_tdb.data[3];
	else
		address = regs->psw.addr;
	return (void __user *) (address - (regs->int_code >> 16));
}

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)
{
	if (user_mode(regs)) {
		force_sig_fault(si_signo, si_code, get_trap_ip(regs));
		report_user_fault(regs, si_signo, 0);
        } else {
		if (!fixup_exception(regs))
			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)
{
	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
		return;
	if (!current->ptrace)
		return;
	force_sig_fault(SIGTRAP, TRAP_HWBKPT,
		(void __force __user *) current->thread.per_event.address);
}
NOKPROBE_SYMBOL(do_per_trap);

static void default_trap_handler(struct pt_regs *regs)
{
	if (user_mode(regs)) {
		report_user_fault(regs, SIGSEGV, 0);
		force_exit_sig(SIGSEGV);
	} else
		die(regs, "Unknown program exception");
}

#define DO_ERROR_INFO(name, signr, sicode, str) \
static 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");
}

static void translation_specification_exception(struct pt_regs *regs)
{
	/* May never happen. */
	panic("Translation-Specification Exception");
}

static void illegal_op(struct pt_regs *regs)
{
        __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)
				force_sig_fault(SIGTRAP, TRAP_BRKPT, location);
			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");

static 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");
}

static void data_exception(struct pt_regs *regs)
{
	save_fpu_regs();
	if (current->thread.fpu.fpc & FPC_DXC_MASK)
		do_fp_trap(regs, current->thread.fpu.fpc);
	else
		do_trap(regs, SIGILL, ILL_ILLOPN, "data exception");
}

static 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");
}

static void monitor_event_exception(struct pt_regs *regs)
{
	if (user_mode(regs))
		return;

	switch (report_bug(regs->psw.addr - (regs->int_code >> 16), regs)) {
	case BUG_TRAP_TYPE_NONE:
		fixup_exception(regs);
		break;
	case BUG_TRAP_TYPE_WARN:
		break;
	case BUG_TRAP_TYPE_BUG:
		die(regs, "monitor event");
		break;
	}
}

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);

static void __init test_monitor_call(void)
{
	int val = 1;

	if (!IS_ENABLED(CONFIG_BUG))
		return;
	asm volatile(
		"	mc	0,0\n"
		"0:	xgr	%0,%0\n"
		"1:\n"
		EX_TABLE(0b,1b)
		: "+d" (val));
	if (!val)
		panic("Monitor call doesn't work!\n");
}

void __init trap_init(void)
{
	local_mcck_enable();
	test_monitor_call();
}

static void (*pgm_check_table[128])(struct pt_regs *regs);

void noinstr __do_pgm_check(struct pt_regs *regs)
{
	unsigned int trapnr;
	irqentry_state_t state;

	regs->int_code = S390_lowcore.pgm_int_code;
	regs->int_parm_long = S390_lowcore.trans_exc_code;

	state = irqentry_enter(regs);

	if (user_mode(regs)) {
		update_timer_sys();
		if (!static_branch_likely(&cpu_has_bear)) {
			if (regs->last_break < 4096)
				regs->last_break = 1;
		}
		current->thread.last_break = regs->last_break;
	}

	if (S390_lowcore.pgm_code & 0x0200) {
		/* transaction abort */
		current->thread.trap_tdb = S390_lowcore.pgm_tdb;
	}

	if (S390_lowcore.pgm_code & PGM_INT_CODE_PER) {
		if (user_mode(regs)) {
			struct per_event *ev = &current->thread.per_event;

			set_thread_flag(TIF_PER_TRAP);
			ev->address = S390_lowcore.per_address;
			ev->cause = S390_lowcore.per_code_combined;
			ev->paid = S390_lowcore.per_access_id;
		} else {
			/* PER event in kernel is kprobes */
			__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
			do_per_trap(regs);
			goto out;
		}
	}

	if (!irqs_disabled_flags(regs->psw.mask))
		trace_hardirqs_on();
	__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);

	trapnr = regs->int_code & PGM_INT_CODE_MASK;
	if (trapnr)
		pgm_check_table[trapnr](regs);
out:
	local_irq_disable();
	irqentry_exit(regs, state);
}

/*
 * The program check table contains exactly 128 (0x00-0x7f) entries. Each
 * line defines the function to be called corresponding to the program check
 * interruption code.
 */
static void (*pgm_check_table[128])(struct pt_regs *regs) = {
	[0x00]		= default_trap_handler,
	[0x01]		= illegal_op,
	[0x02]		= privileged_op,
	[0x03]		= execute_exception,
	[0x04]		= do_protection_exception,
	[0x05]		= addressing_exception,
	[0x06]		= specification_exception,
	[0x07]		= data_exception,
	[0x08]		= overflow_exception,
	[0x09]		= divide_exception,
	[0x0a]		= overflow_exception,
	[0x0b]		= divide_exception,
	[0x0c]		= hfp_overflow_exception,
	[0x0d]		= hfp_underflow_exception,
	[0x0e]		= hfp_significance_exception,
	[0x0f]		= hfp_divide_exception,
	[0x10]		= do_dat_exception,
	[0x11]		= do_dat_exception,
	[0x12]		= translation_specification_exception,
	[0x13]		= special_op_exception,
	[0x14]		= default_trap_handler,
	[0x15]		= operand_exception,
	[0x16]		= default_trap_handler,
	[0x17]		= default_trap_handler,
	[0x18]		= transaction_exception,
	[0x19]		= default_trap_handler,
	[0x1a]		= default_trap_handler,
	[0x1b]		= vector_exception,
	[0x1c]		= space_switch_exception,
	[0x1d]		= hfp_sqrt_exception,
	[0x1e ... 0x37] = default_trap_handler,
	[0x38]		= do_dat_exception,
	[0x39]		= do_dat_exception,
	[0x3a]		= do_dat_exception,
	[0x3b]		= do_dat_exception,
	[0x3c]		= default_trap_handler,
	[0x3d]		= do_secure_storage_access,
	[0x3e]		= do_non_secure_storage_access,
	[0x3f]		= do_secure_storage_violation,
	[0x40]		= monitor_event_exception,
	[0x41 ... 0x7f] = default_trap_handler,
};

#define COND_TRAP(x) asm(			\
	".weak " __stringify(x) "\n\t"		\
	".set  " __stringify(x) ","		\
	__stringify(default_trap_handler))

COND_TRAP(do_secure_storage_access);
COND_TRAP(do_non_secure_storage_access);
COND_TRAP(do_secure_storage_violation);
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4	2	/*
1da177e4	3	* S390 version
a53c8fab	4	* Copyright IBM Corp. 1999, 2000
1da177e4 LT	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	*/
56e62a73 SS	16	#include "asm/irqflags.h"
56e62a73 SS	17	#include "asm/ptrace.h"
1bca09f7 HC	18	#include <linux/kprobes.h>
1bca09f7 HC	19	#include <linux/kdebug.h>
bae1cd36	20	#include <linux/randomize_kstack.h>
dcc096c5	21	#include <linux/extable.h>
73b7d40f	22	#include <linux/ptrace.h>
1bca09f7	23	#include <linux/sched.h>
b17b0153	24	#include <linux/sched/debug.h>
1da177e4	25	#include <linux/mm.h>
80703617	26	#include <linux/slab.h>
7c0f6ba6	27	#include <linux/uaccess.h>
92acfb74	28	#include <linux/cpu.h>
56e62a73	29	#include <linux/entry-common.h>
d09a307f	30	#include <asm/asm-extable.h>
b0753902	31	#include <asm/fpu/api.h>
56e62a73	32	#include <asm/vtime.h>
a806170e	33	#include "entry.h"
1da177e4	34
d35339a4 MS	35	static inline void __user get_trap_ip(struct pt_regs regs)
d35339a4 MS	36	{
d35339a4 MS	37	unsigned long address;
	38
	39	if (regs->int_code & 0x200)
755112b3	40	address = current->thread.trap_tdb.data[3];
d35339a4 MS	41	else
d35339a4 MS	42	address = regs->psw.addr;
9cb1ccec	43	return (void __user *) (address - (regs->int_code >> 16));
d35339a4 MS	44	}
d35339a4 MS	45
c0007f1a HC	46	int is_valid_bugaddr(unsigned long addr)
	47	{
	48	return 1;
	49	}
	50
2a0a5b22	51	void do_report_trap(struct pt_regs regs, int si_signo, int si_code, char str)
aa33c8cb	52	{
7d256175	53	if (user_mode(regs)) {
2e1661d2	54	force_sig_fault(si_signo, si_code, get_trap_ip(regs));
5d7eccec	55	report_user_fault(regs, si_signo, 0);
1da177e4	56	} else {
46fee16f	57	if (!fixup_exception(regs))
aa33c8cb	58	die(regs, str);
1da177e4 LT	59	}
	60	}
	61
7a5388de	62	static void do_trap(struct pt_regs regs, int si_signo, int si_code, char str)
2a0a5b22 JW	63	{
	64	if (notify_die(DIE_TRAP, str, regs, 0,
	65	regs->int_code, si_signo) == NOTIFY_STOP)
	66	return;
	67	do_report_trap(regs, si_signo, si_code, str);
	68	}
7a5388de	69	NOKPROBE_SYMBOL(do_trap);
2a0a5b22	70
7a5388de	71	void do_per_trap(struct pt_regs *regs)
1da177e4	72	{
5e9a2692	73	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
4ba069b8	74	return;
73b7d40f MS	75	if (!current->ptrace)
73b7d40f MS	76	return;
9507a5d0	77	force_sig_fault(SIGTRAP, TRAP_HWBKPT,
2e1661d2	78	(void __force __user *) current->thread.per_event.address);
1da177e4	79	}
7a5388de	80	NOKPROBE_SYMBOL(do_per_trap);
1da177e4	81
17a363dc	82	static void default_trap_handler(struct pt_regs *regs)
1da177e4	83	{
7d256175	84	if (user_mode(regs)) {
5d7eccec	85	report_user_fault(regs, SIGSEGV, 0);
fcb116bc	86	force_exit_sig(SIGSEGV);
1da177e4	87	} else
aa33c8cb	88	die(regs, "Unknown program exception");
1da177e4 LT	89	}
1da177e4 LT	90
1e54622e	91	#define DO_ERROR_INFO(name, signr, sicode, str) \
6f8daa29	92	static void name(struct pt_regs *regs) \
b01a37a7 HC	93	{ \
b01a37a7 HC	94	do_trap(regs, signr, sicode, str); \
1da177e4 LT	95	}
1da177e4 LT	96
1e54622e MS	97	DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
	98	"addressing exception")
	99	DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
	100	"execute exception")
	101	DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
	102	"fixpoint divide exception")
	103	DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
	104	"fixpoint overflow exception")
	105	DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
	106	"HFP overflow exception")
	107	DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
	108	"HFP underflow exception")
	109	DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
	110	"HFP significance exception")
	111	DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
	112	"HFP divide exception")
	113	DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
	114	"HFP square root exception")
	115	DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
	116	"operand exception")
	117	DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
	118	"privileged operation")
	119	DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
	120	"special operation exception")
d35339a4 MS	121	DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
d35339a4 MS	122	"transaction constraint exception")
d35339a4	123
9977e886	124	static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
1da177e4	125	{
aa33c8cb	126	int si_code = 0;
1da177e4 LT	127	/* FPC[2] is Data Exception Code */
	128	if ((fpc & 0x00000300) == 0) {
	129	/* bits 6 and 7 of DXC are 0 iff IEEE exception */
	130	if (fpc & 0x8000) /* invalid fp operation */
aa33c8cb	131	si_code = FPE_FLTINV;
1da177e4	132	else if (fpc & 0x4000) /* div by 0 */
aa33c8cb	133	si_code = FPE_FLTDIV;
1da177e4	134	else if (fpc & 0x2000) /* overflow */
aa33c8cb	135	si_code = FPE_FLTOVF;
1da177e4	136	else if (fpc & 0x1000) /* underflow */
aa33c8cb	137	si_code = FPE_FLTUND;
1da177e4	138	else if (fpc & 0x0800) /* inexact */
aa33c8cb	139	si_code = FPE_FLTRES;
1da177e4	140	}
aa33c8cb	141	do_trap(regs, SIGFPE, si_code, "floating point exception");
1da177e4 LT	142	}
1da177e4 LT	143
f09354ff	144	static void translation_specification_exception(struct pt_regs *regs)
e56da345 HC	145	{
e56da345 HC	146	/* May never happen. */
f09354ff	147	panic("Translation-Specification Exception");
e56da345 HC	148	}
e56da345 HC	149
6f8daa29	150	static void illegal_op(struct pt_regs *regs)
1da177e4	151	{
1da177e4	152	__u8 opcode[6];
d2c993d8	153	__u16 __user *location;
2a0a5b22	154	int is_uprobe_insn = 0;
1da177e4 LT	155	int signal = 0;
1da177e4 LT	156
d35339a4	157	location = get_trap_ip(regs);
1da177e4	158
7d256175	159	if (user_mode(regs)) {
12bae235 HC	160	if (get_user(((__u16 ) opcode), (__u16 __user *) location))
12bae235 HC	161	return;
1da177e4	162	if (((__u16 ) opcode) == S390_BREAKPOINT_U16) {
9507a5d0	163	if (current->ptrace)
2e1661d2	164	force_sig_fault(SIGTRAP, TRAP_BRKPT, location);
9507a5d0	165	else
1da177e4	166	signal = SIGILL;
2a0a5b22 JW	167	#ifdef CONFIG_UPROBES
	168	} else if (((__u16 ) opcode) == UPROBE_SWBP_INSN) {
	169	is_uprobe_insn = 1;
1da177e4 LT	170	#endif
	171	} else
	172	signal = SIGILL;
2a0a5b22 JW	173	}
	174	/*
	175	* We got either an illegal op in kernel mode, or user space trapped
	176	* on a uprobes illegal instruction. See if kprobes or uprobes picks
	177	* it up. If not, SIGILL.
	178	*/
	179	if (is_uprobe_insn \|\| !user_mode(regs)) {
aa33c8cb	180	if (notify_die(DIE_BPT, "bpt", regs, 0,
35df8d53 HC	181	3, SIGTRAP) != NOTIFY_STOP)
	182	signal = SIGILL;
	183	}
aa33c8cb MS	184	if (signal)
aa33c8cb MS	185	do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
1da177e4	186	}
7a5388de	187	NOKPROBE_SYMBOL(illegal_op);
1da177e4	188
1e54622e MS	189	DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
1e54622e MS	190	"specification exception");
1da177e4	191
6f8daa29	192	static void vector_exception(struct pt_regs *regs)
80703617 MS	193	{
	194	int si_code, vic;
	195
	196	if (!MACHINE_HAS_VX) {
	197	do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
	198	return;
	199	}
	200
	201	/* get vector interrupt code from fpc */
d0164ee2	202	save_fpu_regs();
904818e2	203	vic = (current->thread.fpu.fpc & 0xf00) >> 8;
80703617 MS	204	switch (vic) {
	205	case 1: /* invalid vector operation */
	206	si_code = FPE_FLTINV;
	207	break;
	208	case 2: /* division by zero */
	209	si_code = FPE_FLTDIV;
	210	break;
	211	case 3: /* overflow */
	212	si_code = FPE_FLTOVF;
	213	break;
	214	case 4: /* underflow */
	215	si_code = FPE_FLTUND;
	216	break;
	217	case 5: /* inexact */
	218	si_code = FPE_FLTRES;
	219	break;
	220	default: /* unknown cause */
	221	si_code = 0;
	222	}
	223	do_trap(regs, SIGFPE, si_code, "vector exception");
	224	}
	225
6f8daa29	226	static void data_exception(struct pt_regs *regs)
1da177e4	227	{
d0164ee2	228	save_fpu_regs();
904818e2	229	if (current->thread.fpu.fpc & FPC_DXC_MASK)
904818e2	230	do_fp_trap(regs, current->thread.fpu.fpc);
b4e3133b VG	231	else
b4e3133b VG	232	do_trap(regs, SIGILL, ILL_ILLOPN, "data exception");
1da177e4 LT	233	}
1da177e4 LT	234
6f8daa29	235	static void space_switch_exception(struct pt_regs *regs)
1da177e4	236	{
1da177e4	237	/* Set user psw back to home space mode. */
7d256175	238	if (user_mode(regs))
1da177e4 LT	239	regs->psw.mask \|= PSW_ASC_HOME;
1da177e4 LT	240	/* Send SIGILL. */
aa33c8cb	241	do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
1da177e4 LT	242	}
1da177e4 LT	243
6f8daa29	244	static void monitor_event_exception(struct pt_regs *regs)
17248ea0	245	{
17248ea0 SS	246	if (user_mode(regs))
	247	return;
	248
	249	switch (report_bug(regs->psw.addr - (regs->int_code >> 16), regs)) {
	250	case BUG_TRAP_TYPE_NONE:
46fee16f	251	fixup_exception(regs);
17248ea0 SS	252	break;
	253	case BUG_TRAP_TYPE_WARN:
	254	break;
	255	case BUG_TRAP_TYPE_BUG:
	256	die(regs, "monitor event");
	257	break;
	258	}
	259	}
	260
7a5388de	261	void kernel_stack_overflow(struct pt_regs *regs)
1da177e4	262	{
77eb65cb HC	263	bust_spinlocks(1);
	264	printk("Kernel stack overflow.\n");
	265	show_regs(regs);
	266	bust_spinlocks(0);
1da177e4 LT	267	panic("Corrupt kernel stack, can't continue.");
1da177e4 LT	268	}
7a5388de	269	NOKPROBE_SYMBOL(kernel_stack_overflow);
1da177e4	270
1d49688d	271	static void __init test_monitor_call(void)
17248ea0 SS	272	{
	273	int val = 1;
	274
b8e9cc20 IL	275	if (!IS_ENABLED(CONFIG_BUG))
b8e9cc20 IL	276	return;
17248ea0 SS	277	asm volatile(
	278	" mc 0,0\n"
	279	"0: xgr %0,%0\n"
	280	"1:\n"
	281	EX_TABLE(0b,1b)
	282	: "+d" (val));
	283	if (!val)
	284	panic("Monitor call doesn't work!\n");
	285	}
	286
1da177e4 LT	287	void __init trap_init(void)
1da177e4 LT	288	{
f3e1a273	289	local_mcck_enable();
17248ea0	290	test_monitor_call();
1da177e4	291	}
56e62a73	292
6f8daa29 HC	293	static void (pgm_check_table[128])(struct pt_regs regs);
6f8daa29 HC	294
56e62a73 SS	295	void noinstr __do_pgm_check(struct pt_regs *regs)
56e62a73 SS	296	{
fbf50f47	297	unsigned int trapnr;
56e62a73 SS	298	irqentry_state_t state;
56e62a73 SS	299
52b739e2	300	regs->int_code = S390_lowcore.pgm_int_code;
56e62a73 SS	301	regs->int_parm_long = S390_lowcore.trans_exc_code;
	302
	303	state = irqentry_enter(regs);
	304
	305	if (user_mode(regs)) {
	306	update_timer_sys();
3b051e89 SS	307	if (!static_branch_likely(&cpu_has_bear)) {
	308	if (regs->last_break < 4096)
	309	regs->last_break = 1;
	310	}
	311	current->thread.last_break = regs->last_break;
56e62a73 SS	312	}
	313
	314	if (S390_lowcore.pgm_code & 0x0200) {
	315	/* transaction abort */
755112b3	316	current->thread.trap_tdb = S390_lowcore.pgm_tdb;
56e62a73 SS	317	}
	318
	319	if (S390_lowcore.pgm_code & PGM_INT_CODE_PER) {
	320	if (user_mode(regs)) {
	321	struct per_event *ev = &current->thread.per_event;
	322
	323	set_thread_flag(TIF_PER_TRAP);
	324	ev->address = S390_lowcore.per_address;
998e7800	325	ev->cause = S390_lowcore.per_code_combined;
56e62a73 SS	326	ev->paid = S390_lowcore.per_access_id;
	327	} else {
	328	/* PER event in kernel is kprobes */
	329	__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
	330	do_per_trap(regs);
	331	goto out;
	332	}
	333	}
	334
	335	if (!irqs_disabled_flags(regs->psw.mask))
	336	trace_hardirqs_on();
	337	__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
	338
	339	trapnr = regs->int_code & PGM_INT_CODE_MASK;
	340	if (trapnr)
	341	pgm_check_table[trapnr](regs);
56e62a73 SS	342	out:
	343	local_irq_disable();
	344	irqentry_exit(regs, state);
56e62a73	345	}
6f8daa29 HC	346
	347	/*
	348	* The program check table contains exactly 128 (0x00-0x7f) entries. Each
	349	* line defines the function to be called corresponding to the program check
	350	* interruption code.
	351	*/
	352	static void (pgm_check_table[128])(struct pt_regs regs) = {
	353	[0x00] = default_trap_handler,
	354	[0x01] = illegal_op,
	355	[0x02] = privileged_op,
	356	[0x03] = execute_exception,
	357	[0x04] = do_protection_exception,
	358	[0x05] = addressing_exception,
	359	[0x06] = specification_exception,
	360	[0x07] = data_exception,
	361	[0x08] = overflow_exception,
	362	[0x09] = divide_exception,
	363	[0x0a] = overflow_exception,
	364	[0x0b] = divide_exception,
	365	[0x0c] = hfp_overflow_exception,
	366	[0x0d] = hfp_underflow_exception,
	367	[0x0e] = hfp_significance_exception,
	368	[0x0f] = hfp_divide_exception,
	369	[0x10] = do_dat_exception,
	370	[0x11] = do_dat_exception,
f09354ff	371	[0x12] = translation_specification_exception,
6f8daa29 HC	372	[0x13] = special_op_exception,
	373	[0x14] = default_trap_handler,
	374	[0x15] = operand_exception,
	375	[0x16] = default_trap_handler,
	376	[0x17] = default_trap_handler,
	377	[0x18] = transaction_exception,
	378	[0x19] = default_trap_handler,
	379	[0x1a] = default_trap_handler,
	380	[0x1b] = vector_exception,
	381	[0x1c] = space_switch_exception,
	382	[0x1d] = hfp_sqrt_exception,
	383	[0x1e ... 0x37] = default_trap_handler,
	384	[0x38] = do_dat_exception,
	385	[0x39] = do_dat_exception,
	386	[0x3a] = do_dat_exception,
	387	[0x3b] = do_dat_exception,
	388	[0x3c] = default_trap_handler,
	389	[0x3d] = do_secure_storage_access,
	390	[0x3e] = do_non_secure_storage_access,
	391	[0x3f] = do_secure_storage_violation,
	392	[0x40] = monitor_event_exception,
	393	[0x41 ... 0x7f] = default_trap_handler,
	394	};
17a363dc HC	395
	396	#define COND_TRAP(x) asm( \
	397	".weak " __stringify(x) "\n\t" \
	398	".set " __stringify(x) "," \
	399	__stringify(default_trap_handler))
	400
	401	COND_TRAP(do_secure_storage_access);
	402	COND_TRAP(do_non_secure_storage_access);
	403	COND_TRAP(do_secure_storage_violation);