/*
* arch/s390/kernel/traps.c
*
* S390 version
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* 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/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/atomic.h>
#include <asm/mathemu.h>
#include <asm/cpcmd.h>
#include <asm/s390_ext.h>
#include <asm/lowcore.h>
/* Called from entry.S only */
extern void handle_per_exception(struct pt_regs *regs);
typedef void pgm_check_handler_t(struct pt_regs *, long);
pgm_check_handler_t *pgm_check_table[128];
#ifdef CONFIG_SYSCTL
#ifdef CONFIG_PROCESS_DEBUG
int sysctl_userprocess_debug = 1;
#else
int sysctl_userprocess_debug = 0;
#endif
#endif
extern pgm_check_handler_t do_protection_exception;
extern pgm_check_handler_t do_segment_exception;
extern pgm_check_handler_t do_region_exception;
extern pgm_check_handler_t do_page_exception;
extern pgm_check_handler_t do_pseudo_page_fault;
#ifdef CONFIG_PFAULT
extern int pfault_init(void);
extern void pfault_fini(void);
extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
static ext_int_info_t ext_int_pfault;
#endif
#ifdef CONFIG_VIRT_TIMER
extern pgm_check_handler_t do_monitor_call;
#endif
#define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
#ifndef CONFIG_ARCH_S390X
#define RET_ADDR 56
#define FOURLONG "%08lx %08lx %08lx %08lx\n"
static int kstack_depth_to_print = 12;
#else /* CONFIG_ARCH_S390X */
#define RET_ADDR 112
#define FOURLONG "%016lx %016lx %016lx %016lx\n"
static int kstack_depth_to_print = 20;
#endif /* CONFIG_ARCH_S390X */
void show_trace(struct task_struct *task, unsigned long * stack)
{
unsigned long backchain, low_addr, high_addr, ret_addr;
if (!stack)
stack = (task == NULL) ? *stack_pointer : &(task->thread.ksp);
printk("Call Trace:\n");
low_addr = ((unsigned long) stack) & PSW_ADDR_INSN;
high_addr = (low_addr & (-THREAD_SIZE)) + THREAD_SIZE;
/* Skip the first frame (biased stack) */
backchain = *((unsigned long *) low_addr) & PSW_ADDR_INSN;
/* Print up to 8 lines */
while (backchain > low_addr && backchain <= high_addr) {
ret_addr = *((unsigned long *) (backchain+RET_ADDR)) & PSW_ADDR_INSN;
printk(" [<%016lx>] ", ret_addr);
print_symbol("%s\n", ret_addr);
low_addr = backchain;
backchain = *((unsigned long *) backchain) & PSW_ADDR_INSN;
}
printk("\n");
}
void show_trace_task(struct task_struct *tsk)
{
/*
* We can't print the backtrace of a running process. It is
* unreliable at best and can cause kernel oopses.
*/
if (tsk->state == TASK_RUNNING)
return;
show_trace(tsk, (unsigned long *) tsk->thread.ksp);
}
void show_stack(struct task_struct *task, unsigned long *sp)
{
unsigned long *stack;
int i;
// debugging aid: "show_stack(NULL);" prints the
// back trace for this cpu.
if (!sp) {
if (task)
sp = (unsigned long *) task->thread.ksp;
else
sp = *stack_pointer;
}
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
break;
if (i && ((i * sizeof (long) % 32) == 0))
printk("\n ");
printk("%p ", (void *)*stack++);
}
printk("\n");
show_trace(task, sp);
}
/*
* The architecture-independent dump_stack generator
*/
void dump_stack(void)
{
show_stack(0, 0);
}
EXPORT_SYMBOL(dump_stack);
void show_registers(struct pt_regs *regs)
{
mm_segment_t old_fs;
char *mode;
int i;
mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
printk("%s PSW : %p %p",
mode, (void *) regs->psw.mask,
(void *) regs->psw.addr);
print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
printk("%s GPRS: " FOURLONG, mode,
regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
printk(" " FOURLONG,
regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
printk(" " FOURLONG,
regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
printk(" " FOURLONG,
regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
printk("%s ACRS: %08x %08x %08x %08x\n", mode,
regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
printk(" %08x %08x %08x %08x\n",
regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
printk(" %08x %08x %08x %08x\n",
regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
printk(" %08x %08x %08x %08x\n",
regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
/*
* Print the first 20 byte of the instruction stream at the
* time of the fault.
*/
old_fs = get_fs();
if (regs->psw.mask & PSW_MASK_PSTATE)
set_fs(USER_DS);
else
set_fs(KERNEL_DS);
printk("%s Code: ", mode);
for (i = 0; i < 20; i++) {
unsigned char c;
if (__get_user(c, (char *)(regs->psw.addr + i))) {
printk(" Bad PSW.");
break;
}
printk("%02x ", c);
}
set_fs(old_fs);
printk("\n");
}
/* This is called from fs/proc/array.c */
char *task_show_regs(struct task_struct *task, char *buffer)
{
struct pt_regs *regs;
regs = __KSTK_PTREGS(task);
buffer += sprintf(buffer, "task: %p, ksp: %p\n",
task, (void *)task->thread.ksp);
buffer += sprintf(buffer, "User PSW : %p %p\n",
(void *) regs->psw.mask, (void *)regs->psw.addr);
buffer += sprintf(buffer, "User GPRS: " FOURLONG,
regs->gprs[0], regs->gprs[1],
regs->gprs[2], regs->gprs[3]);
buffer += sprintf(buffer, " " FOURLONG,
regs->gprs[4], regs->gprs[5],
regs->gprs[6], regs->gprs[7]);
buffer += sprintf(buffer, " " FOURLONG,
regs->gprs[8], regs->gprs[9],
regs->gprs[10], regs->gprs[11]);
buffer += sprintf(buffer, " " FOURLONG,
regs->gprs[12], regs->gprs[13],
regs->gprs[14], regs->gprs[15]);
buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
regs->acrs[0], regs->acrs[1],
regs->acrs[2], regs->acrs[3]);
buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
regs->acrs[4], regs->acrs[5],
regs->acrs[6], regs->acrs[7]);
buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
regs->acrs[8], regs->acrs[9],
regs->acrs[10], regs->acrs[11]);
buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
regs->acrs[12], regs->acrs[13],
regs->acrs[14], regs->acrs[15]);
return buffer;
}
spinlock_t die_lock = SPIN_LOCK_UNLOCKED;
void die(const char * str, struct pt_regs * regs, long err)
{
static int die_counter;
console_verbose();
spin_lock_irq(&die_lock);
bust_spinlocks(1);
printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
show_regs(regs);
bust_spinlocks(0);
spin_unlock_irq(&die_lock);
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception: panic_on_oops");
do_exit(SIGSEGV);
}
static void inline do_trap(long interruption_code, int signr, char *str,
struct pt_regs *regs, siginfo_t *info)
{
/*
* We got all needed information from the lowcore and can
* now safely switch on interrupts.
*/
if (regs->psw.mask & PSW_MASK_PSTATE)
local_irq_enable();
if (regs->psw.mask & PSW_MASK_PSTATE) {
struct task_struct *tsk = current;
tsk->thread.trap_no = interruption_code & 0xffff;
if (info)
force_sig_info(signr, info, tsk);
else
force_sig(signr, tsk);
#ifndef CONFIG_SYSCTL
#ifdef CONFIG_PROCESS_DEBUG
printk("User process fault: interruption code 0x%lX\n",
interruption_code);
show_regs(regs);
#endif
#else
if (sysctl_userprocess_debug) {
printk("User process fault: interruption code 0x%lX\n",
interruption_code);
show_regs(regs);
}
#endif
} else {
const struct exception_table_entry *fixup;
fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
if (fixup)
regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
else
die(str, regs, interruption_code);
}
}
static inline void *get_check_address(struct pt_regs *regs)
{
return (void *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
}
static int do_debugger_trap(struct pt_regs *regs)
{
if ((regs->psw.mask & PSW_MASK_PSTATE) &&
(current->ptrace & PT_PTRACED)) {
force_sig(SIGTRAP,current);
return 0;
}
return 1;
}
#define DO_ERROR(signr, str, name) \
asmlinkage void name(struct pt_regs * regs, long interruption_code) \
{ \
do_trap(interruption_code, signr, str, regs, NULL); \
}
#define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
asmlinkage void name(struct pt_regs * regs, long interruption_code) \
{ \
siginfo_t info; \
info.si_signo = signr; \
info.si_errno = 0; \
info.si_code = sicode; \
info.si_addr = (void *)siaddr; \
do_trap(interruption_code, signr, str, regs, &info); \
}
DO_ERROR(SIGSEGV, "Unknown program exception", default_trap_handler)
DO_ERROR_INFO(SIGBUS, "addressing exception", addressing_exception,
BUS_ADRERR, get_check_address(regs))
DO_ERROR_INFO(SIGILL, "execute exception", execute_exception,
ILL_ILLOPN, get_check_address(regs))
DO_ERROR_INFO(SIGFPE, "fixpoint divide exception", divide_exception,
FPE_INTDIV, get_check_address(regs))
DO_ERROR_INFO(SIGILL, "operand exception", operand_exception,
ILL_ILLOPN, get_check_address(regs))
DO_ERROR_INFO(SIGILL, "privileged operation", privileged_op,
ILL_PRVOPC, get_check_address(regs))
DO_ERROR_INFO(SIGILL, "special operation exception", special_op_exception,
ILL_ILLOPN, get_check_address(regs))
DO_ERROR_INFO(SIGILL, "translation exception", translation_exception,
ILL_ILLOPN, get_check_address(regs))
static inline void
do_fp_trap(struct pt_regs *regs, void *location,
int fpc, long interruption_code)
{
siginfo_t si;
si.si_signo = SIGFPE;
si.si_errno = 0;
si.si_addr = location;
si.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.si_code = FPE_FLTINV;
else if (fpc & 0x4000) /* div by 0 */
si.si_code = FPE_FLTDIV;
else if (fpc & 0x2000) /* overflow */
si.si_code = FPE_FLTOVF;
else if (fpc & 0x1000) /* underflow */
si.si_code = FPE_FLTUND;
else if (fpc & 0x0800) /* inexact */
si.si_code = FPE_FLTRES;
}
current->thread.ieee_instruction_pointer = (addr_t) location;
do_trap(interruption_code, SIGFPE,
"floating point exception", regs, &si);
}
asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
{
__u8 opcode[6];
__u16 *location;
int signal = 0;
location = (__u16 *) get_check_address(regs);
/*
* We got all needed information from the lowcore and can
* now safely switch on interrupts.
*/
if (regs->psw.mask & PSW_MASK_PSTATE)
local_irq_enable();
if (regs->psw.mask & PSW_MASK_PSTATE)
get_user(*((__u16 *) opcode), location);
else
*((__u16 *)opcode)=*((__u16 *)location);
if (*((__u16 *)opcode)==S390_BREAKPOINT_U16)
{
if(do_debugger_trap(regs))
signal = SIGILL;
}
#ifdef CONFIG_MATHEMU
else if (regs->psw.mask & PSW_MASK_PSTATE)
{
if (opcode[0] == 0xb3) {
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_b3(opcode, regs);
} else if (opcode[0] == 0xed) {
get_user(*((__u32 *) (opcode+2)),
(__u32 *)(location+1));
signal = math_emu_ed(opcode, regs);
} else if (*((__u16 *) opcode) == 0xb299) {
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_srnm(opcode, regs);
} else if (*((__u16 *) opcode) == 0xb29c) {
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_stfpc(opcode, regs);
} else if (*((__u16 *) opcode) == 0xb29d) {
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_lfpc(opcode, regs);
} else
signal = SIGILL;
}
#endif
else
signal = SIGILL;
if (signal == SIGFPE)
do_fp_trap(regs, location,
current->thread.fp_regs.fpc, interruption_code);
else if (signal)
do_trap(interruption_code, signal,
"illegal operation", regs, NULL);
}
#ifdef CONFIG_MATHEMU
asmlinkage void
specification_exception(struct pt_regs * regs, long interruption_code)
{
__u8 opcode[6];
__u16 *location = NULL;
int signal = 0;
location = (__u16 *) get_check_address(regs);
/*
* We got all needed information from the lowcore and can
* now safely switch on interrupts.
*/
if (regs->psw.mask & PSW_MASK_PSTATE)
local_irq_enable();
if (regs->psw.mask & PSW_MASK_PSTATE) {
get_user(*((__u16 *) opcode), location);
switch (opcode[0]) {
case 0x28: /* LDR Rx,Ry */
signal = math_emu_ldr(opcode);
break;
case 0x38: /* LER Rx,Ry */
signal = math_emu_ler(opcode);
break;
case 0x60: /* STD R,D(X,B) */
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_std(opcode, regs);
break;
case 0x68: /* LD R,D(X,B) */
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_ld(opcode, regs);
break;
case 0x70: /* STE R,D(X,B) */
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_ste(opcode, regs);
break;
case 0x78: /* LE R,D(X,B) */
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_le(opcode, regs);
break;
default:
signal = SIGILL;
break;
}
} else
signal = SIGILL;
if (signal == SIGFPE)
do_fp_trap(regs, location,
current->thread.fp_regs.fpc, interruption_code);
else if (signal) {
siginfo_t info;
info.si_signo = signal;
info.si_errno = 0;
info.si_code = ILL_ILLOPN;
info.si_addr = location;
do_trap(interruption_code, signal,
"specification exception", regs, &info);
}
}
#else
DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
ILL_ILLOPN, get_check_address(regs));
#endif
asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
{
__u16 *location;
int signal = 0;
location = (__u16 *) get_check_address(regs);
/*
* We got all needed information from the lowcore and can
* now safely switch on interrupts.
*/
if (regs->psw.mask & PSW_MASK_PSTATE)
local_irq_enable();
if (MACHINE_HAS_IEEE)
__asm__ volatile ("stfpc %0\n\t"
: "=m" (current->thread.fp_regs.fpc));
#ifdef CONFIG_MATHEMU
else if (regs->psw.mask & PSW_MASK_PSTATE) {
__u8 opcode[6];
get_user(*((__u16 *) opcode), location);
switch (opcode[0]) {
case 0x28: /* LDR Rx,Ry */
signal = math_emu_ldr(opcode);
break;
case 0x38: /* LER Rx,Ry */
signal = math_emu_ler(opcode);
break;
case 0x60: /* STD R,D(X,B) */
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_std(opcode, regs);
break;
case 0x68: /* LD R,D(X,B) */
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_ld(opcode, regs);
break;
case 0x70: /* STE R,D(X,B) */
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_ste(opcode, regs);
break;
case 0x78: /* LE R,D(X,B) */
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_le(opcode, regs);
break;
case 0xb3:
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_b3(opcode, regs);
break;
case 0xed:
get_user(*((__u32 *) (opcode+2)),
(__u32 *)(location+1));
signal = math_emu_ed(opcode, regs);
break;
case 0xb2:
if (opcode[1] == 0x99) {
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_srnm(opcode, regs);
} else if (opcode[1] == 0x9c) {
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_stfpc(opcode, regs);
} else if (opcode[1] == 0x9d) {
get_user(*((__u16 *) (opcode+2)), location+1);
signal = math_emu_lfpc(opcode, regs);
} else
signal = SIGILL;
break;
default:
signal = SIGILL;
break;
}
}
#endif
if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
signal = SIGFPE;
else
signal = SIGILL;
if (signal == SIGFPE)
do_fp_trap(regs, location,
current->thread.fp_regs.fpc, interruption_code);
else if (signal) {
siginfo_t info;
info.si_signo = signal;
info.si_errno = 0;
info.si_code = ILL_ILLOPN;
info.si_addr = location;
do_trap(interruption_code, signal,
"data exception", regs, &info);
}
}
/* init is done in lowcore.S and head.S */
void __init trap_init(void)
{
int i;
for (i = 0; i < 128; i++)
pgm_check_table[i] = &default_trap_handler;
pgm_check_table[1] = &illegal_op;
pgm_check_table[2] = &privileged_op;
pgm_check_table[3] = &execute_exception;
pgm_check_table[4] = &do_protection_exception;
pgm_check_table[5] = &addressing_exception;
pgm_check_table[6] = &specification_exception;
pgm_check_table[7] = &data_exception;
pgm_check_table[9] = ÷_exception;
pgm_check_table[0x10] = &do_segment_exception;
pgm_check_table[0x11] = &do_page_exception;
pgm_check_table[0x12] = &translation_exception;
pgm_check_table[0x13] = &special_op_exception;
#ifndef CONFIG_ARCH_S390X
pgm_check_table[0x14] = &do_pseudo_page_fault;
#else /* CONFIG_ARCH_S390X */
pgm_check_table[0x38] = &addressing_exception;
pgm_check_table[0x3B] = &do_region_exception;
#endif /* CONFIG_ARCH_S390X */
pgm_check_table[0x15] = &operand_exception;
pgm_check_table[0x1C] = &privileged_op;
#ifdef CONFIG_VIRT_TIMER
pgm_check_table[0x40] = &do_monitor_call;
#endif
if (MACHINE_IS_VM) {
/*
* First try to get pfault pseudo page faults going.
* If this isn't available turn on pagex page faults.
*/
#ifdef CONFIG_PFAULT
/* request the 0x2603 external interrupt */
if (register_early_external_interrupt(0x2603, pfault_interrupt,
&ext_int_pfault) != 0)
panic("Couldn't request external interrupt 0x2603");
if (pfault_init() == 0)
return;
/* Tough luck, no pfault. */
unregister_early_external_interrupt(0x2603, pfault_interrupt,
&ext_int_pfault);
#endif
#ifndef CONFIG_ARCH_S390X
cpcmd("SET PAGEX ON", NULL, 0);
#endif
}
}
void handle_per_exception(struct pt_regs *regs)
{
if (regs->psw.mask & PSW_MASK_PSTATE) {
per_struct *per_info=¤t->thread.per_info;
per_info->lowcore.words.perc_atmid=S390_lowcore.per_perc_atmid;
per_info->lowcore.words.address=S390_lowcore.per_address;
per_info->lowcore.words.access_id=S390_lowcore.per_access_id;
}
if (do_debugger_trap(regs)) {
/* I've seen this possibly a task structure being reused ? */
printk("Spurious per exception detected\n");
printk("switching off per tracing for this task.\n");
show_regs(regs);
/* Hopefully switching off per tracing will help us survive */
regs->psw.mask &= ~PSW_MASK_PER;
}
}
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