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/*
* 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/delay.h>
#include <linux/module.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>
/* 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_page_fault;
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);
#endif
int kstack_depth_to_print = 12;
/*
* If the address is either in the .text section of the
* kernel, or in the vmalloc'ed module regions, it *may*
* be the address of a calling routine
*/
extern char _stext, _etext;
#ifdef CONFIG_MODULES
extern struct module *module_list;
extern struct module kernel_module;
static inline int kernel_text_address(unsigned long addr)
{
int retval = 0;
struct module *mod;
if (addr >= (unsigned long) &_stext &&
addr <= (unsigned long) &_etext)
return 1;
for (mod = module_list; mod != &kernel_module; mod = mod->next) {
/* mod_bound tests for addr being inside the vmalloc'ed
* module area. Of course it'd be better to test only
* for the .text subset... */
if (mod_bound(addr, 0, mod)) {
retval = 1;
break;
}
}
return retval;
}
#else
static inline int kernel_text_address(unsigned long addr)
{
return (addr >= (unsigned long) &_stext &&
addr <= (unsigned long) &_etext);
}
#endif
void show_trace(unsigned long * stack)
{
unsigned long backchain, low_addr, high_addr, ret_addr;
int i;
if (!stack)
stack = (unsigned long*)&stack;
printk("Call Trace: ");
low_addr = ((unsigned long) stack) & PSW_ADDR_MASK;
high_addr = (low_addr & (-THREAD_SIZE)) + THREAD_SIZE;
/* Skip the first frame (biased stack) */
backchain = *((unsigned long *) low_addr) & PSW_ADDR_MASK;
/* Print up to 8 lines */
for (i = 0; i < 8; i++) {
if (backchain < low_addr || backchain >= high_addr)
break;
ret_addr = *((unsigned long *) (backchain+56)) & PSW_ADDR_MASK;
if (!kernel_text_address(ret_addr))
break;
if (i && ((i % 6) == 0))
printk("\n ");
printk("[<%08lx>] ", ret_addr);
low_addr = backchain;
backchain = *((unsigned long *) backchain) & PSW_ADDR_MASK;
}
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 (task_has_cpu(tsk))
return;
show_trace((unsigned long *) tsk->thread.ksp);
}
void show_stack(unsigned long *sp)
{
unsigned long *stack;
int i;
// debugging aid: "show_stack(NULL);" prints the
// back trace for this cpu.
if(sp == NULL)
sp = (unsigned long*) &sp;
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
break;
if (i && ((i % 8) == 0))
printk("\n ");
printk("%08lx ", *stack++);
}
printk("\n");
show_trace(sp);
}
void show_registers(struct pt_regs *regs)
{
mm_segment_t old_fs;
char *mode;
int i;
mode = (regs->psw.mask & PSW_PROBLEM_STATE) ? "User" : "Krnl";
printk("%s PSW : %08lx %08lx\n",
mode, (unsigned long) regs->psw.mask,
(unsigned long) regs->psw.addr);
printk("%s GPRS: %08x %08x %08x %08x\n", mode,
regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
printk(" %08x %08x %08x %08x\n",
regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
printk(" %08x %08x %08x %08x\n",
regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
printk(" %08x %08x %08x %08x\n",
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_PROBLEM_STATE)
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: %08lx, ksp: %08x\n",
(unsigned long) task, task->thread.ksp);
buffer += sprintf(buffer, "User PSW : %08lx %08lx\n",
(unsigned long) regs->psw.mask,
(unsigned long) regs->psw.addr);
buffer += sprintf(buffer, "User GPRS: %08x %08x %08x %08x\n",
regs->gprs[0], regs->gprs[1],
regs->gprs[2], regs->gprs[3]);
buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
regs->gprs[4], regs->gprs[5],
regs->gprs[6], regs->gprs[7]);
buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
regs->gprs[8], regs->gprs[9],
regs->gprs[10], regs->gprs[11]);
buffer += sprintf(buffer, " %08x %08x %08x %08x\n",
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)
{
console_verbose();
spin_lock_irq(&die_lock);
bust_spinlocks(1);
printk("%s: %04lx\n", str, err & 0xffff);
show_regs(regs);
bust_spinlocks(0);
spin_unlock_irq(&die_lock);
do_exit(SIGSEGV);
}
#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); \
}
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_PROBLEM_STATE)
__sti();
if (regs->psw.mask & PSW_PROBLEM_STATE) {
struct task_struct *tsk = current;
tsk->thread.trap_no = interruption_code;
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 {
unsigned long fixup = search_exception_table(regs->psw.addr);
if (fixup)
regs->psw.addr = fixup;
else
die(str, regs, interruption_code);
}
}
int do_debugger_trap(struct pt_regs *regs,int signal)
{
if(regs->psw.mask&PSW_PROBLEM_STATE)
{
if(current->ptrace & PT_PTRACED)
force_sig(signal,current);
else
return 1;
}
else
{
#if CONFIG_REMOTE_DEBUG
if(gdb_stub_initialised)
{
gdb_stub_handle_exception(regs, signal);
return 0;
}
#endif
return 1;
}
return 0;
}
DO_ERROR(SIGSEGV, "Unknown program exception", default_trap_handler)
DO_ERROR(SIGILL, "privileged operation", privileged_op)
DO_ERROR(SIGILL, "execute exception", execute_exception)
DO_ERROR(SIGSEGV, "addressing exception", addressing_exception)
DO_ERROR(SIGFPE, "fixpoint divide exception", divide_exception)
DO_ERROR(SIGILL, "translation exception", translation_exception)
DO_ERROR(SIGILL, "special operand exception", special_op_exception)
DO_ERROR(SIGILL, "operand exception", operand_exception)
asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
{
__u8 opcode[6];
__u16 *location;
int signal = 0;
location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
/*
* We got all needed information from the lowcore and can
* now safely switch on interrupts.
*/
if (regs->psw.mask & PSW_PROBLEM_STATE)
__sti();
if (regs->psw.mask & PSW_PROBLEM_STATE)
get_user(*((__u16 *) opcode), location);
else
*((__u16 *)opcode)=*((__u16 *)location);
if (*((__u16 *)opcode)==S390_BREAKPOINT_U16)
{
if(do_debugger_trap(regs,SIGTRAP))
signal = SIGILL;
}
#ifdef CONFIG_MATHEMU
else if (regs->psw.mask & PSW_PROBLEM_STATE)
{
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) {
current->thread.ieee_instruction_pointer = (addr_t) location;
do_trap(interruption_code, signal,
"floating point exception", regs, NULL);
} 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 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
/*
* We got all needed information from the lowcore and can
* now safely switch on interrupts.
*/
if (regs->psw.mask & PSW_PROBLEM_STATE)
__sti();
if (regs->psw.mask & PSW_PROBLEM_STATE) {
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) {
current->thread.ieee_instruction_pointer = (addr_t) location;
do_trap(interruption_code, signal,
"floating point exception", regs, NULL);
} else if (signal)
do_trap(interruption_code, signal,
"specification exception", regs, NULL);
}
#else
DO_ERROR(SIGILL, "specification exception", specification_exception)
#endif
asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
{
__u8 opcode[6];
__u16 *location;
int signal = 0;
location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
/*
* We got all needed information from the lowcore and can
* now safely switch on interrupts.
*/
if (regs->psw.mask & PSW_PROBLEM_STATE)
__sti();
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_PROBLEM_STATE) {
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) {
current->thread.ieee_instruction_pointer = (addr_t) location;
do_trap(interruption_code, signal,
"floating point exception", regs, NULL);
} else if (signal)
do_trap(interruption_code, signal,
"data exception", regs, NULL);
}
/* 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_page_fault;
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_page_fault;
pgm_check_table[0x11] = &do_page_fault;
pgm_check_table[0x12] = &translation_exception;
pgm_check_table[0x13] = &special_op_exception;
pgm_check_table[0x14] = &do_pseudo_page_fault;
pgm_check_table[0x15] = &operand_exception;
pgm_check_table[0x1C] = &privileged_op;
#ifdef CONFIG_PFAULT
if (MACHINE_IS_VM) {
/* request the 0x2603 external interrupt */
if (register_external_interrupt(0x2603, pfault_interrupt) != 0)
panic("Couldn't request external interrupt 0x2603");
/*
* First try to get pfault pseudo page faults going.
* If this isn't available turn on pagex page faults.
*/
if (pfault_init() != 0) {
/* Tough luck, no pfault. */
unregister_external_interrupt(0x2603,
pfault_interrupt);
cpcmd("SET PAGEX ON", NULL, 0);
}
}
#else
if (MACHINE_IS_VM)
cpcmd("SET PAGEX ON", NULL, 0);
#endif
}
void handle_per_exception(struct pt_regs *regs)
{
if(regs->psw.mask&PSW_PROBLEM_STATE)
{
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,SIGTRAP))
{
/* 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_PER_MASK;
}
}
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