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linux/arch/s390/kernel/traps.c
Heiko Carstens 7d25617597 s390: make use of user_mode() macro where possible 
We use the user_mode() helper already at several places but also
have the open coded variant at other places.
Convert the code to always use the helper function.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-07-30 11:03:12 +02:00

655 lines
19 KiB
C
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/*
* 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/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/init.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/kdebug.h>
#include <linux/kallsyms.h>
#include <linux/reboot.h>
#include <linux/kprobes.h>
#include <linux/bug.h>
#include <linux/utsname.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/atomic.h>
#include <asm/mathemu.h>
#include <asm/cpcmd.h>
#include <asm/lowcore.h>
#include <asm/debug.h>
#include <asm/ipl.h>
#include "entry.h"
void (*pgm_check_table[128])(struct pt_regs *regs);
int show_unhandled_signals = 1;
#define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
#ifndef CONFIG_64BIT
#define LONG "%08lx "
#define FOURLONG "%08lx %08lx %08lx %08lx\n"
static int kstack_depth_to_print = 12;
#else /* CONFIG_64BIT */
#define LONG "%016lx "
#define FOURLONG "%016lx %016lx %016lx %016lx\n"
static int kstack_depth_to_print = 20;
#endif /* CONFIG_64BIT */
/*
* For show_trace we have tree different stack to consider:
* - the panic stack which is used if the kernel stack has overflown
* - the asynchronous interrupt stack (cpu related)
* - the synchronous kernel stack (process related)
* The stack trace can start at any of the three stack and can potentially
* touch all of them. The order is: panic stack, async stack, sync stack.
*/
static unsigned long
__show_trace(unsigned long sp, unsigned long low, unsigned long high)
{
struct stack_frame *sf;
struct pt_regs *regs;
while (1) {
sp = sp & PSW_ADDR_INSN;
if (sp < low || sp > high - sizeof(*sf))
return sp;
sf = (struct stack_frame *) sp;
printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
/* Follow the backchain. */
while (1) {
low = sp;
sp = sf->back_chain & PSW_ADDR_INSN;
if (!sp)
break;
if (sp <= low || sp > high - sizeof(*sf))
return sp;
sf = (struct stack_frame *) sp;
printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
}
/* Zero backchain detected, check for interrupt frame. */
sp = (unsigned long) (sf + 1);
if (sp <= low || sp > high - sizeof(*regs))
return sp;
regs = (struct pt_regs *) sp;
printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
low = sp;
sp = regs->gprs[15];
}
}
static void show_trace(struct task_struct *task, unsigned long *stack)
{
register unsigned long __r15 asm ("15");
unsigned long sp;
sp = (unsigned long) stack;
if (!sp)
sp = task ? task->thread.ksp : __r15;
printk("Call Trace:\n");
#ifdef CONFIG_CHECK_STACK
sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
S390_lowcore.panic_stack);
#endif
sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
S390_lowcore.async_stack);
if (task)
__show_trace(sp, (unsigned long) task_stack_page(task),
(unsigned long) task_stack_page(task) + THREAD_SIZE);
else
__show_trace(sp, S390_lowcore.thread_info,
S390_lowcore.thread_info + THREAD_SIZE);
if (!task)
task = current;
debug_show_held_locks(task);
}
void show_stack(struct task_struct *task, unsigned long *sp)
{
register unsigned long * __r15 asm ("15");
unsigned long *stack;
int i;
if (!sp)
stack = task ? (unsigned long *) task->thread.ksp : __r15;
else
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
break;
if ((i * sizeof(long) % 32) == 0)
printk("%s ", i == 0 ? "" : "\n");
printk(LONG, *stack++);
}
printk("\n");
show_trace(task, sp);
}
static void show_last_breaking_event(struct pt_regs *regs)
{
#ifdef CONFIG_64BIT
printk("Last Breaking-Event-Address:\n");
printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
#endif
}
/*
* The architecture-independent dump_stack generator
*/
void dump_stack(void)
{
printk("CPU: %d %s %s %.*s\n",
task_thread_info(current)->cpu, print_tainted(),
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version);
printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
current->comm, current->pid, current,
(void *) current->thread.ksp);
show_stack(NULL, NULL);
}
EXPORT_SYMBOL(dump_stack);
static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
{
return (regs->psw.mask & bits) / ((~bits + 1) & bits);
}
void show_registers(struct pt_regs *regs)
{
char *mode;
mode = user_mode(regs) ? "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(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
"P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
#ifdef CONFIG_64BIT
printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA));
#endif
printk("\n%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]);
show_code(regs);
}
void show_regs(struct pt_regs *regs)
{
print_modules();
printk("CPU: %d %s %s %.*s\n",
task_thread_info(current)->cpu, print_tainted(),
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version);
printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
current->comm, current->pid, current,
(void *) current->thread.ksp);
show_registers(regs);
/* Show stack backtrace if pt_regs is from kernel mode */
if (!user_mode(regs))
show_trace(NULL, (unsigned long *) regs->gprs[15]);
show_last_breaking_event(regs);
}
static DEFINE_SPINLOCK(die_lock);
void die(struct pt_regs *regs, const char *str)
{
static int die_counter;
oops_enter();
lgr_info_log();
debug_stop_all();
console_verbose();
spin_lock_irq(&die_lock);
bust_spinlocks(1);
printk("%s: %04x [#%d] ", str, regs->int_code & 0xffff, ++die_counter);
#ifdef CONFIG_PREEMPT
printk("PREEMPT ");
#endif
#ifdef CONFIG_SMP
printk("SMP ");
#endif
#ifdef CONFIG_DEBUG_PAGEALLOC
printk("DEBUG_PAGEALLOC");
#endif
printk("\n");
notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
show_regs(regs);
bust_spinlocks(0);
add_taint(TAINT_DIE);
spin_unlock_irq(&die_lock);
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception: panic_on_oops");
oops_exit();
do_exit(SIGSEGV);
}
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 0x%X ", regs->int_code);
print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
printk("\n");
show_regs(regs);
}
int is_valid_bugaddr(unsigned long addr)
{
return 1;
}
static inline void __user *get_psw_address(struct pt_regs *regs)
{
return (void __user *)
((regs->psw.addr - (regs->int_code >> 16)) & PSW_ADDR_INSN);
}
static void __kprobes do_trap(struct pt_regs *regs,
int si_signo, int si_code, char *str)
{
siginfo_t info;
if (notify_die(DIE_TRAP, str, regs, 0,
regs->int_code, si_signo) == NOTIFY_STOP)
return;
if (user_mode(regs)) {
info.si_signo = si_signo;
info.si_errno = 0;
info.si_code = si_code;
info.si_addr = get_psw_address(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 = 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);
}
}
}
void __kprobes 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);
}
static 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) \
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(translation_exception, SIGILL, ILL_ILLOPN,
"translation exception")
static inline void do_fp_trap(struct pt_regs *regs, int 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 __kprobes illegal_op(struct pt_regs *regs)
{
siginfo_t info;
__u8 opcode[6];
__u16 __user *location;
int signal = 0;
location = get_psw_address(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_MATHEMU
} else if (opcode[0] == 0xb3) {
if (get_user(*((__u16 *) (opcode+2)), location+1))
return;
signal = math_emu_b3(opcode, regs);
} else if (opcode[0] == 0xed) {
if (get_user(*((__u32 *) (opcode+2)),
(__u32 __user *)(location+1)))
return;
signal = math_emu_ed(opcode, regs);
} else if (*((__u16 *) opcode) == 0xb299) {
if (get_user(*((__u16 *) (opcode+2)), location+1))
return;
signal = math_emu_srnm(opcode, regs);
} else if (*((__u16 *) opcode) == 0xb29c) {
if (get_user(*((__u16 *) (opcode+2)), location+1))
return;
signal = math_emu_stfpc(opcode, regs);
} else if (*((__u16 *) opcode) == 0xb29d) {
if (get_user(*((__u16 *) (opcode+2)), location+1))
return;
signal = math_emu_lfpc(opcode, regs);
#endif
} else
signal = SIGILL;
} else {
/*
* If we get an illegal op in kernel mode, send it through the
* kprobes notifier. If kprobes doesn't pick it up, SIGILL
*/
if (notify_die(DIE_BPT, "bpt", regs, 0,
3, SIGTRAP) != NOTIFY_STOP)
signal = SIGILL;
}
#ifdef CONFIG_MATHEMU
if (signal == SIGFPE)
do_fp_trap(regs, current->thread.fp_regs.fpc);
else if (signal == SIGSEGV)
do_trap(regs, signal, SEGV_MAPERR, "user address fault");
else
#endif
if (signal)
do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
}
#ifdef CONFIG_MATHEMU
void specification_exception(struct pt_regs *regs)
{
__u8 opcode[6];
__u16 __user *location = NULL;
int signal = 0;
location = (__u16 __user *) get_psw_address(regs);
if (user_mode(regs)) {
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, current->thread.fp_regs.fpc);
else if (signal)
do_trap(regs, signal, ILL_ILLOPN, "specification exception");
}
#else
DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
"specification exception");
#endif
static void data_exception(struct pt_regs *regs)
{
__u16 __user *location;
int signal = 0;
location = get_psw_address(regs);
if (MACHINE_HAS_IEEE)
asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
#ifdef CONFIG_MATHEMU
else if (user_mode(regs)) {
__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 __user *)(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, current->thread.fp_regs.fpc);
else if (signal)
do_trap(regs, signal, 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");
}
void __kprobes 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.");
}
/* 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[8] = &overflow_exception;
pgm_check_table[9] = &divide_exception;
pgm_check_table[0x0A] = &overflow_exception;
pgm_check_table[0x0B] = &divide_exception;
pgm_check_table[0x0C] = &hfp_overflow_exception;
pgm_check_table[0x0D] = &hfp_underflow_exception;
pgm_check_table[0x0E] = &hfp_significance_exception;
pgm_check_table[0x0F] = &hfp_divide_exception;
pgm_check_table[0x10] = &do_dat_exception;
pgm_check_table[0x11] = &do_dat_exception;
pgm_check_table[0x12] = &translation_exception;
pgm_check_table[0x13] = &special_op_exception;
#ifdef CONFIG_64BIT
pgm_check_table[0x38] = &do_asce_exception;
pgm_check_table[0x39] = &do_dat_exception;
pgm_check_table[0x3A] = &do_dat_exception;
pgm_check_table[0x3B] = &do_dat_exception;
#endif /* CONFIG_64BIT */
pgm_check_table[0x15] = &operand_exception;
pgm_check_table[0x1C] = &space_switch_exception;
pgm_check_table[0x1D] = &hfp_sqrt_exception;
/* Enable machine checks early. */
local_mcck_enable();
}
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