mirror of
https://github.com/torvalds/linux.git
synced 2024-12-21 02:21:36 +00:00
e56da345eb
Translation exceptions should never happen, since that implies that either we screwed up the page tables or missed to properly flush the TLB. In both cases we should not just simply kill user space or walk the kernel exception tables. Instead an oops or a panic (panic_on_oops) is the better answer. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
492 lines
13 KiB
C
492 lines
13 KiB
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/switch_to.h>
|
|
#include "entry.h"
|
|
|
|
int show_unhandled_signals = 1;
|
|
|
|
static inline void __user *get_trap_ip(struct pt_regs *regs)
|
|
{
|
|
#ifdef CONFIG_64BIT
|
|
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);
|
|
#else
|
|
return (void __user *)
|
|
((regs->psw.addr - (regs->int_code >> 16)) & PSW_ADDR_INSN);
|
|
#endif
|
|
}
|
|
|
|
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")
|
|
|
|
#ifdef CONFIG_64BIT
|
|
DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
|
|
"transaction constraint exception")
|
|
#endif
|
|
|
|
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");
|
|
}
|
|
|
|
void translation_exception(struct pt_regs *regs)
|
|
{
|
|
/* May never happen. */
|
|
die(regs, "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
|
|
#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;
|
|
}
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
#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");
|
|
}
|
|
NOKPROBE_SYMBOL(illegal_op);
|
|
|
|
#ifdef CONFIG_MATHEMU
|
|
void specification_exception(struct pt_regs *regs)
|
|
{
|
|
__u8 opcode[6];
|
|
__u16 __user *location = NULL;
|
|
int signal = 0;
|
|
|
|
location = (__u16 __user *) get_trap_ip(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
|
|
|
|
#ifdef CONFIG_64BIT
|
|
int alloc_vector_registers(struct task_struct *tsk)
|
|
{
|
|
__vector128 *vxrs;
|
|
int i;
|
|
|
|
/* Allocate vector register save area. */
|
|
vxrs = kzalloc(sizeof(__vector128) * __NUM_VXRS,
|
|
GFP_KERNEL|__GFP_REPEAT);
|
|
if (!vxrs)
|
|
return -ENOMEM;
|
|
preempt_disable();
|
|
if (tsk == current)
|
|
save_fp_regs(tsk->thread.fp_regs.fprs);
|
|
/* Copy the 16 floating point registers */
|
|
for (i = 0; i < 16; i++)
|
|
*(freg_t *) &vxrs[i] = tsk->thread.fp_regs.fprs[i];
|
|
tsk->thread.vxrs = vxrs;
|
|
if (tsk == current) {
|
|
__ctl_set_bit(0, 17);
|
|
restore_vx_regs(vxrs);
|
|
}
|
|
preempt_enable();
|
|
return 0;
|
|
}
|
|
|
|
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 */
|
|
asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
|
|
vic = (current->thread.fp_regs.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 int __init disable_vector_extension(char *str)
|
|
{
|
|
S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
|
|
return 1;
|
|
}
|
|
__setup("novx", disable_vector_extension);
|
|
#endif
|
|
|
|
void data_exception(struct pt_regs *regs)
|
|
{
|
|
__u16 __user *location;
|
|
int signal = 0;
|
|
|
|
location = get_trap_ip(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
|
|
#ifdef CONFIG_64BIT
|
|
/* Check for vector register enablement */
|
|
if (MACHINE_HAS_VX && !current->thread.vxrs &&
|
|
(current->thread.fp_regs.fpc & FPC_DXC_MASK) == 0xfe00) {
|
|
alloc_vector_registers(current);
|
|
/* Vector data exception is suppressing, rewind psw. */
|
|
regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
|
|
clear_pt_regs_flag(regs, PIF_PER_TRAP);
|
|
return;
|
|
}
|
|
#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");
|
|
}
|
|
|
|
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();
|
|
}
|