5a79859ae0
Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.
The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e58 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.
Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
342 lines
8.8 KiB
C
342 lines
8.8 KiB
C
/*
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* S390 version
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* Copyright IBM Corp. 1999, 2000
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
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* Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
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*
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* Derived from "arch/i386/kernel/traps.c"
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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/*
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* 'Traps.c' handles hardware traps and faults after we have saved some
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* state in 'asm.s'.
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*/
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#include <linux/kprobes.h>
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#include <linux/kdebug.h>
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#include <linux/module.h>
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#include <linux/ptrace.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <asm/switch_to.h>
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#include "entry.h"
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int show_unhandled_signals = 1;
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static inline void __user *get_trap_ip(struct pt_regs *regs)
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{
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unsigned long address;
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if (regs->int_code & 0x200)
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address = *(unsigned long *)(current->thread.trap_tdb + 24);
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else
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address = regs->psw.addr;
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return (void __user *)
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((address - (regs->int_code >> 16)) & PSW_ADDR_INSN);
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}
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static inline void report_user_fault(struct pt_regs *regs, int signr)
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{
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if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
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return;
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if (!unhandled_signal(current, signr))
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return;
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if (!printk_ratelimit())
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return;
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printk("User process fault: interruption code %04x ilc:%d ",
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regs->int_code & 0xffff, regs->int_code >> 17);
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print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
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printk("\n");
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show_regs(regs);
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}
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int is_valid_bugaddr(unsigned long addr)
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{
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return 1;
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}
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void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
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{
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siginfo_t info;
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if (user_mode(regs)) {
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info.si_signo = si_signo;
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info.si_errno = 0;
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info.si_code = si_code;
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info.si_addr = get_trap_ip(regs);
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force_sig_info(si_signo, &info, current);
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report_user_fault(regs, si_signo);
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} else {
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const struct exception_table_entry *fixup;
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fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
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if (fixup)
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regs->psw.addr = extable_fixup(fixup) | PSW_ADDR_AMODE;
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else {
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enum bug_trap_type btt;
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btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
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if (btt == BUG_TRAP_TYPE_WARN)
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return;
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die(regs, str);
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}
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}
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}
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static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
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{
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if (notify_die(DIE_TRAP, str, regs, 0,
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regs->int_code, si_signo) == NOTIFY_STOP)
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return;
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do_report_trap(regs, si_signo, si_code, str);
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}
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NOKPROBE_SYMBOL(do_trap);
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void do_per_trap(struct pt_regs *regs)
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{
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siginfo_t info;
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if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
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return;
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if (!current->ptrace)
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return;
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info.si_signo = SIGTRAP;
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info.si_errno = 0;
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info.si_code = TRAP_HWBKPT;
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info.si_addr =
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(void __force __user *) current->thread.per_event.address;
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force_sig_info(SIGTRAP, &info, current);
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}
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NOKPROBE_SYMBOL(do_per_trap);
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void default_trap_handler(struct pt_regs *regs)
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{
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if (user_mode(regs)) {
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report_user_fault(regs, SIGSEGV);
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do_exit(SIGSEGV);
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} else
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die(regs, "Unknown program exception");
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}
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#define DO_ERROR_INFO(name, signr, sicode, str) \
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void name(struct pt_regs *regs) \
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{ \
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do_trap(regs, signr, sicode, str); \
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}
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DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
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"addressing exception")
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DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
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"execute exception")
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DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
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"fixpoint divide exception")
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DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
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"fixpoint overflow exception")
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DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
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"HFP overflow exception")
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DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
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"HFP underflow exception")
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DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
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"HFP significance exception")
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DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
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"HFP divide exception")
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DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
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"HFP square root exception")
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DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
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"operand exception")
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DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
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"privileged operation")
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DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
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"special operation exception")
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DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
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"transaction constraint exception")
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static inline void do_fp_trap(struct pt_regs *regs, int fpc)
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{
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int si_code = 0;
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/* FPC[2] is Data Exception Code */
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if ((fpc & 0x00000300) == 0) {
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/* bits 6 and 7 of DXC are 0 iff IEEE exception */
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if (fpc & 0x8000) /* invalid fp operation */
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si_code = FPE_FLTINV;
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else if (fpc & 0x4000) /* div by 0 */
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si_code = FPE_FLTDIV;
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else if (fpc & 0x2000) /* overflow */
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si_code = FPE_FLTOVF;
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else if (fpc & 0x1000) /* underflow */
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si_code = FPE_FLTUND;
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else if (fpc & 0x0800) /* inexact */
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si_code = FPE_FLTRES;
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}
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do_trap(regs, SIGFPE, si_code, "floating point exception");
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}
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void translation_exception(struct pt_regs *regs)
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{
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/* May never happen. */
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die(regs, "Translation exception");
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}
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void illegal_op(struct pt_regs *regs)
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{
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siginfo_t info;
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__u8 opcode[6];
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__u16 __user *location;
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int is_uprobe_insn = 0;
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int signal = 0;
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location = get_trap_ip(regs);
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if (user_mode(regs)) {
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if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
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return;
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if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
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if (current->ptrace) {
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info.si_signo = SIGTRAP;
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info.si_errno = 0;
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info.si_code = TRAP_BRKPT;
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info.si_addr = location;
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force_sig_info(SIGTRAP, &info, current);
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} else
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signal = SIGILL;
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#ifdef CONFIG_UPROBES
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} else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
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is_uprobe_insn = 1;
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#endif
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} else
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signal = SIGILL;
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}
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/*
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* We got either an illegal op in kernel mode, or user space trapped
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* on a uprobes illegal instruction. See if kprobes or uprobes picks
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* it up. If not, SIGILL.
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*/
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if (is_uprobe_insn || !user_mode(regs)) {
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if (notify_die(DIE_BPT, "bpt", regs, 0,
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3, SIGTRAP) != NOTIFY_STOP)
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signal = SIGILL;
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}
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if (signal)
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do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
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}
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NOKPROBE_SYMBOL(illegal_op);
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DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
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"specification exception");
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int alloc_vector_registers(struct task_struct *tsk)
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{
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__vector128 *vxrs;
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int i;
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/* Allocate vector register save area. */
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vxrs = kzalloc(sizeof(__vector128) * __NUM_VXRS,
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GFP_KERNEL|__GFP_REPEAT);
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if (!vxrs)
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return -ENOMEM;
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preempt_disable();
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if (tsk == current)
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save_fp_regs(tsk->thread.fp_regs.fprs);
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/* Copy the 16 floating point registers */
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for (i = 0; i < 16; i++)
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*(freg_t *) &vxrs[i] = tsk->thread.fp_regs.fprs[i];
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tsk->thread.vxrs = vxrs;
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if (tsk == current) {
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__ctl_set_bit(0, 17);
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restore_vx_regs(vxrs);
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}
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preempt_enable();
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return 0;
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}
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void vector_exception(struct pt_regs *regs)
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{
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int si_code, vic;
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if (!MACHINE_HAS_VX) {
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do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
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return;
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}
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/* get vector interrupt code from fpc */
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asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
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vic = (current->thread.fp_regs.fpc & 0xf00) >> 8;
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switch (vic) {
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case 1: /* invalid vector operation */
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si_code = FPE_FLTINV;
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break;
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case 2: /* division by zero */
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si_code = FPE_FLTDIV;
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break;
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case 3: /* overflow */
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si_code = FPE_FLTOVF;
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break;
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case 4: /* underflow */
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si_code = FPE_FLTUND;
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break;
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case 5: /* inexact */
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si_code = FPE_FLTRES;
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break;
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default: /* unknown cause */
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si_code = 0;
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}
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do_trap(regs, SIGFPE, si_code, "vector exception");
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}
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static int __init disable_vector_extension(char *str)
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{
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S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
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return 1;
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}
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__setup("novx", disable_vector_extension);
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void data_exception(struct pt_regs *regs)
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{
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__u16 __user *location;
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int signal = 0;
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location = get_trap_ip(regs);
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asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
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/* Check for vector register enablement */
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if (MACHINE_HAS_VX && !current->thread.vxrs &&
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(current->thread.fp_regs.fpc & FPC_DXC_MASK) == 0xfe00) {
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alloc_vector_registers(current);
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/* Vector data exception is suppressing, rewind psw. */
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regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
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clear_pt_regs_flag(regs, PIF_PER_TRAP);
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return;
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}
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if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
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signal = SIGFPE;
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else
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signal = SIGILL;
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if (signal == SIGFPE)
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do_fp_trap(regs, current->thread.fp_regs.fpc);
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else if (signal)
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do_trap(regs, signal, ILL_ILLOPN, "data exception");
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}
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void space_switch_exception(struct pt_regs *regs)
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{
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/* Set user psw back to home space mode. */
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if (user_mode(regs))
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regs->psw.mask |= PSW_ASC_HOME;
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/* Send SIGILL. */
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do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
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}
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void kernel_stack_overflow(struct pt_regs *regs)
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{
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bust_spinlocks(1);
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printk("Kernel stack overflow.\n");
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show_regs(regs);
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bust_spinlocks(0);
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panic("Corrupt kernel stack, can't continue.");
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}
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NOKPROBE_SYMBOL(kernel_stack_overflow);
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void __init trap_init(void)
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{
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local_mcck_enable();
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}
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