404 lines
10 KiB
C
404 lines
10 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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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 "asm/irqflags.h"
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#include "asm/ptrace.h"
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#include <linux/kprobes.h>
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#include <linux/kdebug.h>
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#include <linux/randomize_kstack.h>
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#include <linux/extable.h>
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#include <linux/ptrace.h>
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#include <linux/sched.h>
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#include <linux/sched/debug.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/cpu.h>
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#include <linux/entry-common.h>
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#include <asm/asm-extable.h>
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#include <asm/fpu/api.h>
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#include <asm/vtime.h>
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#include "entry.h"
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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 = current->thread.trap_tdb.data[3];
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else
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address = regs->psw.addr;
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return (void __user *) (address - (regs->int_code >> 16));
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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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if (user_mode(regs)) {
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force_sig_fault(si_signo, si_code, get_trap_ip(regs));
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report_user_fault(regs, si_signo, 0);
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} else {
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if (!fixup_exception(regs))
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die(regs, str);
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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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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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force_sig_fault(SIGTRAP, TRAP_HWBKPT,
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(void __force __user *) current->thread.per_event.address);
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}
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NOKPROBE_SYMBOL(do_per_trap);
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static 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, 0);
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force_exit_sig(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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static 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, __u32 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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static void translation_specification_exception(struct pt_regs *regs)
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{
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/* May never happen. */
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panic("Translation-Specification Exception");
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}
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static void illegal_op(struct pt_regs *regs)
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{
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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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force_sig_fault(SIGTRAP, TRAP_BRKPT, location);
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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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static 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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save_fpu_regs();
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vic = (current->thread.fpu.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 void data_exception(struct pt_regs *regs)
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{
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save_fpu_regs();
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if (current->thread.fpu.fpc & FPC_DXC_MASK)
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do_fp_trap(regs, current->thread.fpu.fpc);
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else
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do_trap(regs, SIGILL, ILL_ILLOPN, "data exception");
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}
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static 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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static void monitor_event_exception(struct pt_regs *regs)
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{
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if (user_mode(regs))
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return;
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switch (report_bug(regs->psw.addr - (regs->int_code >> 16), regs)) {
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case BUG_TRAP_TYPE_NONE:
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fixup_exception(regs);
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break;
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case BUG_TRAP_TYPE_WARN:
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break;
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case BUG_TRAP_TYPE_BUG:
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die(regs, "monitor event");
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break;
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}
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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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static void __init test_monitor_call(void)
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{
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int val = 1;
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if (!IS_ENABLED(CONFIG_BUG))
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return;
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asm volatile(
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" mc 0,0\n"
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"0: xgr %0,%0\n"
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"1:\n"
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EX_TABLE(0b,1b)
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: "+d" (val));
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if (!val)
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panic("Monitor call doesn't work!\n");
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}
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void __init trap_init(void)
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{
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local_mcck_enable();
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test_monitor_call();
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}
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static void (*pgm_check_table[128])(struct pt_regs *regs);
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void noinstr __do_pgm_check(struct pt_regs *regs)
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{
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unsigned int trapnr;
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irqentry_state_t state;
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regs->int_code = S390_lowcore.pgm_int_code;
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regs->int_parm_long = S390_lowcore.trans_exc_code;
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state = irqentry_enter(regs);
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if (user_mode(regs)) {
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update_timer_sys();
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if (!static_branch_likely(&cpu_has_bear)) {
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if (regs->last_break < 4096)
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regs->last_break = 1;
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}
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current->thread.last_break = regs->last_break;
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}
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if (S390_lowcore.pgm_code & 0x0200) {
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/* transaction abort */
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current->thread.trap_tdb = S390_lowcore.pgm_tdb;
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}
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if (S390_lowcore.pgm_code & PGM_INT_CODE_PER) {
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if (user_mode(regs)) {
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struct per_event *ev = ¤t->thread.per_event;
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set_thread_flag(TIF_PER_TRAP);
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ev->address = S390_lowcore.per_address;
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ev->cause = S390_lowcore.per_code_combined;
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ev->paid = S390_lowcore.per_access_id;
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} else {
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/* PER event in kernel is kprobes */
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__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
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do_per_trap(regs);
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goto out;
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}
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}
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if (!irqs_disabled_flags(regs->psw.mask))
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trace_hardirqs_on();
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__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
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trapnr = regs->int_code & PGM_INT_CODE_MASK;
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if (trapnr)
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pgm_check_table[trapnr](regs);
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out:
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local_irq_disable();
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irqentry_exit(regs, state);
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}
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/*
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* The program check table contains exactly 128 (0x00-0x7f) entries. Each
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* line defines the function to be called corresponding to the program check
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* interruption code.
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*/
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static void (*pgm_check_table[128])(struct pt_regs *regs) = {
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[0x00] = default_trap_handler,
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[0x01] = illegal_op,
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[0x02] = privileged_op,
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[0x03] = execute_exception,
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[0x04] = do_protection_exception,
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[0x05] = addressing_exception,
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[0x06] = specification_exception,
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[0x07] = data_exception,
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[0x08] = overflow_exception,
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[0x09] = divide_exception,
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[0x0a] = overflow_exception,
|
||
|
|
[0x0b] = divide_exception,
|
||
|
|
[0x0c] = hfp_overflow_exception,
|
||
|
|
[0x0d] = hfp_underflow_exception,
|
||
|
|
[0x0e] = hfp_significance_exception,
|
||
|
|
[0x0f] = hfp_divide_exception,
|
||
|
|
[0x10] = do_dat_exception,
|
||
|
|
[0x11] = do_dat_exception,
|
||
|
|
[0x12] = translation_specification_exception,
|
||
|
|
[0x13] = special_op_exception,
|
||
|
|
[0x14] = default_trap_handler,
|
||
|
|
[0x15] = operand_exception,
|
||
|
|
[0x16] = default_trap_handler,
|
||
|
|
[0x17] = default_trap_handler,
|
||
|
|
[0x18] = transaction_exception,
|
||
|
|
[0x19] = default_trap_handler,
|
||
|
|
[0x1a] = default_trap_handler,
|
||
|
|
[0x1b] = vector_exception,
|
||
|
|
[0x1c] = space_switch_exception,
|
||
|
|
[0x1d] = hfp_sqrt_exception,
|
||
|
|
[0x1e ... 0x37] = default_trap_handler,
|
||
|
|
[0x38] = do_dat_exception,
|
||
|
|
[0x39] = do_dat_exception,
|
||
|
|
[0x3a] = do_dat_exception,
|
||
|
|
[0x3b] = do_dat_exception,
|
||
|
|
[0x3c] = default_trap_handler,
|
||
|
|
[0x3d] = do_secure_storage_access,
|
||
|
|
[0x3e] = do_non_secure_storage_access,
|
||
|
|
[0x3f] = do_secure_storage_violation,
|
||
|
|
[0x40] = monitor_event_exception,
|
||
|
|
[0x41 ... 0x7f] = default_trap_handler,
|
||
|
|
};
|
||
|
|
|
||
|
|
#define COND_TRAP(x) asm( \
|
||
|
|
".weak " __stringify(x) "\n\t" \
|
||
|
|
".set " __stringify(x) "," \
|
||
|
|
__stringify(default_trap_handler))
|
||
|
|
|
||
|
|
COND_TRAP(do_secure_storage_access);
|
||
|
|
COND_TRAP(do_non_secure_storage_access);
|
||
|
|
COND_TRAP(do_secure_storage_violation);
|