1 /* 2 * Traps/Non-MMU Exception handling for ARC 3 * 4 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * Rahul Trivedi: Codito Technologies 2004 11 */ 12 13 #include <linux/sched.h> 14 #include <linux/kdebug.h> 15 #include <linux/uaccess.h> 16 #include <asm/ptrace.h> 17 #include <asm/setup.h> 18 19 void __init trap_init(void) 20 { 21 return; 22 } 23 24 void die(const char *str, struct pt_regs *regs, unsigned long address, 25 unsigned long cause_reg) 26 { 27 show_kernel_fault_diag(str, regs, address, cause_reg); 28 29 /* DEAD END */ 30 __asm__("flag 1"); 31 } 32 33 /* 34 * Helper called for bulk of exceptions NOT needing specific handling 35 * -for user faults enqueues requested signal 36 * -for kernel, chk if due to copy_(to|from)_user, otherwise die() 37 */ 38 static noinline int handle_exception(unsigned long cause, char *str, 39 struct pt_regs *regs, siginfo_t *info) 40 { 41 if (user_mode(regs)) { 42 struct task_struct *tsk = current; 43 44 tsk->thread.fault_address = (__force unsigned int)info->si_addr; 45 tsk->thread.cause_code = cause; 46 47 force_sig_info(info->si_signo, info, tsk); 48 49 } else { 50 /* If not due to copy_(to|from)_user, we are doomed */ 51 if (fixup_exception(regs)) 52 return 0; 53 54 die(str, regs, (unsigned long)info->si_addr, cause); 55 } 56 57 return 1; 58 } 59 60 #define DO_ERROR_INFO(signr, str, name, sicode) \ 61 int name(unsigned long cause, unsigned long address, struct pt_regs *regs) \ 62 { \ 63 siginfo_t info = { \ 64 .si_signo = signr, \ 65 .si_errno = 0, \ 66 .si_code = sicode, \ 67 .si_addr = (void __user *)address, \ 68 }; \ 69 return handle_exception(cause, str, regs, &info);\ 70 } 71 72 /* 73 * Entry points for exceptions NOT needing specific handling 74 */ 75 DO_ERROR_INFO(SIGILL, "Priv Op/Disabled Extn", do_privilege_fault, ILL_PRVOPC) 76 DO_ERROR_INFO(SIGILL, "Invalid Extn Insn", do_extension_fault, ILL_ILLOPC) 77 DO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC) 78 DO_ERROR_INFO(SIGBUS, "Invalid Mem Access", do_memory_error, BUS_ADRERR) 79 DO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT) 80 81 DO_ERROR_INFO(SIGSEGV, "Misaligned Access", do_misaligned_access, SEGV_ACCERR) 82 83 /* 84 * Entry point for miscll errors such as Nested Exceptions 85 * -Duplicate TLB entry is handled seperately though 86 */ 87 void do_machine_check_fault(unsigned long cause, unsigned long address, 88 struct pt_regs *regs) 89 { 90 die("Machine Check Exception", regs, address, cause); 91 } 92 93 /* 94 * Entry point for traps induced by ARCompact TRAP_S <n> insn 95 * This is same family as TRAP0/SWI insn (use the same vector). 96 * The only difference being SWI insn take no operand, while TRAP_S does 97 * which reflects in ECR Reg as 8 bit param. 98 * Thus TRAP_S <n> can be used for specific purpose 99 * -1 used for software breakpointing (gdb) 100 * -2 used by kprobes 101 */ 102 void do_non_swi_trap(unsigned long cause, unsigned long address, 103 struct pt_regs *regs) 104 { 105 unsigned int param = cause & 0xff; 106 107 switch (param) { 108 case 1: 109 trap_is_brkpt(cause, address, regs); 110 break; 111 112 default: 113 break; 114 } 115 } 116 117 /* 118 * Entry point for Instruction Error Exception 119 */ 120 void do_insterror_or_kprobe(unsigned long cause, 121 unsigned long address, 122 struct pt_regs *regs) 123 { 124 insterror_is_error(cause, address, regs); 125 } 126