Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 2 | /* |
| 3 | * Traps/Non-MMU Exception handling for ARC |
| 4 | * |
| 5 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| 6 | * |
Vineet Gupta | 2e651ea | 2013-01-23 16:30:36 +0530 | [diff] [blame] | 7 | * vineetg: May 2011 |
| 8 | * -user-space unaligned access emulation |
| 9 | * |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 10 | * Rahul Trivedi: Codito Technologies 2004 |
| 11 | */ |
| 12 | |
Ingo Molnar | 3f07c01 | 2017-02-08 18:51:30 +0100 | [diff] [blame] | 13 | #include <linux/sched/signal.h> |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 14 | #include <linux/kdebug.h> |
| 15 | #include <linux/uaccess.h> |
Sachin Kamat | 1ec9db1 | 2013-03-06 16:53:44 +0530 | [diff] [blame] | 16 | #include <linux/ptrace.h> |
| 17 | #include <linux/kprobes.h> |
| 18 | #include <linux/kgdb.h> |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 19 | #include <asm/setup.h> |
Vineet Gupta | 2e651ea | 2013-01-23 16:30:36 +0530 | [diff] [blame] | 20 | #include <asm/unaligned.h> |
Christian Ruppert | 5b00029 | 2013-04-09 11:50:45 +0200 | [diff] [blame] | 21 | #include <asm/kprobes.h> |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 22 | |
| 23 | void __init trap_init(void) |
| 24 | { |
| 25 | return; |
| 26 | } |
| 27 | |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 28 | void die(const char *str, struct pt_regs *regs, unsigned long address) |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 29 | { |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 30 | show_kernel_fault_diag(str, regs, address); |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 31 | |
| 32 | /* DEAD END */ |
| 33 | __asm__("flag 1"); |
| 34 | } |
| 35 | |
| 36 | /* |
| 37 | * Helper called for bulk of exceptions NOT needing specific handling |
| 38 | * -for user faults enqueues requested signal |
| 39 | * -for kernel, chk if due to copy_(to|from)_user, otherwise die() |
| 40 | */ |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 41 | static noinline int |
Eric W. Biederman | 4445229 | 2018-04-19 19:20:58 -0500 | [diff] [blame] | 42 | unhandled_exception(const char *str, struct pt_regs *regs, |
| 43 | int signo, int si_code, void __user *addr) |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 44 | { |
| 45 | if (user_mode(regs)) { |
| 46 | struct task_struct *tsk = current; |
| 47 | |
Eric W. Biederman | 4445229 | 2018-04-19 19:20:58 -0500 | [diff] [blame] | 48 | tsk->thread.fault_address = (__force unsigned int)addr; |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 49 | |
Eric W. Biederman | 2e1661d2 | 2019-05-23 11:04:24 -0500 | [diff] [blame] | 50 | force_sig_fault(signo, si_code, addr); |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 51 | |
| 52 | } else { |
| 53 | /* If not due to copy_(to|from)_user, we are doomed */ |
| 54 | if (fixup_exception(regs)) |
| 55 | return 0; |
| 56 | |
Eric W. Biederman | 4445229 | 2018-04-19 19:20:58 -0500 | [diff] [blame] | 57 | die(str, regs, (unsigned long)addr); |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 58 | } |
| 59 | |
| 60 | return 1; |
| 61 | } |
| 62 | |
| 63 | #define DO_ERROR_INFO(signr, str, name, sicode) \ |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 64 | int name(unsigned long address, struct pt_regs *regs) \ |
Eric W. Biederman | 4445229 | 2018-04-19 19:20:58 -0500 | [diff] [blame] | 65 | { \ |
| 66 | return unhandled_exception(str, regs, signr, sicode, \ |
| 67 | (void __user *)address); \ |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 68 | } |
| 69 | |
| 70 | /* |
| 71 | * Entry points for exceptions NOT needing specific handling |
| 72 | */ |
| 73 | DO_ERROR_INFO(SIGILL, "Priv Op/Disabled Extn", do_privilege_fault, ILL_PRVOPC) |
| 74 | DO_ERROR_INFO(SIGILL, "Invalid Extn Insn", do_extension_fault, ILL_ILLOPC) |
| 75 | DO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC) |
Noam Camus | 9833949 | 2017-06-13 17:03:45 +0300 | [diff] [blame] | 76 | DO_ERROR_INFO(SIGBUS, "Invalid Mem Access", __weak do_memory_error, BUS_ADRERR) |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 77 | DO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT) |
Vineet Gupta | c723ea4 | 2013-04-04 14:37:52 +0530 | [diff] [blame] | 78 | DO_ERROR_INFO(SIGBUS, "Misaligned Access", do_misaligned_error, BUS_ADRALN) |
Vineet Gupta | f5a16b9 | 2017-12-20 12:37:54 -0800 | [diff] [blame] | 79 | DO_ERROR_INFO(SIGSEGV, "gcc generated __builtin_trap", do_trap5_error, 0) |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 80 | |
Vineet Gupta | 2e651ea | 2013-01-23 16:30:36 +0530 | [diff] [blame] | 81 | /* |
| 82 | * Entry Point for Misaligned Data access Exception, for emulating in software |
| 83 | */ |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 84 | int do_misaligned_access(unsigned long address, struct pt_regs *regs, |
| 85 | struct callee_regs *cregs) |
Vineet Gupta | 2e651ea | 2013-01-23 16:30:36 +0530 | [diff] [blame] | 86 | { |
Vineet Gupta | 07ba69a | 2013-09-18 18:08:01 +0530 | [diff] [blame] | 87 | /* If emulation not enabled, or failed, kill the task */ |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 88 | if (misaligned_fixup(address, regs, cregs) != 0) |
| 89 | return do_misaligned_error(address, regs); |
Vineet Gupta | 2e651ea | 2013-01-23 16:30:36 +0530 | [diff] [blame] | 90 | |
Vineet Gupta | 2e651ea | 2013-01-23 16:30:36 +0530 | [diff] [blame] | 91 | return 0; |
| 92 | } |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 93 | |
| 94 | /* |
| 95 | * Entry point for miscll errors such as Nested Exceptions |
| 96 | * -Duplicate TLB entry is handled seperately though |
| 97 | */ |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 98 | void do_machine_check_fault(unsigned long address, struct pt_regs *regs) |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 99 | { |
Jose Abreu | aa7e3a5 | 2017-08-29 10:14:20 +0100 | [diff] [blame] | 100 | die("Unhandled Machine Check Exception", regs, address); |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 101 | } |
| 102 | |
Vineet Gupta | 4d86dfb | 2013-01-22 17:03:59 +0530 | [diff] [blame] | 103 | |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 104 | /* |
| 105 | * Entry point for traps induced by ARCompact TRAP_S <n> insn |
| 106 | * This is same family as TRAP0/SWI insn (use the same vector). |
| 107 | * The only difference being SWI insn take no operand, while TRAP_S does |
| 108 | * which reflects in ECR Reg as 8 bit param. |
| 109 | * Thus TRAP_S <n> can be used for specific purpose |
| 110 | * -1 used for software breakpointing (gdb) |
| 111 | * -2 used by kprobes |
Vineet Gupta | f5a16b9 | 2017-12-20 12:37:54 -0800 | [diff] [blame] | 112 | * -5 __builtin_trap() generated by gcc (2018.03 onwards) for toggle such as |
| 113 | * -fno-isolate-erroneous-paths-dereference |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 114 | */ |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 115 | void do_non_swi_trap(unsigned long address, struct pt_regs *regs) |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 116 | { |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 117 | unsigned int param = regs->ecr_param; |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 118 | |
| 119 | switch (param) { |
| 120 | case 1: |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 121 | trap_is_brkpt(address, regs); |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 122 | break; |
| 123 | |
Vineet Gupta | 4d86dfb | 2013-01-22 17:03:59 +0530 | [diff] [blame] | 124 | case 2: |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 125 | trap_is_kprobe(address, regs); |
Vineet Gupta | 4d86dfb | 2013-01-22 17:03:59 +0530 | [diff] [blame] | 126 | break; |
| 127 | |
Mischa Jonker | f46121b | 2013-01-18 15:12:24 +0530 | [diff] [blame] | 128 | case 3: |
| 129 | case 4: |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 130 | kgdb_trap(regs); |
Mischa Jonker | f46121b | 2013-01-18 15:12:24 +0530 | [diff] [blame] | 131 | break; |
| 132 | |
Vineet Gupta | f5a16b9 | 2017-12-20 12:37:54 -0800 | [diff] [blame] | 133 | case 5: |
| 134 | do_trap5_error(address, regs); |
| 135 | break; |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 136 | default: |
| 137 | break; |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | /* |
| 142 | * Entry point for Instruction Error Exception |
Vineet Gupta | 4d86dfb | 2013-01-22 17:03:59 +0530 | [diff] [blame] | 143 | * -For a corner case, ARC kprobes implementation resorts to using |
| 144 | * this exception, hence the check |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 145 | */ |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 146 | void do_insterror_or_kprobe(unsigned long address, struct pt_regs *regs) |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 147 | { |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 148 | int rc; |
| 149 | |
Vineet Gupta | 4d86dfb | 2013-01-22 17:03:59 +0530 | [diff] [blame] | 150 | /* Check if this exception is caused by kprobes */ |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 151 | rc = notify_die(DIE_IERR, "kprobe_ierr", regs, address, 0, SIGILL); |
| 152 | if (rc == NOTIFY_STOP) |
Vineet Gupta | 4d86dfb | 2013-01-22 17:03:59 +0530 | [diff] [blame] | 153 | return; |
| 154 | |
Vineet Gupta | 38a9ff6 | 2013-06-12 15:13:40 +0530 | [diff] [blame] | 155 | insterror_is_error(address, regs); |
Vineet Gupta | 054419e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 156 | } |
Vineet Gupta | af1be2e | 2017-12-08 08:45:57 -0800 | [diff] [blame] | 157 | |
| 158 | /* |
| 159 | * abort() call generated by older gcc for __builtin_trap() |
| 160 | */ |
| 161 | void abort(void) |
| 162 | { |
| 163 | __asm__ __volatile__("trap_s 5\n"); |
| 164 | } |