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