1054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta/* 2054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * Traps/Non-MMU Exception handling for ARC 3054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * 4054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 5054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * 6054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * This program is free software; you can redistribute it and/or modify 7054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * it under the terms of the GNU General Public License version 2 as 8054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * published by the Free Software Foundation. 9054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * 102e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta * vineetg: May 2011 112e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta * -user-space unaligned access emulation 122e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta * 13054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * Rahul Trivedi: Codito Technologies 2004 14054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta */ 15054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 16054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta#include <linux/sched.h> 17054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta#include <linux/kdebug.h> 18054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta#include <linux/uaccess.h> 191ec9db1056b0c4b8b9dfca4736634c7c8e0833d5Sachin Kamat#include <linux/ptrace.h> 201ec9db1056b0c4b8b9dfca4736634c7c8e0833d5Sachin Kamat#include <linux/kprobes.h> 211ec9db1056b0c4b8b9dfca4736634c7c8e0833d5Sachin Kamat#include <linux/kgdb.h> 22054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta#include <asm/setup.h> 232e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta#include <asm/unaligned.h> 245b00029e30ef821152fa82502658e538172d6b75Christian Ruppert#include <asm/kprobes.h> 25054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 26054419ed8405da7aa93f88f698d696980efd3e37Vineet Guptavoid __init trap_init(void) 27054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta{ 28054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta return; 29054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta} 30054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 3138a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Guptavoid die(const char *str, struct pt_regs *regs, unsigned long address) 32054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta{ 3338a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta show_kernel_fault_diag(str, regs, address); 34054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 35054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta /* DEAD END */ 36054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta __asm__("flag 1"); 37054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta} 38054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 39054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta/* 40054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * Helper called for bulk of exceptions NOT needing specific handling 41054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * -for user faults enqueues requested signal 42054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * -for kernel, chk if due to copy_(to|from)_user, otherwise die() 43054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta */ 4438a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Guptastatic noinline int 4538a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Guptahandle_exception(const char *str, struct pt_regs *regs, siginfo_t *info) 46054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta{ 47054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta if (user_mode(regs)) { 48054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta struct task_struct *tsk = current; 49054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 50054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta tsk->thread.fault_address = (__force unsigned int)info->si_addr; 51054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 52054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta force_sig_info(info->si_signo, info, tsk); 53054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 54054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta } else { 55054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta /* If not due to copy_(to|from)_user, we are doomed */ 56054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta if (fixup_exception(regs)) 57054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta return 0; 58054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 5938a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta die(str, regs, (unsigned long)info->si_addr); 60054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta } 61054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 62054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta return 1; 63054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta} 64054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 65054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta#define DO_ERROR_INFO(signr, str, name, sicode) \ 6638a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Guptaint name(unsigned long address, struct pt_regs *regs) \ 67054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta{ \ 68054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta siginfo_t info = { \ 69054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta .si_signo = signr, \ 70054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta .si_errno = 0, \ 71054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta .si_code = sicode, \ 72054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta .si_addr = (void __user *)address, \ 73054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta }; \ 7438a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta return handle_exception(str, regs, &info);\ 75054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta} 76054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 77054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta/* 78054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * Entry points for exceptions NOT needing specific handling 79054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta */ 80054419ed8405da7aa93f88f698d696980efd3e37Vineet GuptaDO_ERROR_INFO(SIGILL, "Priv Op/Disabled Extn", do_privilege_fault, ILL_PRVOPC) 81054419ed8405da7aa93f88f698d696980efd3e37Vineet GuptaDO_ERROR_INFO(SIGILL, "Invalid Extn Insn", do_extension_fault, ILL_ILLOPC) 82054419ed8405da7aa93f88f698d696980efd3e37Vineet GuptaDO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC) 83054419ed8405da7aa93f88f698d696980efd3e37Vineet GuptaDO_ERROR_INFO(SIGBUS, "Invalid Mem Access", do_memory_error, BUS_ADRERR) 84054419ed8405da7aa93f88f698d696980efd3e37Vineet GuptaDO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT) 85c723ea4620a67fb0dbed5f5c33183543799e2177Vineet GuptaDO_ERROR_INFO(SIGBUS, "Misaligned Access", do_misaligned_error, BUS_ADRALN) 86054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 872e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta/* 882e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta * Entry Point for Misaligned Data access Exception, for emulating in software 892e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta */ 9038a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Guptaint do_misaligned_access(unsigned long address, struct pt_regs *regs, 9138a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta struct callee_regs *cregs) 922e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta{ 9307ba69a46c3394fe6675483275337e5a79a959e0Vineet Gupta /* If emulation not enabled, or failed, kill the task */ 9438a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta if (misaligned_fixup(address, regs, cregs) != 0) 9538a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta return do_misaligned_error(address, regs); 96c723ea4620a67fb0dbed5f5c33183543799e2177Vineet Gupta 972e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta return 0; 982e651ea1596b0ee25af4fcdc4cd13cbb33ffc254Vineet Gupta} 99054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 100054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta/* 101054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * Entry point for miscll errors such as Nested Exceptions 102054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * -Duplicate TLB entry is handled seperately though 103054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta */ 10438a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Guptavoid do_machine_check_fault(unsigned long address, struct pt_regs *regs) 105054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta{ 10638a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta die("Machine Check Exception", regs, address); 107054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta} 108054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 1094d86dfbbda09b3c67bcaeb370f22a2cc7f39205bVineet Gupta 110054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta/* 111054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * Entry point for traps induced by ARCompact TRAP_S <n> insn 112054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * This is same family as TRAP0/SWI insn (use the same vector). 113054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * The only difference being SWI insn take no operand, while TRAP_S does 114054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * which reflects in ECR Reg as 8 bit param. 115054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * Thus TRAP_S <n> can be used for specific purpose 116054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * -1 used for software breakpointing (gdb) 117054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * -2 used by kprobes 118054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta */ 11938a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Guptavoid do_non_swi_trap(unsigned long address, struct pt_regs *regs) 120054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta{ 12138a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta unsigned int param = regs->ecr_param; 122054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 123054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta switch (param) { 124054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta case 1: 12538a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta trap_is_brkpt(address, regs); 126054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta break; 127054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 1284d86dfbbda09b3c67bcaeb370f22a2cc7f39205bVineet Gupta case 2: 12938a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta trap_is_kprobe(address, regs); 1304d86dfbbda09b3c67bcaeb370f22a2cc7f39205bVineet Gupta break; 1314d86dfbbda09b3c67bcaeb370f22a2cc7f39205bVineet Gupta 132f46121bd26d7957866739313f1e098a682e8d3e4Mischa Jonker case 3: 133f46121bd26d7957866739313f1e098a682e8d3e4Mischa Jonker case 4: 13438a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta kgdb_trap(regs); 135f46121bd26d7957866739313f1e098a682e8d3e4Mischa Jonker break; 136f46121bd26d7957866739313f1e098a682e8d3e4Mischa Jonker 137054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta default: 138054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta break; 139054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta } 140054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta} 141054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta 142054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta/* 143054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta * Entry point for Instruction Error Exception 1444d86dfbbda09b3c67bcaeb370f22a2cc7f39205bVineet Gupta * -For a corner case, ARC kprobes implementation resorts to using 1454d86dfbbda09b3c67bcaeb370f22a2cc7f39205bVineet Gupta * this exception, hence the check 146054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta */ 14738a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Guptavoid do_insterror_or_kprobe(unsigned long address, struct pt_regs *regs) 148054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta{ 14938a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta int rc; 15038a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta 1514d86dfbbda09b3c67bcaeb370f22a2cc7f39205bVineet Gupta /* Check if this exception is caused by kprobes */ 15238a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta rc = notify_die(DIE_IERR, "kprobe_ierr", regs, address, 0, SIGILL); 15338a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta if (rc == NOTIFY_STOP) 1544d86dfbbda09b3c67bcaeb370f22a2cc7f39205bVineet Gupta return; 1554d86dfbbda09b3c67bcaeb370f22a2cc7f39205bVineet Gupta 15638a9ff6d247cf9afcbe55ea245b650b8955029fdVineet Gupta insterror_is_error(address, regs); 157054419ed8405da7aa93f88f698d696980efd3e37Vineet Gupta} 158