1 /* 2 * HW exception handling 3 * 4 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> 5 * Copyright (C) 2008 PetaLogix 6 * 7 * This file is subject to the terms and conditions of the GNU General 8 * Public License. See the file COPYING in the main directory of this 9 * archive for more details. 10 */ 11 12 /* 13 * This file handles the architecture-dependent parts of hardware exceptions 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/signal.h> 18 #include <linux/sched.h> 19 #include <linux/kallsyms.h> 20 #include <linux/module.h> 21 22 #include <asm/exceptions.h> 23 #include <asm/entry.h> /* For KM CPU var */ 24 #include <linux/uaccess.h> 25 #include <linux/errno.h> 26 #include <linux/ptrace.h> 27 #include <asm/current.h> 28 29 #define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02 30 #define MICROBLAZE_IBUS_EXCEPTION 0x03 31 #define MICROBLAZE_DBUS_EXCEPTION 0x04 32 #define MICROBLAZE_DIV_ZERO_EXCEPTION 0x05 33 #define MICROBLAZE_FPU_EXCEPTION 0x06 34 #define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07 35 36 static DEFINE_SPINLOCK(die_lock); 37 38 void die(const char *str, struct pt_regs *fp, long err) 39 { 40 console_verbose(); 41 spin_lock_irq(&die_lock); 42 printk(KERN_WARNING "Oops: %s, sig: %ld\n", str, err); 43 show_regs(fp); 44 spin_unlock_irq(&die_lock); 45 /* do_exit() should take care of panic'ing from an interrupt 46 * context so we don't handle it here 47 */ 48 do_exit(err); 49 } 50 51 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) 52 { 53 siginfo_t info; 54 55 if (kernel_mode(regs)) { 56 debugger(regs); 57 die("Exception in kernel mode", regs, signr); 58 } 59 info.si_signo = signr; 60 info.si_errno = 0; 61 info.si_code = code; 62 info.si_addr = (void __user *) addr; 63 force_sig_info(signr, &info, current); 64 } 65 66 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type, 67 int fsr, int addr) 68 { 69 #ifdef CONFIG_MMU 70 int code; 71 addr = regs->pc; 72 #endif 73 74 #if 0 75 printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \ 76 "ESR=%08x\n", 77 type, user_mode(regs) ? "user" : "kernel", fsr, 78 (unsigned int) regs->pc, (unsigned int) regs->esr); 79 #endif 80 81 switch (type & 0x1F) { 82 case MICROBLAZE_ILL_OPCODE_EXCEPTION: 83 if (user_mode(regs)) { 84 pr_debug(KERN_WARNING "Illegal opcode exception " \ 85 "in user mode.\n"); 86 _exception(SIGILL, regs, ILL_ILLOPC, addr); 87 return; 88 } 89 printk(KERN_WARNING "Illegal opcode exception " \ 90 "in kernel mode.\n"); 91 die("opcode exception", regs, SIGBUS); 92 break; 93 case MICROBLAZE_IBUS_EXCEPTION: 94 if (user_mode(regs)) { 95 pr_debug(KERN_WARNING "Instruction bus error " \ 96 "exception in user mode.\n"); 97 _exception(SIGBUS, regs, BUS_ADRERR, addr); 98 return; 99 } 100 printk(KERN_WARNING "Instruction bus error exception " \ 101 "in kernel mode.\n"); 102 die("bus exception", regs, SIGBUS); 103 break; 104 case MICROBLAZE_DBUS_EXCEPTION: 105 if (user_mode(regs)) { 106 pr_debug(KERN_WARNING "Data bus error exception " \ 107 "in user mode.\n"); 108 _exception(SIGBUS, regs, BUS_ADRERR, addr); 109 return; 110 } 111 printk(KERN_WARNING "Data bus error exception " \ 112 "in kernel mode.\n"); 113 die("bus exception", regs, SIGBUS); 114 break; 115 case MICROBLAZE_DIV_ZERO_EXCEPTION: 116 if (user_mode(regs)) { 117 pr_debug(KERN_WARNING "Divide by zero exception " \ 118 "in user mode\n"); 119 _exception(SIGILL, regs, FPE_INTDIV, addr); 120 return; 121 } 122 printk(KERN_WARNING "Divide by zero exception " \ 123 "in kernel mode.\n"); 124 die("Divide by exception", regs, SIGBUS); 125 break; 126 case MICROBLAZE_FPU_EXCEPTION: 127 pr_debug(KERN_WARNING "FPU exception\n"); 128 /* IEEE FP exception */ 129 /* I removed fsr variable and use code var for storing fsr */ 130 if (fsr & FSR_IO) 131 fsr = FPE_FLTINV; 132 else if (fsr & FSR_OF) 133 fsr = FPE_FLTOVF; 134 else if (fsr & FSR_UF) 135 fsr = FPE_FLTUND; 136 else if (fsr & FSR_DZ) 137 fsr = FPE_FLTDIV; 138 else if (fsr & FSR_DO) 139 fsr = FPE_FLTRES; 140 _exception(SIGFPE, regs, fsr, addr); 141 break; 142 143 #ifdef CONFIG_MMU 144 case MICROBLAZE_PRIVILEGED_EXCEPTION: 145 pr_debug(KERN_WARNING "Privileged exception\n"); 146 /* "brk r0,r0" - used as debug breakpoint */ 147 if (get_user(code, (unsigned long *)regs->pc) == 0 148 && code == 0x980c0000) { 149 _exception(SIGTRAP, regs, TRAP_BRKPT, addr); 150 } else { 151 _exception(SIGILL, regs, ILL_PRVOPC, addr); 152 } 153 break; 154 #endif 155 default: 156 /* FIXME what to do in unexpected exception */ 157 printk(KERN_WARNING "Unexpected exception %02x " 158 "PC=%08x in %s mode\n", type, (unsigned int) addr, 159 kernel_mode(regs) ? "kernel" : "user"); 160 } 161 return; 162 } 163