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 /* for user application debugging */ 52 void sw_exception(struct pt_regs *regs) 53 { 54 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16); 55 } 56 57 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) 58 { 59 siginfo_t info; 60 61 if (kernel_mode(regs)) { 62 die("Exception in kernel mode", regs, signr); 63 } 64 info.si_signo = signr; 65 info.si_errno = 0; 66 info.si_code = code; 67 info.si_addr = (void __user *) addr; 68 force_sig_info(signr, &info, current); 69 } 70 71 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type, 72 int fsr, int addr) 73 { 74 #ifdef CONFIG_MMU 75 int code; 76 addr = regs->pc; 77 #endif 78 79 #if 0 80 printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \ 81 "ESR=%08x\n", 82 type, user_mode(regs) ? "user" : "kernel", fsr, 83 (unsigned int) regs->pc, (unsigned int) regs->esr); 84 #endif 85 86 switch (type & 0x1F) { 87 case MICROBLAZE_ILL_OPCODE_EXCEPTION: 88 if (user_mode(regs)) { 89 pr_debug(KERN_WARNING "Illegal opcode exception " \ 90 "in user mode.\n"); 91 _exception(SIGILL, regs, ILL_ILLOPC, addr); 92 return; 93 } 94 printk(KERN_WARNING "Illegal opcode exception " \ 95 "in kernel mode.\n"); 96 die("opcode exception", regs, SIGBUS); 97 break; 98 case MICROBLAZE_IBUS_EXCEPTION: 99 if (user_mode(regs)) { 100 pr_debug(KERN_WARNING "Instruction bus error " \ 101 "exception in user mode.\n"); 102 _exception(SIGBUS, regs, BUS_ADRERR, addr); 103 return; 104 } 105 printk(KERN_WARNING "Instruction bus error exception " \ 106 "in kernel mode.\n"); 107 die("bus exception", regs, SIGBUS); 108 break; 109 case MICROBLAZE_DBUS_EXCEPTION: 110 if (user_mode(regs)) { 111 pr_debug(KERN_WARNING "Data bus error exception " \ 112 "in user mode.\n"); 113 _exception(SIGBUS, regs, BUS_ADRERR, addr); 114 return; 115 } 116 printk(KERN_WARNING "Data bus error exception " \ 117 "in kernel mode.\n"); 118 die("bus exception", regs, SIGBUS); 119 break; 120 case MICROBLAZE_DIV_ZERO_EXCEPTION: 121 if (user_mode(regs)) { 122 pr_debug(KERN_WARNING "Divide by zero exception " \ 123 "in user mode\n"); 124 _exception(SIGILL, regs, FPE_INTDIV, addr); 125 return; 126 } 127 printk(KERN_WARNING "Divide by zero exception " \ 128 "in kernel mode.\n"); 129 die("Divide by zero exception", regs, SIGBUS); 130 break; 131 case MICROBLAZE_FPU_EXCEPTION: 132 pr_debug(KERN_WARNING "FPU exception\n"); 133 /* IEEE FP exception */ 134 /* I removed fsr variable and use code var for storing fsr */ 135 if (fsr & FSR_IO) 136 fsr = FPE_FLTINV; 137 else if (fsr & FSR_OF) 138 fsr = FPE_FLTOVF; 139 else if (fsr & FSR_UF) 140 fsr = FPE_FLTUND; 141 else if (fsr & FSR_DZ) 142 fsr = FPE_FLTDIV; 143 else if (fsr & FSR_DO) 144 fsr = FPE_FLTRES; 145 _exception(SIGFPE, regs, fsr, addr); 146 break; 147 148 #ifdef CONFIG_MMU 149 case MICROBLAZE_PRIVILEGED_EXCEPTION: 150 pr_debug(KERN_WARNING "Privileged exception\n"); 151 /* "brk r0,r0" - used as debug breakpoint - old toolchain */ 152 if (get_user(code, (unsigned long *)regs->pc) == 0 153 && code == 0x980c0000) { 154 _exception(SIGTRAP, regs, TRAP_BRKPT, addr); 155 } else { 156 _exception(SIGILL, regs, ILL_PRVOPC, addr); 157 } 158 break; 159 #endif 160 default: 161 /* FIXME what to do in unexpected exception */ 162 printk(KERN_WARNING "Unexpected exception %02x " 163 "PC=%08x in %s mode\n", type, (unsigned int) addr, 164 kernel_mode(regs) ? "kernel" : "user"); 165 } 166 return; 167 } 168