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/export.h> 17 #include <linux/kernel.h> 18 #include <linux/signal.h> 19 #include <linux/sched.h> 20 #include <linux/sched/debug.h> 21 #include <linux/kallsyms.h> 22 23 #include <asm/exceptions.h> 24 #include <asm/entry.h> /* For KM CPU var */ 25 #include <linux/uaccess.h> 26 #include <linux/errno.h> 27 #include <linux/ptrace.h> 28 #include <asm/current.h> 29 #include <asm/cacheflush.h> 30 31 #define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02 32 #define MICROBLAZE_IBUS_EXCEPTION 0x03 33 #define MICROBLAZE_DBUS_EXCEPTION 0x04 34 #define MICROBLAZE_DIV_ZERO_EXCEPTION 0x05 35 #define MICROBLAZE_FPU_EXCEPTION 0x06 36 #define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07 37 38 static DEFINE_SPINLOCK(die_lock); 39 40 void die(const char *str, struct pt_regs *fp, long err) 41 { 42 console_verbose(); 43 spin_lock_irq(&die_lock); 44 pr_warn("Oops: %s, sig: %ld\n", str, err); 45 show_regs(fp); 46 spin_unlock_irq(&die_lock); 47 /* do_exit() should take care of panic'ing from an interrupt 48 * context so we don't handle it here 49 */ 50 do_exit(err); 51 } 52 53 /* for user application debugging */ 54 asmlinkage void sw_exception(struct pt_regs *regs) 55 { 56 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16); 57 flush_dcache_range(regs->r16, regs->r16 + 0x4); 58 flush_icache_range(regs->r16, regs->r16 + 0x4); 59 } 60 61 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) 62 { 63 siginfo_t info; 64 65 if (kernel_mode(regs)) 66 die("Exception in kernel mode", regs, signr); 67 68 info.si_signo = signr; 69 info.si_errno = 0; 70 info.si_code = code; 71 info.si_addr = (void __user *) addr; 72 force_sig_info(signr, &info, current); 73 } 74 75 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type, 76 int fsr, int addr) 77 { 78 #ifdef CONFIG_MMU 79 addr = regs->pc; 80 #endif 81 82 #if 0 83 pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n", 84 type, user_mode(regs) ? "user" : "kernel", fsr, 85 (unsigned int) regs->pc, (unsigned int) regs->esr); 86 #endif 87 88 switch (type & 0x1F) { 89 case MICROBLAZE_ILL_OPCODE_EXCEPTION: 90 if (user_mode(regs)) { 91 pr_debug("Illegal opcode exception in user mode\n"); 92 _exception(SIGILL, regs, ILL_ILLOPC, addr); 93 return; 94 } 95 pr_warn("Illegal opcode exception 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("Instruction bus error exception in user mode\n"); 101 _exception(SIGBUS, regs, BUS_ADRERR, addr); 102 return; 103 } 104 pr_warn("Instruction bus error exception in kernel mode.\n"); 105 die("bus exception", regs, SIGBUS); 106 break; 107 case MICROBLAZE_DBUS_EXCEPTION: 108 if (user_mode(regs)) { 109 pr_debug("Data bus error exception in user mode\n"); 110 _exception(SIGBUS, regs, BUS_ADRERR, addr); 111 return; 112 } 113 pr_warn("Data bus error exception in kernel mode.\n"); 114 die("bus exception", regs, SIGBUS); 115 break; 116 case MICROBLAZE_DIV_ZERO_EXCEPTION: 117 if (user_mode(regs)) { 118 pr_debug("Divide by zero exception in user mode\n"); 119 _exception(SIGFPE, regs, FPE_INTDIV, addr); 120 return; 121 } 122 pr_warn("Divide by zero exception in kernel mode.\n"); 123 die("Divide by zero exception", regs, SIGBUS); 124 break; 125 case MICROBLAZE_FPU_EXCEPTION: 126 pr_debug("FPU exception\n"); 127 /* IEEE FP exception */ 128 /* I removed fsr variable and use code var for storing fsr */ 129 if (fsr & FSR_IO) 130 fsr = FPE_FLTINV; 131 else if (fsr & FSR_OF) 132 fsr = FPE_FLTOVF; 133 else if (fsr & FSR_UF) 134 fsr = FPE_FLTUND; 135 else if (fsr & FSR_DZ) 136 fsr = FPE_FLTDIV; 137 else if (fsr & FSR_DO) 138 fsr = FPE_FLTRES; 139 _exception(SIGFPE, regs, fsr, addr); 140 break; 141 142 #ifdef CONFIG_MMU 143 case MICROBLAZE_PRIVILEGED_EXCEPTION: 144 pr_debug("Privileged exception\n"); 145 _exception(SIGILL, regs, ILL_PRVOPC, addr); 146 break; 147 #endif 148 default: 149 /* FIXME what to do in unexpected exception */ 150 pr_warn("Unexpected exception %02x PC=%08x in %s mode\n", 151 type, (unsigned int) addr, 152 kernel_mode(regs) ? "kernel" : "user"); 153 } 154 return; 155 } 156