1 /* 2 * Hardware exception handling 3 * 4 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch> 5 * Copyright (C) 2004 Microtronix Datacom Ltd. 6 * Copyright (C) 2001 Vic Phillips 7 * 8 * This file is subject to the terms and conditions of the GNU General 9 * Public License. See the file COPYING in the main directory of this 10 * archive for more details. 11 */ 12 13 #include <linux/sched.h> 14 #include <linux/kernel.h> 15 #include <linux/signal.h> 16 #include <linux/export.h> 17 #include <linux/mm.h> 18 #include <linux/ptrace.h> 19 20 #include <asm/traps.h> 21 #include <asm/sections.h> 22 #include <linux/uaccess.h> 23 24 static DEFINE_SPINLOCK(die_lock); 25 26 static void _send_sig(int signo, int code, unsigned long addr) 27 { 28 siginfo_t info; 29 30 info.si_signo = signo; 31 info.si_errno = 0; 32 info.si_code = code; 33 info.si_addr = (void __user *) addr; 34 force_sig_info(signo, &info, current); 35 } 36 37 void die(const char *str, struct pt_regs *regs, long err) 38 { 39 console_verbose(); 40 spin_lock_irq(&die_lock); 41 pr_warn("Oops: %s, sig: %ld\n", str, err); 42 show_regs(regs); 43 spin_unlock_irq(&die_lock); 44 /* 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 signo, struct pt_regs *regs, int code, unsigned long addr) 52 { 53 if (!user_mode(regs)) 54 die("Exception in kernel mode", regs, signo); 55 56 _send_sig(signo, code, addr); 57 } 58 59 /* 60 * The show_stack is an external API which we do not use ourselves. 61 */ 62 63 int kstack_depth_to_print = 48; 64 65 void show_stack(struct task_struct *task, unsigned long *stack) 66 { 67 unsigned long *endstack, addr; 68 int i; 69 70 if (!stack) { 71 if (task) 72 stack = (unsigned long *)task->thread.ksp; 73 else 74 stack = (unsigned long *)&stack; 75 } 76 77 addr = (unsigned long) stack; 78 endstack = (unsigned long *) PAGE_ALIGN(addr); 79 80 pr_emerg("Stack from %08lx:", (unsigned long)stack); 81 for (i = 0; i < kstack_depth_to_print; i++) { 82 if (stack + 1 > endstack) 83 break; 84 if (i % 8 == 0) 85 pr_emerg("\n "); 86 pr_emerg(" %08lx", *stack++); 87 } 88 89 pr_emerg("\nCall Trace:"); 90 i = 0; 91 while (stack + 1 <= endstack) { 92 addr = *stack++; 93 /* 94 * If the address is either in the text segment of the 95 * kernel, or in the region which contains vmalloc'ed 96 * memory, it *may* be the address of a calling 97 * routine; if so, print it so that someone tracing 98 * down the cause of the crash will be able to figure 99 * out the call path that was taken. 100 */ 101 if (((addr >= (unsigned long) _stext) && 102 (addr <= (unsigned long) _etext))) { 103 if (i % 4 == 0) 104 pr_emerg("\n "); 105 pr_emerg(" [<%08lx>]", addr); 106 i++; 107 } 108 } 109 pr_emerg("\n"); 110 } 111 112 void __init trap_init(void) 113 { 114 /* Nothing to do here */ 115 } 116 117 /* Breakpoint handler */ 118 asmlinkage void breakpoint_c(struct pt_regs *fp) 119 { 120 /* 121 * The breakpoint entry code has moved the PC on by 4 bytes, so we must 122 * move it back. This could be done on the host but we do it here 123 * because monitor.S of JTAG gdbserver does it too. 124 */ 125 fp->ea -= 4; 126 _exception(SIGTRAP, fp, TRAP_BRKPT, fp->ea); 127 } 128 129 #ifndef CONFIG_NIOS2_ALIGNMENT_TRAP 130 /* Alignment exception handler */ 131 asmlinkage void handle_unaligned_c(struct pt_regs *fp, int cause) 132 { 133 unsigned long addr = RDCTL(CTL_BADADDR); 134 135 cause >>= 2; 136 fp->ea -= 4; 137 138 if (fixup_exception(fp)) 139 return; 140 141 if (!user_mode(fp)) { 142 pr_alert("Unaligned access from kernel mode, this might be a hardware\n"); 143 pr_alert("problem, dump registers and restart the instruction\n"); 144 pr_alert(" BADADDR 0x%08lx\n", addr); 145 pr_alert(" cause %d\n", cause); 146 pr_alert(" op-code 0x%08lx\n", *(unsigned long *)(fp->ea)); 147 show_regs(fp); 148 return; 149 } 150 151 _exception(SIGBUS, fp, BUS_ADRALN, addr); 152 } 153 #endif /* CONFIG_NIOS2_ALIGNMENT_TRAP */ 154 155 /* Illegal instruction handler */ 156 asmlinkage void handle_illegal_c(struct pt_regs *fp) 157 { 158 fp->ea -= 4; 159 _exception(SIGILL, fp, ILL_ILLOPC, fp->ea); 160 } 161 162 /* Supervisor instruction handler */ 163 asmlinkage void handle_supervisor_instr(struct pt_regs *fp) 164 { 165 fp->ea -= 4; 166 _exception(SIGILL, fp, ILL_PRVOPC, fp->ea); 167 } 168 169 /* Division error handler */ 170 asmlinkage void handle_diverror_c(struct pt_regs *fp) 171 { 172 fp->ea -= 4; 173 _exception(SIGFPE, fp, FPE_INTDIV, fp->ea); 174 } 175 176 /* Unhandled exception handler */ 177 asmlinkage void unhandled_exception(struct pt_regs *regs, int cause) 178 { 179 unsigned long addr = RDCTL(CTL_BADADDR); 180 181 cause /= 4; 182 183 pr_emerg("Unhandled exception #%d in %s mode (badaddr=0x%08lx)\n", 184 cause, user_mode(regs) ? "user" : "kernel", addr); 185 186 regs->ea -= 4; 187 show_regs(regs); 188 189 pr_emerg("opcode: 0x%08lx\n", *(unsigned long *)(regs->ea)); 190 } 191 192 asmlinkage void handle_trap_1_c(struct pt_regs *fp) 193 { 194 _send_sig(SIGUSR1, 0, fp->ea); 195 } 196 197 asmlinkage void handle_trap_2_c(struct pt_regs *fp) 198 { 199 _send_sig(SIGUSR2, 0, fp->ea); 200 } 201 202 asmlinkage void handle_trap_3_c(struct pt_regs *fp) 203 { 204 _send_sig(SIGILL, ILL_ILLTRP, fp->ea); 205 } 206