1#include <linux/bug.h> 2#include <linux/io.h> 3#include <linux/types.h> 4#include <linux/kdebug.h> 5#include <linux/signal.h> 6#include <linux/sched.h> 7#include <linux/uaccess.h> 8#include <linux/hardirq.h> 9#include <asm/unwinder.h> 10#include <asm/system.h> 11 12#ifdef CONFIG_GENERIC_BUG 13static void handle_BUG(struct pt_regs *regs) 14{ 15 const struct bug_entry *bug; 16 unsigned long bugaddr = regs->pc; 17 enum bug_trap_type tt; 18 19 if (!is_valid_bugaddr(bugaddr)) 20 goto invalid; 21 22 bug = find_bug(bugaddr); 23 24 /* Switch unwinders when unwind_stack() is called */ 25 if (bug->flags & BUGFLAG_UNWINDER) 26 unwinder_faulted = 1; 27 28 tt = report_bug(bugaddr, regs); 29 if (tt == BUG_TRAP_TYPE_WARN) { 30 regs->pc += instruction_size(bugaddr); 31 return; 32 } 33 34invalid: 35 die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); 36} 37 38int is_valid_bugaddr(unsigned long addr) 39{ 40 insn_size_t opcode; 41 42 if (addr < PAGE_OFFSET) 43 return 0; 44 if (probe_kernel_address((insn_size_t *)addr, opcode)) 45 return 0; 46 if (opcode == TRAPA_BUG_OPCODE) 47 return 1; 48 49 return 0; 50} 51#endif 52 53/* 54 * Generic trap handler. 55 */ 56BUILD_TRAP_HANDLER(debug) 57{ 58 TRAP_HANDLER_DECL; 59 60 /* Rewind */ 61 regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); 62 63 if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff, 64 SIGTRAP) == NOTIFY_STOP) 65 return; 66 67 force_sig(SIGTRAP, current); 68} 69 70/* 71 * Special handler for BUG() traps. 72 */ 73BUILD_TRAP_HANDLER(bug) 74{ 75 TRAP_HANDLER_DECL; 76 77 /* Rewind */ 78 regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); 79 80 if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff, 81 SIGTRAP) == NOTIFY_STOP) 82 return; 83 84#ifdef CONFIG_GENERIC_BUG 85 if (__kernel_text_address(instruction_pointer(regs))) { 86 insn_size_t insn = *(insn_size_t *)instruction_pointer(regs); 87 if (insn == TRAPA_BUG_OPCODE) 88 handle_BUG(regs); 89 return; 90 } 91#endif 92 93 force_sig(SIGTRAP, current); 94} 95 96BUILD_TRAP_HANDLER(nmi) 97{ 98 unsigned int cpu = smp_processor_id(); 99 TRAP_HANDLER_DECL; 100 101 nmi_enter(); 102 nmi_count(cpu)++; 103 104 switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) { 105 case NOTIFY_OK: 106 case NOTIFY_STOP: 107 break; 108 case NOTIFY_BAD: 109 die("Fatal Non-Maskable Interrupt", regs, SIGINT); 110 default: 111 printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n"); 112 break; 113 } 114 115 nmi_exit(); 116} 117