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 <asm/system.h> 9 10 #ifdef CONFIG_BUG 11 static void handle_BUG(struct pt_regs *regs) 12 { 13 enum bug_trap_type tt; 14 tt = report_bug(regs->pc, regs); 15 if (tt == BUG_TRAP_TYPE_WARN) { 16 regs->pc += instruction_size(regs->pc); 17 return; 18 } 19 20 die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); 21 } 22 23 int is_valid_bugaddr(unsigned long addr) 24 { 25 unsigned short opcode; 26 27 if (addr < PAGE_OFFSET) 28 return 0; 29 if (probe_kernel_address((u16 *)addr, opcode)) 30 return 0; 31 32 return opcode == TRAPA_BUG_OPCODE; 33 } 34 #endif 35 36 /* 37 * Generic trap handler. 38 */ 39 BUILD_TRAP_HANDLER(debug) 40 { 41 TRAP_HANDLER_DECL; 42 43 /* Rewind */ 44 regs->pc -= instruction_size(ctrl_inw(regs->pc - 4)); 45 46 if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff, 47 SIGTRAP) == NOTIFY_STOP) 48 return; 49 50 force_sig(SIGTRAP, current); 51 } 52 53 /* 54 * Special handler for BUG() traps. 55 */ 56 BUILD_TRAP_HANDLER(bug) 57 { 58 TRAP_HANDLER_DECL; 59 60 /* Rewind */ 61 regs->pc -= instruction_size(ctrl_inw(regs->pc - 4)); 62 63 if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff, 64 SIGTRAP) == NOTIFY_STOP) 65 return; 66 67 #ifdef CONFIG_BUG 68 if (__kernel_text_address(instruction_pointer(regs))) { 69 opcode_t insn = *(opcode_t *)instruction_pointer(regs); 70 if (insn == TRAPA_BUG_OPCODE) 71 handle_BUG(regs); 72 } 73 #endif 74 75 force_sig(SIGTRAP, current); 76 } 77