traps.c

LINUX 2.6.17.4的源码

}

DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
	      ILL_ILLADR, get_check_address(regs))
DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
	      ILL_ILLOPN, get_check_address(regs))
DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
	      FPE_INTDIV, get_check_address(regs))
DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
	      FPE_INTOVF, get_check_address(regs))
DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
	      FPE_FLTOVF, get_check_address(regs))
DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
	      FPE_FLTUND, get_check_address(regs))
DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
	      FPE_FLTRES, get_check_address(regs))
DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
	      FPE_FLTDIV, get_check_address(regs))
DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
	      FPE_FLTINV, get_check_address(regs))
DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
	      ILL_ILLOPN, get_check_address(regs))
DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
	      ILL_PRVOPC, get_check_address(regs))
DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
	      ILL_ILLOPN, get_check_address(regs))
DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
	      ILL_ILLOPN, get_check_address(regs))

static inline void
do_fp_trap(struct pt_regs *regs, void *location,
           int fpc, long interruption_code)
{
	siginfo_t si;

	si.si_signo = SIGFPE;
	si.si_errno = 0;
	si.si_addr = location;
	si.si_code = 0;
	/* FPC[2] is Data Exception Code */
	if ((fpc & 0x00000300) == 0) {
		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
		if (fpc & 0x8000) /* invalid fp operation */
			si.si_code = FPE_FLTINV;
		else if (fpc & 0x4000) /* div by 0 */
			si.si_code = FPE_FLTDIV;
		else if (fpc & 0x2000) /* overflow */
			si.si_code = FPE_FLTOVF;
		else if (fpc & 0x1000) /* underflow */
			si.si_code = FPE_FLTUND;
		else if (fpc & 0x0800) /* inexact */
			si.si_code = FPE_FLTRES;
	}
	current->thread.ieee_instruction_pointer = (addr_t) location;
	do_trap(interruption_code, SIGFPE,
		"floating point exception", regs, &si);
}

asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
{
	siginfo_t info;
        __u8 opcode[6];
	__u16 *location;
	int signal = 0;

	location = (__u16 *) get_check_address(regs);

	/*
	 * We got all needed information from the lowcore and can
	 * now safely switch on interrupts.
	 */
	if (regs->psw.mask & PSW_MASK_PSTATE)
		local_irq_enable();

	if (regs->psw.mask & PSW_MASK_PSTATE) {
		get_user(*((__u16 *) opcode), (__u16 __user *) location);
		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
			if (current->ptrace & PT_PTRACED)
				force_sig(SIGTRAP, current);
			else
				signal = SIGILL;
#ifdef CONFIG_MATHEMU
		} else if (opcode[0] == 0xb3) {
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_b3(opcode, regs);
                } else if (opcode[0] == 0xed) {
			get_user(*((__u32 *) (opcode+2)),
				 (__u32 *)(location+1));
			signal = math_emu_ed(opcode, regs);
		} else if (*((__u16 *) opcode) == 0xb299) {
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_srnm(opcode, regs);
		} else if (*((__u16 *) opcode) == 0xb29c) {
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_stfpc(opcode, regs);
		} else if (*((__u16 *) opcode) == 0xb29d) {
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_lfpc(opcode, regs);
#endif
		} else
			signal = SIGILL;
	} else
		signal = SIGILL;

#ifdef CONFIG_MATHEMU
        if (signal == SIGFPE)
		do_fp_trap(regs, location,
                           current->thread.fp_regs.fpc, interruption_code);
        else if (signal == SIGSEGV) {
		info.si_signo = signal;
		info.si_errno = 0;
		info.si_code = SEGV_MAPERR;
		info.si_addr = (void *) location;
		do_trap(interruption_code, signal,
			"user address fault", regs, &info);
	} else
#endif
        if (signal) {
		info.si_signo = signal;
		info.si_errno = 0;
		info.si_code = ILL_ILLOPC;
		info.si_addr = (void __user *) location;
		do_trap(interruption_code, signal,
			"illegal operation", regs, &info);
	}
}


#ifdef CONFIG_MATHEMU
asmlinkage void 
specification_exception(struct pt_regs * regs, long interruption_code)
{
        __u8 opcode[6];
	__u16 *location = NULL;
	int signal = 0;

	location = (__u16 *) get_check_address(regs);

	/*
	 * We got all needed information from the lowcore and can
	 * now safely switch on interrupts.
	 */
        if (regs->psw.mask & PSW_MASK_PSTATE)
		local_irq_enable();

        if (regs->psw.mask & PSW_MASK_PSTATE) {
		get_user(*((__u16 *) opcode), location);
		switch (opcode[0]) {
		case 0x28: /* LDR Rx,Ry   */
			signal = math_emu_ldr(opcode);
			break;
		case 0x38: /* LER Rx,Ry   */
			signal = math_emu_ler(opcode);
			break;
		case 0x60: /* STD R,D(X,B) */
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_std(opcode, regs);
			break;
		case 0x68: /* LD R,D(X,B) */
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_ld(opcode, regs);
			break;
		case 0x70: /* STE R,D(X,B) */
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_ste(opcode, regs);
			break;
		case 0x78: /* LE R,D(X,B) */
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_le(opcode, regs);
			break;
		default:
			signal = SIGILL;
			break;
                }
        } else
		signal = SIGILL;

        if (signal == SIGFPE)
		do_fp_trap(regs, location,
                           current->thread.fp_regs.fpc, interruption_code);
        else if (signal) {
		siginfo_t info;
		info.si_signo = signal;
		info.si_errno = 0;
		info.si_code = ILL_ILLOPN;
		info.si_addr = location;
		do_trap(interruption_code, signal, 
			"specification exception", regs, &info);
	}
}
#else
DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
	      ILL_ILLOPN, get_check_address(regs));
#endif

asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
{
	__u16 *location;
	int signal = 0;

	location = (__u16 *) get_check_address(regs);

	/*
	 * We got all needed information from the lowcore and can
	 * now safely switch on interrupts.
	 */
	if (regs->psw.mask & PSW_MASK_PSTATE)
		local_irq_enable();

	if (MACHINE_HAS_IEEE)
		__asm__ volatile ("stfpc %0\n\t" 
				  : "=m" (current->thread.fp_regs.fpc));

#ifdef CONFIG_MATHEMU
        else if (regs->psw.mask & PSW_MASK_PSTATE) {
        	__u8 opcode[6];
		get_user(*((__u16 *) opcode), location);
		switch (opcode[0]) {
		case 0x28: /* LDR Rx,Ry   */
			signal = math_emu_ldr(opcode);
			break;
		case 0x38: /* LER Rx,Ry   */
			signal = math_emu_ler(opcode);
			break;
		case 0x60: /* STD R,D(X,B) */
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_std(opcode, regs);
			break;
		case 0x68: /* LD R,D(X,B) */
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_ld(opcode, regs);
			break;
		case 0x70: /* STE R,D(X,B) */
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_ste(opcode, regs);
			break;
		case 0x78: /* LE R,D(X,B) */
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_le(opcode, regs);
			break;
		case 0xb3:
			get_user(*((__u16 *) (opcode+2)), location+1);
			signal = math_emu_b3(opcode, regs);
			break;
                case 0xed:
			get_user(*((__u32 *) (opcode+2)),
				 (__u32 *)(location+1));
			signal = math_emu_ed(opcode, regs);
			break;
	        case 0xb2:
			if (opcode[1] == 0x99) {
				get_user(*((__u16 *) (opcode+2)), location+1);
				signal = math_emu_srnm(opcode, regs);
			} else if (opcode[1] == 0x9c) {
				get_user(*((__u16 *) (opcode+2)), location+1);
				signal = math_emu_stfpc(opcode, regs);
			} else if (opcode[1] == 0x9d) {
				get_user(*((__u16 *) (opcode+2)), location+1);
				signal = math_emu_lfpc(opcode, regs);
			} else
				signal = SIGILL;
			break;
		default:
			signal = SIGILL;
			break;
                }
        }
#endif 
	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
		signal = SIGFPE;
	else
		signal = SIGILL;
        if (signal == SIGFPE)
		do_fp_trap(regs, location,
                           current->thread.fp_regs.fpc, interruption_code);
        else if (signal) {
		siginfo_t info;
		info.si_signo = signal;
		info.si_errno = 0;
		info.si_code = ILL_ILLOPN;
		info.si_addr = location;
		do_trap(interruption_code, signal, 
			"data exception", regs, &info);
	}
}

asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
{
        siginfo_t info;

	/* Set user psw back to home space mode. */
	if (regs->psw.mask & PSW_MASK_PSTATE)
		regs->psw.mask |= PSW_ASC_HOME;
	/* Send SIGILL. */
        info.si_signo = SIGILL;
        info.si_errno = 0;
        info.si_code = ILL_PRVOPC;
        info.si_addr = get_check_address(regs);
        do_trap(int_code, SIGILL, "space switch event", regs, &info);
}

asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
{
	bust_spinlocks(1);
	printk("Kernel stack overflow.\n");
	show_regs(regs);
	bust_spinlocks(0);
	panic("Corrupt kernel stack, can't continue.");
}

/* init is done in lowcore.S and head.S */

void __init trap_init(void)
{
        int i;

        for (i = 0; i < 128; i++)
          pgm_check_table[i] = &default_trap_handler;
        pgm_check_table[1] = &illegal_op;
        pgm_check_table[2] = &privileged_op;
        pgm_check_table[3] = &execute_exception;
        pgm_check_table[4] = &do_protection_exception;
        pgm_check_table[5] = &addressing_exception;
        pgm_check_table[6] = &specification_exception;
        pgm_check_table[7] = &data_exception;
        pgm_check_table[8] = &overflow_exception;
        pgm_check_table[9] = &divide_exception;
        pgm_check_table[0x0A] = &overflow_exception;
        pgm_check_table[0x0B] = &divide_exception;
        pgm_check_table[0x0C] = &hfp_overflow_exception;
        pgm_check_table[0x0D] = &hfp_underflow_exception;
        pgm_check_table[0x0E] = &hfp_significance_exception;
        pgm_check_table[0x0F] = &hfp_divide_exception;
        pgm_check_table[0x10] = &do_dat_exception;
        pgm_check_table[0x11] = &do_dat_exception;
        pgm_check_table[0x12] = &translation_exception;
        pgm_check_table[0x13] = &special_op_exception;
#ifdef CONFIG_64BIT
        pgm_check_table[0x38] = &do_dat_exception;
	pgm_check_table[0x39] = &do_dat_exception;
	pgm_check_table[0x3A] = &do_dat_exception;
        pgm_check_table[0x3B] = &do_dat_exception;
#endif /* CONFIG_64BIT */
        pgm_check_table[0x15] = &operand_exception;
        pgm_check_table[0x1C] = &space_switch_exception;
        pgm_check_table[0x1D] = &hfp_sqrt_exception;
	pgm_check_table[0x40] = &do_monitor_call;

	if (MACHINE_IS_VM) {
#ifdef CONFIG_PFAULT
		/*
		 * Try to get pfault pseudo page faults going.
		 */
		if (register_early_external_interrupt(0x2603, pfault_interrupt,
						      &ext_int_pfault) != 0)
			panic("Couldn't request external interrupt 0x2603");

		if (pfault_init() == 0) 
			return;
		
		/* Tough luck, no pfault. */
		unregister_early_external_interrupt(0x2603, pfault_interrupt,
						    &ext_int_pfault);
#endif
	}
}