arch/s390/kernel/traps.c - linux - Git at Google

 /*
  *  S390 version
  *    Copyright IBM Corp. 1999, 2000
  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
  *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
  *
  *  Derived from "arch/i386/kernel/traps.c"
  *    Copyright (C) 1991, 1992 Linus Torvalds
  */

 /*
  * 'Traps.c' handles hardware traps and faults after we have saved some
  * state in 'asm.s'.
  */
 #include <linux/kprobes.h>
 #include <linux/kdebug.h>
 #include <linux/module.h>
 #include <linux/ptrace.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <asm/fpu/api.h>
 #include "entry.h"

 static inline void __user *get_trap_ip(struct pt_regs *regs)
 {
 	unsigned long address;

 	if (regs->int_code & 0x200)
 		address = *(unsigned long *)(current->thread.trap_tdb + 24);
 	else
 		address = regs->psw.addr;
 	return (void __user *) (address - (regs->int_code >> 16));
 }

 int is_valid_bugaddr(unsigned long addr)
 {
 	return 1;
 }

 void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
 {
 	siginfo_t info;

 	if (user_mode(regs)) {
 		info.si_signo = si_signo;
 		info.si_errno = 0;
 		info.si_code = si_code;
 		info.si_addr = get_trap_ip(regs);
 		force_sig_info(si_signo, &info, current);
 		report_user_fault(regs, si_signo, 0);
         } else {
                 const struct exception_table_entry *fixup;
 		fixup = search_exception_tables(regs->psw.addr);
                 if (fixup)
 			regs->psw.addr = extable_fixup(fixup);
 		else {
 			enum bug_trap_type btt;

 			btt = report_bug(regs->psw.addr, regs);
 			if (btt == BUG_TRAP_TYPE_WARN)
 				return;
 			die(regs, str);
 		}
         }
 }

 static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
 {
 	if (notify_die(DIE_TRAP, str, regs, 0,
 		       regs->int_code, si_signo) == NOTIFY_STOP)
 		return;
 	do_report_trap(regs, si_signo, si_code, str);
 }
 NOKPROBE_SYMBOL(do_trap);

 void do_per_trap(struct pt_regs *regs)
 {
 	siginfo_t info;

 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
 		return;
 	if (!current->ptrace)
 		return;
 	info.si_signo = SIGTRAP;
 	info.si_errno = 0;
 	info.si_code = TRAP_HWBKPT;
 	info.si_addr =
 		(void __force __user *) current->thread.per_event.address;
 	force_sig_info(SIGTRAP, &info, current);
 }
 NOKPROBE_SYMBOL(do_per_trap);

 void default_trap_handler(struct pt_regs *regs)
 {
 	if (user_mode(regs)) {
 		report_user_fault(regs, SIGSEGV, 0);
 		do_exit(SIGSEGV);
 	} else
 		die(regs, "Unknown program exception");
 }

 #define DO_ERROR_INFO(name, signr, sicode, str) \
 void name(struct pt_regs *regs)			\
 {						\
 	do_trap(regs, signr, sicode, str);	\
 }

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

 static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
 {
 	int 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_code = FPE_FLTINV;
 		else if (fpc & 0x4000) /* div by 0 */
 			si_code = FPE_FLTDIV;
 		else if (fpc & 0x2000) /* overflow */
 			si_code = FPE_FLTOVF;
 		else if (fpc & 0x1000) /* underflow */
 			si_code = FPE_FLTUND;
 		else if (fpc & 0x0800) /* inexact */
 			si_code = FPE_FLTRES;
 	}
 	do_trap(regs, SIGFPE, si_code, "floating point exception");
 }

 void translation_exception(struct pt_regs *regs)
 {
 	/* May never happen. */
 	panic("Translation exception");
 }

 void illegal_op(struct pt_regs *regs)
 {
 	siginfo_t info;
         __u8 opcode[6];
 	__u16 __user *location;
 	int is_uprobe_insn = 0;
 	int signal = 0;

 	location = get_trap_ip(regs);

 	if (user_mode(regs)) {
 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
 			return;
 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 			if (current->ptrace) {
 				info.si_signo = SIGTRAP;
 				info.si_errno = 0;
 				info.si_code = TRAP_BRKPT;
 				info.si_addr = location;
 				force_sig_info(SIGTRAP, &info, current);
 			} else
 				signal = SIGILL;
 #ifdef CONFIG_UPROBES
 		} else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
 			is_uprobe_insn = 1;
 #endif
 		} else
 			signal = SIGILL;
 	}
 	/*
 	 * We got either an illegal op in kernel mode, or user space trapped
 	 * on a uprobes illegal instruction. See if kprobes or uprobes picks
 	 * it up. If not, SIGILL.
 	 */
 	if (is_uprobe_insn || !user_mode(regs)) {
 		if (notify_die(DIE_BPT, "bpt", regs, 0,
 			       3, SIGTRAP) != NOTIFY_STOP)
 			signal = SIGILL;
 	}
 	if (signal)
 		do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
 }
 NOKPROBE_SYMBOL(illegal_op);

 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
 	      "specification exception");

 void vector_exception(struct pt_regs *regs)
 {
 	int si_code, vic;

 	if (!MACHINE_HAS_VX) {
 		do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
 		return;
 	}

 	/* get vector interrupt code from fpc */
 	save_fpu_regs();
 	vic = (current->thread.fpu.fpc & 0xf00) >> 8;
 	switch (vic) {
 	case 1: /* invalid vector operation */
 		si_code = FPE_FLTINV;
 		break;
 	case 2: /* division by zero */
 		si_code = FPE_FLTDIV;
 		break;
 	case 3: /* overflow */
 		si_code = FPE_FLTOVF;
 		break;
 	case 4: /* underflow */
 		si_code = FPE_FLTUND;
 		break;
 	case 5:	/* inexact */
 		si_code = FPE_FLTRES;
 		break;
 	default: /* unknown cause */
 		si_code = 0;
 	}
 	do_trap(regs, SIGFPE, si_code, "vector exception");
 }

 void data_exception(struct pt_regs *regs)
 {
 	int signal = 0;

 	save_fpu_regs();
 	if (current->thread.fpu.fpc & FPC_DXC_MASK)
 		signal = SIGFPE;
 	else
 		signal = SIGILL;
 	if (signal == SIGFPE)
 		do_fp_trap(regs, current->thread.fpu.fpc);
 	else if (signal)
 		do_trap(regs, signal, ILL_ILLOPN, "data exception");
 }

 void space_switch_exception(struct pt_regs *regs)
 {
 	/* Set user psw back to home space mode. */
 	if (user_mode(regs))
 		regs->psw.mask |= PSW_ASC_HOME;
 	/* Send SIGILL. */
 	do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
 }

 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.");
 }
 NOKPROBE_SYMBOL(kernel_stack_overflow);

 void __init trap_init(void)
 {
 	local_mcck_enable();
 }
	/*
	* S390 version
	* Copyright IBM Corp. 1999, 2000
	* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
	* Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
	*
	* Derived from "arch/i386/kernel/traps.c"
	* Copyright (C) 1991, 1992 Linus Torvalds
	*/

	/*
	* 'Traps.c' handles hardware traps and faults after we have saved some
	* state in 'asm.s'.
	*/
	#include <linux/kprobes.h>
	#include <linux/kdebug.h>
	#include <linux/module.h>
	#include <linux/ptrace.h>
	#include <linux/sched.h>
	#include <linux/mm.h>
	#include <linux/slab.h>
	#include <asm/fpu/api.h>
	#include "entry.h"

	static inline void __user get_trap_ip(struct pt_regs regs)
	{
	unsigned long address;

	if (regs->int_code & 0x200)
	address = (unsigned long )(current->thread.trap_tdb + 24);
	else
	address = regs->psw.addr;
	return (void __user *) (address - (regs->int_code >> 16));
	}

	int is_valid_bugaddr(unsigned long addr)
	{
	return 1;
	}

	void do_report_trap(struct pt_regs regs, int si_signo, int si_code, char str)
	{
	siginfo_t info;

	if (user_mode(regs)) {
	info.si_signo = si_signo;
	info.si_errno = 0;
	info.si_code = si_code;
	info.si_addr = get_trap_ip(regs);
	force_sig_info(si_signo, &info, current);
	report_user_fault(regs, si_signo, 0);
	} else {
	const struct exception_table_entry *fixup;
	fixup = search_exception_tables(regs->psw.addr);
	if (fixup)
	regs->psw.addr = extable_fixup(fixup);
	else {
	enum bug_trap_type btt;

	btt = report_bug(regs->psw.addr, regs);
	if (btt == BUG_TRAP_TYPE_WARN)
	return;
	die(regs, str);
	}
	}
	}

	static void do_trap(struct pt_regs regs, int si_signo, int si_code, char str)
	{
	if (notify_die(DIE_TRAP, str, regs, 0,
	regs->int_code, si_signo) == NOTIFY_STOP)
	return;
	do_report_trap(regs, si_signo, si_code, str);
	}
	NOKPROBE_SYMBOL(do_trap);

	void do_per_trap(struct pt_regs *regs)
	{
	siginfo_t info;

	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
	return;
	if (!current->ptrace)
	return;
	info.si_signo = SIGTRAP;
	info.si_errno = 0;
	info.si_code = TRAP_HWBKPT;
	info.si_addr =
	(void __force __user *) current->thread.per_event.address;
	force_sig_info(SIGTRAP, &info, current);
	}
	NOKPROBE_SYMBOL(do_per_trap);

	void default_trap_handler(struct pt_regs *regs)
	{
	if (user_mode(regs)) {
	report_user_fault(regs, SIGSEGV, 0);
	do_exit(SIGSEGV);
	} else
	die(regs, "Unknown program exception");
	}

	#define DO_ERROR_INFO(name, signr, sicode, str) \
	void name(struct pt_regs *regs) \
	{ \
	do_trap(regs, signr, sicode, str); \
	}

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

	static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
	{
	int 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_code = FPE_FLTINV;
	else if (fpc & 0x4000) /* div by 0 */
	si_code = FPE_FLTDIV;
	else if (fpc & 0x2000) /* overflow */
	si_code = FPE_FLTOVF;
	else if (fpc & 0x1000) /* underflow */
	si_code = FPE_FLTUND;
	else if (fpc & 0x0800) /* inexact */
	si_code = FPE_FLTRES;
	}
	do_trap(regs, SIGFPE, si_code, "floating point exception");
	}

	void translation_exception(struct pt_regs *regs)
	{
	/* May never happen. */
	panic("Translation exception");
	}

	void illegal_op(struct pt_regs *regs)
	{
	siginfo_t info;
	__u8 opcode[6];
	__u16 __user *location;
	int is_uprobe_insn = 0;
	int signal = 0;

	location = get_trap_ip(regs);

	if (user_mode(regs)) {
	if (get_user(((__u16 ) opcode), (__u16 __user *) location))
	return;
	if (((__u16 ) opcode) == S390_BREAKPOINT_U16) {
	if (current->ptrace) {
	info.si_signo = SIGTRAP;
	info.si_errno = 0;
	info.si_code = TRAP_BRKPT;
	info.si_addr = location;
	force_sig_info(SIGTRAP, &info, current);
	} else
	signal = SIGILL;
	#ifdef CONFIG_UPROBES
	} else if (((__u16 ) opcode) == UPROBE_SWBP_INSN) {
	is_uprobe_insn = 1;
	#endif
	} else
	signal = SIGILL;
	}
	/*
	* We got either an illegal op in kernel mode, or user space trapped
	* on a uprobes illegal instruction. See if kprobes or uprobes picks
	* it up. If not, SIGILL.
	*/
	if (is_uprobe_insn \|\| !user_mode(regs)) {
	if (notify_die(DIE_BPT, "bpt", regs, 0,
	3, SIGTRAP) != NOTIFY_STOP)
	signal = SIGILL;
	}
	if (signal)
	do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
	}
	NOKPROBE_SYMBOL(illegal_op);

	DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
	"specification exception");

	void vector_exception(struct pt_regs *regs)
	{
	int si_code, vic;

	if (!MACHINE_HAS_VX) {
	do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
	return;
	}

	/* get vector interrupt code from fpc */
	save_fpu_regs();
	vic = (current->thread.fpu.fpc & 0xf00) >> 8;
	switch (vic) {
	case 1: /* invalid vector operation */
	si_code = FPE_FLTINV;
	break;
	case 2: /* division by zero */
	si_code = FPE_FLTDIV;
	break;
	case 3: /* overflow */
	si_code = FPE_FLTOVF;
	break;
	case 4: /* underflow */
	si_code = FPE_FLTUND;
	break;
	case 5: /* inexact */
	si_code = FPE_FLTRES;
	break;
	default: /* unknown cause */
	si_code = 0;
	}
	do_trap(regs, SIGFPE, si_code, "vector exception");
	}

	void data_exception(struct pt_regs *regs)
	{
	int signal = 0;

	save_fpu_regs();
	if (current->thread.fpu.fpc & FPC_DXC_MASK)
	signal = SIGFPE;
	else
	signal = SIGILL;
	if (signal == SIGFPE)
	do_fp_trap(regs, current->thread.fpu.fpc);
	else if (signal)
	do_trap(regs, signal, ILL_ILLOPN, "data exception");
	}

	void space_switch_exception(struct pt_regs *regs)
	{
	/* Set user psw back to home space mode. */
	if (user_mode(regs))
	regs->psw.mask \|= PSW_ASC_HOME;
	/* Send SIGILL. */
	do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
	}

	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.");
	}
	NOKPROBE_SYMBOL(kernel_stack_overflow);

	void __init trap_init(void)
	{
	local_mcck_enable();
	}