patch-2.4.2 linux/arch/s390x/kernel/traps.c

• Lines: 249
• Date: Tue Feb 13 14:13:44 2001
• Orig file: v2.4.1/linux/arch/s390x/kernel/traps.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.1/linux/arch/s390x/kernel/traps.c linux/arch/s390x/kernel/traps.c
@@ -0,0 +1,248 @@
+/*
+ *  arch/s390/kernel/traps.c
+ *
+ *  S390 version
+ *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    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/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/atomic.h>
+#include <asm/mathemu.h>
+#if CONFIG_REMOTE_DEBUG
+#include <asm/gdb-stub.h>
+#endif
+
+/* Called from entry.S only */
+extern void handle_per_exception(struct pt_regs *regs);
+
+typedef void pgm_check_handler_t(struct pt_regs *, long);
+pgm_check_handler_t *pgm_check_table[128];
+
+#ifdef CONFIG_SYSCTL
+#ifdef CONFIG_PROCESS_DEBUG
+int sysctl_userprocess_debug = 1;
+#else
+int sysctl_userprocess_debug = 0;
+#endif
+#endif
+
+extern pgm_check_handler_t do_page_fault;
+
+spinlock_t die_lock;
+
+void die(const char * str, struct pt_regs * regs, long err)
+{
+        console_verbose();
+        spin_lock_irq(&die_lock);
+        printk("%s: %04lx\n", str, err & 0xffff);
+        show_regs(regs);
+        spin_unlock_irq(&die_lock);
+        do_exit(SIGSEGV);
+}
+
+#define DO_ERROR(signr, str, name) \
+asmlinkage void name(struct pt_regs * regs, long interruption_code) \
+{ \
+	do_trap(interruption_code, signr, str, regs, NULL); \
+}
+
+#define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
+asmlinkage void name(struct pt_regs * regs, long interruption_code) \
+{ \
+        siginfo_t info; \
+        info.si_signo = signr; \
+        info.si_errno = 0; \
+        info.si_code = sicode; \
+        info.si_addr = (void *)siaddr; \
+        do_trap(interruption_code, signr, str, regs, &info); \
+}
+
+static void inline do_trap(long interruption_code, int signr, char *str,
+                           struct pt_regs *regs, siginfo_t *info)
+{
+        if (regs->psw.mask & PSW_PROBLEM_STATE) {
+                struct task_struct *tsk = current;
+                tsk->thread.trap_no = interruption_code;
+		if (info)
+			force_sig_info(signr, info, tsk);
+		else
+                	force_sig(signr, tsk);
+#ifndef CONFIG_SYSCTL
+#ifdef CONFIG_PROCESS_DEBUG
+                printk("User process fault: interruption code 0x%lX\n",
+                       interruption_code);
+                show_regs(regs);
+#endif
+#else
+		if (sysctl_userprocess_debug) {
+			printk("User process fault: interruption code 0x%lX\n",
+			       interruption_code);
+			show_regs(regs);
+		}
+#endif
+        } else {
+                unsigned long fixup = search_exception_table(regs->psw.addr);
+                if (fixup)
+                        regs->psw.addr = fixup;
+                else
+                        die(str, regs, interruption_code);
+        }
+}
+
+int do_debugger_trap(struct pt_regs *regs,int signal)
+{
+	if(regs->psw.mask&PSW_PROBLEM_STATE)
+	{
+		if(current->ptrace & PT_PTRACED)
+			force_sig(signal,current);
+		else
+			return 1;
+	}
+	else
+	{
+#if CONFIG_REMOTE_DEBUG
+		if(gdb_stub_initialised)
+		{
+			gdb_stub_handle_exception((gdb_pt_regs *)regs,signal);
+			return 0;
+		}
+#endif
+		return 1;
+	}
+	return 0;
+}
+
+DO_ERROR(SIGSEGV, "Unknown program exception", default_trap_handler)
+DO_ERROR(SIGILL,  "privileged operation", privileged_op)
+DO_ERROR(SIGILL,  "execute exception", execute_exception)
+DO_ERROR(SIGSEGV, "addressing exception", addressing_exception)
+DO_ERROR(SIGFPE,  "fixpoint divide exception", divide_exception)
+DO_ERROR(SIGILL,  "translation exception", translation_exception)
+DO_ERROR(SIGILL,  "special operand exception", special_op_exception)
+DO_ERROR(SIGILL,  "operand exception", operand_exception)
+DO_ERROR(SIGILL,  "specification exception", specification_exception);
+
+asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
+{
+        __u8 opcode[6];
+	__u16 *location;
+	int do_sig = 0;
+
+        lock_kernel();
+	location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
+	/* WARNING don't change this check back to */
+	/* int problem_state=(regs->psw.mask & PSW_PROBLEM_STATE); */
+	/* & then doing if(problem_state) an int is too small for this */
+	/* check on 64 bit. */
+	if(regs->psw.mask & PSW_PROBLEM_STATE)
+		get_user(*((__u16 *) opcode), location);
+	else
+		*((__u16 *)opcode)=*((__u16 *)location);
+	if(*((__u16 *)opcode)==S390_BREAKPOINT_U16)
+        {
+		if(do_debugger_trap(regs,SIGTRAP))
+			do_sig=1;
+	}
+	else
+		do_sig = 1;
+	if (do_sig)
+		do_trap(interruption_code, SIGILL, "illegal operation", regs, NULL);
+        unlock_kernel();
+}
+
+asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
+{
+	__u16 *location;
+	int do_sig = 0;
+
+        lock_kernel();
+	location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
+	__asm__ volatile ("stfpc %0\n\t" 
+			  : "=m" (current->thread.fp_regs.fpc));
+	/* Same code should work when we implement fpu emulation */
+	/* provided we call data exception from the fpu emulator */
+	if(current->thread.fp_regs.fpc&FPC_DXC_MASK)
+	{
+		current->thread.ieee_instruction_pointer=(addr_t)location;
+		force_sig(SIGFPE, current);
+	}
+	else
+		do_sig = 1;
+        if (do_sig)
+                do_trap(interruption_code, SIGILL, "data exception", regs, NULL);
+        unlock_kernel();
+}
+
+
+
+/* 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[5] = &addressing_exception;
+        pgm_check_table[6] = &specification_exception;
+        pgm_check_table[7] = &data_exception;
+        pgm_check_table[9] = &divide_exception;
+        pgm_check_table[0x12] = &translation_exception;
+        pgm_check_table[0x13] = &special_op_exception;
+        pgm_check_table[0x15] = &operand_exception;
+        pgm_check_table[4] = &do_page_fault;
+        pgm_check_table[0x10] = &do_page_fault;
+        pgm_check_table[0x11] = &do_page_fault;
+        pgm_check_table[0x1C] = &privileged_op;
+        pgm_check_table[0x38] = &addressing_exception;
+        pgm_check_table[0x3B] = &do_page_fault;
+}
+
+
+void handle_per_exception(struct pt_regs *regs)
+{
+	if(regs->psw.mask&PSW_PROBLEM_STATE)
+	{
+		per_struct *per_info=&current->thread.per_info;
+		per_info->lowcore.words.perc_atmid=S390_lowcore.per_perc_atmid;
+		per_info->lowcore.words.address=S390_lowcore.per_address;
+		per_info->lowcore.words.access_id=S390_lowcore.per_access_id;
+	}
+	if(do_debugger_trap(regs,SIGTRAP))
+	{
+		/* I've seen this possibly a task structure being reused ? */
+		printk("Spurious per exception detected\n");
+		printk("switching off per tracing for this task.\n");
+		show_regs(regs);
+		/* Hopefully switching off per tracing will help us survive */
+		regs->psw.mask &= ~PSW_PER_MASK;
+	}
+}
+