patch-2.3.99-pre8 linux/arch/s390/kernel/traps.c

• Lines: 481
• Date: Fri May 12 11:41:45 2000
• Orig file: v2.3.99-pre7/linux/arch/s390/kernel/traps.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.99-pre7/linux/arch/s390/kernel/traps.c linux/arch/s390/kernel/traps.c
@@ -0,0 +1,480 @@
+/*
+ *  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];
+
+extern pgm_check_handler_t default_trap_handler;
+extern pgm_check_handler_t do_page_fault;
+
+asmlinkage int system_call(void);
+
+static inline void console_verbose(void)
+{
+        extern int console_loglevel;
+        console_loglevel = 15;
+}
+
+#define DO_ERROR(trapnr, signr, str, name, tsk) \
+asmlinkage void name(struct pt_regs * regs, long error_code) \
+{ \
+        tsk->thread.error_code = error_code; \
+        tsk->thread.trap_no = trapnr; \
+	die_if_no_fixup(str,regs,error_code); \
+        force_sig(signr, tsk); \
+}
+
+
+void page_exception(void);
+
+/* TODO: define these as 'pgm_check_handler_t xxx;'
+asmlinkage void divide_error(void);
+asmlinkage void debug(void);
+asmlinkage void nmi(void);
+asmlinkage void int3(void);
+asmlinkage void overflow(void);
+asmlinkage void bounds(void);
+asmlinkage void invalid_op(void);
+asmlinkage void device_not_available(void);
+asmlinkage void double_fault(void);
+asmlinkage void coprocessor_segment_overrun(void);
+asmlinkage void invalid_TSS(void);
+asmlinkage void segment_not_present(void);
+asmlinkage void stack_segment(void);
+asmlinkage void general_protection(void);
+asmlinkage void coprocessor_error(void);
+asmlinkage void reserved(void);
+asmlinkage void alignment_check(void);
+asmlinkage void spurious_interrupt_bug(void);
+*/
+
+int kstack_depth_to_print = 24;
+
+/*
+ * These constants are for searching for possible module text
+ * segments.  VMALLOC_OFFSET comes from mm/vmalloc.c; MODULE_RANGE is
+ * a guess of how much space is likely to be vmalloced.
+ */
+#define VMALLOC_OFFSET (8*1024*1024)
+#define MODULE_RANGE (8*1024*1024)
+
+void show_crashed_task_info(void)
+{
+	printk("CPU:    %d\n",smp_processor_id());
+	printk("Process %s (pid: %d, stackpage=%08X)\n",
+                current->comm, current->pid, 4096+(addr_t)current);
+	show_regs(current,NULL,NULL);
+}
+#if 0
+static void show_registers(struct pt_regs *regs)
+{
+        printk("CPU:    %d\nPSW:    %08lx %08lx\n",
+                smp_processor_id(), (unsigned long) regs->psw.mask,
+                (unsigned long) regs->psw.addr);
+        printk("GPRS:\n");
+
+        printk("%08lx  %08lx  %08lx  %08lx\n",
+                regs->gprs[0], regs->gprs[1],
+                regs->gprs[2], regs->gprs[3]);
+        printk("%08lx  %08lx  %08lx  %08lx\n",
+                regs->gprs[4], regs->gprs[5],
+                regs->gprs[6], regs->gprs[7]);
+        printk("%08lx  %08lx  %08lx  %08lx\n",
+                regs->gprs[8], regs->gprs[9],
+                regs->gprs[10], regs->gprs[11]);
+        printk("%08lx  %08lx  %08lx  %08lx\n",
+                regs->gprs[12], regs->gprs[13],
+                regs->gprs[14], regs->gprs[15]);
+        printk("Process %s (pid: %d, stackpage=%08lx)\nStack: ",
+                current->comm, current->pid, 4096+(unsigned long)current);
+/*
+        stack = (unsigned long *) esp;
+        for(i=0; i < kstack_depth_to_print; i++) {
+                if (((long) stack & 4095) == 0)
+                        break;
+                if (i && ((i % 8) == 0))
+                        printk("\n       ");
+                printk("%08lx ", get_seg_long(ss,stack++));
+        }
+        printk("\nCall Trace: ");
+        stack = (unsigned long *) esp;
+        i = 1;
+        module_start = PAGE_OFFSET + (max_mapnr << PAGE_SHIFT);
+        module_start = ((module_start + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1));
+        module_end = module_start + MODULE_RANGE;
+        while (((long) stack & 4095) != 0) {
+                addr = get_seg_long(ss, stack++); */
+                /*
+                 * If the address is either in the text segment of the
+                 * kernel, or in the region which contains vmalloc'ed
+                 * memory, it *may* be the address of a calling
+                 * routine; if so, print it so that someone tracing
+                 * down the cause of the crash will be able to figure
+                 * out the call path that was taken.
+                 */
+/*                if (((addr >= (unsigned long) &_stext) &&
+                     (addr <= (unsigned long) &_etext)) ||
+                    ((addr >= module_start) && (addr <= module_end))) {
+                        if (i && ((i % 8) == 0))
+                                printk("\n       ");
+                        printk("[<%08lx>] ", addr);
+                        i++;
+                }
+        }
+        printk("\nCode: ");
+        for(i=0;i<20;i++)
+                printk("%02x ",0xff & get_seg_byte(regs->xcs & 0xffff,(i+(char *)regs->eip)));
+        printk("\n");
+*/
+}
+#endif
+
+
+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_crashed_task_info();
+        spin_unlock_irq(&die_lock);
+        do_exit(SIGSEGV);
+}
+
+int check_for_fixup(struct pt_regs * regs)
+{
+        if (!(regs->psw.mask & PSW_PROBLEM_STATE)) {
+		unsigned long fixup;
+		fixup = search_exception_table(regs->psw.addr);
+		if (fixup) {
+			regs->psw.addr = fixup;
+			return 1;
+		}
+	}
+	return 0;
+}
+
+int do_debugger_trap(struct pt_regs *regs,int signal)
+{
+	if(regs->psw.mask&PSW_PROBLEM_STATE)
+	{
+		if(current->flags & PF_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;
+}
+
+static void die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
+{
+	if (!(regs->psw.mask & PSW_PROBLEM_STATE)) {
+		unsigned long fixup;
+		fixup = search_exception_table(regs->psw.addr);
+		if (fixup) {
+			regs->psw.addr = fixup;
+			return;
+		}
+		die(str, regs, err);
+	}
+}
+
+asmlinkage void default_trap_handler(struct pt_regs * regs, long error_code)
+{
+        current->thread.error_code = error_code;
+        current->thread.trap_no = error_code;
+        die_if_no_fixup("Unknown program exception",regs,error_code);
+        force_sig(SIGSEGV, current);
+}
+
+DO_ERROR(2, SIGILL, "privileged operation", privileged_op, current)
+DO_ERROR(3, SIGILL, "execute exception", execute_exception, current)
+DO_ERROR(5, SIGSEGV, "addressing exception", addressing_exception, current)
+DO_ERROR(9, SIGFPE, "fixpoint divide exception", divide_exception, current)
+DO_ERROR(0x12, SIGILL, "translation exception", translation_exception, current)
+DO_ERROR(0x13, SIGILL, "special operand exception", special_op_exception, current)
+DO_ERROR(0x15, SIGILL, "operand exception", operand_exception, current)
+
+/* need to define
+DO_ERROR( 6, SIGILL,  "invalid operand", invalid_op, current)
+DO_ERROR( 8, SIGSEGV, "double fault", double_fault, current)
+DO_ERROR( 9, SIGFPE,  "coprocessor segment overrun", coprocessor_segment_overrun, last_task_used_math)
+DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS, current)
+DO_ERROR(11, SIGBUS,  "segment not present", segment_not_present, current)
+DO_ERROR(12, SIGBUS,  "stack segment", stack_segment, current)
+DO_ERROR(17, SIGSEGV, "alignment check", alignment_check, current)
+DO_ERROR(18, SIGSEGV, "reserved", reserved, current)
+DO_ERROR(19, SIGSEGV, "cache flush denied", cache_flush_denied, current)
+*/
+
+#ifdef CONFIG_IEEEFPU_EMULATION
+
+asmlinkage void illegal_op(struct pt_regs * regs, long error_code)
+{
+        __u8 opcode[6];
+	__u16 *location;
+	int do_sig = 0;
+	int problem_state=(regs->psw.mask & PSW_PROBLEM_STATE);
+
+        lock_kernel();
+	location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
+	if(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 if (problem_state )
+	{
+		if (opcode[0] == 0xb3) {
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			do_sig = math_emu_b3(opcode, regs);
+                } else if (opcode[0] == 0xed) {
+			get_user(*((__u32 *) (opcode+2)),
+				 (__u32 *)(location+1));
+			do_sig = math_emu_ed(opcode, regs);
+		} else if (*((__u16 *) opcode) == 0xb299) {
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			do_sig = math_emu_srnm(opcode, regs);
+		} else if (*((__u16 *) opcode) == 0xb29c) {
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			do_sig = math_emu_stfpc(opcode, regs);
+		} else if (*((__u16 *) opcode) == 0xb29d) {
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			do_sig = math_emu_lfpc(opcode, regs);
+		} else
+			do_sig = 1;
+        } else
+		do_sig = 1;
+	if (do_sig) {
+		current->thread.error_code = error_code;
+		current->thread.trap_no = 1;
+		force_sig(SIGILL, current);
+		die_if_no_fixup("illegal operation", regs, error_code);
+        }
+        unlock_kernel();
+}
+
+asmlinkage void specification_exception(struct pt_regs * regs, long error_code)
+{
+        __u8 opcode[6];
+	__u16 *location;
+	int do_sig = 0;
+
+        lock_kernel();
+        if (regs->psw.mask & 0x00010000L) {
+		location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
+		get_user(*((__u16 *) opcode), location);
+		switch (opcode[0]) {
+		case 0x28: /* LDR Rx,Ry   */
+			math_emu_ldr(opcode);
+			break;
+		case 0x38: /* LER Rx,Ry   */
+			math_emu_ler(opcode);
+			break;
+		case 0x60: /* STD R,D(X,B) */
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			math_emu_std(opcode, regs);
+			break;
+		case 0x68: /* LD R,D(X,B) */
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			math_emu_ld(opcode, regs);
+			break;
+		case 0x70: /* STE R,D(X,B) */
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			math_emu_ste(opcode, regs);
+			break;
+		case 0x78: /* LE R,D(X,B) */
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			math_emu_le(opcode, regs);
+			break;
+		default:
+			do_sig = 1;
+			break;
+                }
+        } else
+		do_sig = 1;
+	if (do_sig) {
+		current->thread.error_code = error_code;
+		current->thread.trap_no = 1;
+		force_sig(SIGILL, current);
+		die_if_no_fixup("illegal operation", regs, error_code);
+        }
+        unlock_kernel();
+}
+
+asmlinkage void data_exception(struct pt_regs * regs, long error_code)
+{
+        __u8 opcode[6];
+	__u16 *location;
+	int do_sig = 0;
+
+        lock_kernel();
+        if (regs->psw.mask & 0x00010000L) {
+		location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
+		get_user(*((__u16 *) opcode), location);
+		switch (opcode[0]) {
+		case 0x28: /* LDR Rx,Ry   */
+			math_emu_ldr(opcode);
+			break;
+		case 0x38: /* LER Rx,Ry   */
+			math_emu_ler(opcode);
+			break;
+		case 0x60: /* STD R,D(X,B) */
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			math_emu_std(opcode, regs);
+			break;
+		case 0x68: /* LD R,D(X,B) */
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			math_emu_ld(opcode, regs);
+			break;
+		case 0x70: /* STE R,D(X,B) */
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			math_emu_ste(opcode, regs);
+			break;
+		case 0x78: /* LE R,D(X,B) */
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			math_emu_le(opcode, regs);
+			break;
+		case 0xb3:
+			get_user(*((__u16 *) (opcode+2)), location+1);
+			do_sig = math_emu_b3(opcode, regs);
+			break;
+                case 0xed:
+			get_user(*((__u32 *) (opcode+2)),
+				 (__u32 *)(location+1));
+			do_sig = math_emu_ed(opcode, regs);
+			break;
+	        case 0xb2:
+			if (opcode[1] == 0x99) {
+				get_user(*((__u16 *) (opcode+2)), location+1);
+				do_sig = math_emu_srnm(opcode, regs);
+			} else if (opcode[1] == 0x9c) {
+				get_user(*((__u16 *) (opcode+2)), location+1);
+				do_sig = math_emu_stfpc(opcode, regs);
+			} else if (opcode[1] == 0x9d) {
+				get_user(*((__u16 *) (opcode+2)), location+1);
+				do_sig = math_emu_lfpc(opcode, regs);
+			} else
+				do_sig = 1;
+			break;
+		default:
+			do_sig = 1;
+			break;
+                }
+        } else
+		do_sig = 1;
+	if (do_sig) {
+		current->thread.error_code = error_code;
+		current->thread.trap_no = 1;
+		force_sig(SIGILL, current);
+		die_if_no_fixup("illegal operation", regs, error_code);
+        }
+        unlock_kernel();
+}
+
+#else
+DO_ERROR(1, SIGILL, "illegal operation", illegal_op, current)
+DO_ERROR(6, SIGILL, "specification exception", specification_exception, current)
+DO_ERROR(7, SIGILL, "data exception", data_exception, current)
+#endif /* CONFIG_IEEEFPU_EMULATION */
+
+
+/* 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;
+}
+
+
+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_crashed_task_info();
+		/* Hopefully switching off per tracing will help us survive */
+		regs->psw.mask &= ~PSW_PER_MASK;
+	}
+}
+