Subversion Repositories or1k

/*

 *  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 <linux/module.h>

#include <asm/system.h>

#include <asm/uaccess.h>

#include <asm/io.h>

#include <asm/atomic.h>

#if CONFIG_REMOTE_DEBUG

#include <asm/gdb-stub.h>

#endif

#include <asm/cpcmd.h>

#include <asm/s390_ext.h>

/* 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_protection_exception;

extern pgm_check_handler_t do_segment_exception;

extern pgm_check_handler_t do_region_exception;

extern pgm_check_handler_t do_page_exception;

#ifdef CONFIG_PFAULT

extern int pfault_init(void);

extern void pfault_fini(void);

extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);

static ext_int_info_t ext_int_pfault;

#endif

int kstack_depth_to_print = 20;

/*

 * If the address is either in the .text section of the

 * kernel, or in the vmalloc'ed module regions, it *may*

 * be the address of a calling routine

 */

extern char _stext, _etext;

#ifdef CONFIG_MODULES

extern struct module *module_list;

extern struct module kernel_module;

static inline int kernel_text_address(unsigned long addr)

{

        int retval = 0;

        struct module *mod;

        if (addr >= (unsigned long) &_stext &&

            addr <= (unsigned long) &_etext)

                return 1;

        for (mod = module_list; mod != &kernel_module; mod = mod->next) {

                /* mod_bound tests for addr being inside the vmalloc'ed

                 * module area. Of course it'd be better to test only

                 * for the .text subset... */

                if (mod_bound(addr, 0, mod)) {

                        retval = 1;

                        break;

                }

        }

        return retval;

}

#else

static inline int kernel_text_address(unsigned long addr)

{

        return (addr >= (unsigned long) &_stext &&

                addr <= (unsigned long) &_etext);

}

#endif

void show_trace(unsigned long * stack)

{

        unsigned long backchain, low_addr, high_addr, ret_addr;

        int i;

        if (!stack)

                stack = (unsigned long*)&stack;

        printk("Call Trace: ");

        low_addr = ((unsigned long) stack) & PSW_ADDR_MASK;

        high_addr = (low_addr & (-THREAD_SIZE)) + THREAD_SIZE;

        /* Skip the first frame (biased stack) */

        backchain = *((unsigned long *) low_addr) & PSW_ADDR_MASK;

        /* Print up to 8 lines */

        for (i = 0; i < 8; i++) {

                if (backchain < low_addr || backchain >= high_addr)

                        break;

                ret_addr = *((unsigned long *) (backchain+112)) & PSW_ADDR_MASK;

                if (!kernel_text_address(ret_addr))

                        break;

                if (i && ((i % 3) == 0))

                        printk("\n   ");

                printk("[<%016lx>] ", ret_addr);

                low_addr = backchain;

                backchain = *((unsigned long *) backchain) & PSW_ADDR_MASK;

        }

        printk("\n");

}

void show_trace_task(struct task_struct *tsk)

{

        /*

         * We can't print the backtrace of a running process. It is

         * unreliable at best and can cause kernel oopses.

         */

        if (task_has_cpu(tsk))

                return;

        show_trace((unsigned long *) tsk->thread.ksp);

}

void show_stack(unsigned long *sp)

{

        unsigned long *stack;

        int i;

        // debugging aid: "show_stack(NULL);" prints the

        // back trace for this cpu.

        if (sp == NULL)

                sp = (unsigned long*) &sp;

        stack = sp;

        for (i = 0; i < kstack_depth_to_print; i++) {

                if (((addr_t) stack & (THREAD_SIZE-1)) == 0)

                        break;

                if (i && ((i % 4) == 0))

                        printk("\n       ");

                printk("%016lx ", *stack++);

        }

        printk("\n");

        show_trace(sp);

}

void show_registers(struct pt_regs *regs)

{

        mm_segment_t old_fs;

        char *mode;

        int i;

        mode = (regs->psw.mask & PSW_PROBLEM_STATE) ? "User" : "Krnl";

        printk("%s PSW : %016lx %016lx\n",

               mode, (unsigned long) regs->psw.mask,

               (unsigned long) regs->psw.addr);

        printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,

               regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);

        printk("           %016lx %016lx %016lx %016lx\n",

               regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);

        printk("           %016lx %016lx %016lx %016lx\n",

               regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);

        printk("           %016lx %016lx %016lx %016lx\n",

               regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);

        printk("%s ACRS: %08x %08x %08x %08x\n", mode,

               regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);

        printk("           %08x %08x %08x %08x\n",

               regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);

        printk("           %08x %08x %08x %08x\n",

               regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);

        printk("           %08x %08x %08x %08x\n",

               regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);

        /*

         * Print the first 20 byte of the instruction stream at the

         * time of the fault.

         */

        old_fs = get_fs();

        if (regs->psw.mask & PSW_PROBLEM_STATE)

                set_fs(USER_DS);

        else

                set_fs(KERNEL_DS);

        printk("%s Code: ", mode);

        for (i = 0; i < 20; i++) {

                unsigned char c;

                if (__get_user(c, (char *)(regs->psw.addr + i))) {

                        printk(" Bad PSW.");

                        break;

                }

                printk("%02x ", c);

        }

        set_fs(old_fs);

        printk("\n");

}

/* This is called from fs/proc/array.c */

char *task_show_regs(struct task_struct *task, char *buf)

{

        struct pt_regs *regs;

        regs = __KSTK_PTREGS(task);

        buf += sprintf(buf, "task: %016lx, ksp: %016lx\n",

                       (unsigned long) task, task->thread.ksp);

        buf += sprintf(buf, "User PSW : %016lx %016lx\n",

                       (unsigned long) regs->psw.mask,

                       (unsigned long) regs->psw.addr);

        buf += sprintf(buf, "User GPRS: %016lx %016lx %016lx %016lx\n",

                       regs->gprs[0], regs->gprs[1],

                       regs->gprs[2], regs->gprs[3]);

        buf += sprintf(buf, "           %016lx %016lx %016lx %016lx\n",

                       regs->gprs[4], regs->gprs[5],

                       regs->gprs[6], regs->gprs[7]);

        buf += sprintf(buf, "           %016lx %016lx %016lx %016lx\n",

                       regs->gprs[8], regs->gprs[9],

                       regs->gprs[10], regs->gprs[11]);

        buf += sprintf(buf, "           %016lx %016lx %016lx %016lx\n",

                       regs->gprs[12], regs->gprs[13],

                       regs->gprs[14], regs->gprs[15]);

        buf += sprintf(buf, "User ACRS: %08x %08x %08x %08x\n",

                       regs->acrs[0], regs->acrs[1],

                       regs->acrs[2], regs->acrs[3]);

        buf += sprintf(buf, "           %08x %08x %08x %08x\n",

                       regs->acrs[4], regs->acrs[5],

                       regs->acrs[6], regs->acrs[7]);

        buf += sprintf(buf, "           %08x %08x %08x %08x\n",

                       regs->acrs[8], regs->acrs[9],

                       regs->acrs[10], regs->acrs[11]);

        buf += sprintf(buf, "           %08x %08x %08x %08x\n",

                       regs->acrs[12], regs->acrs[13],

                       regs->acrs[14], regs->acrs[15]);

        return buf;

}

spinlock_t die_lock = SPIN_LOCK_UNLOCKED;

void die(const char * str, struct pt_regs * regs, long err)

{

        console_verbose();

        spin_lock_irq(&die_lock);

        bust_spinlocks(1);

        printk("%s: %04lx\n", str, err & 0xffff);

        show_regs(regs);

        bust_spinlocks(0);

        spin_unlock_irq(&die_lock);

        do_exit(SIGSEGV);

}

static void inline do_trap(long interruption_code, int signr, char *str,

                           struct pt_regs *regs, siginfo_t *info)

{

        /*

         * We got all needed information from the lowcore and can

         * now safely switch on interrupts.

         */

        if (regs->psw.mask & PSW_PROBLEM_STATE)

                __sti();

        if (regs->psw.mask & PSW_PROBLEM_STATE) {

                struct task_struct *tsk = current;

                tsk->thread.trap_no = interruption_code & 0xffff;

                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);

        }

}

static inline void *get_check_address(struct pt_regs *regs)

{

        return (void *) ADDR_BITS_REMOVE(regs->psw.addr-S390_lowcore.pgm_ilc);

}

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(regs, signal);

                        return 0;

                }

#endif

                return 1;

        }

        return 0;

}

#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); \

}

DO_ERROR(SIGSEGV, "Unknown program exception", default_trap_handler)

DO_ERROR_INFO(SIGBUS, "addressing exception", addressing_exception,

              BUS_ADRERR, 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(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,  "specification exception", specification_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)

{

        __u8 opcode[6];

        __u16 *location;

        int do_sig = 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_PROBLEM_STATE)

                __sti();

        /* 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);

}

asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)

{

        __u16 *location;

        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_PROBLEM_STATE)

                __sti();

        __asm__ volatile ("stfpc %0\n\t"

                          : "=m" (current->thread.fp_regs.fpc));

        if (current->thread.fp_regs.fpc & FPC_DXC_MASK)

                do_fp_trap(regs, location,

                           current->thread.fp_regs.fpc, interruption_code);

        else {

                siginfo_t info;

                info.si_signo = SIGILL;

                info.si_errno = 0;

                info.si_code = ILL_ILLOPN;

                info.si_addr = location;

                do_trap(interruption_code, SIGILL,

                        "data exception", regs, &info);

        }

}

/* 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[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[0x10] = &do_segment_exception;

        pgm_check_table[0x11] = &do_page_exception;

        pgm_check_table[0x1C] = &privileged_op;

        pgm_check_table[0x38] = &addressing_exception;

        pgm_check_table[0x3B] = &do_region_exception;

#ifdef CONFIG_PFAULT

        if (MACHINE_IS_VM) {

                /* request the 0x2603 external interrupt */

                if (register_early_external_interrupt(0x2603, pfault_interrupt,

                                                      &ext_int_pfault) != 0)

                        panic("Couldn't request external interrupt 0x2603");

                /*

                 * Try to get pfault pseudo page faults going.

                 */

                if (pfault_init() != 0) {

                        /* Tough luck, no pfault. */

                        unregister_early_external_interrupt(0x2603,

                                                            pfault_interrupt,

                                                            &ext_int_pfault);

                }

        }

#endif

}

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;

        }

}