traps.c
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上传日期:2013-02-24
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- /*
- * 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_page_fault;
- #ifdef CONFIG_PFAULT
- extern int pfault_init(void);
- extern void pfault_fini(void);
- extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
- #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 %016lxn",
- mode, (unsigned long) regs->psw.mask,
- (unsigned long) regs->psw.addr);
- printk("%s GPRS: %016lx %016lx %016lx %016lxn", mode,
- regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
- printk(" %016lx %016lx %016lx %016lxn",
- regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
- printk(" %016lx %016lx %016lx %016lxn",
- regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
- printk(" %016lx %016lx %016lx %016lxn",
- regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
- printk("%s ACRS: %08x %08x %08x %08xn", mode,
- regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
- printk(" %08x %08x %08x %08xn",
- regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
- printk(" %08x %08x %08x %08xn",
- regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
- printk(" %08x %08x %08x %08xn",
- 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: %016lxn",
- (unsigned long) task, task->thread.ksp);
- buf += sprintf(buf, "User PSW : %016lx %016lxn",
- (unsigned long) regs->psw.mask,
- (unsigned long) regs->psw.addr);
- buf += sprintf(buf, "User GPRS: %016lx %016lx %016lx %016lxn",
- regs->gprs[0], regs->gprs[1],
- regs->gprs[2], regs->gprs[3]);
- buf += sprintf(buf, " %016lx %016lx %016lx %016lxn",
- regs->gprs[4], regs->gprs[5],
- regs->gprs[6], regs->gprs[7]);
- buf += sprintf(buf, " %016lx %016lx %016lx %016lxn",
- regs->gprs[8], regs->gprs[9],
- regs->gprs[10], regs->gprs[11]);
- buf += sprintf(buf, " %016lx %016lx %016lx %016lxn",
- regs->gprs[12], regs->gprs[13],
- regs->gprs[14], regs->gprs[15]);
- buf += sprintf(buf, "User ACRS: %08x %08x %08x %08xn",
- regs->acrs[0], regs->acrs[1],
- regs->acrs[2], regs->acrs[3]);
- buf += sprintf(buf, " %08x %08x %08x %08xn",
- regs->acrs[4], regs->acrs[5],
- regs->acrs[6], regs->acrs[7]);
- buf += sprintf(buf, " %08x %08x %08x %08xn",
- regs->acrs[8], regs->acrs[9],
- regs->acrs[10], regs->acrs[11]);
- buf += sprintf(buf, " %08x %08x %08x %08xn",
- 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: %04lxn", str, err & 0xffff);
- show_regs(regs);
- bust_spinlocks(0);
- 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)
- {
- /*
- * 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;
- 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%lXn",
- interruption_code);
- show_regs(regs);
- #endif
- #else
- if (sysctl_userprocess_debug) {
- printk("User process fault: interruption code 0x%lXn",
- 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(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;
- location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
- /*
- * 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;
- int do_sig = 0;
- location = (__u16 *)(regs->psw.addr-S390_lowcore.pgm_ilc);
- /*
- * 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 %0nt"
- : "=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);
- }
- /* 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] = ÷_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;
- #ifdef CONFIG_PFAULT
- if (MACHINE_IS_VM) {
- /* request the 0x2603 external interrupt */
- if (register_external_interrupt(0x2603, pfault_interrupt) != 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_external_interrupt(0x2603,
- pfault_interrupt);
- }
- }
- #endif
- }
- void handle_per_exception(struct pt_regs *regs)
- {
- if(regs->psw.mask&PSW_PROBLEM_STATE)
- {
- per_struct *per_info=¤t->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 detectedn");
- 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;
- }
- }