/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if CONFIG_REMOTE_DEBUG #include #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] = ÷_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=¤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 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; } }