/* * 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 #include #include #include /* 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_page_exception; extern pgm_check_handler_t do_pseudo_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); static ext_int_info_t ext_int_pfault; #endif int kstack_depth_to_print = 12; /* * 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+56)) & PSW_ADDR_MASK; if (!kernel_text_address(ret_addr)) break; if (i && ((i % 6) == 0)) printk("\n "); printk("[<%08lx>] ", 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 % 8) == 0)) printk("\n "); printk("%08lx ", *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 : %08lx %08lx\n", mode, (unsigned long) regs->psw.mask, (unsigned long) regs->psw.addr); printk("%s GPRS: %08x %08x %08x %08x\n", mode, regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); printk(" %08x %08x %08x %08x\n", regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); printk(" %08x %08x %08x %08x\n", regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); printk(" %08x %08x %08x %08x\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 *buffer) { struct pt_regs *regs; regs = __KSTK_PTREGS(task); buffer += sprintf(buffer, "task: %08lx, ksp: %08x\n", (unsigned long) task, task->thread.ksp); buffer += sprintf(buffer, "User PSW : %08lx %08lx\n", (unsigned long) regs->psw.mask, (unsigned long) regs->psw.addr); buffer += sprintf(buffer, "User GPRS: %08x %08x %08x %08x\n", regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); buffer += sprintf(buffer, " %08x %08x %08x %08x\n", regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); buffer += sprintf(buffer, " %08x %08x %08x %08x\n", regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); buffer += sprintf(buffer, " %08x %08x %08x %08x\n", regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n", regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]); buffer += sprintf(buffer, " %08x %08x %08x %08x\n", regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]); buffer += sprintf(buffer, " %08x %08x %08x %08x\n", regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]); buffer += sprintf(buffer, " %08x %08x %08x %08x\n", regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]); return buffer; } 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, "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 signal = 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(); 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)) signal = SIGILL; } #ifdef CONFIG_MATHEMU else if (regs->psw.mask & PSW_PROBLEM_STATE) { if (opcode[0] == 0xb3) { get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_b3(opcode, regs); } else if (opcode[0] == 0xed) { get_user(*((__u32 *) (opcode+2)), (__u32 *)(location+1)); signal = math_emu_ed(opcode, regs); } else if (*((__u16 *) opcode) == 0xb299) { get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_srnm(opcode, regs); } else if (*((__u16 *) opcode) == 0xb29c) { get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_stfpc(opcode, regs); } else if (*((__u16 *) opcode) == 0xb29d) { get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_lfpc(opcode, regs); } else signal = SIGILL; } #endif else signal = SIGILL; if (signal == SIGFPE) do_fp_trap(regs, location, current->thread.fp_regs.fpc, interruption_code); else if (signal) do_trap(interruption_code, signal, "illegal operation", regs, NULL); } #ifdef CONFIG_MATHEMU asmlinkage void specification_exception(struct pt_regs * regs, long interruption_code) { __u8 opcode[6]; __u16 *location = NULL; int signal = 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(); if (regs->psw.mask & PSW_PROBLEM_STATE) { get_user(*((__u16 *) opcode), location); switch (opcode[0]) { case 0x28: /* LDR Rx,Ry */ signal = math_emu_ldr(opcode); break; case 0x38: /* LER Rx,Ry */ signal = math_emu_ler(opcode); break; case 0x60: /* STD R,D(X,B) */ get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_std(opcode, regs); break; case 0x68: /* LD R,D(X,B) */ get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_ld(opcode, regs); break; case 0x70: /* STE R,D(X,B) */ get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_ste(opcode, regs); break; case 0x78: /* LE R,D(X,B) */ get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_le(opcode, regs); break; default: signal = SIGILL; break; } } else signal = SIGILL; if (signal == SIGFPE) do_fp_trap(regs, location, current->thread.fp_regs.fpc, interruption_code); else if (signal) { siginfo_t info; info.si_signo = signal; info.si_errno = 0; info.si_code = ILL_ILLOPN; info.si_addr = location; do_trap(interruption_code, signal, "specification exception", regs, &info); } } #else DO_ERROR_INFO(SIGILL, "specification exception", specification_exception, ILL_ILLOPN, get_check_address(regs)); #endif asmlinkage void data_exception(struct pt_regs * regs, long interruption_code) { __u8 opcode[6]; __u16 *location; int signal = 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(); if (MACHINE_HAS_IEEE) __asm__ volatile ("stfpc %0\n\t" : "=m" (current->thread.fp_regs.fpc)); #ifdef CONFIG_MATHEMU else if (regs->psw.mask & PSW_PROBLEM_STATE) { get_user(*((__u16 *) opcode), location); switch (opcode[0]) { case 0x28: /* LDR Rx,Ry */ signal = math_emu_ldr(opcode); break; case 0x38: /* LER Rx,Ry */ signal = math_emu_ler(opcode); break; case 0x60: /* STD R,D(X,B) */ get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_std(opcode, regs); break; case 0x68: /* LD R,D(X,B) */ get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_ld(opcode, regs); break; case 0x70: /* STE R,D(X,B) */ get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_ste(opcode, regs); break; case 0x78: /* LE R,D(X,B) */ get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_le(opcode, regs); break; case 0xb3: get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_b3(opcode, regs); break; case 0xed: get_user(*((__u32 *) (opcode+2)), (__u32 *)(location+1)); signal = math_emu_ed(opcode, regs); break; case 0xb2: if (opcode[1] == 0x99) { get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_srnm(opcode, regs); } else if (opcode[1] == 0x9c) { get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_stfpc(opcode, regs); } else if (opcode[1] == 0x9d) { get_user(*((__u16 *) (opcode+2)), location+1); signal = math_emu_lfpc(opcode, regs); } else signal = SIGILL; break; default: signal = SIGILL; break; } } #endif if (current->thread.fp_regs.fpc & FPC_DXC_MASK) signal = SIGFPE; else signal = SIGILL; if (signal == SIGFPE) do_fp_trap(regs, location, current->thread.fp_regs.fpc, interruption_code); else if (signal) { siginfo_t info; info.si_signo = signal; info.si_errno = 0; info.si_code = ILL_ILLOPN; info.si_addr = location; do_trap(interruption_code, signal, "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] = ÷_exception; pgm_check_table[0x10] = &do_segment_exception; pgm_check_table[0x11] = &do_page_exception; pgm_check_table[0x12] = &translation_exception; pgm_check_table[0x13] = &special_op_exception; pgm_check_table[0x14] = &do_pseudo_page_fault; pgm_check_table[0x15] = &operand_exception; pgm_check_table[0x1C] = &privileged_op; #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"); /* * First try to get pfault pseudo page faults going. * If this isn't available turn on pagex page faults. */ if (pfault_init() != 0) { /* Tough luck, no pfault. */ unregister_early_external_interrupt(0x2603, pfault_interrupt, &ext_int_pfault); cpcmd("SET PAGEX ON", NULL, 0); } } #else if (MACHINE_IS_VM) cpcmd("SET PAGEX ON", NULL, 0); #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 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; } }