/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1994 - 1999, 2000, 01 Ralf Baechle * Copyright (C) 1995, 1996 Paul M. Antoine * Copyright (C) 1998 Ulf Carlsson * Copyright (C) 1999 Silicon Graphics, Inc. * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com * Copyright (C) 2000, 01 MIPS Technologies, Inc. * Copyright (C) 2002, 2003, 2004 Maciej W. Rozycki */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern asmlinkage void __xtlb_mod(void); extern asmlinkage void __xtlb_tlbl(void); extern asmlinkage void __xtlb_tlbs(void); extern asmlinkage void handle_adel(void); extern asmlinkage void handle_ades(void); extern asmlinkage void handle_ibe(void); extern asmlinkage void handle_dbe(void); extern asmlinkage void handle_sys(void); extern asmlinkage void handle_bp(void); extern asmlinkage void handle_ri(void); extern asmlinkage void handle_cpu(void); extern asmlinkage void handle_ov(void); extern asmlinkage void handle_tr(void); extern asmlinkage void handle_fpe(void); extern asmlinkage void handle_mdmx(void); extern asmlinkage void handle_watch(void); extern asmlinkage void handle_mcheck(void); extern asmlinkage void handle_reserved(void); extern int fpu_emulator_cop1Handler(int xcptno, struct pt_regs *xcp, struct mips_fpu_soft_struct *ctx); void (*board_be_init)(void); int (*board_be_handler)(struct pt_regs *regs, int is_fixup); int kstack_depth_to_print = 24; /* * These constant is for searching for possible module text segments. * MODULE_RANGE is a guess of how much space is likely to be vmalloced. */ #define MODULE_RANGE (8*1024*1024) /* * 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 */ #ifdef CONFIG_MODULES extern struct module *module_list; extern struct module kernel_module; static inline int kernel_text_address(long addr) { extern char _stext, _etext; int retval = 0; struct module *mod; if (addr >= (long) &_stext && addr <= (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(long addr) { extern char _stext, _etext; return (addr >= (long) &_stext && addr <= (long) &_etext); } #endif /* * This routine abuses get_user()/put_user() to reference pointers * with at least a bit of error checking ... */ void show_stack(long *sp) { int i; long stackdata; printk("Stack:"); i = 0; while ((long) sp & (PAGE_SIZE - 1)) { if (i && ((i % 4) == 0)) printk("\n "); if (i > 40) { printk(" ..."); break; } if (__get_user(stackdata, sp++)) { printk(" (Bad stack address)"); break; } printk(" %016lx", stackdata); i++; } printk("\n"); } void show_trace(long *sp) { int i; long addr; printk("Call Trace:"); i = 0; while ((long) sp & (PAGE_SIZE - 1)) { if (__get_user(addr, sp++)) { if (i && ((i % 3) == 0)) printk("\n "); printk(" (Bad stack address)\n"); break; } /* * 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 (kernel_text_address(addr)) { if (i && ((i % 3) == 0)) printk("\n "); if (i > 40) { printk(" ..."); break; } printk(" [<%016lx>]", addr); i++; } } printk("\n"); } void show_trace_task(struct task_struct *tsk) { show_trace((long *)tsk->thread.reg29); } void show_code(unsigned int *pc) { long i; printk("\nCode:"); for(i = -3 ; i < 6 ; i++) { unsigned int insn; if (__get_user(insn, pc + i)) { printk(" (Bad address in epc)\n"); break; } printk("%c%08x%c",(i?' ':'<'),insn,(i?' ':'>')); } } void show_regs(struct pt_regs *regs) { printk("Cpu %d\n", smp_processor_id()); /* Saved main processor registers. */ printk("$0 : %016lx %016lx %016lx %016lx\n", 0UL, regs->regs[1], regs->regs[2], regs->regs[3]); printk("$4 : %016lx %016lx %016lx %016lx\n", regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]); printk("$8 : %016lx %016lx %016lx %016lx\n", regs->regs[8], regs->regs[9], regs->regs[10], regs->regs[11]); printk("$12 : %016lx %016lx %016lx %016lx\n", regs->regs[12], regs->regs[13], regs->regs[14], regs->regs[15]); printk("$16 : %016lx %016lx %016lx %016lx\n", regs->regs[16], regs->regs[17], regs->regs[18], regs->regs[19]); printk("$20 : %016lx %016lx %016lx %016lx\n", regs->regs[20], regs->regs[21], regs->regs[22], regs->regs[23]); printk("$24 : %016lx %016lx\n", regs->regs[24], regs->regs[25]); printk("$28 : %016lx %016lx %016lx %016lx\n", regs->regs[28], regs->regs[29], regs->regs[30], regs->regs[31]); printk("Hi : %016lx\n", regs->hi); printk("Lo : %016lx\n", regs->lo); /* Saved cp0 registers. */ printk("epc : %016lx %s\nbadvaddr: %016lx\n", regs->cp0_epc, print_tainted(), regs->cp0_badvaddr); printk("Status : %08x [ ", (unsigned int) regs->cp0_status); if (regs->cp0_status & ST0_KX) printk("KX "); if (regs->cp0_status & ST0_SX) printk("SX "); if (regs->cp0_status & ST0_UX) printk("UX "); switch (regs->cp0_status & ST0_KSU) { case KSU_USER: printk("USER "); break; case KSU_SUPERVISOR: printk("SUPERVISOR "); break; case KSU_KERNEL: printk("KERNEL "); break; default: printk("BAD_MODE "); break; } if (regs->cp0_status & ST0_ERL) printk("ERL "); if (regs->cp0_status & ST0_EXL) printk("EXL "); if (regs->cp0_status & ST0_IE) printk("IE "); printk("]\n"); printk("Cause : %08x\n", (unsigned int) regs->cp0_cause); printk("PrId : %08x\n", read_c0_prid()); } void show_registers(struct pt_regs *regs) { show_regs(regs); printk("Process %s (pid: %d, stackpage=%016lx)\n", current->comm, current->pid, (unsigned long) current); show_stack((long *) regs->regs[29]); show_trace((long *) regs->regs[29]); show_code((unsigned int *) regs->cp0_epc); printk("\n"); } static spinlock_t die_lock = SPIN_LOCK_UNLOCKED; void __die(const char * str, struct pt_regs * regs, const char * file, const char * func, unsigned long line) { console_verbose(); spin_lock_irq(&die_lock); printk("%s", str); if (file && func) printk(" in %s:%s, line %ld", file, func, line); printk(":\n"); show_registers(regs); spin_unlock_irq(&die_lock); do_exit(SIGSEGV); } void __die_if_kernel(const char * str, struct pt_regs * regs, const char * file, const char * func, unsigned long line) { if (!user_mode(regs)) __die(str, regs, file, func, line); } extern const struct exception_table_entry __start___dbe_table[]; extern const struct exception_table_entry __stop___dbe_table[]; void __declare_dbe_table(void) { __asm__ __volatile__( ".section\t__dbe_table,\"a\"\n\t" ".previous" ); } static inline unsigned long search_one_table(const struct exception_table_entry *first, const struct exception_table_entry *last, unsigned long value) { const struct exception_table_entry *mid; long diff; while (first < last) { mid = (last - first) / 2 + first; diff = mid->insn - value; if (diff < 0) first = mid + 1; else last = mid; } return (first == last && first->insn == value) ? first->nextinsn : 0; } extern spinlock_t modlist_lock; static inline unsigned long search_dbe_table(unsigned long addr) { unsigned long ret = 0; #ifndef CONFIG_MODULES /* There is only the kernel to search. */ ret = search_one_table(__start___dbe_table, __stop___dbe_table-1, addr); return ret; #else unsigned long flags; /* The kernel is the last "module" -- no need to treat it special. */ struct module *mp; struct archdata *ap; spin_lock_irqsave(&modlist_lock, flags); for (mp = module_list; mp != NULL; mp = mp->next) { if (!mod_member_present(mp, archdata_end) || !mod_archdata_member_present(mp, struct archdata, dbe_table_end)) continue; ap = (struct archdata *)(mp->archdata_start); if (ap->dbe_table_start == NULL || !(mp->flags & (MOD_RUNNING | MOD_INITIALIZING))) continue; ret = search_one_table(ap->dbe_table_start, ap->dbe_table_end - 1, addr); if (ret) break; } spin_unlock_irqrestore(&modlist_lock, flags); return ret; #endif } asmlinkage void do_be(struct pt_regs *regs) { unsigned long new_epc; unsigned long fixup = 0; int data = regs->cp0_cause & 4; int action = MIPS_BE_FATAL; if (data && !user_mode(regs)) fixup = search_dbe_table(exception_epc(regs)); if (fixup) action = MIPS_BE_FIXUP; if (board_be_handler) action = board_be_handler(regs, fixup != 0); switch (action) { case MIPS_BE_DISCARD: return; case MIPS_BE_FIXUP: if (fixup) { new_epc = fixup_exception(dpf_reg, fixup, regs->cp0_epc); regs->cp0_epc = new_epc; return; } break; default: break; } /* * Assume it would be too dangerous to continue ... */ printk(KERN_ALERT "%s bus error, epc == %08lx, ra == %08lx\n", data ? "Data" : "Instruction", regs->cp0_epc, regs->regs[31]); die_if_kernel("Oops", regs); force_sig(SIGBUS, current); } static inline int get_insn_opcode(struct pt_regs *regs, unsigned int *opcode) { unsigned int *epc; epc = (unsigned int *) regs->cp0_epc + ((regs->cp0_cause & CAUSEF_BD) != 0); if (!get_user(*opcode, epc)) return 0; force_sig(SIGSEGV, current); return 1; } /* * ll/sc emulation */ #define OPCODE 0xfc000000 #define BASE 0x03e00000 #define RT 0x001f0000 #define OFFSET 0x0000ffff #define LL 0xc0000000 #define SC 0xe0000000 /* * The ll_bit is cleared by r*_switch.S */ unsigned long ll_bit; static struct task_struct *ll_task = NULL; static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode) { unsigned long value, *vaddr; long offset; int signal = 0; /* * analyse the ll instruction that just caused a ri exception * and put the referenced address to addr. */ /* sign extend offset */ offset = opcode & OFFSET; offset <<= 16; offset >>= 16; vaddr = (unsigned long *)((long)(regs->regs[(opcode & BASE) >> 21]) + offset); if ((unsigned long)vaddr & 3) { signal = SIGBUS; goto sig; } if (get_user(value, vaddr)) { signal = SIGSEGV; goto sig; } if (ll_task == NULL || ll_task == current) { ll_bit = 1; } else { ll_bit = 0; } ll_task = current; regs->regs[(opcode & RT) >> 16] = value; compute_return_epc(regs); return; sig: force_sig(signal, current); } static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode) { unsigned long *vaddr, reg; long offset; int signal = 0; /* * analyse the sc instruction that just caused a ri exception * and put the referenced address to addr. */ /* sign extend offset */ offset = opcode & OFFSET; offset <<= 16; offset >>= 16; vaddr = (unsigned long *)((long)(regs->regs[(opcode & BASE) >> 21]) + offset); reg = (opcode & RT) >> 16; if ((unsigned long)vaddr & 3) { signal = SIGBUS; goto sig; } if (ll_bit == 0 || ll_task != current) { regs->regs[reg] = 0; compute_return_epc(regs); return; } if (put_user(regs->regs[reg], vaddr)) { signal = SIGSEGV; goto sig; } regs->regs[reg] = 1; compute_return_epc(regs); return; sig: force_sig(signal, current); } /* * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both * opcodes are supposed to result in coprocessor unusable exceptions if * executed on ll/sc-less processors. That's the theory. In practice a * few processors such as NEC's VR4100 throw reserved instruction exceptions * instead, so we're doing the emulation thing in both exception handlers. */ static inline int simulate_llsc(struct pt_regs *regs) { unsigned int opcode; if (unlikely(get_insn_opcode(regs, &opcode))) return -EFAULT; if ((opcode & OPCODE) == LL) { simulate_ll(regs, opcode); return 0; } if ((opcode & OPCODE) == SC) { simulate_sc(regs, opcode); return 0; } return -EFAULT; /* Strange things going on ... */ } asmlinkage void do_ov(struct pt_regs *regs) { siginfo_t info; info.si_code = FPE_INTOVF; info.si_signo = SIGFPE; info.si_errno = 0; info.si_addr = (void *)regs->cp0_epc; force_sig_info(SIGFPE, &info, current); } /* * XXX Delayed fp exceptions when doing a lazy ctx switch XXX */ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31) { if (fcr31 & FPU_CSR_UNI_X) { int sig; /* * Unimplemented operation exception. If we've got the full * software emulator on-board, let's use it... * * Force FPU to dump state into task/thread context. We're * moving a lot of data here for what is probably a single * instruction, but the alternative is to pre-decode the FP * register operands before invoking the emulator, which seems * a bit extreme for what should be an infrequent event. */ save_fp(current); /* Run the emulator */ sig = fpu_emulator_cop1Handler (0, regs, ¤t->thread.fpu.soft); /* * We can't allow the emulated instruction to leave any of * the cause bit set in $fcr31. */ current->thread.fpu.soft.sr &= ~FPU_CSR_ALL_X; /* Restore the hardware register state */ restore_fp(current); /* If something went wrong, signal */ if (sig) force_sig(sig, current); return; } force_sig(SIGFPE, current); } asmlinkage void do_bp(struct pt_regs *regs) { unsigned int opcode, bcode; siginfo_t info; die_if_kernel("Break instruction in kernel code", regs); if (get_insn_opcode(regs, &opcode)) return; /* * There is the ancient bug in the MIPS assemblers that the break * code starts left to bit 16 instead to bit 6 in the opcode. * Gas is bug-compatible, but not always, grrr... * We handle both cases with a simple heuristics. --macro */ bcode = ((opcode >> 6) & ((1 << 20) - 1)); if (bcode < (1 << 10)) bcode <<= 10; /* * (A short test says that IRIX 5.3 sends SIGTRAP for all break * insns, even for break codes that indicate arithmetic failures. * Weird ...) * But should we continue the brokenness??? --macro */ switch (bcode) { case BRK_OVERFLOW << 10: case BRK_DIVZERO << 10: if (bcode == (BRK_DIVZERO << 10)) info.si_code = FPE_INTDIV; else info.si_code = FPE_INTOVF; info.si_signo = SIGFPE; info.si_errno = 0; info.si_addr = (void *)regs->cp0_epc; force_sig_info(SIGFPE, &info, current); break; default: force_sig(SIGTRAP, current); } } asmlinkage void do_tr(struct pt_regs *regs) { unsigned int opcode, tcode = 0; siginfo_t info; if (get_insn_opcode(regs, &opcode)) return; /* Immediate versions don't provide a code. */ if (!(opcode & OPCODE)) tcode = ((opcode >> 6) & ((1 << 10) - 1)); /* * (A short test says that IRIX 5.3 sends SIGTRAP for all trap * insns, even for trap codes that indicate arithmetic failures. * Weird ...) * But should we continue the brokenness??? --macro */ switch (tcode) { case BRK_OVERFLOW: case BRK_DIVZERO: if (tcode == BRK_DIVZERO) info.si_code = FPE_INTDIV; else info.si_code = FPE_INTOVF; info.si_signo = SIGFPE; info.si_errno = 0; info.si_addr = (void *)regs->cp0_epc; force_sig_info(SIGFPE, &info, current); break; default: force_sig(SIGTRAP, current); } } asmlinkage void do_ri(struct pt_regs *regs) { die_if_kernel("Reserved instruction in kernel code", regs); if (!cpu_has_llsc) if (!simulate_llsc(regs)) return; force_sig(SIGILL, current); } asmlinkage void do_cpu(struct pt_regs *regs) { unsigned int cpid; die_if_kernel("do_cpu invoked from kernel context!", regs); cpid = (regs->cp0_cause >> CAUSEB_CE) & 3; switch (cpid) { case 0: if (cpu_has_llsc) break; if (!simulate_llsc(regs)) return; break; case 1: own_fpu(); if (current->used_math) { /* Using the FPU again. */ restore_fp(current); } else { /* First time FPU user. */ init_fpu(); current->used_math = 1; } if (!cpu_has_fpu) { int sig = fpu_emulator_cop1Handler(0, regs, ¤t->thread.fpu.soft); if (sig) force_sig(sig, current); } return; case 2: case 3: break; } force_sig(SIGILL, current); } asmlinkage void do_mdmx(struct pt_regs *regs) { force_sig(SIGILL, current); } asmlinkage void do_watch(struct pt_regs *regs) { /* * We use the watch exception where available to detect stack * overflows. */ dump_tlb_all(); show_regs(regs); panic("Caught WATCH exception - probably caused by stack overflow."); } asmlinkage void do_mcheck(struct pt_regs *regs) { show_regs(regs); dump_tlb_all(); /* * Some chips may have other causes of machine check (e.g. SB1 * graduation timer) */ panic("Caught Machine Check exception - %scaused by multiple " "matching entries in the TLB.", (regs->cp0_status & ST0_TS) ? "" : "not "); } asmlinkage void do_reserved(struct pt_regs *regs) { /* * Game over - no way to handle this if it ever occurs. Most probably * caused by a new unknown cpu type or after another deadly * hard/software error. */ show_regs(regs); panic("Caught reserved exception %ld - should not happen.", (regs->cp0_cause & 0x7f) >> 2); } unsigned long exception_handlers[32]; /* * As a side effect of the way this is implemented we're limited * to interrupt handlers in the address range from * KSEG0 <= x < KSEG0 + 256mb on the Nevada. Oh well ... */ void *set_except_vector(int n, void *addr) { unsigned long handler = (unsigned long) addr; unsigned long old_handler = exception_handlers[n]; exception_handlers[n] = handler; if (n == 0 && cpu_has_divec) { *(volatile u32 *)(KSEG0+0x200) = 0x08000000 | (0x03ffffff & (handler >> 2)); flush_icache_range(KSEG0+0x200, KSEG0 + 0x204); } return (void *)old_handler; } asmlinkage int (*save_fp_context)(struct sigcontext *sc); asmlinkage int (*restore_fp_context)(struct sigcontext *sc); asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc); asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc); extern asmlinkage int _save_fp_context(struct sigcontext *sc); extern asmlinkage int _restore_fp_context(struct sigcontext *sc); extern asmlinkage int _save_fp_context32(struct sigcontext32 *sc); extern asmlinkage int _restore_fp_context32(struct sigcontext32 *sc); extern asmlinkage int fpu_emulator_save_context(struct sigcontext *sc); extern asmlinkage int fpu_emulator_restore_context(struct sigcontext *sc); extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 *sc); extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 *sc); void __init per_cpu_trap_init(void) { unsigned int cpu = smp_processor_id(); /* Some firmware leaves the BEV flag set, clear it. */ clear_c0_status(ST0_CU1|ST0_CU2|ST0_CU3|ST0_BEV); set_c0_status(ST0_CU0|ST0_FR|ST0_KX|ST0_SX|ST0_UX); if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV) set_c0_status(ST0_XX); /* * Some MIPS CPUs have a dedicated interrupt vector which reduces the * interrupt processing overhead. Use it where available. */ if (cpu_has_divec) set_c0_cause(CAUSEF_IV); cpu_data[cpu].asid_cache = ASID_FIRST_VERSION; write_c0_context(((long)(&pgd_current[cpu])) << 23); write_c0_wired(0); atomic_inc(&init_mm.mm_count); current->active_mm = &init_mm; if (current->mm) BUG(); enter_lazy_tlb(&init_mm, current, cpu); } void __init trap_init(void) { extern char except_vec0_generic; extern char except_vec3_generic, except_vec3_r4000; extern char except_vec4; unsigned long i; per_cpu_trap_init(); /* Copy the generic exception handlers to their final destination. */ memcpy((void *) KSEG0 , &except_vec0_generic, 0x80); memcpy((void *)(KSEG0 + 0x180), &except_vec3_generic, 0x80); /* * Setup default vectors */ for (i = 0; i <= 31; i++) set_except_vector(i, handle_reserved); /* * Only some CPUs have the watch exceptions. */ if (cpu_has_watch) set_except_vector(23, handle_watch); /* * Some MIPS CPUs have a dedicated interrupt vector which reduces the * interrupt processing overhead. Use it where available. */ if (cpu_has_divec) memcpy((void *)(KSEG0 + 0x200), &except_vec4, 0x8); /* * The Data Bus Errors / Instruction Bus Errors are signaled * by external hardware. Therefore these two exceptions * may have board specific handlers. */ if (board_be_init) board_be_init(); set_except_vector(1, __xtlb_mod); set_except_vector(2, __xtlb_tlbl); set_except_vector(3, __xtlb_tlbs); set_except_vector(4, handle_adel); set_except_vector(5, handle_ades); set_except_vector(6, handle_ibe); set_except_vector(7, handle_dbe); set_except_vector(8, handle_sys); set_except_vector(9, handle_bp); set_except_vector(10, handle_ri); set_except_vector(11, handle_cpu); set_except_vector(12, handle_ov); set_except_vector(13, handle_tr); set_except_vector(22, handle_mdmx); if (cpu_has_fpu && !cpu_has_nofpuex) set_except_vector(15, handle_fpe); if (cpu_has_mcheck) set_except_vector(24, handle_mcheck); if (cpu_has_vce) memcpy((void *)(KSEG0 + 0x180), &except_vec3_r4000, 0x100); else if (cpu_has_4kex) memcpy((void *)(KSEG0 + 0x180), &except_vec3_generic, 0x80); else memcpy((void *)(KSEG0 + 0x080), &except_vec3_generic, 0x80); if (current_cpu_data.cputype == CPU_R6000 || current_cpu_data.cputype == CPU_R6000A) { /* * The R6000 is the only R-series CPU that features a machine * check exception (similar to the R4000 cache error) and * unaligned ldc1/sdc1 exception. The handlers have not been * written yet. Well, anyway there is no R6000 machine on the * current list of targets for Linux/MIPS. * (Duh, crap, there is someone with a tripple R6k machine) */ //set_except_vector(14, handle_mc); //set_except_vector(15, handle_ndc); } if (cpu_has_fpu) { save_fp_context = _save_fp_context; restore_fp_context = _restore_fp_context; save_fp_context32 = _save_fp_context32; restore_fp_context32 = _restore_fp_context32; } else { save_fp_context = fpu_emulator_save_context; restore_fp_context = fpu_emulator_restore_context; save_fp_context32 = fpu_emulator_save_context32; restore_fp_context32 = fpu_emulator_restore_context32; } flush_icache_range(KSEG0, KSEG0 + 0x400); atomic_inc(&init_mm.mm_count); /* XXX UP? */ current->active_mm = &init_mm; }