/* * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Modified by Cort Dougan (cort@cs.nmt.edu) * and Paul Mackerras (paulus@samba.org) */ /* * This file handles the architecture-dependent parts of hardware exceptions */ #include <linux/errno.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/stddef.h> #include <linux/unistd.h> #include <linux/ptrace.h> #include <linux/slab.h> #include <linux/user.h> #include <linux/interrupt.h> #include <linux/init.h> #include <linux/module.h> #include <linux/prctl.h> #include <linux/delay.h> #include <linux/kprobes.h> #include <linux/kexec.h> #include <linux/backlight.h> #include <linux/bug.h> #include <linux/kdebug.h> #include <linux/debugfs.h> #include <asm/emulated_ops.h> #include <asm/pgtable.h> #include <asm/uaccess.h> #include <asm/system.h> #include <asm/io.h> #include <asm/machdep.h> #include <asm/rtas.h> #include <asm/pmc.h> #ifdef CONFIG_PPC32 #include <asm/reg.h> #endif #ifdef CONFIG_PMAC_BACKLIGHT #include <asm/backlight.h> #endif #ifdef CONFIG_PPC64 #include <asm/firmware.h> #include <asm/processor.h> #endif #include <asm/kexec.h> #include <asm/ppc-opcode.h> #ifdef CONFIG_FSL_BOOKE #include <asm/dbell.h> #endif #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC) int (*__debugger)(struct pt_regs *regs); int (*__debugger_ipi)(struct pt_regs *regs); int (*__debugger_bpt)(struct pt_regs *regs); int (*__debugger_sstep)(struct pt_regs *regs); int (*__debugger_iabr_match)(struct pt_regs *regs); int (*__debugger_dabr_match)(struct pt_regs *regs); int (*__debugger_fault_handler)(struct pt_regs *regs); EXPORT_SYMBOL(__debugger); EXPORT_SYMBOL(__debugger_ipi); EXPORT_SYMBOL(__debugger_bpt); EXPORT_SYMBOL(__debugger_sstep); EXPORT_SYMBOL(__debugger_iabr_match); EXPORT_SYMBOL(__debugger_dabr_match); EXPORT_SYMBOL(__debugger_fault_handler); #endif /* * Trap & Exception support */ #ifdef CONFIG_PMAC_BACKLIGHT static void pmac_backlight_unblank(void) { mutex_lock(&pmac_backlight_mutex); if (pmac_backlight) { struct backlight_properties *props; props = &pmac_backlight->props; props->brightness = props->max_brightness; props->power = FB_BLANK_UNBLANK; backlight_update_status(pmac_backlight); } mutex_unlock(&pmac_backlight_mutex); } #else static inline void pmac_backlight_unblank(void) { } #endif int die(const char *str, struct pt_regs *regs, long err) { static struct { spinlock_t lock; u32 lock_owner; int lock_owner_depth; } die = { .lock = __SPIN_LOCK_UNLOCKED(die.lock), .lock_owner = -1, .lock_owner_depth = 0 }; static int die_counter; unsigned long flags; if (debugger(regs)) return 1; oops_enter(); if (die.lock_owner != raw_smp_processor_id()) { console_verbose(); spin_lock_irqsave(&die.lock, flags); die.lock_owner = smp_processor_id(); die.lock_owner_depth = 0; bust_spinlocks(1); if (machine_is(powermac)) pmac_backlight_unblank(); } else { local_save_flags(flags); } if (++die.lock_owner_depth < 3) { printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); #ifdef CONFIG_PREEMPT printk("PREEMPT "); #endif #ifdef CONFIG_SMP printk("SMP NR_CPUS=%d ", NR_CPUS); #endif #ifdef CONFIG_DEBUG_PAGEALLOC printk("DEBUG_PAGEALLOC "); #endif #ifdef CONFIG_NUMA printk("NUMA "); #endif printk("%s\n", ppc_md.name ? ppc_md.name : ""); print_modules(); show_regs(regs); } else { printk("Recursive die() failure, output suppressed\n"); } bust_spinlocks(0); die.lock_owner = -1; add_taint(TAINT_DIE); spin_unlock_irqrestore(&die.lock, flags); if (kexec_should_crash(current) || kexec_sr_activated(smp_processor_id())) crash_kexec(regs); crash_kexec_secondary(regs); if (in_interrupt()) panic("Fatal exception in interrupt"); if (panic_on_oops) panic("Fatal exception"); oops_exit(); do_exit(err); return 0; } void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) { siginfo_t info; const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \ "at %08lx nip %08lx lr %08lx code %x\n"; const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \ "at %016lx nip %016lx lr %016lx code %x\n"; if (!user_mode(regs)) { if (die("Exception in kernel mode", regs, signr)) return; } else if (show_unhandled_signals && unhandled_signal(current, signr) && printk_ratelimit()) { printk(regs->msr & MSR_SF ? fmt64 : fmt32, current->comm, current->pid, signr, addr, regs->nip, regs->link, code); } memset(&info, 0, sizeof(info)); info.si_signo = signr; info.si_code = code; info.si_addr = (void __user *) addr; force_sig_info(signr, &info, current); /* * Init gets no signals that it doesn't have a handler for. * That's all very well, but if it has caused a synchronous * exception and we ignore the resulting signal, it will just * generate the same exception over and over again and we get * nowhere. Better to kill it and let the kernel panic. */ if (is_global_init(current)) { __sighandler_t handler; spin_lock_irq(¤t->sighand->siglock); handler = current->sighand->action[signr-1].sa.sa_handler; spin_unlock_irq(¤t->sighand->siglock); if (handler == SIG_DFL) { /* init has generated a synchronous exception and it doesn't have a handler for the signal */ printk(KERN_CRIT "init has generated signal %d " "but has no handler for it\n", signr); do_exit(signr); } } } #ifdef CONFIG_PPC64 void system_reset_exception(struct pt_regs *regs) { /* See if any machine dependent calls */ if (ppc_md.system_reset_exception) { if (ppc_md.system_reset_exception(regs)) return; } #ifdef CONFIG_KEXEC cpu_set(smp_processor_id(), cpus_in_sr); #endif die("System Reset", regs, SIGABRT); /* * Some CPUs when released from the debugger will execute this path. * These CPUs entered the debugger via a soft-reset. If the CPU was * hung before entering the debugger it will return to the hung * state when exiting this function. This causes a problem in * kdump since the hung CPU(s) will not respond to the IPI sent * from kdump. To prevent the problem we call crash_kexec_secondary() * here. If a kdump had not been initiated or we exit the debugger * with the "exit and recover" command (x) crash_kexec_secondary() * will return after 5ms and the CPU returns to its previous state. */ crash_kexec_secondary(regs); /* Must die if the interrupt is not recoverable */ if (!(regs->msr & MSR_RI)) panic("Unrecoverable System Reset"); /* What should we do here? We could issue a shutdown or hard reset. */ } #endif /* * I/O accesses can cause machine checks on powermacs. * Check if the NIP corresponds to the address of a sync * instruction for which there is an entry in the exception * table. * Note that the 601 only takes a machine check on TEA * (transfer error ack) signal assertion, and does not * set any of the top 16 bits of SRR1. * -- paulus. */ static inline int check_io_access(struct pt_regs *regs) { #ifdef CONFIG_PPC32 unsigned long msr = regs->msr; const struct exception_table_entry *entry; unsigned int *nip = (unsigned int *)regs->nip; if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000))) && (entry = search_exception_tables(regs->nip)) != NULL) { /* * Check that it's a sync instruction, or somewhere * in the twi; isync; nop sequence that inb/inw/inl uses. * As the address is in the exception table * we should be able to read the instr there. * For the debug message, we look at the preceding * load or store. */ if (*nip == 0x60000000) /* nop */ nip -= 2; else if (*nip == 0x4c00012c) /* isync */ --nip; if (*nip == 0x7c0004ac || (*nip >> 26) == 3) { /* sync or twi */ unsigned int rb; --nip; rb = (*nip >> 11) & 0x1f; printk(KERN_DEBUG "%s bad port %lx at %p\n", (*nip & 0x100)? "OUT to": "IN from", regs->gpr[rb] - _IO_BASE, nip); regs->msr |= MSR_RI; regs->nip = entry->fixup; return 1; } } #endif /* CONFIG_PPC32 */ return 0; } #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) /* On 4xx, the reason for the machine check or program exception is in the ESR. */ #define get_reason(regs) ((regs)->dsisr) #ifndef CONFIG_FSL_BOOKE #define get_mc_reason(regs) ((regs)->dsisr) #else #define get_mc_reason(regs) (mfspr(SPRN_MCSR) & MCSR_MASK) #endif #define REASON_FP ESR_FP #define REASON_ILLEGAL (ESR_PIL | ESR_PUO) #define REASON_PRIVILEGED ESR_PPR #define REASON_TRAP ESR_PTR /* single-step stuff */ #define single_stepping(regs) (current->thread.dbcr0 & DBCR0_IC) #define clear_single_step(regs) (current->thread.dbcr0 &= ~DBCR0_IC) #else /* On non-4xx, the reason for the machine check or program exception is in the MSR. */ #define get_reason(regs) ((regs)->msr) #define get_mc_reason(regs) ((regs)->msr) #define REASON_FP 0x100000 #define REASON_ILLEGAL 0x80000 #define REASON_PRIVILEGED 0x40000 #define REASON_TRAP 0x20000 #define single_stepping(regs) ((regs)->msr & MSR_SE) #define clear_single_step(regs) ((regs)->msr &= ~MSR_SE) #endif #if defined(CONFIG_4xx) int machine_check_4xx(struct pt_regs *regs) { unsigned long reason = get_mc_reason(regs); if (reason & ESR_IMCP) { printk("Instruction"); mtspr(SPRN_ESR, reason & ~ESR_IMCP); } else printk("Data"); printk(" machine check in kernel mode.\n"); return 0; } int machine_check_440A(struct pt_regs *regs) { unsigned long reason = get_mc_reason(regs); printk("Machine check in kernel mode.\n"); if (reason & ESR_IMCP){ printk("Instruction Synchronous Machine Check exception\n"); mtspr(SPRN_ESR, reason & ~ESR_IMCP); } else { u32 mcsr = mfspr(SPRN_MCSR); if (mcsr & MCSR_IB) printk("Instruction Read PLB Error\n"); if (mcsr & MCSR_DRB) printk("Data Read PLB Error\n"); if (mcsr & MCSR_DWB) printk("Data Write PLB Error\n"); if (mcsr & MCSR_TLBP) printk("TLB Parity Error\n"); if (mcsr & MCSR_ICP){ flush_instruction_cache(); printk("I-Cache Parity Error\n"); } if (mcsr & MCSR_DCSP) printk("D-Cache Search Parity Error\n"); if (mcsr & MCSR_DCFP) printk("D-Cache Flush Parity Error\n"); if (mcsr & MCSR_IMPE) printk("Machine Check exception is imprecise\n"); /* Clear MCSR */ mtspr(SPRN_MCSR, mcsr); } return 0; } #elif defined(CONFIG_E500) int machine_check_e500(struct pt_regs *regs) { unsigned long reason = get_mc_reason(regs); printk("Machine check in kernel mode.\n"); printk("Caused by (from MCSR=%lx): ", reason); if (reason & MCSR_MCP) printk("Machine Check Signal\n"); if (reason & MCSR_ICPERR) printk("Instruction Cache Parity Error\n"); if (reason & MCSR_DCP_PERR) printk("Data Cache Push Parity Error\n"); if (reason & MCSR_DCPERR) printk("Data Cache Parity Error\n"); if (reason & MCSR_BUS_IAERR) printk("Bus - Instruction Address Error\n"); if (reason & MCSR_BUS_RAERR) printk("Bus - Read Address Error\n"); if (reason & MCSR_BUS_WAERR) printk("Bus - Write Address Error\n"); if (reason & MCSR_BUS_IBERR) printk("Bus - Instruction Data Error\n"); if (reason & MCSR_BUS_RBERR) printk("Bus - Read Data Bus Error\n"); if (reason & MCSR_BUS_WBERR) printk("Bus - Read Data Bus Error\n"); if (reason & MCSR_BUS_IPERR) printk("Bus - Instruction Parity Error\n"); if (reason & MCSR_BUS_RPERR) printk("Bus - Read Parity Error\n"); return 0; } #elif defined(CONFIG_E200) int machine_check_e200(struct pt_regs *regs) { unsigned long reason = get_mc_reason(regs); printk("Machine check in kernel mode.\n"); printk("Caused by (from MCSR=%lx): ", reason); if (reason & MCSR_MCP) printk("Machine Check Signal\n"); if (reason & MCSR_CP_PERR) printk("Cache Push Parity Error\n"); if (reason & MCSR_CPERR) printk("Cache Parity Error\n"); if (reason & MCSR_EXCP_ERR) printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n"); if (reason & MCSR_BUS_IRERR) printk("Bus - Read Bus Error on instruction fetch\n"); if (reason & MCSR_BUS_DRERR) printk("Bus - Read Bus Error on data load\n"); if (reason & MCSR_BUS_WRERR) printk("Bus - Write Bus Error on buffered store or cache line push\n"); return 0; } #else int machine_check_generic(struct pt_regs *regs) { unsigned long reason = get_mc_reason(regs); printk("Machine check in kernel mode.\n"); printk("Caused by (from SRR1=%lx): ", reason); switch (reason & 0x601F0000) { case 0x80000: printk("Machine check signal\n"); break; case 0: /* for 601 */ case 0x40000: case 0x140000: /* 7450 MSS error and TEA */ printk("Transfer error ack signal\n"); break; case 0x20000: printk("Data parity error signal\n"); break; case 0x10000: printk("Address parity error signal\n"); break; case 0x20000000: printk("L1 Data Cache error\n"); break; case 0x40000000: printk("L1 Instruction Cache error\n"); break; case 0x00100000: printk("L2 data cache parity error\n"); break; default: printk("Unknown values in msr\n"); } return 0; } #endif /* everything else */ void machine_check_exception(struct pt_regs *regs) { int recover = 0; /* See if any machine dependent calls. In theory, we would want * to call the CPU first, and call the ppc_md. one if the CPU * one returns a positive number. However there is existing code * that assumes the board gets a first chance, so let's keep it * that way for now and fix things later. --BenH. */ if (ppc_md.machine_check_exception) recover = ppc_md.machine_check_exception(regs); else if (cur_cpu_spec->machine_check) recover = cur_cpu_spec->machine_check(regs); if (recover > 0) return; if (user_mode(regs)) { regs->msr |= MSR_RI; _exception(SIGBUS, regs, BUS_ADRERR, regs->nip); return; } #if defined(CONFIG_8xx) && defined(CONFIG_PCI) /* the qspan pci read routines can cause machine checks -- Cort * * yuck !!! that totally needs to go away ! There are better ways * to deal with that than having a wart in the mcheck handler. * -- BenH */ bad_page_fault(regs, regs->dar, SIGBUS); return; #endif if (debugger_fault_handler(regs)) { regs->msr |= MSR_RI; return; } if (check_io_access(regs)) return; if (debugger_fault_handler(regs)) return; die("Machine check", regs, SIGBUS); /* Must die if the interrupt is not recoverable */ if (!(regs->msr & MSR_RI)) panic("Unrecoverable Machine check"); } void SMIException(struct pt_regs *regs) { die("System Management Interrupt", regs, SIGABRT); } void unknown_exception(struct pt_regs *regs) { printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", regs->nip, regs->msr, regs->trap); _exception(SIGTRAP, regs, 0, 0); } void instruction_breakpoint_exception(struct pt_regs *regs) { if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) return; if (debugger_iabr_match(regs)) return; _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip); } void RunModeException(struct pt_regs *regs) { _exception(SIGTRAP, regs, 0, 0); } void __kprobes single_step_exception(struct pt_regs *regs) { regs->msr &= ~(MSR_SE | MSR_BE); /* Turn off 'trace' bits */ if (notify_die(DIE_SSTEP, "single_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) return; if (debugger_sstep(regs)) return; _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip); } /* * After we have successfully emulated an instruction, we have to * check if the instruction was being single-stepped, and if so, * pretend we got a single-step exception. This was pointed out * by Kumar Gala. -- paulus */ static void emulate_single_step(struct pt_regs *regs) { if (single_stepping(regs)) { clear_single_step(regs); _exception(SIGTRAP, regs, TRAP_TRACE, 0); } } static inline int __parse_fpscr(unsigned long fpscr) { int ret = 0; /* Invalid operation */ if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX)) ret = FPE_FLTINV; /* Overflow */ else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX)) ret = FPE_FLTOVF; /* Underflow */ else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX)) ret = FPE_FLTUND; /* Divide by zero */ else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX)) ret = FPE_FLTDIV; /* Inexact result */ else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX)) ret = FPE_FLTRES; return ret; } static void parse_fpe(struct pt_regs *regs) { int code = 0; flush_fp_to_thread(current); code = __parse_fpscr(current->thread.fpscr.val); _exception(SIGFPE, regs, code, regs->nip); } /* * Illegal instruction emulation support. Originally written to * provide the PVR to user applications using the mfspr rd, PVR. * Return non-zero if we can't emulate, or -EFAULT if the associated * memory access caused an access fault. Return zero on success. * * There are a couple of ways to do this, either "decode" the instruction * or directly match lots of bits. In this case, matching lots of * bits is faster and easier. * */ static int emulate_string_inst(struct pt_regs *regs, u32 instword) { u8 rT = (instword >> 21) & 0x1f; u8 rA = (instword >> 16) & 0x1f; u8 NB_RB = (instword >> 11) & 0x1f; u32 num_bytes; unsigned long EA; int pos = 0; /* Early out if we are an invalid form of lswx */ if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX) if ((rT == rA) || (rT == NB_RB)) return -EINVAL; EA = (rA == 0) ? 0 : regs->gpr[rA]; switch (instword & PPC_INST_STRING_MASK) { case PPC_INST_LSWX: case PPC_INST_STSWX: EA += NB_RB; num_bytes = regs->xer & 0x7f; break; case PPC_INST_LSWI: case PPC_INST_STSWI: num_bytes = (NB_RB == 0) ? 32 : NB_RB; break; default: return -EINVAL; } while (num_bytes != 0) { u8 val; u32 shift = 8 * (3 - (pos & 0x3)); switch ((instword & PPC_INST_STRING_MASK)) { case PPC_INST_LSWX: case PPC_INST_LSWI: if (get_user(val, (u8 __user *)EA)) return -EFAULT; /* first time updating this reg, * zero it out */ if (pos == 0) regs->gpr[rT] = 0; regs->gpr[rT] |= val << shift; break; case PPC_INST_STSWI: case PPC_INST_STSWX: val = regs->gpr[rT] >> shift; if (put_user(val, (u8 __user *)EA)) return -EFAULT; break; } /* move EA to next address */ EA += 1; num_bytes--; /* manage our position within the register */ if (++pos == 4) { pos = 0; if (++rT == 32) rT = 0; } } return 0; } static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword) { u32 ra,rs; unsigned long tmp; ra = (instword >> 16) & 0x1f; rs = (instword >> 21) & 0x1f; tmp = regs->gpr[rs]; tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL); tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL); tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL; regs->gpr[ra] = tmp; return 0; } static int emulate_isel(struct pt_regs *regs, u32 instword) { u8 rT = (instword >> 21) & 0x1f; u8 rA = (instword >> 16) & 0x1f; u8 rB = (instword >> 11) & 0x1f; u8 BC = (instword >> 6) & 0x1f; u8 bit; unsigned long tmp; tmp = (rA == 0) ? 0 : regs->gpr[rA]; bit = (regs->ccr >> (31 - BC)) & 0x1; regs->gpr[rT] = bit ? tmp : regs->gpr[rB]; return 0; } static int emulate_instruction(struct pt_regs *regs) { u32 instword; u32 rd; if (!user_mode(regs) || (regs->msr & MSR_LE)) return -EINVAL; CHECK_FULL_REGS(regs); if (get_user(instword, (u32 __user *)(regs->nip))) return -EFAULT; /* Emulate the mfspr rD, PVR. */ if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) { PPC_WARN_EMULATED(mfpvr); rd = (instword >> 21) & 0x1f; regs->gpr[rd] = mfspr(SPRN_PVR); return 0; } /* Emulating the dcba insn is just a no-op. */ if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) { PPC_WARN_EMULATED(dcba); return 0; } /* Emulate the mcrxr insn. */ if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) { int shift = (instword >> 21) & 0x1c; unsigned long msk = 0xf0000000UL >> shift; PPC_WARN_EMULATED(mcrxr); regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk); regs->xer &= ~0xf0000000UL; return 0; } /* Emulate load/store string insn. */ if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) { PPC_WARN_EMULATED(string); return emulate_string_inst(regs, instword); } /* Emulate the popcntb (Population Count Bytes) instruction. */ if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) { PPC_WARN_EMULATED(popcntb); return emulate_popcntb_inst(regs, instword); } /* Emulate isel (Integer Select) instruction */ if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) { PPC_WARN_EMULATED(isel); return emulate_isel(regs, instword); } return -EINVAL; } int is_valid_bugaddr(unsigned long addr) { return is_kernel_addr(addr); } void __kprobes program_check_exception(struct pt_regs *regs) { unsigned int reason = get_reason(regs); extern int do_mathemu(struct pt_regs *regs); /* We can now get here via a FP Unavailable exception if the core * has no FPU, in that case the reason flags will be 0 */ if (reason & REASON_FP) { /* IEEE FP exception */ parse_fpe(regs); return; } if (reason & REASON_TRAP) { /* trap exception */ if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) return; if (debugger_bpt(regs)) return; if (!(regs->msr & MSR_PR) && /* not user-mode */ report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) { regs->nip += 4; return; } _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip); return; } local_irq_enable(); #ifdef CONFIG_MATH_EMULATION /* (reason & REASON_ILLEGAL) would be the obvious thing here, * but there seems to be a hardware bug on the 405GP (RevD) * that means ESR is sometimes set incorrectly - either to * ESR_DST (!?) or 0. In the process of chasing this with the * hardware people - not sure if it can happen on any illegal * instruction or only on FP instructions, whether there is a * pattern to occurences etc. -dgibson 31/Mar/2003 */ switch (do_mathemu(regs)) { case 0: emulate_single_step(regs); return; case 1: { int code = 0; code = __parse_fpscr(current->thread.fpscr.val); _exception(SIGFPE, regs, code, regs->nip); return; } case -EFAULT: _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); return; } /* fall through on any other errors */ #endif /* CONFIG_MATH_EMULATION */ /* Try to emulate it if we should. */ if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) { switch (emulate_instruction(regs)) { case 0: regs->nip += 4; emulate_single_step(regs); return; case -EFAULT: _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); return; } } if (reason & REASON_PRIVILEGED) _exception(SIGILL, regs, ILL_PRVOPC, regs->nip); else _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); } void alignment_exception(struct pt_regs *regs) { int sig, code, fixed = 0; /* we don't implement logging of alignment exceptions */ if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS)) fixed = fix_alignment(regs); if (fixed == 1) { regs->nip += 4; /* skip over emulated instruction */ emulate_single_step(regs); return; } /* Operand address was bad */ if (fixed == -EFAULT) { sig = SIGSEGV; code = SEGV_ACCERR; } else { sig = SIGBUS; code = BUS_ADRALN; } if (user_mode(regs)) _exception(sig, regs, code, regs->dar); else bad_page_fault(regs, regs->dar, sig); } void StackOverflow(struct pt_regs *regs) { printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n", current, regs->gpr[1]); debugger(regs); show_regs(regs); panic("kernel stack overflow"); } void nonrecoverable_exception(struct pt_regs *regs) { printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n", regs->nip, regs->msr); debugger(regs); die("nonrecoverable exception", regs, SIGKILL); } void trace_syscall(struct pt_regs *regs) { printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld %s\n", current, task_pid_nr(current), regs->nip, regs->link, regs->gpr[0], regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted()); } void kernel_fp_unavailable_exception(struct pt_regs *regs) { printk(KERN_EMERG "Unrecoverable FP Unavailable Exception " "%lx at %lx\n", regs->trap, regs->nip); die("Unrecoverable FP Unavailable Exception", regs, SIGABRT); } void altivec_unavailable_exception(struct pt_regs *regs) { if (user_mode(regs)) { /* A user program has executed an altivec instruction, but this kernel doesn't support altivec. */ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); return; } printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception " "%lx at %lx\n", regs->trap, regs->nip); die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT); } void vsx_unavailable_exception(struct pt_regs *regs) { if (user_mode(regs)) { /* A user program has executed an vsx instruction, but this kernel doesn't support vsx. */ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); return; } printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception " "%lx at %lx\n", regs->trap, regs->nip); die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT); } void performance_monitor_exception(struct pt_regs *regs) { perf_irq(regs); } #ifdef CONFIG_8xx void SoftwareEmulation(struct pt_regs *regs) { extern int do_mathemu(struct pt_regs *); extern int Soft_emulate_8xx(struct pt_regs *); #if defined(CONFIG_MATH_EMULATION) || defined(CONFIG_8XX_MINIMAL_FPEMU) int errcode; #endif CHECK_FULL_REGS(regs); if (!user_mode(regs)) { debugger(regs); die("Kernel Mode Software FPU Emulation", regs, SIGFPE); } #ifdef CONFIG_MATH_EMULATION errcode = do_mathemu(regs); if (errcode >= 0) PPC_WARN_EMULATED(math); switch (errcode) { case 0: emulate_single_step(regs); return; case 1: { int code = 0; code = __parse_fpscr(current->thread.fpscr.val); _exception(SIGFPE, regs, code, regs->nip); return; } case -EFAULT: _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); return; default: _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); return; } #elif defined(CONFIG_8XX_MINIMAL_FPEMU) errcode = Soft_emulate_8xx(regs); if (errcode >= 0) PPC_WARN_EMULATED(8xx); switch (errcode) { case 0: emulate_single_step(regs); return; case 1: _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); return; case -EFAULT: _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); return; } #else _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); #endif } #endif /* CONFIG_8xx */ #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status) { /* Hack alert: On BookE, Branch Taken stops on the branch itself, while * on server, it stops on the target of the branch. In order to simulate * the server behaviour, we thus restart right away with a single step * instead of stopping here when hitting a BT */ if (debug_status & DBSR_BT) { regs->msr &= ~MSR_DE; /* Disable BT */ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT); /* Clear the BT event */ mtspr(SPRN_DBSR, DBSR_BT); /* Do the single step trick only when coming from userspace */ if (user_mode(regs)) { current->thread.dbcr0 &= ~DBCR0_BT; current->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC; regs->msr |= MSR_DE; return; } if (notify_die(DIE_SSTEP, "block_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) { return; } if (debugger_sstep(regs)) return; } else if (debug_status & DBSR_IC) { /* Instruction complete */ regs->msr &= ~MSR_DE; /* Disable instruction completion */ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC); /* Clear the instruction completion event */ mtspr(SPRN_DBSR, DBSR_IC); if (notify_die(DIE_SSTEP, "single_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) { return; } if (debugger_sstep(regs)) return; if (user_mode(regs)) current->thread.dbcr0 &= ~(DBCR0_IC); _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip); } else if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) { regs->msr &= ~MSR_DE; if (user_mode(regs)) { current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W | DBCR0_IDM); } else { /* Disable DAC interupts */ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R | DBSR_DAC1W | DBCR0_IDM)); /* Clear the DAC event */ mtspr(SPRN_DBSR, (DBSR_DAC1R | DBSR_DAC1W)); } /* Setup and send the trap to the handler */ do_dabr(regs, mfspr(SPRN_DAC1), debug_status); } } #endif /* CONFIG_4xx || CONFIG_BOOKE */ #if !defined(CONFIG_TAU_INT) void TAUException(struct pt_regs *regs) { printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx %s\n", regs->nip, regs->msr, regs->trap, print_tainted()); } #endif /* CONFIG_INT_TAU */ #ifdef CONFIG_ALTIVEC void altivec_assist_exception(struct pt_regs *regs) { int err; if (!user_mode(regs)) { printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode" " at %lx\n", regs->nip); die("Kernel VMX/Altivec assist exception", regs, SIGILL); } flush_altivec_to_thread(current); PPC_WARN_EMULATED(altivec); err = emulate_altivec(regs); if (err == 0) { regs->nip += 4; /* skip emulated instruction */ emulate_single_step(regs); return; } if (err == -EFAULT) { /* got an error reading the instruction */ _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); } else { /* didn't recognize the instruction */ /* XXX quick hack for now: set the non-Java bit in the VSCR */ if (printk_ratelimit()) printk(KERN_ERR "Unrecognized altivec instruction " "in %s at %lx\n", current->comm, regs->nip); current->thread.vscr.u[3] |= 0x10000; } } #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_VSX void vsx_assist_exception(struct pt_regs *regs) { if (!user_mode(regs)) { printk(KERN_EMERG "VSX assist exception in kernel mode" " at %lx\n", regs->nip); die("Kernel VSX assist exception", regs, SIGILL); } flush_vsx_to_thread(current); printk(KERN_INFO "VSX assist not supported at %lx\n", regs->nip); _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); } #endif /* CONFIG_VSX */ #ifdef CONFIG_FSL_BOOKE void doorbell_exception(struct pt_regs *regs) { #ifdef CONFIG_SMP int cpu = smp_processor_id(); int msg; if (num_online_cpus() < 2) return; for (msg = 0; msg < 4; msg++) if (test_and_clear_bit(msg, &dbell_smp_message[cpu])) smp_message_recv(msg); #else printk(KERN_WARNING "Received doorbell on non-smp system\n"); #endif } void CacheLockingException(struct pt_regs *regs, unsigned long address, unsigned long error_code) { /* We treat cache locking instructions from the user * as priv ops, in the future we could try to do * something smarter */ if (error_code & (ESR_DLK|ESR_ILK)) _exception(SIGILL, regs, ILL_PRVOPC, regs->nip); return; } #endif /* CONFIG_FSL_BOOKE */ #ifdef CONFIG_SPE void SPEFloatingPointException(struct pt_regs *regs) { extern int do_spe_mathemu(struct pt_regs *regs); unsigned long spefscr; int fpexc_mode; int code = 0; int err; preempt_disable(); if (regs->msr & MSR_SPE) giveup_spe(current); preempt_enable(); spefscr = current->thread.spefscr; fpexc_mode = current->thread.fpexc_mode; if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) { code = FPE_FLTOVF; } else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) { code = FPE_FLTUND; } else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV)) code = FPE_FLTDIV; else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) { code = FPE_FLTINV; } else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES)) code = FPE_FLTRES; err = do_spe_mathemu(regs); if (err == 0) { regs->nip += 4; /* skip emulated instruction */ emulate_single_step(regs); return; } if (err == -EFAULT) { /* got an error reading the instruction */ _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); } else if (err == -EINVAL) { /* didn't recognize the instruction */ printk(KERN_ERR "unrecognized spe instruction " "in %s at %lx\n", current->comm, regs->nip); } else { _exception(SIGFPE, regs, code, regs->nip); } return; } void SPEFloatingPointRoundException(struct pt_regs *regs) { extern int speround_handler(struct pt_regs *regs); int err; preempt_disable(); if (regs->msr & MSR_SPE) giveup_spe(current); preempt_enable(); regs->nip -= 4; err = speround_handler(regs); if (err == 0) { regs->nip += 4; /* skip emulated instruction */ emulate_single_step(regs); return; } if (err == -EFAULT) { /* got an error reading the instruction */ _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip); } else if (err == -EINVAL) { /* didn't recognize the instruction */ printk(KERN_ERR "unrecognized spe instruction " "in %s at %lx\n", current->comm, regs->nip); } else { _exception(SIGFPE, regs, 0, regs->nip); return; } } #endif /* * We enter here if we get an unrecoverable exception, that is, one * that happened at a point where the RI (recoverable interrupt) bit * in the MSR is 0. This indicates that SRR0/1 are live, and that * we therefore lost state by taking this exception. */ void unrecoverable_exception(struct pt_regs *regs) { printk(KERN_EMERG "Unrecoverable exception %lx at %lx\n", regs->trap, regs->nip); die("Unrecoverable exception", regs, SIGABRT); } #ifdef CONFIG_BOOKE_WDT /* * Default handler for a Watchdog exception, * spins until a reboot occurs */ void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs) { /* Generic WatchdogHandler, implement your own */ mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE)); return; } void WatchdogException(struct pt_regs *regs) { printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n"); WatchdogHandler(regs); } #endif /* * We enter here if we discover during exception entry that we are * running in supervisor mode with a userspace value in the stack pointer. */ void kernel_bad_stack(struct pt_regs *regs) { printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n", regs->gpr[1], regs->nip); die("Bad kernel stack pointer", regs, SIGABRT); } void __init trap_init(void) { } #ifdef CONFIG_PPC_EMULATED_STATS #define WARN_EMULATED_SETUP(type) .type = { .name = #type } struct ppc_emulated ppc_emulated = { #ifdef CONFIG_ALTIVEC WARN_EMULATED_SETUP(altivec), #endif WARN_EMULATED_SETUP(dcba), WARN_EMULATED_SETUP(dcbz), WARN_EMULATED_SETUP(fp_pair), WARN_EMULATED_SETUP(isel), WARN_EMULATED_SETUP(mcrxr), WARN_EMULATED_SETUP(mfpvr), WARN_EMULATED_SETUP(multiple), WARN_EMULATED_SETUP(popcntb), WARN_EMULATED_SETUP(spe), WARN_EMULATED_SETUP(string), WARN_EMULATED_SETUP(unaligned), #ifdef CONFIG_MATH_EMULATION WARN_EMULATED_SETUP(math), #elif defined(CONFIG_8XX_MINIMAL_FPEMU) WARN_EMULATED_SETUP(8xx), #endif #ifdef CONFIG_VSX WARN_EMULATED_SETUP(vsx), #endif }; u32 ppc_warn_emulated; void ppc_warn_emulated_print(const char *type) { if (printk_ratelimit()) pr_warning("%s used emulated %s instruction\n", current->comm, type); } static int __init ppc_warn_emulated_init(void) { struct dentry *dir, *d; unsigned int i; struct ppc_emulated_entry *entries = (void *)&ppc_emulated; if (!powerpc_debugfs_root) return -ENODEV; dir = debugfs_create_dir("emulated_instructions", powerpc_debugfs_root); if (!dir) return -ENOMEM; d = debugfs_create_u32("do_warn", S_IRUGO | S_IWUSR, dir, &ppc_warn_emulated); if (!d) goto fail; for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) { d = debugfs_create_u32(entries[i].name, S_IRUGO | S_IWUSR, dir, (u32 *)&entries[i].val.counter); if (!d) goto fail; } return 0; fail: debugfs_remove_recursive(dir); return -ENOMEM; } device_initcall(ppc_warn_emulated_init); #endif /* CONFIG_PPC_EMULATED_STATS */