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-rw-r--r--arch/powerpc/kernel/traps.c1101
1 files changed, 1101 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
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--- /dev/null
+++ b/arch/powerpc/kernel/traps.c
@@ -0,0 +1,1101 @@
+/*
+ * 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/config.h>
+#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/a.out.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 <asm/kdebug.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/xmon.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>
+#include <asm/systemcfg.h>
+#endif
+
+#ifdef CONFIG_PPC64 /* XXX */
+#define _IO_BASE pci_io_base
+#endif
+
+#ifdef CONFIG_DEBUGGER
+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
+
+struct notifier_block *powerpc_die_chain;
+static DEFINE_SPINLOCK(die_notifier_lock);
+
+int register_die_notifier(struct notifier_block *nb)
+{
+ int err = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&die_notifier_lock, flags);
+ err = notifier_chain_register(&powerpc_die_chain, nb);
+ spin_unlock_irqrestore(&die_notifier_lock, flags);
+ return err;
+}
+
+/*
+ * Trap & Exception support
+ */
+
+static DEFINE_SPINLOCK(die_lock);
+
+int die(const char *str, struct pt_regs *regs, long err)
+{
+ static int die_counter;
+ int nl = 0;
+
+ if (debugger(regs))
+ return 1;
+
+ console_verbose();
+ spin_lock_irq(&die_lock);
+ bust_spinlocks(1);
+#ifdef CONFIG_PMAC_BACKLIGHT
+ if (_machine == _MACH_Pmac) {
+ set_backlight_enable(1);
+ set_backlight_level(BACKLIGHT_MAX);
+ }
+#endif
+ printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
+#ifdef CONFIG_PREEMPT
+ printk("PREEMPT ");
+ nl = 1;
+#endif
+#ifdef CONFIG_SMP
+ printk("SMP NR_CPUS=%d ", NR_CPUS);
+ nl = 1;
+#endif
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ printk("DEBUG_PAGEALLOC ");
+ nl = 1;
+#endif
+#ifdef CONFIG_NUMA
+ printk("NUMA ");
+ nl = 1;
+#endif
+#ifdef CONFIG_PPC64
+ switch (systemcfg->platform) {
+ case PLATFORM_PSERIES:
+ printk("PSERIES ");
+ nl = 1;
+ break;
+ case PLATFORM_PSERIES_LPAR:
+ printk("PSERIES LPAR ");
+ nl = 1;
+ break;
+ case PLATFORM_ISERIES_LPAR:
+ printk("ISERIES LPAR ");
+ nl = 1;
+ break;
+ case PLATFORM_POWERMAC:
+ printk("POWERMAC ");
+ nl = 1;
+ break;
+ case PLATFORM_BPA:
+ printk("BPA ");
+ nl = 1;
+ break;
+ }
+#endif
+ if (nl)
+ printk("\n");
+ print_modules();
+ show_regs(regs);
+ bust_spinlocks(0);
+ spin_unlock_irq(&die_lock);
+
+ if (in_interrupt())
+ panic("Fatal exception in interrupt");
+
+ if (panic_on_oops) {
+#ifdef CONFIG_PPC64
+ printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
+ ssleep(5);
+#endif
+ panic("Fatal exception");
+ }
+ do_exit(err);
+
+ return 0;
+}
+
+void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
+{
+ siginfo_t info;
+
+ if (!user_mode(regs)) {
+ if (die("Exception in kernel mode", regs, signr))
+ return;
+ }
+
+ 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 (current->pid == 1) {
+ __sighandler_t handler;
+
+ spin_lock_irq(&current->sighand->siglock);
+ handler = current->sighand->action[signr-1].sa.sa_handler;
+ spin_unlock_irq(&current->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)
+ ppc_md.system_reset_exception(regs);
+
+ die("System Reset", regs, SIGABRT);
+
+ /* 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_PPC_PMAC
+ 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_PPC_PMAC */
+ 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))
+#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
+
+/*
+ * This is "fall-back" implementation for configurations
+ * which don't provide platform-specific machine check info
+ */
+void __attribute__ ((weak))
+platform_machine_check(struct pt_regs *regs)
+{
+}
+
+void machine_check_exception(struct pt_regs *regs)
+{
+#ifdef CONFIG_PPC64
+ int recover = 0;
+
+ /* See if any machine dependent calls */
+ if (ppc_md.machine_check_exception)
+ recover = ppc_md.machine_check_exception(regs);
+
+ if (recover)
+ return;
+#else
+ unsigned long reason = get_mc_reason(regs);
+
+ 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 */
+ 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 defined(CONFIG_4xx) && !defined(CONFIG_440A)
+ if (reason & ESR_IMCP) {
+ printk("Instruction");
+ mtspr(SPRN_ESR, reason & ~ESR_IMCP);
+ } else
+ printk("Data");
+ printk(" machine check in kernel mode.\n");
+#elif defined(CONFIG_440A)
+ 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);
+ }
+#elif defined (CONFIG_E500)
+ 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_GL_CI)
+ printk("Guarded Load or Cache-Inhibited stwcx.\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");
+#elif defined (CONFIG_E200)
+ 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");
+#else /* !CONFIG_4xx && !CONFIG_E500 && !CONFIG_E200 */
+ 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");
+ }
+#endif /* CONFIG_4xx */
+
+ /*
+ * Optional platform-provided routine to print out
+ * additional info, e.g. bus error registers.
+ */
+ platform_machine_check(regs);
+#endif /* CONFIG_PPC64 */
+
+ 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 void parse_fpe(struct pt_regs *regs)
+{
+ int code = 0;
+ unsigned long fpscr;
+
+ flush_fp_to_thread(current);
+
+ fpscr = current->thread.fpscr.val;
+
+ /* Invalid operation */
+ if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
+ code = FPE_FLTINV;
+
+ /* Overflow */
+ else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
+ code = FPE_FLTOVF;
+
+ /* Underflow */
+ else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
+ code = FPE_FLTUND;
+
+ /* Divide by zero */
+ else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
+ code = FPE_FLTDIV;
+
+ /* Inexact result */
+ else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
+ code = FPE_FLTRES;
+
+ _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.
+ *
+ */
+#define INST_MFSPR_PVR 0x7c1f42a6
+#define INST_MFSPR_PVR_MASK 0xfc1fffff
+
+#define INST_DCBA 0x7c0005ec
+#define INST_DCBA_MASK 0x7c0007fe
+
+#define INST_MCRXR 0x7c000400
+#define INST_MCRXR_MASK 0x7c0007fe
+
+#define INST_STRING 0x7c00042a
+#define INST_STRING_MASK 0x7c0007fe
+#define INST_STRING_GEN_MASK 0x7c00067e
+#define INST_LSWI 0x7c0004aa
+#define INST_LSWX 0x7c00042a
+#define INST_STSWI 0x7c0005aa
+#define INST_STSWX 0x7c00052a
+
+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 & INST_STRING_MASK) == INST_LSWX)
+ if ((rT == rA) || (rT == NB_RB))
+ return -EINVAL;
+
+ EA = (rA == 0) ? 0 : regs->gpr[rA];
+
+ switch (instword & INST_STRING_MASK) {
+ case INST_LSWX:
+ case INST_STSWX:
+ EA += NB_RB;
+ num_bytes = regs->xer & 0x7f;
+ break;
+ case INST_LSWI:
+ case 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 & INST_STRING_MASK)) {
+ case INST_LSWX:
+ case 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 INST_STSWI:
+ case 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_instruction(struct pt_regs *regs)
+{
+ u32 instword;
+ u32 rd;
+
+ if (!user_mode(regs))
+ return -EINVAL;
+ CHECK_FULL_REGS(regs);
+
+ if (get_user(instword, (u32 __user *)(regs->nip)))
+ return -EFAULT;
+
+ /* Emulate the mfspr rD, PVR. */
+ if ((instword & INST_MFSPR_PVR_MASK) == INST_MFSPR_PVR) {
+ rd = (instword >> 21) & 0x1f;
+ regs->gpr[rd] = mfspr(SPRN_PVR);
+ return 0;
+ }
+
+ /* Emulating the dcba insn is just a no-op. */
+ if ((instword & INST_DCBA_MASK) == INST_DCBA)
+ return 0;
+
+ /* Emulate the mcrxr insn. */
+ if ((instword & INST_MCRXR_MASK) == INST_MCRXR) {
+ int shift = (instword >> 21) & 0x1c;
+ unsigned long msk = 0xf0000000UL >> shift;
+
+ regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
+ regs->xer &= ~0xf0000000UL;
+ return 0;
+ }
+
+ /* Emulate load/store string insn. */
+ if ((instword & INST_STRING_GEN_MASK) == INST_STRING)
+ return emulate_string_inst(regs, instword);
+
+ return -EINVAL;
+}
+
+/*
+ * Look through the list of trap instructions that are used for BUG(),
+ * BUG_ON() and WARN_ON() and see if we hit one. At this point we know
+ * that the exception was caused by a trap instruction of some kind.
+ * Returns 1 if we should continue (i.e. it was a WARN_ON) or 0
+ * otherwise.
+ */
+extern struct bug_entry __start___bug_table[], __stop___bug_table[];
+
+#ifndef CONFIG_MODULES
+#define module_find_bug(x) NULL
+#endif
+
+struct bug_entry *find_bug(unsigned long bugaddr)
+{
+ struct bug_entry *bug;
+
+ for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
+ if (bugaddr == bug->bug_addr)
+ return bug;
+ return module_find_bug(bugaddr);
+}
+
+static int check_bug_trap(struct pt_regs *regs)
+{
+ struct bug_entry *bug;
+ unsigned long addr;
+
+ if (regs->msr & MSR_PR)
+ return 0; /* not in kernel */
+ addr = regs->nip; /* address of trap instruction */
+ if (addr < PAGE_OFFSET)
+ return 0;
+ bug = find_bug(regs->nip);
+ if (bug == NULL)
+ return 0;
+ if (bug->line & BUG_WARNING_TRAP) {
+ /* this is a WARN_ON rather than BUG/BUG_ON */
+#ifdef CONFIG_XMON
+ xmon_printf(KERN_ERR "Badness in %s at %s:%d\n",
+ bug->function, bug->file,
+ bug->line & ~BUG_WARNING_TRAP);
+#endif /* CONFIG_XMON */
+ printk(KERN_ERR "Badness in %s at %s:%d\n",
+ bug->function, bug->file,
+ bug->line & ~BUG_WARNING_TRAP);
+ dump_stack();
+ return 1;
+ }
+#ifdef CONFIG_XMON
+ xmon_printf(KERN_CRIT "kernel BUG in %s at %s:%d!\n",
+ bug->function, bug->file, bug->line);
+ xmon(regs);
+#endif /* CONFIG_XMON */
+ printk(KERN_CRIT "kernel BUG in %s at %s:%d!\n",
+ bug->function, bug->file, bug->line);
+
+ return 0;
+}
+
+void __kprobes program_check_exception(struct pt_regs *regs)
+{
+ unsigned int reason = get_reason(regs);
+ extern int do_mathemu(struct pt_regs *regs);
+
+#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 */
+ if (!(reason & REASON_TRAP) && do_mathemu(regs) == 0) {
+ emulate_single_step(regs);
+ return;
+ }
+#endif /* CONFIG_MATH_EMULATION */
+
+ 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 (check_bug_trap(regs)) {
+ regs->nip += 4;
+ return;
+ }
+ _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
+ return;
+ }
+
+ /* 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 fixed;
+
+ 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) {
+ if (user_mode(regs))
+ _exception(SIGSEGV, regs, SEGV_ACCERR, regs->dar);
+ else
+ /* Search exception table */
+ bad_page_fault(regs, regs->dar, SIGSEGV);
+ return;
+ }
+ _exception(SIGBUS, regs, BUS_ADRALN, regs->dar);
+}
+
+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, current->pid, 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 !defined(CONFIG_ALTIVEC)
+ 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;
+ }
+#endif
+ printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
+ "%lx at %lx\n", regs->trap, regs->nip);
+ die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
+}
+
+#ifdef CONFIG_PPC64
+extern perf_irq_t perf_irq;
+#endif
+
+#if defined(CONFIG_PPC64) || defined(CONFIG_E500)
+void performance_monitor_exception(struct pt_regs *regs)
+{
+ perf_irq(regs);
+}
+#endif
+
+#ifdef CONFIG_8xx
+void SoftwareEmulation(struct pt_regs *regs)
+{
+ extern int do_mathemu(struct pt_regs *);
+ extern int Soft_emulate_8xx(struct pt_regs *);
+ int errcode;
+
+ 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);
+#else
+ errcode = Soft_emulate_8xx(regs);
+#endif
+ if (errcode) {
+ if (errcode > 0)
+ _exception(SIGFPE, regs, 0, 0);
+ else if (errcode == -EFAULT)
+ _exception(SIGSEGV, regs, 0, 0);
+ else
+ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+ } else
+ emulate_single_step(regs);
+}
+#endif /* CONFIG_8xx */
+
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+
+void DebugException(struct pt_regs *regs, unsigned long debug_status)
+{
+ if (debug_status & DBSR_IC) { /* instruction completion */
+ regs->msr &= ~MSR_DE;
+ if (user_mode(regs)) {
+ current->thread.dbcr0 &= ~DBCR0_IC;
+ } else {
+ /* Disable instruction completion */
+ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
+ /* Clear the instruction completion event */
+ mtspr(SPRN_DBSR, DBSR_IC);
+ if (debugger_sstep(regs))
+ return;
+ }
+ _exception(SIGTRAP, regs, TRAP_TRACE, 0);
+ }
+}
+#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);
+
+ 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_FSL_BOOKE
+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)
+{
+ unsigned long spefscr;
+ int fpexc_mode;
+ int code = 0;
+
+ spefscr = current->thread.spefscr;
+ fpexc_mode = current->thread.fpexc_mode;
+
+ /* Hardware does not neccessarily set sticky
+ * underflow/overflow/invalid flags */
+ if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
+ code = FPE_FLTOVF;
+ spefscr |= SPEFSCR_FOVFS;
+ }
+ else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
+ code = FPE_FLTUND;
+ spefscr |= SPEFSCR_FUNFS;
+ }
+ 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;
+ spefscr |= SPEFSCR_FINVS;
+ }
+ else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
+ code = FPE_FLTRES;
+
+ current->thread.spefscr = spefscr;
+
+ _exception(SIGFPE, regs, code, 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)
+{
+}
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