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-rw-r--r--arch/ppc64/kernel/traps.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/traps.c b/arch/ppc64/kernel/traps.c
new file mode 100644
index 000000000000..10fc61f3f6a4
--- /dev/null
+++ b/arch/ppc64/kernel/traps.c
@@ -0,0 +1,565 @@
+/*
+ * linux/arch/ppc64/kernel/traps.c
+ *
+ * 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@cs.anu.edu.au)
+ */
+
+/*
+ * 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/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/delay.h>
+#include <asm/kdebug.h>
+
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/ppcdebug.h>
+#include <asm/rtas.h>
+#include <asm/systemcfg.h>
+#include <asm/machdep.h>
+#include <asm/pmc.h>
+
+#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 *ppc64_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(&ppc64_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);
+ 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
+ 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;
+ }
+ 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) {
+ printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
+ ssleep(5);
+ panic("Fatal exception");
+ }
+ do_exit(SIGSEGV);
+
+ 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);
+}
+
+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, 0);
+
+ /* 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. */
+}
+
+void machine_check_exception(struct pt_regs *regs)
+{
+ 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;
+
+ if (debugger_fault_handler(regs))
+ return;
+ die("Machine check", regs, 0);
+
+ /* Must die if the interrupt is not recoverable */
+ if (!(regs->msr & MSR_RI))
+ panic("Unrecoverable Machine check");
+}
+
+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 single_step_exception(struct pt_regs *regs)
+{
+ regs->msr &= ~MSR_SE; /* Turn off 'trace' bit */
+
+ 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 inline void emulate_single_step(struct pt_regs *regs)
+{
+ if (regs->msr & MSR_SE)
+ single_step_exception(regs);
+}
+
+static void parse_fpe(struct pt_regs *regs)
+{
+ int code = 0;
+ unsigned long fpscr;
+
+ flush_fp_to_thread(current);
+
+ fpscr = current->thread.fpscr;
+
+ /* 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. Return non-zero if we can't
+ * emulate, or -EFAULT if the associated memory access caused an access
+ * fault. Return zero on success.
+ */
+
+#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
+
+static int emulate_instruction(struct pt_regs *regs)
+{
+ unsigned int instword;
+
+ if (!user_mode(regs))
+ return -EINVAL;
+
+ CHECK_FULL_REGS(regs);
+
+ if (get_user(instword, (unsigned int __user *)(regs->nip)))
+ return -EFAULT;
+
+ /* Emulate the mfspr rD, PVR. */
+ if ((instword & INST_MFSPR_PVR_MASK) == INST_MFSPR_PVR) {
+ unsigned int rd;
+
+ 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) {
+ static int warned;
+
+ if (!warned) {
+ printk(KERN_WARNING
+ "process %d (%s) uses obsolete 'dcba' insn\n",
+ current->pid, current->comm);
+ warned = 1;
+ }
+ return 0;
+ }
+
+ /* Emulate the mcrxr insn. */
+ if ((instword & INST_MCRXR_MASK) == INST_MCRXR) {
+ static int warned;
+ unsigned int shift;
+
+ if (!warned) {
+ printk(KERN_WARNING
+ "process %d (%s) uses obsolete 'mcrxr' insn\n",
+ current->pid, current->comm);
+ warned = 1;
+ }
+
+ shift = (instword >> 21) & 0x1c;
+ regs->ccr &= ~(0xf0000000 >> shift);
+ regs->ccr |= (regs->xer & 0xf0000000) >> shift;
+ regs->xer &= ~0xf0000000;
+ return 0;
+ }
+
+ 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 */
+ printk(KERN_ERR "Badness in %s at %s:%d\n",
+ bug->function, bug->file,
+ (unsigned int)bug->line & ~BUG_WARNING_TRAP);
+ show_stack(current, (void *)regs->gpr[1]);
+ return 1;
+ }
+ printk(KERN_CRIT "kernel BUG in %s at %s:%d!\n",
+ bug->function, bug->file, (unsigned int)bug->line);
+ return 0;
+}
+
+void program_check_exception(struct pt_regs *regs)
+{
+ if (debugger_fault_handler(regs))
+ return;
+
+ if (regs->msr & 0x100000) {
+ /* IEEE FP exception */
+ parse_fpe(regs);
+ } else if (regs->msr & 0x20000) {
+ /* 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);
+
+ } else {
+ /* Privileged or illegal instruction; try to emulate it. */
+ switch (emulate_instruction(regs)) {
+ case 0:
+ regs->nip += 4;
+ emulate_single_step(regs);
+ break;
+
+ case -EFAULT:
+ _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
+ break;
+
+ default:
+ if (regs->msr & 0x40000)
+ /* priveleged */
+ _exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
+ else
+ /* illegal */
+ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+ break;
+ }
+ }
+}
+
+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)
+{
+#ifndef 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);
+}
+
+extern perf_irq_t perf_irq;
+
+void performance_monitor_exception(struct pt_regs *regs)
+{
+ perf_irq(regs);
+}
+
+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_MAPERR, regs->dar);
+ } else {
+ /* Search exception table */
+ bad_page_fault(regs, regs->dar, SIGSEGV);
+ }
+
+ return;
+ }
+
+ _exception(SIGBUS, regs, BUS_ADRALN, regs->nip);
+}
+
+#ifdef CONFIG_ALTIVEC
+void altivec_assist_exception(struct pt_regs *regs)
+{
+ int err;
+ siginfo_t info;
+
+ 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 */
+ info.si_signo = SIGSEGV;
+ info.si_errno = 0;
+ info.si_code = SEGV_MAPERR;
+ info.si_addr = (void __user *) regs->nip;
+ force_sig_info(SIGSEGV, &info, current);
+ } 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 */
+
+/*
+ * 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);
+}
+
+/*
+ * 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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