397 lines
11 KiB
C
397 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* arch/sparc/kernel/traps.c
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*
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* Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
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* Copyright 2000 Jakub Jelinek (jakub@redhat.com)
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*/
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/*
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* I hate traps on the sparc, grrr...
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*/
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#include <linux/sched/mm.h>
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#include <linux/sched/debug.h>
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#include <linux/mm_types.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/smp.h>
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#include <linux/kdebug.h>
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#include <linux/export.h>
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#include <asm/delay.h>
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#include <asm/ptrace.h>
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#include <asm/oplib.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/unistd.h>
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#include <asm/traps.h>
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#include "entry.h"
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#include "kernel.h"
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/* #define TRAP_DEBUG */
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static void instruction_dump(unsigned long *pc)
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{
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int i;
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if((((unsigned long) pc) & 3))
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return;
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for(i = -3; i < 6; i++)
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printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
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printk("\n");
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}
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#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
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#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
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void __noreturn die_if_kernel(char *str, struct pt_regs *regs)
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{
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static int die_counter;
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int count = 0;
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/* Amuse the user. */
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printk(
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" \\|/ ____ \\|/\n"
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" \"@'/ ,. \\`@\"\n"
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" /_| \\__/ |_\\\n"
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" \\__U_/\n");
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printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
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show_regs(regs);
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add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
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__SAVE; __SAVE; __SAVE; __SAVE;
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__SAVE; __SAVE; __SAVE; __SAVE;
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__RESTORE; __RESTORE; __RESTORE; __RESTORE;
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__RESTORE; __RESTORE; __RESTORE; __RESTORE;
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{
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struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];
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/* Stop the back trace when we hit userland or we
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* find some badly aligned kernel stack. Set an upper
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* bound in case our stack is trashed and we loop.
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*/
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while(rw &&
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count++ < 30 &&
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(((unsigned long) rw) >= PAGE_OFFSET) &&
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!(((unsigned long) rw) & 0x7)) {
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printk("Caller[%08lx]: %pS\n", rw->ins[7],
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(void *) rw->ins[7]);
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rw = (struct reg_window32 *)rw->ins[6];
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}
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}
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printk("Instruction DUMP:");
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instruction_dump ((unsigned long *) regs->pc);
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if(regs->psr & PSR_PS)
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do_exit(SIGKILL);
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do_exit(SIGSEGV);
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}
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void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
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{
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if(type < 0x80) {
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/* Sun OS's puke from bad traps, Linux survives! */
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printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
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die_if_kernel("Whee... Hello Mr. Penguin", regs);
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}
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if(regs->psr & PSR_PS)
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die_if_kernel("Kernel bad trap", regs);
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force_sig_fault(SIGILL, ILL_ILLTRP,
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(void __user *)regs->pc, type - 0x80);
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}
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void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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if(psr & PSR_PS)
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die_if_kernel("Kernel illegal instruction", regs);
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#ifdef TRAP_DEBUG
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printk("Ill instr. at pc=%08lx instruction is %08lx\n",
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regs->pc, *(unsigned long *)regs->pc);
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#endif
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send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, 0, current);
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}
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void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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if(psr & PSR_PS)
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die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
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send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, 0, current);
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}
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/* XXX User may want to be allowed to do this. XXX */
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void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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if(regs->psr & PSR_PS) {
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printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
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regs->u_regs[UREG_RETPC]);
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die_if_kernel("BOGUS", regs);
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/* die_if_kernel("Kernel MNA access", regs); */
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}
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#if 0
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show_regs (regs);
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instruction_dump ((unsigned long *) regs->pc);
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printk ("do_MNA!\n");
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#endif
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send_sig_fault(SIGBUS, BUS_ADRALN,
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/* FIXME: Should dig out mna address */ (void *)0,
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0, current);
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}
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static unsigned long init_fsr = 0x0UL;
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static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
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{ ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
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~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
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~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
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~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
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void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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/* Sanity check... */
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if(psr & PSR_PS)
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die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
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put_psr(get_psr() | PSR_EF); /* Allow FPU ops. */
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regs->psr |= PSR_EF;
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#ifndef CONFIG_SMP
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if(last_task_used_math == current)
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return;
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if(last_task_used_math) {
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/* Other processes fpu state, save away */
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struct task_struct *fptask = last_task_used_math;
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fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
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&fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
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}
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last_task_used_math = current;
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if(used_math()) {
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fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
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} else {
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/* Set initial sane state. */
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fpload(&init_fregs[0], &init_fsr);
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set_used_math();
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}
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#else
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if(!used_math()) {
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fpload(&init_fregs[0], &init_fsr);
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set_used_math();
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} else {
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fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
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}
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set_thread_flag(TIF_USEDFPU);
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#endif
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}
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static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
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static unsigned long fake_fsr;
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static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
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static unsigned long fake_depth;
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void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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static int calls;
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unsigned long fsr;
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int ret = 0;
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int code;
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#ifndef CONFIG_SMP
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struct task_struct *fpt = last_task_used_math;
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#else
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struct task_struct *fpt = current;
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#endif
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put_psr(get_psr() | PSR_EF);
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/* If nobody owns the fpu right now, just clear the
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* error into our fake static buffer and hope it don't
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* happen again. Thank you crashme...
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*/
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#ifndef CONFIG_SMP
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if(!fpt) {
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#else
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if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
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#endif
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fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
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regs->psr &= ~PSR_EF;
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return;
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}
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fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
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&fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
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#ifdef DEBUG_FPU
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printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
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#endif
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switch ((fpt->thread.fsr & 0x1c000)) {
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/* switch on the contents of the ftt [floating point trap type] field */
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#ifdef DEBUG_FPU
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case (1 << 14):
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printk("IEEE_754_exception\n");
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break;
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#endif
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case (2 << 14): /* unfinished_FPop (underflow & co) */
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case (3 << 14): /* unimplemented_FPop (quad stuff, maybe sqrt) */
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ret = do_mathemu(regs, fpt);
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break;
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#ifdef DEBUG_FPU
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case (4 << 14):
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printk("sequence_error (OS bug...)\n");
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break;
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case (5 << 14):
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printk("hardware_error (uhoh!)\n");
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break;
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case (6 << 14):
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printk("invalid_fp_register (user error)\n");
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break;
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#endif /* DEBUG_FPU */
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}
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/* If we successfully emulated the FPop, we pretend the trap never happened :-> */
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if (ret) {
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fpload(¤t->thread.float_regs[0], ¤t->thread.fsr);
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return;
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}
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/* nope, better SIGFPE the offending process... */
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#ifdef CONFIG_SMP
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clear_tsk_thread_flag(fpt, TIF_USEDFPU);
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#endif
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if(psr & PSR_PS) {
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/* The first fsr store/load we tried trapped,
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* the second one will not (we hope).
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*/
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printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
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regs->pc);
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regs->pc = regs->npc;
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regs->npc += 4;
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calls++;
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if(calls > 2)
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die_if_kernel("Too many Penguin-FPU traps from kernel mode",
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regs);
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return;
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}
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fsr = fpt->thread.fsr;
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code = FPE_FLTUNK;
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if ((fsr & 0x1c000) == (1 << 14)) {
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if (fsr & 0x10)
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code = FPE_FLTINV;
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else if (fsr & 0x08)
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code = FPE_FLTOVF;
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else if (fsr & 0x04)
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code = FPE_FLTUND;
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else if (fsr & 0x02)
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code = FPE_FLTDIV;
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else if (fsr & 0x01)
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code = FPE_FLTRES;
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}
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send_sig_fault(SIGFPE, code, (void __user *)pc, 0, fpt);
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#ifndef CONFIG_SMP
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last_task_used_math = NULL;
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#endif
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regs->psr &= ~PSR_EF;
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if(calls > 0)
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calls=0;
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}
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void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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if(psr & PSR_PS)
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die_if_kernel("Penguin overflow trap from kernel mode", regs);
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send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, 0, current);
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}
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void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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#ifdef TRAP_DEBUG
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printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
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pc, npc, psr);
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#endif
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if(psr & PSR_PS)
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panic("Tell me what a watchpoint trap is, and I'll then deal "
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"with such a beast...");
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}
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void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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#ifdef TRAP_DEBUG
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printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
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pc, npc, psr);
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#endif
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force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)pc, 0);
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}
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void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, 0, current);
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}
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void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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#ifdef TRAP_DEBUG
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printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
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pc, npc, psr);
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#endif
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send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, 0, current);
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}
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void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
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unsigned long psr)
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{
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send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, 0, current);
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}
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#ifdef CONFIG_DEBUG_BUGVERBOSE
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void do_BUG(const char *file, int line)
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{
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// bust_spinlocks(1); XXX Not in our original BUG()
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printk("kernel BUG at %s:%d!\n", file, line);
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}
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EXPORT_SYMBOL(do_BUG);
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#endif
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/* Since we have our mappings set up, on multiprocessors we can spin them
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* up here so that timer interrupts work during initialization.
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*/
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void trap_init(void)
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{
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extern void thread_info_offsets_are_bolixed_pete(void);
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/* Force linker to barf if mismatched */
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if (TI_UWINMASK != offsetof(struct thread_info, uwinmask) ||
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TI_TASK != offsetof(struct thread_info, task) ||
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TI_FLAGS != offsetof(struct thread_info, flags) ||
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TI_CPU != offsetof(struct thread_info, cpu) ||
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TI_PREEMPT != offsetof(struct thread_info, preempt_count) ||
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TI_SOFTIRQ != offsetof(struct thread_info, softirq_count) ||
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TI_HARDIRQ != offsetof(struct thread_info, hardirq_count) ||
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TI_KSP != offsetof(struct thread_info, ksp) ||
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TI_KPC != offsetof(struct thread_info, kpc) ||
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TI_KPSR != offsetof(struct thread_info, kpsr) ||
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TI_KWIM != offsetof(struct thread_info, kwim) ||
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TI_REG_WINDOW != offsetof(struct thread_info, reg_window) ||
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TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) ||
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TI_W_SAVED != offsetof(struct thread_info, w_saved))
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thread_info_offsets_are_bolixed_pete();
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/* Attach to the address space of init_task. */
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mmgrab(&init_mm);
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current->active_mm = &init_mm;
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/* NOTE: Other cpus have this done as they are started
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* up on SMP.
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*/
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}
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