[linux-block.git] / arch / sparc / kernel / traps_32.c

// SPDX-License-Identifier: GPL-2.0
/*
 * arch/sparc/kernel/traps.c
 *
 * Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
 * Copyright 2000 Jakub Jelinek (jakub@redhat.com)
 */

/*
 * I hate traps on the sparc, grrr...
 */

#include <linux/sched/mm.h>
#include <linux/sched/debug.h>
#include <linux/mm_types.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/kdebug.h>
#include <linux/export.h>
#include <linux/pgtable.h>

#include <asm/delay.h>
#include <asm/ptrace.h>
#include <asm/oplib.h>
#include <asm/page.h>
#include <asm/unistd.h>
#include <asm/traps.h>

#include "entry.h"
#include "kernel.h"

/* #define TRAP_DEBUG */

static void instruction_dump(unsigned long *pc)
{
	int i;
	
	if((((unsigned long) pc) & 3))
                return;

	for(i = -3; i < 6; i++)
		printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
	printk("\n");
}

#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")

void __noreturn die_if_kernel(char *str, struct pt_regs *regs)
{
	static int die_counter;
	int count = 0;

	/* Amuse the user. */
	printk(
"              \\|/ ____ \\|/\n"
"              \"@'/ ,. \\`@\"\n"
"              /_| \\__/ |_\\\n"
"                 \\__U_/\n");

	printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
	show_regs(regs);
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);

	__SAVE; __SAVE; __SAVE; __SAVE;
	__SAVE; __SAVE; __SAVE; __SAVE;
	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
	__RESTORE; __RESTORE; __RESTORE; __RESTORE;

	{
		struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];

		/* Stop the back trace when we hit userland or we
		 * find some badly aligned kernel stack. Set an upper
		 * bound in case our stack is trashed and we loop.
		 */
		while(rw					&&
		      count++ < 30				&&
                      (((unsigned long) rw) >= PAGE_OFFSET)	&&
		      !(((unsigned long) rw) & 0x7)) {
			printk("Caller[%08lx]: %pS\n", rw->ins[7],
			       (void *) rw->ins[7]);
			rw = (struct reg_window32 *)rw->ins[6];
		}
	}
	printk("Instruction DUMP:");
	instruction_dump ((unsigned long *) regs->pc);
	make_task_dead((regs->psr & PSR_PS) ? SIGKILL : SIGSEGV);
}

void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
{
	if(type < 0x80) {
		/* Sun OS's puke from bad traps, Linux survives! */
		printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
		die_if_kernel("Whee... Hello Mr. Penguin", regs);
	}	

	if(regs->psr & PSR_PS)
		die_if_kernel("Kernel bad trap", regs);

	force_sig_fault_trapno(SIGILL, ILL_ILLTRP,
			       (void __user *)regs->pc, type - 0x80);
}

void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			    unsigned long psr)
{
	if(psr & PSR_PS)
		die_if_kernel("Kernel illegal instruction", regs);
#ifdef TRAP_DEBUG
	printk("Ill instr. at pc=%08lx instruction is %08lx\n",
	       regs->pc, *(unsigned long *)regs->pc);
#endif

	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, current);
}

void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
	if(psr & PSR_PS)
		die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
	send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, current);
}

/* XXX User may want to be allowed to do this. XXX */

void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			    unsigned long psr)
{
	if(regs->psr & PSR_PS) {
		printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
		       regs->u_regs[UREG_RETPC]);
		die_if_kernel("BOGUS", regs);
		/* die_if_kernel("Kernel MNA access", regs); */
	}
#if 0
	show_regs (regs);
	instruction_dump ((unsigned long *) regs->pc);
	printk ("do_MNA!\n");
#endif
	send_sig_fault(SIGBUS, BUS_ADRALN,
		       /* FIXME: Should dig out mna address */ (void *)0,
		       current);
}

static unsigned long init_fsr = 0x0UL;
static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
                { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
		  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
		  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
		  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };

void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		 unsigned long psr)
{
	/* Sanity check... */
	if(psr & PSR_PS)
		die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);

	put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
	regs->psr |= PSR_EF;
#ifndef CONFIG_SMP
	if(last_task_used_math == current)
		return;
	if(last_task_used_math) {
		/* Other processes fpu state, save away */
		struct task_struct *fptask = last_task_used_math;
		fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
		       &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
	}
	last_task_used_math = current;
	if(used_math()) {
		fpload(&current->thread.float_regs[0], &current->thread.fsr);
	} else {
		/* Set initial sane state. */
		fpload(&init_fregs[0], &init_fsr);
		set_used_math();
	}
#else
	if(!used_math()) {
		fpload(&init_fregs[0], &init_fsr);
		set_used_math();
	} else {
		fpload(&current->thread.float_regs[0], &current->thread.fsr);
	}
	set_thread_flag(TIF_USEDFPU);
#endif
}

static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
static unsigned long fake_fsr;
static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
static unsigned long fake_depth;

void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		 unsigned long psr)
{
	static int calls;
	unsigned long fsr;
	int ret = 0;
	int code;
#ifndef CONFIG_SMP
	struct task_struct *fpt = last_task_used_math;
#else
	struct task_struct *fpt = current;
#endif
	put_psr(get_psr() | PSR_EF);
	/* If nobody owns the fpu right now, just clear the
	 * error into our fake static buffer and hope it don't
	 * happen again.  Thank you crashme...
	 */
#ifndef CONFIG_SMP
	if(!fpt) {
#else
	if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
#endif
		fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
		regs->psr &= ~PSR_EF;
		return;
	}
	fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
	       &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
#ifdef DEBUG_FPU
	printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
#endif

	switch ((fpt->thread.fsr & 0x1c000)) {
	/* switch on the contents of the ftt [floating point trap type] field */
#ifdef DEBUG_FPU
	case (1 << 14):
		printk("IEEE_754_exception\n");
		break;
#endif
	case (2 << 14):  /* unfinished_FPop (underflow & co) */
	case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
		ret = do_mathemu(regs, fpt);
		break;
#ifdef DEBUG_FPU
	case (4 << 14):
		printk("sequence_error (OS bug...)\n");
		break;
	case (5 << 14):
		printk("hardware_error (uhoh!)\n");
		break;
	case (6 << 14):
		printk("invalid_fp_register (user error)\n");
		break;
#endif /* DEBUG_FPU */
	}
	/* If we successfully emulated the FPop, we pretend the trap never happened :-> */
	if (ret) {
		fpload(&current->thread.float_regs[0], &current->thread.fsr);
		return;
	}
	/* nope, better SIGFPE the offending process... */
	       
#ifdef CONFIG_SMP
	clear_tsk_thread_flag(fpt, TIF_USEDFPU);
#endif
	if(psr & PSR_PS) {
		/* The first fsr store/load we tried trapped,
		 * the second one will not (we hope).
		 */
		printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
		       regs->pc);
		regs->pc = regs->npc;
		regs->npc += 4;
		calls++;
		if(calls > 2)
			die_if_kernel("Too many Penguin-FPU traps from kernel mode",
				      regs);
		return;
	}

	fsr = fpt->thread.fsr;
	code = FPE_FLTUNK;
	if ((fsr & 0x1c000) == (1 << 14)) {
		if (fsr & 0x10)
			code = FPE_FLTINV;
		else if (fsr & 0x08)
			code = FPE_FLTOVF;
		else if (fsr & 0x04)
			code = FPE_FLTUND;
		else if (fsr & 0x02)
			code = FPE_FLTDIV;
		else if (fsr & 0x01)
			code = FPE_FLTRES;
	}
	send_sig_fault(SIGFPE, code, (void __user *)pc, fpt);
#ifndef CONFIG_SMP
	last_task_used_math = NULL;
#endif
	regs->psr &= ~PSR_EF;
	if(calls > 0)
		calls=0;
}

void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
	if(psr & PSR_PS)
		die_if_kernel("Penguin overflow trap from kernel mode", regs);
	send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, current);
}

void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		       unsigned long psr)
{
#ifdef TRAP_DEBUG
	printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
	       pc, npc, psr);
#endif
	if(psr & PSR_PS)
		panic("Tell me what a watchpoint trap is, and I'll then deal "
		      "with such a beast...");
}

void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		       unsigned long psr)
{
#ifdef TRAP_DEBUG
	printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
	       pc, npc, psr);
#endif
	force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)pc);
}

void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			unsigned long psr)
{
	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
}

void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
#ifdef TRAP_DEBUG
	printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
	       pc, npc, psr);
#endif
	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
}

void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		       unsigned long psr)
{
	send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, current);
}

#ifdef CONFIG_DEBUG_BUGVERBOSE
void do_BUG(const char *file, int line)
{
        // bust_spinlocks(1);   XXX Not in our original BUG()
        printk("kernel BUG at %s:%d!\n", file, line);
}
EXPORT_SYMBOL(do_BUG);
#endif

/* Since we have our mappings set up, on multiprocessors we can spin them
 * up here so that timer interrupts work during initialization.
 */

void trap_init(void)
{
	extern void thread_info_offsets_are_bolixed_pete(void);

	/* Force linker to barf if mismatched */
	if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
	    TI_TASK        != offsetof(struct thread_info, task) ||
	    TI_FLAGS       != offsetof(struct thread_info, flags) ||
	    TI_CPU         != offsetof(struct thread_info, cpu) ||
	    TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
	    TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
	    TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
	    TI_KSP         != offsetof(struct thread_info, ksp) ||
	    TI_KPC         != offsetof(struct thread_info, kpc) ||
	    TI_KPSR        != offsetof(struct thread_info, kpsr) ||
	    TI_KWIM        != offsetof(struct thread_info, kwim) ||
	    TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
	    TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
	    TI_W_SAVED     != offsetof(struct thread_info, w_saved))
		thread_info_offsets_are_bolixed_pete();

	/* Attach to the address space of init_task. */
	mmgrab(&init_mm);
	current->active_mm = &init_mm;

	/* NOTE: Other cpus have this done as they are started
	 *       up on SMP.
	 */
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
88278ca2	2	/*
1da177e4 LT	3	* arch/sparc/kernel/traps.c
1da177e4 LT	4	*
4fe3ebec	5	* Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
1da177e4 LT	6	* Copyright 2000 Jakub Jelinek (jakub@redhat.com)
	7	*/
	8
	9	/*
	10	* I hate traps on the sparc, grrr...
	11	*/
	12
68e21be2	13	#include <linux/sched/mm.h>
b17b0153	14	#include <linux/sched/debug.h>
589ee628	15	#include <linux/mm_types.h>
1da177e4	16	#include <linux/kernel.h>
1da177e4 LT	17	#include <linux/signal.h>
1da177e4 LT	18	#include <linux/smp.h>
1eeb66a1	19	#include <linux/kdebug.h>
7b64db60	20	#include <linux/export.h>
65fddcfc	21	#include <linux/pgtable.h>
1da177e4 LT	22
1da177e4 LT	23	#include <asm/delay.h>
1da177e4 LT	24	#include <asm/ptrace.h>
	25	#include <asm/oplib.h>
	26	#include <asm/page.h>
1da177e4 LT	27	#include <asm/unistd.h>
	28	#include <asm/traps.h>
	29
8d74e32a SR	30	#include "entry.h"
8d74e32a SR	31	#include "kernel.h"
1da177e4	32
8d74e32a	33	/* #define TRAP_DEBUG */
1da177e4	34
c61c65cd	35	static void instruction_dump(unsigned long *pc)
1da177e4 LT	36	{
	37	int i;
	38
	39	if((((unsigned long) pc) & 3))
	40	return;
	41
	42	for(i = -3; i < 6; i++)
	43	printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
	44	printk("\n");
	45	}
	46
	47	#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
	48	#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
	49
fcd0196b	50	void __noreturn die_if_kernel(char str, struct pt_regs regs)
1da177e4 LT	51	{
	52	static int die_counter;
	53	int count = 0;
	54
	55	/* Amuse the user. */
	56	printk(
	57	" \\\|/ ____ \\\|/\n"
	58	" \"@'/ ,. \\`@\"\n"
	59	" /_\| \\__/ \|_\\\n"
	60	" \\__U_/\n");
	61
19c5870c	62	printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
1da177e4	63	show_regs(regs);
373d4d09	64	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
1da177e4 LT	65
	66	__SAVE; __SAVE; __SAVE; __SAVE;
	67	__SAVE; __SAVE; __SAVE; __SAVE;
	68	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
	69	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
	70
	71	{
4d7b92ad	72	struct reg_window32 rw = (struct reg_window32 )regs->u_regs[UREG_FP];
1da177e4 LT	73
	74	/* Stop the back trace when we hit userland or we
	75	* find some badly aligned kernel stack. Set an upper
	76	* bound in case our stack is trashed and we loop.
	77	*/
	78	while(rw &&
	79	count++ < 30 &&
	80	(((unsigned long) rw) >= PAGE_OFFSET) &&
	81	!(((unsigned long) rw) & 0x7)) {
4fe3ebec DM	82	printk("Caller[%08lx]: %pS\n", rw->ins[7],
4fe3ebec DM	83	(void *) rw->ins[7]);
4d7b92ad	84	rw = (struct reg_window32 *)rw->ins[6];
1da177e4 LT	85	}
	86	}
	87	printk("Instruction DUMP:");
	88	instruction_dump ((unsigned long *) regs->pc);
0e25498f	89	make_task_dead((regs->psr & PSR_PS) ? SIGKILL : SIGSEGV);
1da177e4 LT	90	}
	91
	92	void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
	93	{
1da177e4 LT	94	if(type < 0x80) {
	95	/* Sun OS's puke from bad traps, Linux survives! */
	96	printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
	97	die_if_kernel("Whee... Hello Mr. Penguin", regs);
	98	}
	99
	100	if(regs->psr & PSR_PS)
	101	die_if_kernel("Kernel bad trap", regs);
	102
2c9f7eaf EB	103	force_sig_fault_trapno(SIGILL, ILL_ILLTRP,
2c9f7eaf EB	104	(void __user *)regs->pc, type - 0x80);
1da177e4 LT	105	}
	106
	107	void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	108	unsigned long psr)
	109	{
1da177e4 LT	110	if(psr & PSR_PS)
	111	die_if_kernel("Kernel illegal instruction", regs);
	112	#ifdef TRAP_DEBUG
	113	printk("Ill instr. at pc=%08lx instruction is %08lx\n",
	114	regs->pc, (unsigned long )regs->pc);
	115	#endif
1da177e4	116
2c9f7eaf	117	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, current);
1da177e4 LT	118	}
	119
	120	void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	121	unsigned long psr)
	122	{
1da177e4 LT	123	if(psr & PSR_PS)
1da177e4 LT	124	die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
2c9f7eaf	125	send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, current);
1da177e4 LT	126	}
	127
	128	/* XXX User may want to be allowed to do this. XXX */
	129
	130	void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	131	unsigned long psr)
	132	{
1da177e4 LT	133	if(regs->psr & PSR_PS) {
	134	printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
	135	regs->u_regs[UREG_RETPC]);
	136	die_if_kernel("BOGUS", regs);
	137	/* die_if_kernel("Kernel MNA access", regs); */
	138	}
	139	#if 0
	140	show_regs (regs);
	141	instruction_dump ((unsigned long *) regs->pc);
	142	printk ("do_MNA!\n");
	143	#endif
0e3d9f1e EB	144	send_sig_fault(SIGBUS, BUS_ADRALN,
0e3d9f1e EB	145	/* FIXME: Should dig out mna address / (void )0,
2c9f7eaf	146	current);
1da177e4 LT	147	}
1da177e4 LT	148
1da177e4 LT	149	static unsigned long init_fsr = 0x0UL;
	150	static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
	151	{ ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
	152	~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
	153	~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
	154	~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
	155
	156	void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	157	unsigned long psr)
	158	{
	159	/* Sanity check... */
	160	if(psr & PSR_PS)
	161	die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
	162
	163	put_psr(get_psr() \| PSR_EF); /* Allow FPU ops. */
	164	regs->psr \|= PSR_EF;
	165	#ifndef CONFIG_SMP
	166	if(last_task_used_math == current)
	167	return;
	168	if(last_task_used_math) {
	169	/* Other processes fpu state, save away */
	170	struct task_struct *fptask = last_task_used_math;
	171	fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
	172	&fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
	173	}
	174	last_task_used_math = current;
	175	if(used_math()) {
	176	fpload(&current->thread.float_regs[0], &current->thread.fsr);
	177	} else {
	178	/* Set initial sane state. */
	179	fpload(&init_fregs[0], &init_fsr);
	180	set_used_math();
	181	}
	182	#else
	183	if(!used_math()) {
	184	fpload(&init_fregs[0], &init_fsr);
	185	set_used_math();
	186	} else {
	187	fpload(&current->thread.float_regs[0], &current->thread.fsr);
	188	}
54f565ea	189	set_thread_flag(TIF_USEDFPU);
1da177e4 LT	190	#endif
	191	}
	192
	193	static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
	194	static unsigned long fake_fsr;
	195	static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
	196	static unsigned long fake_depth;
	197
1da177e4 LT	198	void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	199	unsigned long psr)
	200	{
	201	static int calls;
1da177e4 LT	202	unsigned long fsr;
1da177e4 LT	203	int ret = 0;
0e3d9f1e	204	int code;
1da177e4 LT	205	#ifndef CONFIG_SMP
	206	struct task_struct *fpt = last_task_used_math;
	207	#else
	208	struct task_struct *fpt = current;
	209	#endif
	210	put_psr(get_psr() \| PSR_EF);
	211	/* If nobody owns the fpu right now, just clear the
	212	* error into our fake static buffer and hope it don't
	213	* happen again. Thank you crashme...
	214	*/
	215	#ifndef CONFIG_SMP
	216	if(!fpt) {
	217	#else
54f565ea	218	if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
1da177e4 LT	219	#endif
	220	fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
	221	regs->psr &= ~PSR_EF;
	222	return;
	223	}
	224	fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
	225	&fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
	226	#ifdef DEBUG_FPU
	227	printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
	228	#endif
	229
	230	switch ((fpt->thread.fsr & 0x1c000)) {
	231	/* switch on the contents of the ftt [floating point trap type] field */
	232	#ifdef DEBUG_FPU
	233	case (1 << 14):
	234	printk("IEEE_754_exception\n");
	235	break;
	236	#endif
	237	case (2 << 14): /* unfinished_FPop (underflow & co) */
	238	case (3 << 14): /* unimplemented_FPop (quad stuff, maybe sqrt) */
	239	ret = do_mathemu(regs, fpt);
	240	break;
	241	#ifdef DEBUG_FPU
	242	case (4 << 14):
	243	printk("sequence_error (OS bug...)\n");
	244	break;
	245	case (5 << 14):
	246	printk("hardware_error (uhoh!)\n");
	247	break;
	248	case (6 << 14):
	249	printk("invalid_fp_register (user error)\n");
	250	break;
	251	#endif /* DEBUG_FPU */
	252	}
	253	/* If we successfully emulated the FPop, we pretend the trap never happened :-> */
	254	if (ret) {
	255	fpload(&current->thread.float_regs[0], &current->thread.fsr);
	256	return;
	257	}
	258	/* nope, better SIGFPE the offending process... */
	259
	260	#ifdef CONFIG_SMP
54f565ea	261	clear_tsk_thread_flag(fpt, TIF_USEDFPU);
1da177e4 LT	262	#endif
	263	if(psr & PSR_PS) {
	264	/* The first fsr store/load we tried trapped,
	265	* the second one will not (we hope).
	266	*/
	267	printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
	268	regs->pc);
	269	regs->pc = regs->npc;
	270	regs->npc += 4;
	271	calls++;
	272	if(calls > 2)
	273	die_if_kernel("Too many Penguin-FPU traps from kernel mode",
	274	regs);
	275	return;
	276	}
	277
	278	fsr = fpt->thread.fsr;
0e3d9f1e	279	code = FPE_FLTUNK;
1da177e4 LT	280	if ((fsr & 0x1c000) == (1 << 14)) {
1da177e4 LT	281	if (fsr & 0x10)
0e3d9f1e	282	code = FPE_FLTINV;
1da177e4	283	else if (fsr & 0x08)
0e3d9f1e	284	code = FPE_FLTOVF;
1da177e4	285	else if (fsr & 0x04)
0e3d9f1e	286	code = FPE_FLTUND;
1da177e4	287	else if (fsr & 0x02)
0e3d9f1e	288	code = FPE_FLTDIV;
1da177e4	289	else if (fsr & 0x01)
0e3d9f1e	290	code = FPE_FLTRES;
1da177e4	291	}
2c9f7eaf	292	send_sig_fault(SIGFPE, code, (void __user *)pc, fpt);
1da177e4 LT	293	#ifndef CONFIG_SMP
	294	last_task_used_math = NULL;
	295	#endif
	296	regs->psr &= ~PSR_EF;
	297	if(calls > 0)
	298	calls=0;
	299	}
	300
	301	void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	302	unsigned long psr)
	303	{
1da177e4 LT	304	if(psr & PSR_PS)
1da177e4 LT	305	die_if_kernel("Penguin overflow trap from kernel mode", regs);
2c9f7eaf	306	send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, current);
1da177e4 LT	307	}
	308
	309	void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	310	unsigned long psr)
	311	{
	312	#ifdef TRAP_DEBUG
	313	printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
	314	pc, npc, psr);
	315	#endif
	316	if(psr & PSR_PS)
	317	panic("Tell me what a watchpoint trap is, and I'll then deal "
	318	"with such a beast...");
	319	}
	320
	321	void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	322	unsigned long psr)
	323	{
1da177e4 LT	324	#ifdef TRAP_DEBUG
	325	printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
	326	pc, npc, psr);
	327	#endif
2c9f7eaf	328	force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)pc);
1da177e4 LT	329	}
	330
	331	void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	332	unsigned long psr)
	333	{
2c9f7eaf	334	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
1da177e4 LT	335	}
	336
	337	void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	338	unsigned long psr)
	339	{
1da177e4 LT	340	#ifdef TRAP_DEBUG
	341	printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
	342	pc, npc, psr);
	343	#endif
2c9f7eaf	344	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
1da177e4 LT	345	}
	346
	347	void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	348	unsigned long psr)
	349	{
2c9f7eaf	350	send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, current);
1da177e4 LT	351	}
	352
	353	#ifdef CONFIG_DEBUG_BUGVERBOSE
	354	void do_BUG(const char *file, int line)
	355	{
	356	// bust_spinlocks(1); XXX Not in our original BUG()
	357	printk("kernel BUG at %s:%d!\n", file, line);
	358	}
6943f3da	359	EXPORT_SYMBOL(do_BUG);
1da177e4 LT	360	#endif
	361
	362	/* Since we have our mappings set up, on multiprocessors we can spin them
	363	* up here so that timer interrupts work during initialization.
	364	*/
	365
1da177e4 LT	366	void trap_init(void)
	367	{
	368	extern void thread_info_offsets_are_bolixed_pete(void);
	369
	370	/* Force linker to barf if mismatched */
	371	if (TI_UWINMASK != offsetof(struct thread_info, uwinmask) \|\|
	372	TI_TASK != offsetof(struct thread_info, task) \|\|
1da177e4 LT	373	TI_FLAGS != offsetof(struct thread_info, flags) \|\|
	374	TI_CPU != offsetof(struct thread_info, cpu) \|\|
	375	TI_PREEMPT != offsetof(struct thread_info, preempt_count) \|\|
	376	TI_SOFTIRQ != offsetof(struct thread_info, softirq_count) \|\|
	377	TI_HARDIRQ != offsetof(struct thread_info, hardirq_count) \|\|
	378	TI_KSP != offsetof(struct thread_info, ksp) \|\|
	379	TI_KPC != offsetof(struct thread_info, kpc) \|\|
	380	TI_KPSR != offsetof(struct thread_info, kpsr) \|\|
	381	TI_KWIM != offsetof(struct thread_info, kwim) \|\|
	382	TI_REG_WINDOW != offsetof(struct thread_info, reg_window) \|\|
	383	TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) \|\|
	384	TI_W_SAVED != offsetof(struct thread_info, w_saved))
	385	thread_info_offsets_are_bolixed_pete();
	386
	387	/* Attach to the address space of init_task. */
f1f10076	388	mmgrab(&init_mm);
1da177e4 LT	389	current->active_mm = &init_mm;
	390
	391	/* NOTE: Other cpus have this done as they are started
	392	* up on SMP.
	393	*/
	394	}