[mirror_ubuntu-artful-kernel.git] / arch / sparc / kernel / traps_32.c

/*
 * 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 <asm/delay.h>
#include <asm/ptrace.h>
#include <asm/oplib.h>
#include <asm/page.h>
#include <asm/pgtable.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);
	if(regs->psr & PSR_PS)
		do_exit(SIGKILL);
	do_exit(SIGSEGV);
}

void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
{
	siginfo_t info;

	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);

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_ILLTRP;
	info.si_addr = (void __user *)regs->pc;
	info.si_trapno = type - 0x80;
	force_sig_info(SIGILL, &info, current);
}

void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			    unsigned long psr)
{
	siginfo_t info;

	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

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_ILLOPC;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGILL, &info, current);
}

void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
	siginfo_t info;

	if(psr & PSR_PS)
		die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_PRVOPC;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGILL, &info, 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)
{
	siginfo_t info;

	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
	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_ADRALN;
	info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
	info.si_trapno = 0;
	send_sig_info(SIGBUS, &info, 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;
	siginfo_t info;
	unsigned long fsr;
	int ret = 0;
#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;
	info.si_signo = SIGFPE;
	info.si_errno = 0;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	info.si_code = __SI_FAULT;
	if ((fsr & 0x1c000) == (1 << 14)) {
		if (fsr & 0x10)
			info.si_code = FPE_FLTINV;
		else if (fsr & 0x08)
			info.si_code = FPE_FLTOVF;
		else if (fsr & 0x04)
			info.si_code = FPE_FLTUND;
		else if (fsr & 0x02)
			info.si_code = FPE_FLTDIV;
		else if (fsr & 0x01)
			info.si_code = FPE_FLTRES;
	}
	send_sig_info(SIGFPE, &info, 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)
{
	siginfo_t info;

	if(psr & PSR_PS)
		die_if_kernel("Penguin overflow trap from kernel mode", regs);
	info.si_signo = SIGEMT;
	info.si_errno = 0;
	info.si_code = EMT_TAGOVF;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGEMT, &info, 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)
{
	siginfo_t info;

#ifdef TRAP_DEBUG
	printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
	       pc, npc, psr);
#endif
	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_OBJERR;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	force_sig_info(SIGBUS, &info, current);
}

void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			unsigned long psr)
{
	siginfo_t info;

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_COPROC;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGILL, &info, current);
}

void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
			 unsigned long psr)
{
	siginfo_t info;

#ifdef TRAP_DEBUG
	printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
	       pc, npc, psr);
#endif
	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_COPROC;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGILL, &info, current);
}

void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
		       unsigned long psr)
{
	siginfo_t info;

	info.si_signo = SIGFPE;
	info.si_errno = 0;
	info.si_code = FPE_INTDIV;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	send_sig_info(SIGFPE, &info, 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
88278ca2	1	/*
1da177e4 LT	2	* arch/sparc/kernel/traps.c
1da177e4 LT	3	*
4fe3ebec	4	* Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
1da177e4 LT	5	* Copyright 2000 Jakub Jelinek (jakub@redhat.com)
	6	*/
	7
	8	/*
	9	* I hate traps on the sparc, grrr...
	10	*/
	11
68e21be2	12	#include <linux/sched/mm.h>
b17b0153	13	#include <linux/sched/debug.h>
589ee628	14	#include <linux/mm_types.h>
1da177e4	15	#include <linux/kernel.h>
1da177e4 LT	16	#include <linux/signal.h>
1da177e4 LT	17	#include <linux/smp.h>
1eeb66a1	18	#include <linux/kdebug.h>
7b64db60	19	#include <linux/export.h>
1da177e4 LT	20
1da177e4 LT	21	#include <asm/delay.h>
1da177e4 LT	22	#include <asm/ptrace.h>
	23	#include <asm/oplib.h>
	24	#include <asm/page.h>
	25	#include <asm/pgtable.h>
1da177e4 LT	26	#include <asm/unistd.h>
	27	#include <asm/traps.h>
	28
8d74e32a SR	29	#include "entry.h"
8d74e32a SR	30	#include "kernel.h"
1da177e4	31
8d74e32a	32	/* #define TRAP_DEBUG */
1da177e4	33
c61c65cd	34	static void instruction_dump(unsigned long *pc)
1da177e4 LT	35	{
	36	int i;
	37
	38	if((((unsigned long) pc) & 3))
	39	return;
	40
	41	for(i = -3; i < 6; i++)
	42	printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
	43	printk("\n");
	44	}
	45
	46	#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
	47	#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
	48
fcd0196b	49	void __noreturn die_if_kernel(char str, struct pt_regs regs)
1da177e4 LT	50	{
	51	static int die_counter;
	52	int count = 0;
	53
	54	/* Amuse the user. */
	55	printk(
	56	" \\\|/ ____ \\\|/\n"
	57	" \"@'/ ,. \\`@\"\n"
	58	" /_\| \\__/ \|_\\\n"
	59	" \\__U_/\n");
	60
19c5870c	61	printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
1da177e4	62	show_regs(regs);
373d4d09	63	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
1da177e4 LT	64
	65	__SAVE; __SAVE; __SAVE; __SAVE;
	66	__SAVE; __SAVE; __SAVE; __SAVE;
	67	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
	68	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
	69
	70	{
4d7b92ad	71	struct reg_window32 rw = (struct reg_window32 )regs->u_regs[UREG_FP];
1da177e4 LT	72
	73	/* Stop the back trace when we hit userland or we
	74	* find some badly aligned kernel stack. Set an upper
	75	* bound in case our stack is trashed and we loop.
	76	*/
	77	while(rw &&
	78	count++ < 30 &&
	79	(((unsigned long) rw) >= PAGE_OFFSET) &&
	80	!(((unsigned long) rw) & 0x7)) {
4fe3ebec DM	81	printk("Caller[%08lx]: %pS\n", rw->ins[7],
4fe3ebec DM	82	(void *) rw->ins[7]);
4d7b92ad	83	rw = (struct reg_window32 *)rw->ins[6];
1da177e4 LT	84	}
	85	}
	86	printk("Instruction DUMP:");
	87	instruction_dump ((unsigned long *) regs->pc);
	88	if(regs->psr & PSR_PS)
	89	do_exit(SIGKILL);
	90	do_exit(SIGSEGV);
	91	}
	92
	93	void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
	94	{
	95	siginfo_t info;
	96
	97	if(type < 0x80) {
	98	/* Sun OS's puke from bad traps, Linux survives! */
	99	printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
	100	die_if_kernel("Whee... Hello Mr. Penguin", regs);
	101	}
	102
	103	if(regs->psr & PSR_PS)
	104	die_if_kernel("Kernel bad trap", regs);
	105
	106	info.si_signo = SIGILL;
	107	info.si_errno = 0;
	108	info.si_code = ILL_ILLTRP;
	109	info.si_addr = (void __user *)regs->pc;
	110	info.si_trapno = type - 0x80;
	111	force_sig_info(SIGILL, &info, current);
	112	}
	113
	114	void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	115	unsigned long psr)
	116	{
1da177e4 LT	117	siginfo_t info;
	118
	119	if(psr & PSR_PS)
	120	die_if_kernel("Kernel illegal instruction", regs);
	121	#ifdef TRAP_DEBUG
	122	printk("Ill instr. at pc=%08lx instruction is %08lx\n",
	123	regs->pc, (unsigned long )regs->pc);
	124	#endif
1da177e4 LT	125
	126	info.si_signo = SIGILL;
	127	info.si_errno = 0;
	128	info.si_code = ILL_ILLOPC;
	129	info.si_addr = (void __user *)pc;
	130	info.si_trapno = 0;
	131	send_sig_info(SIGILL, &info, current);
	132	}
	133
	134	void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	135	unsigned long psr)
	136	{
	137	siginfo_t info;
	138
	139	if(psr & PSR_PS)
	140	die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
	141	info.si_signo = SIGILL;
	142	info.si_errno = 0;
	143	info.si_code = ILL_PRVOPC;
	144	info.si_addr = (void __user *)pc;
	145	info.si_trapno = 0;
	146	send_sig_info(SIGILL, &info, current);
	147	}
	148
	149	/* XXX User may want to be allowed to do this. XXX */
	150
	151	void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	152	unsigned long psr)
	153	{
	154	siginfo_t info;
	155
	156	if(regs->psr & PSR_PS) {
	157	printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
	158	regs->u_regs[UREG_RETPC]);
	159	die_if_kernel("BOGUS", regs);
	160	/* die_if_kernel("Kernel MNA access", regs); */
	161	}
	162	#if 0
	163	show_regs (regs);
	164	instruction_dump ((unsigned long *) regs->pc);
	165	printk ("do_MNA!\n");
	166	#endif
	167	info.si_signo = SIGBUS;
	168	info.si_errno = 0;
	169	info.si_code = BUS_ADRALN;
	170	info.si_addr = /* FIXME: Should dig out mna address / (void )0;
	171	info.si_trapno = 0;
	172	send_sig_info(SIGBUS, &info, current);
	173	}
	174
1da177e4 LT	175	static unsigned long init_fsr = 0x0UL;
	176	static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
	177	{ ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
	178	~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
	179	~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
	180	~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
	181
	182	void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	183	unsigned long psr)
	184	{
	185	/* Sanity check... */
	186	if(psr & PSR_PS)
	187	die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
	188
	189	put_psr(get_psr() \| PSR_EF); /* Allow FPU ops. */
	190	regs->psr \|= PSR_EF;
	191	#ifndef CONFIG_SMP
	192	if(last_task_used_math == current)
	193	return;
	194	if(last_task_used_math) {
	195	/* Other processes fpu state, save away */
	196	struct task_struct *fptask = last_task_used_math;
	197	fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
	198	&fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
	199	}
	200	last_task_used_math = current;
	201	if(used_math()) {
	202	fpload(&current->thread.float_regs[0], &current->thread.fsr);
	203	} else {
	204	/* Set initial sane state. */
	205	fpload(&init_fregs[0], &init_fsr);
	206	set_used_math();
	207	}
	208	#else
	209	if(!used_math()) {
	210	fpload(&init_fregs[0], &init_fsr);
	211	set_used_math();
	212	} else {
	213	fpload(&current->thread.float_regs[0], &current->thread.fsr);
	214	}
54f565ea	215	set_thread_flag(TIF_USEDFPU);
1da177e4 LT	216	#endif
	217	}
	218
	219	static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
	220	static unsigned long fake_fsr;
	221	static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
	222	static unsigned long fake_depth;
	223
1da177e4 LT	224	void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	225	unsigned long psr)
	226	{
	227	static int calls;
	228	siginfo_t info;
	229	unsigned long fsr;
	230	int ret = 0;
	231	#ifndef CONFIG_SMP
	232	struct task_struct *fpt = last_task_used_math;
	233	#else
	234	struct task_struct *fpt = current;
	235	#endif
	236	put_psr(get_psr() \| PSR_EF);
	237	/* If nobody owns the fpu right now, just clear the
	238	* error into our fake static buffer and hope it don't
	239	* happen again. Thank you crashme...
	240	*/
	241	#ifndef CONFIG_SMP
	242	if(!fpt) {
	243	#else
54f565ea	244	if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
1da177e4 LT	245	#endif
	246	fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
	247	regs->psr &= ~PSR_EF;
	248	return;
	249	}
	250	fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
	251	&fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
	252	#ifdef DEBUG_FPU
	253	printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
	254	#endif
	255
	256	switch ((fpt->thread.fsr & 0x1c000)) {
	257	/* switch on the contents of the ftt [floating point trap type] field */
	258	#ifdef DEBUG_FPU
	259	case (1 << 14):
	260	printk("IEEE_754_exception\n");
	261	break;
	262	#endif
	263	case (2 << 14): /* unfinished_FPop (underflow & co) */
	264	case (3 << 14): /* unimplemented_FPop (quad stuff, maybe sqrt) */
	265	ret = do_mathemu(regs, fpt);
	266	break;
	267	#ifdef DEBUG_FPU
	268	case (4 << 14):
	269	printk("sequence_error (OS bug...)\n");
	270	break;
	271	case (5 << 14):
	272	printk("hardware_error (uhoh!)\n");
	273	break;
	274	case (6 << 14):
	275	printk("invalid_fp_register (user error)\n");
	276	break;
	277	#endif /* DEBUG_FPU */
	278	}
	279	/* If we successfully emulated the FPop, we pretend the trap never happened :-> */
	280	if (ret) {
	281	fpload(&current->thread.float_regs[0], &current->thread.fsr);
	282	return;
	283	}
	284	/* nope, better SIGFPE the offending process... */
	285
	286	#ifdef CONFIG_SMP
54f565ea	287	clear_tsk_thread_flag(fpt, TIF_USEDFPU);
1da177e4 LT	288	#endif
	289	if(psr & PSR_PS) {
	290	/* The first fsr store/load we tried trapped,
	291	* the second one will not (we hope).
	292	*/
	293	printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
	294	regs->pc);
	295	regs->pc = regs->npc;
	296	regs->npc += 4;
	297	calls++;
	298	if(calls > 2)
	299	die_if_kernel("Too many Penguin-FPU traps from kernel mode",
	300	regs);
	301	return;
	302	}
	303
	304	fsr = fpt->thread.fsr;
	305	info.si_signo = SIGFPE;
	306	info.si_errno = 0;
	307	info.si_addr = (void __user *)pc;
	308	info.si_trapno = 0;
	309	info.si_code = __SI_FAULT;
	310	if ((fsr & 0x1c000) == (1 << 14)) {
	311	if (fsr & 0x10)
	312	info.si_code = FPE_FLTINV;
	313	else if (fsr & 0x08)
	314	info.si_code = FPE_FLTOVF;
	315	else if (fsr & 0x04)
	316	info.si_code = FPE_FLTUND;
	317	else if (fsr & 0x02)
	318	info.si_code = FPE_FLTDIV;
	319	else if (fsr & 0x01)
	320	info.si_code = FPE_FLTRES;
	321	}
	322	send_sig_info(SIGFPE, &info, fpt);
	323	#ifndef CONFIG_SMP
	324	last_task_used_math = NULL;
	325	#endif
	326	regs->psr &= ~PSR_EF;
	327	if(calls > 0)
	328	calls=0;
	329	}
	330
	331	void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	332	unsigned long psr)
	333	{
	334	siginfo_t info;
	335
	336	if(psr & PSR_PS)
	337	die_if_kernel("Penguin overflow trap from kernel mode", regs);
	338	info.si_signo = SIGEMT;
	339	info.si_errno = 0;
	340	info.si_code = EMT_TAGOVF;
	341	info.si_addr = (void __user *)pc;
	342	info.si_trapno = 0;
	343	send_sig_info(SIGEMT, &info, current);
	344	}
	345
	346	void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
	347	unsigned long psr)
	348	{
	349	#ifdef TRAP_DEBUG
	350	printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
	351	pc, npc, psr);
352	#endif
353	if(psr & PSR_PS)
354	panic("Tell me what a watchpoint trap is, and I'll then deal "
355	"with such a beast...");
356	}
357
358	void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
359	unsigned long psr)
360	{
361	siginfo_t info;
362
363	#ifdef TRAP_DEBUG
364	printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
365	pc, npc, psr);
366	#endif
367	info.si_signo = SIGBUS;
368	info.si_errno = 0;
369	info.si_code = BUS_OBJERR;
370	info.si_addr = (void __user *)pc;
371	info.si_trapno = 0;
372	force_sig_info(SIGBUS, &info, current);
373	}
374
375	void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
376	unsigned long psr)
377	{
378	siginfo_t info;
379
380	info.si_signo = SIGILL;
381	info.si_errno = 0;
382	info.si_code = ILL_COPROC;
383	info.si_addr = (void __user *)pc;
384	info.si_trapno = 0;
385	send_sig_info(SIGILL, &info, current);
386	}
387
388	void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
389	unsigned long psr)
390	{
391	siginfo_t info;
392
393	#ifdef TRAP_DEBUG
394	printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
395	pc, npc, psr);
396	#endif
397	info.si_signo = SIGILL;
398	info.si_errno = 0;
399	info.si_code = ILL_COPROC;
400	info.si_addr = (void __user *)pc;
401	info.si_trapno = 0;
402	send_sig_info(SIGILL, &info, current);
403	}
404
405	void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
406	unsigned long psr)
407	{
408	siginfo_t info;
409
410	info.si_signo = SIGFPE;
411	info.si_errno = 0;
412	info.si_code = FPE_INTDIV;
413	info.si_addr = (void __user *)pc;
414	info.si_trapno = 0;
415	send_sig_info(SIGFPE, &info, current);
416	}
417
418	#ifdef CONFIG_DEBUG_BUGVERBOSE
419	void do_BUG(const char *file, int line)
420	{
421	// bust_spinlocks(1); XXX Not in our original BUG()
422	printk("kernel BUG at %s:%d!\n", file, line);
423	}
6943f3da	424	EXPORT_SYMBOL(do_BUG);
1da177e4 LT	425	#endif
	426
	427	/* Since we have our mappings set up, on multiprocessors we can spin them
	428	* up here so that timer interrupts work during initialization.
	429	*/
	430
1da177e4 LT	431	void trap_init(void)
	432	{
	433	extern void thread_info_offsets_are_bolixed_pete(void);
	434
	435	/* Force linker to barf if mismatched */
	436	if (TI_UWINMASK != offsetof(struct thread_info, uwinmask) \|\|
	437	TI_TASK != offsetof(struct thread_info, task) \|\|
1da177e4 LT	438	TI_FLAGS != offsetof(struct thread_info, flags) \|\|
	439	TI_CPU != offsetof(struct thread_info, cpu) \|\|
	440	TI_PREEMPT != offsetof(struct thread_info, preempt_count) \|\|
	441	TI_SOFTIRQ != offsetof(struct thread_info, softirq_count) \|\|
	442	TI_HARDIRQ != offsetof(struct thread_info, hardirq_count) \|\|
	443	TI_KSP != offsetof(struct thread_info, ksp) \|\|
	444	TI_KPC != offsetof(struct thread_info, kpc) \|\|
	445	TI_KPSR != offsetof(struct thread_info, kpsr) \|\|
	446	TI_KWIM != offsetof(struct thread_info, kwim) \|\|
	447	TI_REG_WINDOW != offsetof(struct thread_info, reg_window) \|\|
	448	TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) \|\|
	449	TI_W_SAVED != offsetof(struct thread_info, w_saved))
	450	thread_info_offsets_are_bolixed_pete();
	451
	452	/* Attach to the address space of init_task. */
f1f10076	453	mmgrab(&init_mm);
1da177e4 LT	454	current->active_mm = &init_mm;
	455
	456	/* NOTE: Other cpus have this done as they are started
	457	* up on SMP.
	458	*/
	459	}