traps.c 24.1 KB
Newer Older
L
Linus Torvalds 已提交
1 2
/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
3
 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
L
Linus Torvalds 已提交
4 5 6 7 8 9
 *
 *  Pentium III FXSR, SSE support
 *	Gareth Hughes <gareth@valinux.com>, May 2000
 */

/*
10
 * Handle hardware traps and faults.
L
Linus Torvalds 已提交
11
 */
I
Ingo Molnar 已提交
12 13 14 15 16 17 18
#include <linux/interrupt.h>
#include <linux/kallsyms.h>
#include <linux/spinlock.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/utsname.h>
#include <linux/kdebug.h>
L
Linus Torvalds 已提交
19
#include <linux/kernel.h>
I
Ingo Molnar 已提交
20 21
#include <linux/module.h>
#include <linux/ptrace.h>
L
Linus Torvalds 已提交
22
#include <linux/string.h>
I
Ingo Molnar 已提交
23
#include <linux/delay.h>
L
Linus Torvalds 已提交
24
#include <linux/errno.h>
I
Ingo Molnar 已提交
25 26
#include <linux/kexec.h>
#include <linux/sched.h>
L
Linus Torvalds 已提交
27 28
#include <linux/timer.h>
#include <linux/init.h>
J
Jeremy Fitzhardinge 已提交
29
#include <linux/bug.h>
I
Ingo Molnar 已提交
30 31
#include <linux/nmi.h>
#include <linux/mm.h>
32 33
#include <linux/smp.h>
#include <linux/io.h>
L
Linus Torvalds 已提交
34 35 36 37 38 39 40 41 42 43

#ifdef CONFIG_EISA
#include <linux/ioport.h>
#include <linux/eisa.h>
#endif

#ifdef CONFIG_MCA
#include <linux/mca.h>
#endif

D
Dave Jiang 已提交
44 45 46 47
#if defined(CONFIG_EDAC)
#include <linux/edac.h>
#endif

I
Ingo Molnar 已提交
48
#include <asm/stacktrace.h>
L
Linus Torvalds 已提交
49 50
#include <asm/processor.h>
#include <asm/debugreg.h>
I
Ingo Molnar 已提交
51 52
#include <asm/atomic.h>
#include <asm/system.h>
53
#include <asm/traps.h>
L
Linus Torvalds 已提交
54 55
#include <asm/desc.h>
#include <asm/i387.h>
56

57
#include <asm/mach_traps.h>
58

59 60 61 62
#ifdef CONFIG_X86_64
#include <asm/pgalloc.h>
#include <asm/proto.h>
#else
63
#include <asm/processor-flags.h>
I
Ingo Molnar 已提交
64
#include <asm/setup.h>
65
#include <asm/traps.h>
L
Linus Torvalds 已提交
66

67
#include "cpu/mcheck/mce.h"
L
Linus Torvalds 已提交
68 69 70 71

asmlinkage int system_call(void);

/* Do we ignore FPU interrupts ? */
I
Ingo Molnar 已提交
72
char ignore_fpu_irq;
L
Linus Torvalds 已提交
73 74 75 76 77 78

/*
 * The IDT has to be page-aligned to simplify the Pentium
 * F0 0F bug workaround.. We have a special link segment
 * for this.
 */
79
gate_desc idt_table[256]
80
	__attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
81
#endif
L
Linus Torvalds 已提交
82

83 84 85
DECLARE_BITMAP(used_vectors, NR_VECTORS);
EXPORT_SYMBOL_GPL(used_vectors);

86
static int ignore_nmis;
87

88 89 90 91 92 93
static inline void conditional_sti(struct pt_regs *regs)
{
	if (regs->flags & X86_EFLAGS_IF)
		local_irq_enable();
}

94 95 96 97 98 99 100
static inline void preempt_conditional_sti(struct pt_regs *regs)
{
	inc_preempt_count();
	if (regs->flags & X86_EFLAGS_IF)
		local_irq_enable();
}

T
Thomas Gleixner 已提交
101 102 103 104 105 106
static inline void conditional_cli(struct pt_regs *regs)
{
	if (regs->flags & X86_EFLAGS_IF)
		local_irq_disable();
}

107 108 109 110 111 112 113
static inline void preempt_conditional_cli(struct pt_regs *regs)
{
	if (regs->flags & X86_EFLAGS_IF)
		local_irq_disable();
	dec_preempt_count();
}

114
#ifdef CONFIG_X86_32
I
Ingo Molnar 已提交
115 116
static inline void
die_if_kernel(const char *str, struct pt_regs *regs, long err)
L
Linus Torvalds 已提交
117
{
118
	if (!user_mode_vm(regs))
L
Linus Torvalds 已提交
119 120
		die(str, regs, err);
}
121
#endif
122

I
Ingo Molnar 已提交
123
static void __kprobes
124
do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
I
Ingo Molnar 已提交
125
	long error_code, siginfo_t *info)
L
Linus Torvalds 已提交
126
{
127 128
	struct task_struct *tsk = current;

129
#ifdef CONFIG_X86_32
130
	if (regs->flags & X86_VM_MASK) {
131 132 133 134 135
		/*
		 * traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
		 * On nmi (interrupt 2), do_trap should not be called.
		 */
		if (trapnr < 6)
L
Linus Torvalds 已提交
136 137 138
			goto vm86_trap;
		goto trap_signal;
	}
139
#endif
L
Linus Torvalds 已提交
140

141
	if (!user_mode(regs))
L
Linus Torvalds 已提交
142 143
		goto kernel_trap;

144
#ifdef CONFIG_X86_32
I
Ingo Molnar 已提交
145
trap_signal:
146
#endif
I
Ingo Molnar 已提交
147 148 149 150 151 152 153 154 155 156 157
	/*
	 * We want error_code and trap_no set for userspace faults and
	 * kernelspace faults which result in die(), but not
	 * kernelspace faults which are fixed up.  die() gives the
	 * process no chance to handle the signal and notice the
	 * kernel fault information, so that won't result in polluting
	 * the information about previously queued, but not yet
	 * delivered, faults.  See also do_general_protection below.
	 */
	tsk->thread.error_code = error_code;
	tsk->thread.trap_no = trapnr;
158

159 160 161 162 163 164 165 166 167 168 169 170
#ifdef CONFIG_X86_64
	if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
	    printk_ratelimit()) {
		printk(KERN_INFO
		       "%s[%d] trap %s ip:%lx sp:%lx error:%lx",
		       tsk->comm, tsk->pid, str,
		       regs->ip, regs->sp, error_code);
		print_vma_addr(" in ", regs->ip);
		printk("\n");
	}
#endif

I
Ingo Molnar 已提交
171 172 173 174 175
	if (info)
		force_sig_info(signr, info, tsk);
	else
		force_sig(signr, tsk);
	return;
L
Linus Torvalds 已提交
176

I
Ingo Molnar 已提交
177 178 179 180 181
kernel_trap:
	if (!fixup_exception(regs)) {
		tsk->thread.error_code = error_code;
		tsk->thread.trap_no = trapnr;
		die(str, regs, error_code);
L
Linus Torvalds 已提交
182
	}
I
Ingo Molnar 已提交
183
	return;
L
Linus Torvalds 已提交
184

185
#ifdef CONFIG_X86_32
I
Ingo Molnar 已提交
186 187 188 189 190
vm86_trap:
	if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
						error_code, trapnr))
		goto trap_signal;
	return;
191
#endif
L
Linus Torvalds 已提交
192 193
}

I
Ingo Molnar 已提交
194
#define DO_ERROR(trapnr, signr, str, name)				\
195
dotraplinkage void do_##name(struct pt_regs *regs, long error_code)	\
I
Ingo Molnar 已提交
196 197
{									\
	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr)	\
198
							== NOTIFY_STOP)	\
I
Ingo Molnar 已提交
199
		return;							\
200
	conditional_sti(regs);						\
201
	do_trap(trapnr, signr, str, regs, error_code, NULL);		\
L
Linus Torvalds 已提交
202 203
}

204
#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr)		\
205
dotraplinkage void do_##name(struct pt_regs *regs, long error_code)	\
I
Ingo Molnar 已提交
206 207 208 209 210 211 212
{									\
	siginfo_t info;							\
	info.si_signo = signr;						\
	info.si_errno = 0;						\
	info.si_code = sicode;						\
	info.si_addr = (void __user *)siaddr;				\
	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr)	\
213
							== NOTIFY_STOP)	\
I
Ingo Molnar 已提交
214
		return;							\
215
	conditional_sti(regs);						\
216
	do_trap(trapnr, signr, str, regs, error_code, &info);		\
L
Linus Torvalds 已提交
217 218
}

219 220 221 222
DO_ERROR_INFO(0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip)
DO_ERROR(4, SIGSEGV, "overflow", overflow)
DO_ERROR(5, SIGSEGV, "bounds", bounds)
DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip)
223
DO_ERROR(9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
224
DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
225
DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
226
#ifdef CONFIG_X86_32
227
DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
228
#endif
229
DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
L
Linus Torvalds 已提交
230

231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253
#ifdef CONFIG_X86_64
/* Runs on IST stack */
dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
{
	if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
			12, SIGBUS) == NOTIFY_STOP)
		return;
	preempt_conditional_sti(regs);
	do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
	preempt_conditional_cli(regs);
}

dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
{
	static const char str[] = "double fault";
	struct task_struct *tsk = current;

	/* Return not checked because double check cannot be ignored */
	notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);

	tsk->thread.error_code = error_code;
	tsk->thread.trap_no = 8;

254 255 256 257
	/*
	 * This is always a kernel trap and never fixable (and thus must
	 * never return).
	 */
258 259 260 261 262
	for (;;)
		die(str, regs, error_code);
}
#endif

263
dotraplinkage void __kprobes
264
do_general_protection(struct pt_regs *regs, long error_code)
L
Linus Torvalds 已提交
265
{
266
	struct task_struct *tsk;
I
Ingo Molnar 已提交
267

268 269
	conditional_sti(regs);

270
#ifdef CONFIG_X86_32
271
	if (regs->flags & X86_VM_MASK)
L
Linus Torvalds 已提交
272
		goto gp_in_vm86;
273
#endif
L
Linus Torvalds 已提交
274

275
	tsk = current;
276
	if (!user_mode(regs))
L
Linus Torvalds 已提交
277 278
		goto gp_in_kernel;

279 280
	tsk->thread.error_code = error_code;
	tsk->thread.trap_no = 13;
I
Ingo Molnar 已提交
281

282 283
	if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
			printk_ratelimit()) {
284
		printk(KERN_INFO
285 286 287
			"%s[%d] general protection ip:%lx sp:%lx error:%lx",
			tsk->comm, task_pid_nr(tsk),
			regs->ip, regs->sp, error_code);
288 289 290
		print_vma_addr(" in ", regs->ip);
		printk("\n");
	}
291

292
	force_sig(SIGSEGV, tsk);
L
Linus Torvalds 已提交
293 294
	return;

295
#ifdef CONFIG_X86_32
L
Linus Torvalds 已提交
296 297 298 299
gp_in_vm86:
	local_irq_enable();
	handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
	return;
300
#endif
L
Linus Torvalds 已提交
301 302

gp_in_kernel:
303 304 305 306 307 308
	if (fixup_exception(regs))
		return;

	tsk->thread.error_code = error_code;
	tsk->thread.trap_no = 13;
	if (notify_die(DIE_GPF, "general protection fault", regs,
L
Linus Torvalds 已提交
309
				error_code, 13, SIGSEGV) == NOTIFY_STOP)
310 311
		return;
	die("general protection fault", regs, error_code);
L
Linus Torvalds 已提交
312 313
}

314
static notrace __kprobes void
I
Ingo Molnar 已提交
315
mem_parity_error(unsigned char reason, struct pt_regs *regs)
L
Linus Torvalds 已提交
316
{
I
Ingo Molnar 已提交
317 318 319 320 321 322
	printk(KERN_EMERG
		"Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
			reason, smp_processor_id());

	printk(KERN_EMERG
		"You have some hardware problem, likely on the PCI bus.\n");
D
Dave Jiang 已提交
323 324

#if defined(CONFIG_EDAC)
I
Ingo Molnar 已提交
325
	if (edac_handler_set()) {
D
Dave Jiang 已提交
326 327 328 329 330
		edac_atomic_assert_error();
		return;
	}
#endif

331
	if (panic_on_unrecovered_nmi)
I
Ingo Molnar 已提交
332
		panic("NMI: Not continuing");
L
Linus Torvalds 已提交
333

334
	printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
L
Linus Torvalds 已提交
335 336

	/* Clear and disable the memory parity error line. */
337 338
	reason = (reason & 0xf) | 4;
	outb(reason, 0x61);
L
Linus Torvalds 已提交
339 340
}

341
static notrace __kprobes void
I
Ingo Molnar 已提交
342
io_check_error(unsigned char reason, struct pt_regs *regs)
L
Linus Torvalds 已提交
343 344 345
{
	unsigned long i;

346
	printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n");
L
Linus Torvalds 已提交
347 348 349 350 351
	show_registers(regs);

	/* Re-enable the IOCK line, wait for a few seconds */
	reason = (reason & 0xf) | 8;
	outb(reason, 0x61);
I
Ingo Molnar 已提交
352

L
Linus Torvalds 已提交
353
	i = 2000;
I
Ingo Molnar 已提交
354 355 356
	while (--i)
		udelay(1000);

L
Linus Torvalds 已提交
357 358 359 360
	reason &= ~8;
	outb(reason, 0x61);
}

361
static notrace __kprobes void
I
Ingo Molnar 已提交
362
unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
L
Linus Torvalds 已提交
363
{
364 365
	if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) ==
			NOTIFY_STOP)
J
Jason Wessel 已提交
366
		return;
L
Linus Torvalds 已提交
367
#ifdef CONFIG_MCA
I
Ingo Molnar 已提交
368 369 370 371 372
	/*
	 * Might actually be able to figure out what the guilty party
	 * is:
	 */
	if (MCA_bus) {
L
Linus Torvalds 已提交
373 374 375 376
		mca_handle_nmi();
		return;
	}
#endif
I
Ingo Molnar 已提交
377 378 379 380
	printk(KERN_EMERG
		"Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
			reason, smp_processor_id());

381
	printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
382
	if (panic_on_unrecovered_nmi)
I
Ingo Molnar 已提交
383
		panic("NMI: Not continuing");
384

385
	printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
L
Linus Torvalds 已提交
386 387
}

388
static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
L
Linus Torvalds 已提交
389 390
{
	unsigned char reason = 0;
391 392 393
	int cpu;

	cpu = smp_processor_id();
L
Linus Torvalds 已提交
394

395 396
	/* Only the BSP gets external NMIs from the system. */
	if (!cpu)
L
Linus Torvalds 已提交
397
		reason = get_nmi_reason();
I
Ingo Molnar 已提交
398

L
Linus Torvalds 已提交
399
	if (!(reason & 0xc0)) {
400
		if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
401
								== NOTIFY_STOP)
L
Linus Torvalds 已提交
402 403 404 405 406 407
			return;
#ifdef CONFIG_X86_LOCAL_APIC
		/*
		 * Ok, so this is none of the documented NMI sources,
		 * so it must be the NMI watchdog.
		 */
408
		if (nmi_watchdog_tick(regs, reason))
L
Linus Torvalds 已提交
409
			return;
410
		if (!do_nmi_callback(regs, cpu))
411
			unknown_nmi_error(reason, regs);
I
Ingo Molnar 已提交
412 413 414
#else
		unknown_nmi_error(reason, regs);
#endif
415

L
Linus Torvalds 已提交
416 417
		return;
	}
418
	if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
L
Linus Torvalds 已提交
419
		return;
420 421

	/* AK: following checks seem to be broken on modern chipsets. FIXME */
L
Linus Torvalds 已提交
422 423 424 425
	if (reason & 0x80)
		mem_parity_error(reason, regs);
	if (reason & 0x40)
		io_check_error(reason, regs);
426
#ifdef CONFIG_X86_32
L
Linus Torvalds 已提交
427 428
	/*
	 * Reassert NMI in case it became active meanwhile
I
Ingo Molnar 已提交
429
	 * as it's edge-triggered:
L
Linus Torvalds 已提交
430 431
	 */
	reassert_nmi();
432
#endif
L
Linus Torvalds 已提交
433 434
}

435 436
dotraplinkage notrace __kprobes void
do_nmi(struct pt_regs *regs, long error_code)
L
Linus Torvalds 已提交
437 438 439
{
	nmi_enter();

440
	inc_irq_stat(__nmi_count);
L
Linus Torvalds 已提交
441

442 443
	if (!ignore_nmis)
		default_do_nmi(regs);
L
Linus Torvalds 已提交
444 445 446 447

	nmi_exit();
}

448 449 450 451 452 453 454 455 456 457 458 459
void stop_nmi(void)
{
	acpi_nmi_disable();
	ignore_nmis++;
}

void restart_nmi(void)
{
	ignore_nmis--;
	acpi_nmi_enable();
}

460
/* May run on IST stack. */
461
dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
L
Linus Torvalds 已提交
462
{
463
#ifdef CONFIG_KPROBES
L
Linus Torvalds 已提交
464 465
	if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
			== NOTIFY_STOP)
466
		return;
467 468 469 470 471
#else
	if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP)
			== NOTIFY_STOP)
		return;
#endif
I
Ingo Molnar 已提交
472

473
	preempt_conditional_sti(regs);
474
	do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
475
	preempt_conditional_cli(regs);
L
Linus Torvalds 已提交
476 477
}

478
#ifdef CONFIG_X86_64
479 480 481 482 483
/*
 * Help handler running on IST stack to switch back to user stack
 * for scheduling or signal handling. The actual stack switch is done in
 * entry.S
 */
484 485 486 487 488 489 490 491 492
asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
{
	struct pt_regs *regs = eregs;
	/* Did already sync */
	if (eregs == (struct pt_regs *)eregs->sp)
		;
	/* Exception from user space */
	else if (user_mode(eregs))
		regs = task_pt_regs(current);
493 494 495 496
	/*
	 * Exception from kernel and interrupts are enabled. Move to
	 * kernel process stack.
	 */
497 498 499 500 501 502 503 504
	else if (eregs->flags & X86_EFLAGS_IF)
		regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
	if (eregs != regs)
		*regs = *eregs;
	return regs;
}
#endif

L
Linus Torvalds 已提交
505 506 507 508 509 510 511 512 513 514
/*
 * Our handling of the processor debug registers is non-trivial.
 * We do not clear them on entry and exit from the kernel. Therefore
 * it is possible to get a watchpoint trap here from inside the kernel.
 * However, the code in ./ptrace.c has ensured that the user can
 * only set watchpoints on userspace addresses. Therefore the in-kernel
 * watchpoint trap can only occur in code which is reading/writing
 * from user space. Such code must not hold kernel locks (since it
 * can equally take a page fault), therefore it is safe to call
 * force_sig_info even though that claims and releases locks.
I
Ingo Molnar 已提交
515
 *
L
Linus Torvalds 已提交
516 517 518 519 520 521 522 523 524 525
 * Code in ./signal.c ensures that the debug control register
 * is restored before we deliver any signal, and therefore that
 * user code runs with the correct debug control register even though
 * we clear it here.
 *
 * Being careful here means that we don't have to be as careful in a
 * lot of more complicated places (task switching can be a bit lazy
 * about restoring all the debug state, and ptrace doesn't have to
 * find every occurrence of the TF bit that could be saved away even
 * by user code)
526 527
 *
 * May run on IST stack.
L
Linus Torvalds 已提交
528
 */
529
dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
L
Linus Torvalds 已提交
530 531
{
	struct task_struct *tsk = current;
532
	unsigned long condition;
533
	int si_code;
L
Linus Torvalds 已提交
534

535
	get_debugreg(condition, 6);
L
Linus Torvalds 已提交
536

537 538 539 540 541 542
	/*
	 * The processor cleared BTF, so don't mark that we need it set.
	 */
	clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
	tsk->thread.debugctlmsr = 0;

L
Linus Torvalds 已提交
543
	if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
544
						SIGTRAP) == NOTIFY_STOP)
L
Linus Torvalds 已提交
545
		return;
546

L
Linus Torvalds 已提交
547
	/* It's safe to allow irq's after DR6 has been saved */
548
	preempt_conditional_sti(regs);
L
Linus Torvalds 已提交
549 550 551

	/* Mask out spurious debug traps due to lazy DR7 setting */
	if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
552
		if (!tsk->thread.debugreg7)
L
Linus Torvalds 已提交
553 554 555
			goto clear_dr7;
	}

556
#ifdef CONFIG_X86_32
557
	if (regs->flags & X86_VM_MASK)
L
Linus Torvalds 已提交
558
		goto debug_vm86;
559
#endif
L
Linus Torvalds 已提交
560 561

	/* Save debug status register where ptrace can see it */
562
	tsk->thread.debugreg6 = condition;
L
Linus Torvalds 已提交
563 564 565 566 567 568

	/*
	 * Single-stepping through TF: make sure we ignore any events in
	 * kernel space (but re-enable TF when returning to user mode).
	 */
	if (condition & DR_STEP) {
569
		if (!user_mode(regs))
L
Linus Torvalds 已提交
570 571 572
			goto clear_TF_reenable;
	}

573
	si_code = get_si_code(condition);
L
Linus Torvalds 已提交
574
	/* Ok, finally something we can handle */
575
	send_sigtrap(tsk, regs, error_code, si_code);
L
Linus Torvalds 已提交
576

I
Ingo Molnar 已提交
577 578
	/*
	 * Disable additional traps. They'll be re-enabled when
L
Linus Torvalds 已提交
579 580 581
	 * the signal is delivered.
	 */
clear_dr7:
582
	set_debugreg(0, 7);
583
	preempt_conditional_cli(regs);
L
Linus Torvalds 已提交
584 585
	return;

586
#ifdef CONFIG_X86_32
L
Linus Torvalds 已提交
587
debug_vm86:
T
Thomas Gleixner 已提交
588 589
	/* reenable preemption: handle_vm86_trap() might sleep */
	dec_preempt_count();
L
Linus Torvalds 已提交
590
	handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
T
Thomas Gleixner 已提交
591
	conditional_cli(regs);
L
Linus Torvalds 已提交
592
	return;
593
#endif
L
Linus Torvalds 已提交
594 595 596

clear_TF_reenable:
	set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
597
	regs->flags &= ~X86_EFLAGS_TF;
598
	preempt_conditional_cli(regs);
L
Linus Torvalds 已提交
599 600 601
	return;
}

602 603 604 605 606 607 608 609 610 611 612 613 614 615
#ifdef CONFIG_X86_64
static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
{
	if (fixup_exception(regs))
		return 1;

	notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
	/* Illegal floating point operation in the kernel */
	current->thread.trap_no = trapnr;
	die(str, regs, 0);
	return 0;
}
#endif

L
Linus Torvalds 已提交
616 617 618 619 620
/*
 * Note that we play around with the 'TS' bit in an attempt to get
 * the correct behaviour even in the presence of the asynchronous
 * IRQ13 behaviour
 */
621
void math_error(void __user *ip)
L
Linus Torvalds 已提交
622
{
I
Ingo Molnar 已提交
623
	struct task_struct *task;
L
Linus Torvalds 已提交
624
	siginfo_t info;
625
	unsigned short cwd, swd, err;
L
Linus Torvalds 已提交
626 627 628 629 630 631 632 633 634 635

	/*
	 * Save the info for the exception handler and clear the error.
	 */
	task = current;
	save_init_fpu(task);
	task->thread.trap_no = 16;
	task->thread.error_code = 0;
	info.si_signo = SIGFPE;
	info.si_errno = 0;
636
	info.si_addr = ip;
L
Linus Torvalds 已提交
637 638 639 640 641 642
	/*
	 * (~cwd & swd) will mask out exceptions that are not set to unmasked
	 * status.  0x3f is the exception bits in these regs, 0x200 is the
	 * C1 reg you need in case of a stack fault, 0x040 is the stack
	 * fault bit.  We should only be taking one exception at a time,
	 * so if this combination doesn't produce any single exception,
643
	 * then we have a bad program that isn't synchronizing its FPU usage
L
Linus Torvalds 已提交
644 645 646 647 648
	 * and it will suffer the consequences since we won't be able to
	 * fully reproduce the context of the exception
	 */
	cwd = get_fpu_cwd(task);
	swd = get_fpu_swd(task);
649

650
	err = swd & ~cwd;
651 652

	if (err & 0x001) {	/* Invalid op */
I
Ingo Molnar 已提交
653 654 655 656 657 658
		/*
		 * swd & 0x240 == 0x040: Stack Underflow
		 * swd & 0x240 == 0x240: Stack Overflow
		 * User must clear the SF bit (0x40) if set
		 */
		info.si_code = FPE_FLTINV;
659
	} else if (err & 0x004) { /* Divide by Zero */
I
Ingo Molnar 已提交
660
		info.si_code = FPE_FLTDIV;
661
	} else if (err & 0x008) { /* Overflow */
I
Ingo Molnar 已提交
662
		info.si_code = FPE_FLTOVF;
663 664 665
	} else if (err & 0x012) { /* Denormal, Underflow */
		info.si_code = FPE_FLTUND;
	} else if (err & 0x020) { /* Precision */
I
Ingo Molnar 已提交
666
		info.si_code = FPE_FLTRES;
667
	} else {
668 669 670 671
		/*
		 * If we're using IRQ 13, or supposedly even some trap 16
		 * implementations, it's possible we get a spurious trap...
		 */
672
		return;		/* Spurious trap, no error */
L
Linus Torvalds 已提交
673 674 675 676
	}
	force_sig_info(SIGFPE, &info, task);
}

677
dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
L
Linus Torvalds 已提交
678
{
679
	conditional_sti(regs);
680 681

#ifdef CONFIG_X86_32
L
Linus Torvalds 已提交
682
	ignore_fpu_irq = 1;
683 684 685 686 687 688
#else
	if (!user_mode(regs) &&
	    kernel_math_error(regs, "kernel x87 math error", 16))
		return;
#endif

689
	math_error((void __user *)regs->ip);
L
Linus Torvalds 已提交
690 691
}

692
static void simd_math_error(void __user *ip)
L
Linus Torvalds 已提交
693
{
I
Ingo Molnar 已提交
694 695
	struct task_struct *task;
	siginfo_t info;
696
	unsigned short mxcsr;
L
Linus Torvalds 已提交
697 698 699 700 701 702 703 704 705 706 707

	/*
	 * Save the info for the exception handler and clear the error.
	 */
	task = current;
	save_init_fpu(task);
	task->thread.trap_no = 19;
	task->thread.error_code = 0;
	info.si_signo = SIGFPE;
	info.si_errno = 0;
	info.si_code = __SI_FAULT;
708
	info.si_addr = ip;
L
Linus Torvalds 已提交
709 710 711 712 713 714 715 716
	/*
	 * The SIMD FPU exceptions are handled a little differently, as there
	 * is only a single status/control register.  Thus, to determine which
	 * unmasked exception was caught we must mask the exception mask bits
	 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
	 */
	mxcsr = get_fpu_mxcsr(task);
	switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
I
Ingo Molnar 已提交
717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735
	case 0x000:
	default:
		break;
	case 0x001: /* Invalid Op */
		info.si_code = FPE_FLTINV;
		break;
	case 0x002: /* Denormalize */
	case 0x010: /* Underflow */
		info.si_code = FPE_FLTUND;
		break;
	case 0x004: /* Zero Divide */
		info.si_code = FPE_FLTDIV;
		break;
	case 0x008: /* Overflow */
		info.si_code = FPE_FLTOVF;
		break;
	case 0x020: /* Precision */
		info.si_code = FPE_FLTRES;
		break;
L
Linus Torvalds 已提交
736 737 738 739
	}
	force_sig_info(SIGFPE, &info, task);
}

740 741
dotraplinkage void
do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
L
Linus Torvalds 已提交
742
{
743 744
	conditional_sti(regs);

745
#ifdef CONFIG_X86_32
L
Linus Torvalds 已提交
746 747 748
	if (cpu_has_xmm) {
		/* Handle SIMD FPU exceptions on PIII+ processors. */
		ignore_fpu_irq = 1;
749
		simd_math_error((void __user *)regs->ip);
I
Ingo Molnar 已提交
750 751 752 753 754 755
		return;
	}
	/*
	 * Handle strange cache flush from user space exception
	 * in all other cases.  This is undocumented behaviour.
	 */
756
	if (regs->flags & X86_VM_MASK) {
I
Ingo Molnar 已提交
757 758
		handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
		return;
L
Linus Torvalds 已提交
759
	}
I
Ingo Molnar 已提交
760 761 762 763
	current->thread.trap_no = 19;
	current->thread.error_code = error_code;
	die_if_kernel("cache flush denied", regs, error_code);
	force_sig(SIGSEGV, current);
764 765 766 767 768 769
#else
	if (!user_mode(regs) &&
			kernel_math_error(regs, "kernel simd math error", 19))
		return;
	simd_math_error((void __user *)regs->ip);
#endif
L
Linus Torvalds 已提交
770 771
}

772 773
dotraplinkage void
do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
L
Linus Torvalds 已提交
774
{
775
	conditional_sti(regs);
L
Linus Torvalds 已提交
776 777
#if 0
	/* No need to warn about this any longer. */
I
Ingo Molnar 已提交
778
	printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
L
Linus Torvalds 已提交
779 780 781
#endif
}

782
#ifdef CONFIG_X86_32
I
Ingo Molnar 已提交
783
unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp)
L
Linus Torvalds 已提交
784
{
G
Glauber Costa 已提交
785
	struct desc_struct *gdt = get_cpu_gdt_table(smp_processor_id());
S
Stas Sergeev 已提交
786 787 788 789
	unsigned long base = (kesp - uesp) & -THREAD_SIZE;
	unsigned long new_kesp = kesp - base;
	unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT;
	__u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS];
I
Ingo Molnar 已提交
790

S
Stas Sergeev 已提交
791
	/* Set up base for espfix segment */
I
Ingo Molnar 已提交
792 793
	desc &= 0x00f0ff0000000000ULL;
	desc |=	((((__u64)base) << 16) & 0x000000ffffff0000ULL) |
S
Stas Sergeev 已提交
794 795 796 797
		((((__u64)base) << 32) & 0xff00000000000000ULL) |
		((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) |
		(lim_pages & 0xffff);
	*(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc;
I
Ingo Molnar 已提交
798

S
Stas Sergeev 已提交
799
	return new_kesp;
L
Linus Torvalds 已提交
800
}
801 802
#endif

803 804 805 806
asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
{
}

807
asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void)
808 809
{
}
L
Linus Torvalds 已提交
810 811

/*
I
Ingo Molnar 已提交
812
 * 'math_state_restore()' saves the current math information in the
L
Linus Torvalds 已提交
813 814 815 816 817 818 819 820
 * old math state array, and gets the new ones from the current task
 *
 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
 * Don't touch unless you *really* know how it works.
 *
 * Must be called with kernel preemption disabled (in this case,
 * local interrupts are disabled at the call-site in entry.S).
 */
821
asmlinkage void math_state_restore(void)
L
Linus Torvalds 已提交
822 823 824 825
{
	struct thread_info *thread = current_thread_info();
	struct task_struct *tsk = thread->task;

826 827 828 829 830 831 832 833 834 835 836 837 838 839 840
	if (!tsk_used_math(tsk)) {
		local_irq_enable();
		/*
		 * does a slab alloc which can sleep
		 */
		if (init_fpu(tsk)) {
			/*
			 * ran out of memory!
			 */
			do_group_exit(SIGKILL);
			return;
		}
		local_irq_disable();
	}

I
Ingo Molnar 已提交
841
	clts();				/* Allow maths ops (or we recurse) */
842
#ifdef CONFIG_X86_32
L
Linus Torvalds 已提交
843
	restore_fpu(tsk);
844 845 846 847 848 849 850 851 852 853
#else
	/*
	 * Paranoid restore. send a SIGSEGV if we fail to restore the state.
	 */
	if (unlikely(restore_fpu_checking(tsk))) {
		stts();
		force_sig(SIGSEGV, tsk);
		return;
	}
#endif
L
Linus Torvalds 已提交
854
	thread->status |= TS_USEDFPU;	/* So we fnsave on switch_to() */
855
	tsk->fpu_counter++;
L
Linus Torvalds 已提交
856
}
857
EXPORT_SYMBOL_GPL(math_state_restore);
L
Linus Torvalds 已提交
858 859

#ifndef CONFIG_MATH_EMULATION
860
void math_emulate(struct math_emu_info *info)
L
Linus Torvalds 已提交
861
{
I
Ingo Molnar 已提交
862 863 864 865
	printk(KERN_EMERG
		"math-emulation not enabled and no coprocessor found.\n");
	printk(KERN_EMERG "killing %s.\n", current->comm);
	force_sig(SIGFPE, current);
L
Linus Torvalds 已提交
866 867 868 869
	schedule();
}
#endif /* CONFIG_MATH_EMULATION */

870
dotraplinkage void __kprobes
871
do_device_not_available(struct pt_regs *regs, long error_code)
872
{
873
#ifdef CONFIG_X86_32
874
	if (read_cr0() & X86_CR0_EM) {
875 876
		struct math_emu_info info = { };

877
		conditional_sti(regs);
878

879
		info.regs = regs;
880
		math_emulate(&info);
881 882 883 884
	} else {
		math_state_restore(); /* interrupts still off */
		conditional_sti(regs);
	}
885 886 887
#else
	math_state_restore();
#endif
888 889
}

890
#ifdef CONFIG_X86_32
891
dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
892 893 894 895 896 897 898
{
	siginfo_t info;
	local_irq_enable();

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_BADSTK;
899
	info.si_addr = NULL;
900 901 902
	if (notify_die(DIE_TRAP, "iret exception",
			regs, error_code, 32, SIGILL) == NOTIFY_STOP)
		return;
903
	do_trap(32, SIGILL, "iret exception", regs, error_code, &info);
904
}
905
#endif
906

L
Linus Torvalds 已提交
907 908
void __init trap_init(void)
{
909 910
	int i;

L
Linus Torvalds 已提交
911
#ifdef CONFIG_EISA
I
Ingo Molnar 已提交
912
	void __iomem *p = early_ioremap(0x0FFFD9, 4);
I
Ingo Molnar 已提交
913 914

	if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
L
Linus Torvalds 已提交
915
		EISA_bus = 1;
I
Ingo Molnar 已提交
916
	early_iounmap(p, 4);
L
Linus Torvalds 已提交
917 918
#endif

919
	set_intr_gate(0, &divide_error);
920 921 922 923 924 925
	set_intr_gate_ist(1, &debug, DEBUG_STACK);
	set_intr_gate_ist(2, &nmi, NMI_STACK);
	/* int3 can be called from all */
	set_system_intr_gate_ist(3, &int3, DEBUG_STACK);
	/* int4 can be called from all */
	set_system_intr_gate(4, &overflow);
926
	set_intr_gate(5, &bounds);
927
	set_intr_gate(6, &invalid_op);
928
	set_intr_gate(7, &device_not_available);
929
#ifdef CONFIG_X86_32
930
	set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS);
931 932 933
#else
	set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK);
#endif
934
	set_intr_gate(9, &coprocessor_segment_overrun);
935
	set_intr_gate(10, &invalid_TSS);
936
	set_intr_gate(11, &segment_not_present);
937
	set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK);
938
	set_intr_gate(13, &general_protection);
I
Ingo Molnar 已提交
939
	set_intr_gate(14, &page_fault);
940
	set_intr_gate(15, &spurious_interrupt_bug);
941
	set_intr_gate(16, &coprocessor_error);
942
	set_intr_gate(17, &alignment_check);
L
Linus Torvalds 已提交
943
#ifdef CONFIG_X86_MCE
944
	set_intr_gate_ist(18, &machine_check, MCE_STACK);
L
Linus Torvalds 已提交
945
#endif
946
	set_intr_gate(19, &simd_coprocessor_error);
L
Linus Torvalds 已提交
947

948 949 950 951 952
#ifdef CONFIG_IA32_EMULATION
	set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
#endif

#ifdef CONFIG_X86_32
953 954 955 956 957 958
	if (cpu_has_fxsr) {
		printk(KERN_INFO "Enabling fast FPU save and restore... ");
		set_in_cr4(X86_CR4_OSFXSR);
		printk("done.\n");
	}
	if (cpu_has_xmm) {
I
Ingo Molnar 已提交
959 960
		printk(KERN_INFO
			"Enabling unmasked SIMD FPU exception support... ");
961 962 963 964
		set_in_cr4(X86_CR4_OSXMMEXCPT);
		printk("done.\n");
	}

965
	set_system_trap_gate(SYSCALL_VECTOR, &system_call);
966
#endif
L
Linus Torvalds 已提交
967

I
Ingo Molnar 已提交
968
	/* Reserve all the builtin and the syscall vector: */
969 970
	for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
		set_bit(i, used_vectors);
I
Ingo Molnar 已提交
971

972 973 974
#ifdef CONFIG_X86_64
	set_bit(IA32_SYSCALL_VECTOR, used_vectors);
#else
975
	set_bit(SYSCALL_VECTOR, used_vectors);
976
#endif
L
Linus Torvalds 已提交
977
	/*
I
Ingo Molnar 已提交
978
	 * Should be a barrier for any external CPU state:
L
Linus Torvalds 已提交
979 980 981
	 */
	cpu_init();

982
#ifdef CONFIG_X86_32
I
Ingo Molnar 已提交
983
	x86_quirk_trap_init();
984
#endif
L
Linus Torvalds 已提交
985
}