x86: Unspaghettize do_general_protection()
[deliverable/linux.git] / arch / x86 / kernel / traps.c
CommitLineData
1da177e4 1/*
1da177e4 2 * Copyright (C) 1991, 1992 Linus Torvalds
a8c1be9d 3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
1da177e4
LT
4 *
5 * Pentium III FXSR, SSE support
6 * Gareth Hughes <gareth@valinux.com>, May 2000
7 */
8
9/*
c1d518c8 10 * Handle hardware traps and faults.
1da177e4 11 */
c767a54b
JP
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
b5964405
IM
15#include <linux/interrupt.h>
16#include <linux/kallsyms.h>
17#include <linux/spinlock.h>
b5964405
IM
18#include <linux/kprobes.h>
19#include <linux/uaccess.h>
b5964405 20#include <linux/kdebug.h>
f503b5ae 21#include <linux/kgdb.h>
1da177e4 22#include <linux/kernel.h>
b5964405
IM
23#include <linux/module.h>
24#include <linux/ptrace.h>
1da177e4 25#include <linux/string.h>
b5964405 26#include <linux/delay.h>
1da177e4 27#include <linux/errno.h>
b5964405
IM
28#include <linux/kexec.h>
29#include <linux/sched.h>
1da177e4 30#include <linux/timer.h>
1da177e4 31#include <linux/init.h>
91768d6c 32#include <linux/bug.h>
b5964405
IM
33#include <linux/nmi.h>
34#include <linux/mm.h>
c1d518c8
AH
35#include <linux/smp.h>
36#include <linux/io.h>
1da177e4
LT
37
38#ifdef CONFIG_EISA
39#include <linux/ioport.h>
40#include <linux/eisa.h>
41#endif
42
c0d12172
DJ
43#if defined(CONFIG_EDAC)
44#include <linux/edac.h>
45#endif
46
f8561296 47#include <asm/kmemcheck.h>
b5964405 48#include <asm/stacktrace.h>
1da177e4 49#include <asm/processor.h>
1da177e4 50#include <asm/debugreg.h>
60063497 51#include <linux/atomic.h>
08d636b6 52#include <asm/ftrace.h>
c1d518c8 53#include <asm/traps.h>
1da177e4
LT
54#include <asm/desc.h>
55#include <asm/i387.h>
1361b83a 56#include <asm/fpu-internal.h>
9e55e44e 57#include <asm/mce.h>
c1d518c8 58
1164dd00 59#include <asm/mach_traps.h>
c1d518c8 60
081f75bb 61#ifdef CONFIG_X86_64
428cf902 62#include <asm/x86_init.h>
081f75bb
AH
63#include <asm/pgalloc.h>
64#include <asm/proto.h>
081f75bb 65#else
c1d518c8 66#include <asm/processor-flags.h>
8e6dafd6 67#include <asm/setup.h>
1da177e4 68
1da177e4
LT
69asmlinkage int system_call(void);
70
1da177e4 71/* Do we ignore FPU interrupts ? */
b5964405 72char ignore_fpu_irq;
1da177e4
LT
73
74/*
75 * The IDT has to be page-aligned to simplify the Pentium
07e81d61 76 * F0 0F bug workaround.
1da177e4 77 */
07e81d61 78gate_desc idt_table[NR_VECTORS] __page_aligned_data = { { { { 0, 0 } } }, };
081f75bb 79#endif
1da177e4 80
b77b881f
YL
81DECLARE_BITMAP(used_vectors, NR_VECTORS);
82EXPORT_SYMBOL_GPL(used_vectors);
83
762db434
AH
84static inline void conditional_sti(struct pt_regs *regs)
85{
86 if (regs->flags & X86_EFLAGS_IF)
87 local_irq_enable();
88}
89
3d2a71a5
AH
90static inline void preempt_conditional_sti(struct pt_regs *regs)
91{
92 inc_preempt_count();
93 if (regs->flags & X86_EFLAGS_IF)
94 local_irq_enable();
95}
96
be716615
TG
97static inline void conditional_cli(struct pt_regs *regs)
98{
99 if (regs->flags & X86_EFLAGS_IF)
100 local_irq_disable();
101}
102
3d2a71a5
AH
103static inline void preempt_conditional_cli(struct pt_regs *regs)
104{
105 if (regs->flags & X86_EFLAGS_IF)
106 local_irq_disable();
107 dec_preempt_count();
108}
109
b5964405 110static void __kprobes
3c1326f8 111do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
b5964405 112 long error_code, siginfo_t *info)
1da177e4 113{
4f339ecb 114 struct task_struct *tsk = current;
4f339ecb 115
081f75bb 116#ifdef CONFIG_X86_32
6b6891f9 117 if (regs->flags & X86_VM_MASK) {
3c1326f8
AH
118 /*
119 * traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
120 * On nmi (interrupt 2), do_trap should not be called.
121 */
c9408265 122 if (trapnr < X86_TRAP_UD)
1da177e4
LT
123 goto vm86_trap;
124 goto trap_signal;
125 }
081f75bb 126#endif
1da177e4 127
717b594a 128 if (!user_mode(regs))
1da177e4
LT
129 goto kernel_trap;
130
081f75bb 131#ifdef CONFIG_X86_32
b5964405 132trap_signal:
081f75bb 133#endif
b5964405 134 /*
51e7dc70 135 * We want error_code and trap_nr set for userspace faults and
b5964405
IM
136 * kernelspace faults which result in die(), but not
137 * kernelspace faults which are fixed up. die() gives the
138 * process no chance to handle the signal and notice the
139 * kernel fault information, so that won't result in polluting
140 * the information about previously queued, but not yet
141 * delivered, faults. See also do_general_protection below.
142 */
143 tsk->thread.error_code = error_code;
51e7dc70 144 tsk->thread.trap_nr = trapnr;
d1895183 145
081f75bb
AH
146#ifdef CONFIG_X86_64
147 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
148 printk_ratelimit()) {
c767a54b
JP
149 pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx",
150 tsk->comm, tsk->pid, str,
151 regs->ip, regs->sp, error_code);
081f75bb 152 print_vma_addr(" in ", regs->ip);
c767a54b 153 pr_cont("\n");
081f75bb
AH
154 }
155#endif
156
b5964405
IM
157 if (info)
158 force_sig_info(signr, info, tsk);
159 else
160 force_sig(signr, tsk);
161 return;
1da177e4 162
b5964405
IM
163kernel_trap:
164 if (!fixup_exception(regs)) {
165 tsk->thread.error_code = error_code;
51e7dc70 166 tsk->thread.trap_nr = trapnr;
b5964405 167 die(str, regs, error_code);
1da177e4 168 }
b5964405 169 return;
1da177e4 170
081f75bb 171#ifdef CONFIG_X86_32
b5964405
IM
172vm86_trap:
173 if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
174 error_code, trapnr))
175 goto trap_signal;
176 return;
081f75bb 177#endif
1da177e4
LT
178}
179
b5964405 180#define DO_ERROR(trapnr, signr, str, name) \
e407d620 181dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
b5964405
IM
182{ \
183 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
a8c1be9d 184 == NOTIFY_STOP) \
b5964405 185 return; \
61aef7d2 186 conditional_sti(regs); \
3c1326f8 187 do_trap(trapnr, signr, str, regs, error_code, NULL); \
1da177e4
LT
188}
189
3c1326f8 190#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
e407d620 191dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
b5964405
IM
192{ \
193 siginfo_t info; \
194 info.si_signo = signr; \
195 info.si_errno = 0; \
196 info.si_code = sicode; \
197 info.si_addr = (void __user *)siaddr; \
b5964405 198 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
a8c1be9d 199 == NOTIFY_STOP) \
b5964405 200 return; \
61aef7d2 201 conditional_sti(regs); \
3c1326f8 202 do_trap(trapnr, signr, str, regs, error_code, &info); \
1da177e4
LT
203}
204
c9408265
KC
205DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV,
206 regs->ip)
207DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow)
208DO_ERROR(X86_TRAP_BR, SIGSEGV, "bounds", bounds)
209DO_ERROR_INFO(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN,
210 regs->ip)
211DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun",
212 coprocessor_segment_overrun)
213DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS)
214DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present)
081f75bb 215#ifdef CONFIG_X86_32
c9408265 216DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment)
081f75bb 217#endif
c9408265
KC
218DO_ERROR_INFO(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check,
219 BUS_ADRALN, 0)
1da177e4 220
081f75bb
AH
221#ifdef CONFIG_X86_64
222/* Runs on IST stack */
223dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
224{
225 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
c9408265 226 X86_TRAP_SS, SIGBUS) == NOTIFY_STOP)
081f75bb
AH
227 return;
228 preempt_conditional_sti(regs);
c9408265 229 do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL);
081f75bb
AH
230 preempt_conditional_cli(regs);
231}
232
233dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
234{
235 static const char str[] = "double fault";
236 struct task_struct *tsk = current;
237
238 /* Return not checked because double check cannot be ignored */
c9408265 239 notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
081f75bb
AH
240
241 tsk->thread.error_code = error_code;
51e7dc70 242 tsk->thread.trap_nr = X86_TRAP_DF;
081f75bb 243
bd8b96df
IM
244 /*
245 * This is always a kernel trap and never fixable (and thus must
246 * never return).
247 */
081f75bb
AH
248 for (;;)
249 die(str, regs, error_code);
250}
251#endif
252
e407d620 253dotraplinkage void __kprobes
13485ab5 254do_general_protection(struct pt_regs *regs, long error_code)
1da177e4 255{
13485ab5 256 struct task_struct *tsk;
b5964405 257
c6df0d71
AH
258 conditional_sti(regs);
259
081f75bb 260#ifdef CONFIG_X86_32
ef3f6288
FW
261 if (regs->flags & X86_VM_MASK) {
262 local_irq_enable();
263 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
264 return;
265 }
081f75bb 266#endif
1da177e4 267
13485ab5 268 tsk = current;
ef3f6288
FW
269 if (!user_mode(regs)) {
270 if (fixup_exception(regs))
271 return;
272
273 tsk->thread.error_code = error_code;
274 tsk->thread.trap_nr = X86_TRAP_GP;
275 if (!notify_die(DIE_GPF, "general protection fault", regs, error_code,
276 X86_TRAP_GP, SIGSEGV) == NOTIFY_STOP)
277 die("general protection fault", regs, error_code);
278 return;
279 }
1da177e4 280
13485ab5 281 tsk->thread.error_code = error_code;
51e7dc70 282 tsk->thread.trap_nr = X86_TRAP_GP;
b5964405 283
13485ab5
AH
284 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
285 printk_ratelimit()) {
c767a54b 286 pr_info("%s[%d] general protection ip:%lx sp:%lx error:%lx",
13485ab5
AH
287 tsk->comm, task_pid_nr(tsk),
288 regs->ip, regs->sp, error_code);
03252919 289 print_vma_addr(" in ", regs->ip);
c767a54b 290 pr_cont("\n");
03252919 291 }
abd4f750 292
13485ab5 293 force_sig(SIGSEGV, tsk);
1da177e4 294 return;
1da177e4
LT
295}
296
c1d518c8 297/* May run on IST stack. */
08d636b6 298dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_code)
1da177e4 299{
08d636b6 300#ifdef CONFIG_DYNAMIC_FTRACE
a192cd04
SR
301 /*
302 * ftrace must be first, everything else may cause a recursive crash.
303 * See note by declaration of modifying_ftrace_code in ftrace.c
304 */
305 if (unlikely(atomic_read(&modifying_ftrace_code)) &&
306 ftrace_int3_handler(regs))
08d636b6
SR
307 return;
308#endif
f503b5ae 309#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
c9408265
KC
310 if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
311 SIGTRAP) == NOTIFY_STOP)
f503b5ae
JW
312 return;
313#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
cc3a1bf5 314
c9408265
KC
315 if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
316 SIGTRAP) == NOTIFY_STOP)
48c88211 317 return;
b5964405 318
42181186
SR
319 /*
320 * Let others (NMI) know that the debug stack is in use
321 * as we may switch to the interrupt stack.
322 */
323 debug_stack_usage_inc();
4915a35e 324 preempt_conditional_sti(regs);
c9408265 325 do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
4915a35e 326 preempt_conditional_cli(regs);
42181186 327 debug_stack_usage_dec();
1da177e4 328}
1da177e4 329
081f75bb 330#ifdef CONFIG_X86_64
bd8b96df
IM
331/*
332 * Help handler running on IST stack to switch back to user stack
333 * for scheduling or signal handling. The actual stack switch is done in
334 * entry.S
335 */
081f75bb
AH
336asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
337{
338 struct pt_regs *regs = eregs;
339 /* Did already sync */
340 if (eregs == (struct pt_regs *)eregs->sp)
341 ;
342 /* Exception from user space */
343 else if (user_mode(eregs))
344 regs = task_pt_regs(current);
bd8b96df
IM
345 /*
346 * Exception from kernel and interrupts are enabled. Move to
347 * kernel process stack.
348 */
081f75bb
AH
349 else if (eregs->flags & X86_EFLAGS_IF)
350 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
351 if (eregs != regs)
352 *regs = *eregs;
353 return regs;
354}
355#endif
356
1da177e4
LT
357/*
358 * Our handling of the processor debug registers is non-trivial.
359 * We do not clear them on entry and exit from the kernel. Therefore
360 * it is possible to get a watchpoint trap here from inside the kernel.
361 * However, the code in ./ptrace.c has ensured that the user can
362 * only set watchpoints on userspace addresses. Therefore the in-kernel
363 * watchpoint trap can only occur in code which is reading/writing
364 * from user space. Such code must not hold kernel locks (since it
365 * can equally take a page fault), therefore it is safe to call
366 * force_sig_info even though that claims and releases locks.
b5964405 367 *
1da177e4
LT
368 * Code in ./signal.c ensures that the debug control register
369 * is restored before we deliver any signal, and therefore that
370 * user code runs with the correct debug control register even though
371 * we clear it here.
372 *
373 * Being careful here means that we don't have to be as careful in a
374 * lot of more complicated places (task switching can be a bit lazy
375 * about restoring all the debug state, and ptrace doesn't have to
376 * find every occurrence of the TF bit that could be saved away even
377 * by user code)
c1d518c8
AH
378 *
379 * May run on IST stack.
1da177e4 380 */
e407d620 381dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
1da177e4 382{
1da177e4 383 struct task_struct *tsk = current;
a1e80faf 384 int user_icebp = 0;
08d68323 385 unsigned long dr6;
da654b74 386 int si_code;
1da177e4 387
08d68323 388 get_debugreg(dr6, 6);
1da177e4 389
40f9249a
P
390 /* Filter out all the reserved bits which are preset to 1 */
391 dr6 &= ~DR6_RESERVED;
392
a1e80faf
FW
393 /*
394 * If dr6 has no reason to give us about the origin of this trap,
395 * then it's very likely the result of an icebp/int01 trap.
396 * User wants a sigtrap for that.
397 */
398 if (!dr6 && user_mode(regs))
399 user_icebp = 1;
400
f8561296 401 /* Catch kmemcheck conditions first of all! */
eadb8a09 402 if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
f8561296
VN
403 return;
404
08d68323
P
405 /* DR6 may or may not be cleared by the CPU */
406 set_debugreg(0, 6);
10faa81e 407
ea8e61b7
PZ
408 /*
409 * The processor cleared BTF, so don't mark that we need it set.
410 */
411 clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP);
412
08d68323
P
413 /* Store the virtualized DR6 value */
414 tsk->thread.debugreg6 = dr6;
415
62edab90
P
416 if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code,
417 SIGTRAP) == NOTIFY_STOP)
1da177e4 418 return;
3d2a71a5 419
42181186
SR
420 /*
421 * Let others (NMI) know that the debug stack is in use
422 * as we may switch to the interrupt stack.
423 */
424 debug_stack_usage_inc();
425
1da177e4 426 /* It's safe to allow irq's after DR6 has been saved */
3d2a71a5 427 preempt_conditional_sti(regs);
1da177e4 428
08d68323 429 if (regs->flags & X86_VM_MASK) {
c9408265
KC
430 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
431 X86_TRAP_DB);
6554287b 432 preempt_conditional_cli(regs);
42181186 433 debug_stack_usage_dec();
08d68323 434 return;
1da177e4
LT
435 }
436
1da177e4 437 /*
08d68323
P
438 * Single-stepping through system calls: ignore any exceptions in
439 * kernel space, but re-enable TF when returning to user mode.
440 *
441 * We already checked v86 mode above, so we can check for kernel mode
442 * by just checking the CPL of CS.
1da177e4 443 */
08d68323
P
444 if ((dr6 & DR_STEP) && !user_mode(regs)) {
445 tsk->thread.debugreg6 &= ~DR_STEP;
446 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
447 regs->flags &= ~X86_EFLAGS_TF;
1da177e4 448 }
08d68323 449 si_code = get_si_code(tsk->thread.debugreg6);
a1e80faf 450 if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
08d68323 451 send_sigtrap(tsk, regs, error_code, si_code);
3d2a71a5 452 preempt_conditional_cli(regs);
42181186 453 debug_stack_usage_dec();
1da177e4 454
1da177e4
LT
455 return;
456}
457
458/*
459 * Note that we play around with the 'TS' bit in an attempt to get
460 * the correct behaviour even in the presence of the asynchronous
461 * IRQ13 behaviour
462 */
9b6dba9e 463void math_error(struct pt_regs *regs, int error_code, int trapnr)
1da177e4 464{
e2e75c91 465 struct task_struct *task = current;
1da177e4 466 siginfo_t info;
9b6dba9e 467 unsigned short err;
c9408265
KC
468 char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" :
469 "simd exception";
e2e75c91
BG
470
471 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP)
472 return;
473 conditional_sti(regs);
474
475 if (!user_mode_vm(regs))
476 {
477 if (!fixup_exception(regs)) {
478 task->thread.error_code = error_code;
51e7dc70 479 task->thread.trap_nr = trapnr;
e2e75c91
BG
480 die(str, regs, error_code);
481 }
482 return;
483 }
1da177e4
LT
484
485 /*
486 * Save the info for the exception handler and clear the error.
487 */
1da177e4 488 save_init_fpu(task);
51e7dc70 489 task->thread.trap_nr = trapnr;
9b6dba9e 490 task->thread.error_code = error_code;
1da177e4
LT
491 info.si_signo = SIGFPE;
492 info.si_errno = 0;
9b6dba9e 493 info.si_addr = (void __user *)regs->ip;
c9408265 494 if (trapnr == X86_TRAP_MF) {
9b6dba9e
BG
495 unsigned short cwd, swd;
496 /*
497 * (~cwd & swd) will mask out exceptions that are not set to unmasked
498 * status. 0x3f is the exception bits in these regs, 0x200 is the
499 * C1 reg you need in case of a stack fault, 0x040 is the stack
500 * fault bit. We should only be taking one exception at a time,
501 * so if this combination doesn't produce any single exception,
502 * then we have a bad program that isn't synchronizing its FPU usage
503 * and it will suffer the consequences since we won't be able to
504 * fully reproduce the context of the exception
505 */
506 cwd = get_fpu_cwd(task);
507 swd = get_fpu_swd(task);
adf77bac 508
9b6dba9e
BG
509 err = swd & ~cwd;
510 } else {
511 /*
512 * The SIMD FPU exceptions are handled a little differently, as there
513 * is only a single status/control register. Thus, to determine which
514 * unmasked exception was caught we must mask the exception mask bits
515 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
516 */
517 unsigned short mxcsr = get_fpu_mxcsr(task);
518 err = ~(mxcsr >> 7) & mxcsr;
519 }
adf77bac
PA
520
521 if (err & 0x001) { /* Invalid op */
b5964405
IM
522 /*
523 * swd & 0x240 == 0x040: Stack Underflow
524 * swd & 0x240 == 0x240: Stack Overflow
525 * User must clear the SF bit (0x40) if set
526 */
527 info.si_code = FPE_FLTINV;
adf77bac 528 } else if (err & 0x004) { /* Divide by Zero */
b5964405 529 info.si_code = FPE_FLTDIV;
adf77bac 530 } else if (err & 0x008) { /* Overflow */
b5964405 531 info.si_code = FPE_FLTOVF;
adf77bac
PA
532 } else if (err & 0x012) { /* Denormal, Underflow */
533 info.si_code = FPE_FLTUND;
534 } else if (err & 0x020) { /* Precision */
b5964405 535 info.si_code = FPE_FLTRES;
adf77bac 536 } else {
bd8b96df 537 /*
c9408265
KC
538 * If we're using IRQ 13, or supposedly even some trap
539 * X86_TRAP_MF implementations, it's possible
540 * we get a spurious trap, which is not an error.
bd8b96df 541 */
c9408265 542 return;
1da177e4
LT
543 }
544 force_sig_info(SIGFPE, &info, task);
545}
546
e407d620 547dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
1da177e4 548{
081f75bb 549#ifdef CONFIG_X86_32
1da177e4 550 ignore_fpu_irq = 1;
081f75bb
AH
551#endif
552
c9408265 553 math_error(regs, error_code, X86_TRAP_MF);
1da177e4
LT
554}
555
e407d620
AH
556dotraplinkage void
557do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
1da177e4 558{
c9408265 559 math_error(regs, error_code, X86_TRAP_XF);
1da177e4
LT
560}
561
e407d620
AH
562dotraplinkage void
563do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
1da177e4 564{
cf81978d 565 conditional_sti(regs);
1da177e4
LT
566#if 0
567 /* No need to warn about this any longer. */
c767a54b 568 pr_info("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
1da177e4
LT
569#endif
570}
571
081f75bb 572asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
1da177e4 573{
1da177e4 574}
4efc0670 575
7856f6cc 576asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void)
081f75bb
AH
577{
578}
579
1da177e4 580/*
b5964405 581 * 'math_state_restore()' saves the current math information in the
1da177e4
LT
582 * old math state array, and gets the new ones from the current task
583 *
584 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
585 * Don't touch unless you *really* know how it works.
586 *
be98c2cd
LT
587 * Must be called with kernel preemption disabled (eg with local
588 * local interrupts as in the case of do_device_not_available).
1da177e4 589 */
be98c2cd 590void math_state_restore(void)
1da177e4 591{
f94edacf 592 struct task_struct *tsk = current;
1da177e4 593
aa283f49
SS
594 if (!tsk_used_math(tsk)) {
595 local_irq_enable();
596 /*
597 * does a slab alloc which can sleep
598 */
599 if (init_fpu(tsk)) {
600 /*
601 * ran out of memory!
602 */
603 do_group_exit(SIGKILL);
604 return;
605 }
606 local_irq_disable();
607 }
608
f94edacf 609 __thread_fpu_begin(tsk);
80ab6f1e
LT
610 /*
611 * Paranoid restore. send a SIGSEGV if we fail to restore the state.
612 */
613 if (unlikely(restore_fpu_checking(tsk))) {
614 __thread_fpu_end(tsk);
615 force_sig(SIGSEGV, tsk);
616 return;
617 }
b3b0870e
LT
618
619 tsk->fpu_counter++;
1da177e4 620}
5992b6da 621EXPORT_SYMBOL_GPL(math_state_restore);
1da177e4 622
e407d620 623dotraplinkage void __kprobes
aa78bcfa 624do_device_not_available(struct pt_regs *regs, long error_code)
7643e9b9 625{
a334fe43 626#ifdef CONFIG_MATH_EMULATION
7643e9b9 627 if (read_cr0() & X86_CR0_EM) {
d315760f
TH
628 struct math_emu_info info = { };
629
7643e9b9 630 conditional_sti(regs);
d315760f 631
aa78bcfa 632 info.regs = regs;
d315760f 633 math_emulate(&info);
a334fe43 634 return;
7643e9b9 635 }
a334fe43
BG
636#endif
637 math_state_restore(); /* interrupts still off */
638#ifdef CONFIG_X86_32
639 conditional_sti(regs);
081f75bb 640#endif
7643e9b9
AH
641}
642
081f75bb 643#ifdef CONFIG_X86_32
e407d620 644dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
f8e0870f
AH
645{
646 siginfo_t info;
647 local_irq_enable();
648
649 info.si_signo = SIGILL;
650 info.si_errno = 0;
651 info.si_code = ILL_BADSTK;
fc6fcdfb 652 info.si_addr = NULL;
c9408265
KC
653 if (notify_die(DIE_TRAP, "iret exception", regs, error_code,
654 X86_TRAP_IRET, SIGILL) == NOTIFY_STOP)
f8e0870f 655 return;
c9408265
KC
656 do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code,
657 &info);
f8e0870f 658}
081f75bb 659#endif
f8e0870f 660
29c84391
JK
661/* Set of traps needed for early debugging. */
662void __init early_trap_init(void)
663{
c9408265 664 set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK);
29c84391 665 /* int3 can be called from all */
c9408265
KC
666 set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK);
667 set_intr_gate(X86_TRAP_PF, &page_fault);
29c84391
JK
668 load_idt(&idt_descr);
669}
670
1da177e4
LT
671void __init trap_init(void)
672{
dbeb2be2
RR
673 int i;
674
1da177e4 675#ifdef CONFIG_EISA
927222b1 676 void __iomem *p = early_ioremap(0x0FFFD9, 4);
b5964405
IM
677
678 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
1da177e4 679 EISA_bus = 1;
927222b1 680 early_iounmap(p, 4);
1da177e4
LT
681#endif
682
c9408265
KC
683 set_intr_gate(X86_TRAP_DE, &divide_error);
684 set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK);
699d2937 685 /* int4 can be called from all */
c9408265
KC
686 set_system_intr_gate(X86_TRAP_OF, &overflow);
687 set_intr_gate(X86_TRAP_BR, &bounds);
688 set_intr_gate(X86_TRAP_UD, &invalid_op);
689 set_intr_gate(X86_TRAP_NM, &device_not_available);
081f75bb 690#ifdef CONFIG_X86_32
c9408265 691 set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS);
081f75bb 692#else
c9408265 693 set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK);
081f75bb 694#endif
c9408265
KC
695 set_intr_gate(X86_TRAP_OLD_MF, &coprocessor_segment_overrun);
696 set_intr_gate(X86_TRAP_TS, &invalid_TSS);
697 set_intr_gate(X86_TRAP_NP, &segment_not_present);
698 set_intr_gate_ist(X86_TRAP_SS, &stack_segment, STACKFAULT_STACK);
699 set_intr_gate(X86_TRAP_GP, &general_protection);
700 set_intr_gate(X86_TRAP_SPURIOUS, &spurious_interrupt_bug);
701 set_intr_gate(X86_TRAP_MF, &coprocessor_error);
702 set_intr_gate(X86_TRAP_AC, &alignment_check);
1da177e4 703#ifdef CONFIG_X86_MCE
c9408265 704 set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK);
1da177e4 705#endif
c9408265 706 set_intr_gate(X86_TRAP_XF, &simd_coprocessor_error);
1da177e4 707
bb3f0b59
YL
708 /* Reserve all the builtin and the syscall vector: */
709 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
710 set_bit(i, used_vectors);
711
081f75bb
AH
712#ifdef CONFIG_IA32_EMULATION
713 set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
bb3f0b59 714 set_bit(IA32_SYSCALL_VECTOR, used_vectors);
081f75bb
AH
715#endif
716
717#ifdef CONFIG_X86_32
699d2937 718 set_system_trap_gate(SYSCALL_VECTOR, &system_call);
dbeb2be2 719 set_bit(SYSCALL_VECTOR, used_vectors);
081f75bb 720#endif
bb3f0b59 721
1da177e4 722 /*
b5964405 723 * Should be a barrier for any external CPU state:
1da177e4
LT
724 */
725 cpu_init();
726
428cf902 727 x86_init.irqs.trap_init();
228bdaa9
SR
728
729#ifdef CONFIG_X86_64
730 memcpy(&nmi_idt_table, &idt_table, IDT_ENTRIES * 16);
c9408265
KC
731 set_nmi_gate(X86_TRAP_DB, &debug);
732 set_nmi_gate(X86_TRAP_BP, &int3);
228bdaa9 733#endif
1da177e4 734}
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