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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 | */ |
b5964405 IM |
12 | #include <linux/interrupt.h> |
13 | #include <linux/kallsyms.h> | |
14 | #include <linux/spinlock.h> | |
b5964405 IM |
15 | #include <linux/kprobes.h> |
16 | #include <linux/uaccess.h> | |
b5964405 | 17 | #include <linux/kdebug.h> |
f503b5ae | 18 | #include <linux/kgdb.h> |
1da177e4 | 19 | #include <linux/kernel.h> |
b5964405 IM |
20 | #include <linux/module.h> |
21 | #include <linux/ptrace.h> | |
1da177e4 | 22 | #include <linux/string.h> |
b5964405 | 23 | #include <linux/delay.h> |
1da177e4 | 24 | #include <linux/errno.h> |
b5964405 IM |
25 | #include <linux/kexec.h> |
26 | #include <linux/sched.h> | |
1da177e4 | 27 | #include <linux/timer.h> |
1da177e4 | 28 | #include <linux/init.h> |
91768d6c | 29 | #include <linux/bug.h> |
b5964405 IM |
30 | #include <linux/nmi.h> |
31 | #include <linux/mm.h> | |
c1d518c8 AH |
32 | #include <linux/smp.h> |
33 | #include <linux/io.h> | |
1da177e4 LT |
34 | |
35 | #ifdef CONFIG_EISA | |
36 | #include <linux/ioport.h> | |
37 | #include <linux/eisa.h> | |
38 | #endif | |
39 | ||
40 | #ifdef CONFIG_MCA | |
41 | #include <linux/mca.h> | |
42 | #endif | |
43 | ||
c0d12172 DJ |
44 | #if defined(CONFIG_EDAC) |
45 | #include <linux/edac.h> | |
46 | #endif | |
47 | ||
f8561296 | 48 | #include <asm/kmemcheck.h> |
b5964405 | 49 | #include <asm/stacktrace.h> |
1da177e4 | 50 | #include <asm/processor.h> |
1da177e4 | 51 | #include <asm/debugreg.h> |
60063497 | 52 | #include <linux/atomic.h> |
b5964405 | 53 | #include <asm/system.h> |
c1d518c8 | 54 | #include <asm/traps.h> |
1da177e4 LT |
55 | #include <asm/desc.h> |
56 | #include <asm/i387.h> | |
1361b83a | 57 | #include <asm/fpu-internal.h> |
9e55e44e | 58 | #include <asm/mce.h> |
c1d518c8 | 59 | |
1164dd00 | 60 | #include <asm/mach_traps.h> |
c1d518c8 | 61 | |
081f75bb | 62 | #ifdef CONFIG_X86_64 |
428cf902 | 63 | #include <asm/x86_init.h> |
081f75bb AH |
64 | #include <asm/pgalloc.h> |
65 | #include <asm/proto.h> | |
081f75bb | 66 | #else |
c1d518c8 | 67 | #include <asm/processor-flags.h> |
8e6dafd6 | 68 | #include <asm/setup.h> |
1da177e4 | 69 | |
1da177e4 LT |
70 | asmlinkage int system_call(void); |
71 | ||
1da177e4 | 72 | /* Do we ignore FPU interrupts ? */ |
b5964405 | 73 | char ignore_fpu_irq; |
1da177e4 LT |
74 | |
75 | /* | |
76 | * The IDT has to be page-aligned to simplify the Pentium | |
07e81d61 | 77 | * F0 0F bug workaround. |
1da177e4 | 78 | */ |
07e81d61 | 79 | gate_desc idt_table[NR_VECTORS] __page_aligned_data = { { { { 0, 0 } } }, }; |
081f75bb | 80 | #endif |
1da177e4 | 81 | |
b77b881f YL |
82 | DECLARE_BITMAP(used_vectors, NR_VECTORS); |
83 | EXPORT_SYMBOL_GPL(used_vectors); | |
84 | ||
762db434 AH |
85 | static inline void conditional_sti(struct pt_regs *regs) |
86 | { | |
87 | if (regs->flags & X86_EFLAGS_IF) | |
88 | local_irq_enable(); | |
89 | } | |
90 | ||
3d2a71a5 AH |
91 | static inline void preempt_conditional_sti(struct pt_regs *regs) |
92 | { | |
93 | inc_preempt_count(); | |
94 | if (regs->flags & X86_EFLAGS_IF) | |
95 | local_irq_enable(); | |
96 | } | |
97 | ||
be716615 TG |
98 | static inline void conditional_cli(struct pt_regs *regs) |
99 | { | |
100 | if (regs->flags & X86_EFLAGS_IF) | |
101 | local_irq_disable(); | |
102 | } | |
103 | ||
3d2a71a5 AH |
104 | static inline void preempt_conditional_cli(struct pt_regs *regs) |
105 | { | |
106 | if (regs->flags & X86_EFLAGS_IF) | |
107 | local_irq_disable(); | |
108 | dec_preempt_count(); | |
109 | } | |
110 | ||
b5964405 | 111 | static void __kprobes |
3c1326f8 | 112 | do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, |
b5964405 | 113 | long error_code, siginfo_t *info) |
1da177e4 | 114 | { |
4f339ecb | 115 | struct task_struct *tsk = current; |
4f339ecb | 116 | |
081f75bb | 117 | #ifdef CONFIG_X86_32 |
6b6891f9 | 118 | if (regs->flags & X86_VM_MASK) { |
3c1326f8 AH |
119 | /* |
120 | * traps 0, 1, 3, 4, and 5 should be forwarded to vm86. | |
121 | * On nmi (interrupt 2), do_trap should not be called. | |
122 | */ | |
123 | if (trapnr < 6) | |
1da177e4 LT |
124 | goto vm86_trap; |
125 | goto trap_signal; | |
126 | } | |
081f75bb | 127 | #endif |
1da177e4 | 128 | |
717b594a | 129 | if (!user_mode(regs)) |
1da177e4 LT |
130 | goto kernel_trap; |
131 | ||
081f75bb | 132 | #ifdef CONFIG_X86_32 |
b5964405 | 133 | trap_signal: |
081f75bb | 134 | #endif |
b5964405 IM |
135 | /* |
136 | * We want error_code and trap_no set for userspace faults and | |
137 | * kernelspace faults which result in die(), but not | |
138 | * kernelspace faults which are fixed up. die() gives the | |
139 | * process no chance to handle the signal and notice the | |
140 | * kernel fault information, so that won't result in polluting | |
141 | * the information about previously queued, but not yet | |
142 | * delivered, faults. See also do_general_protection below. | |
143 | */ | |
144 | tsk->thread.error_code = error_code; | |
145 | tsk->thread.trap_no = trapnr; | |
d1895183 | 146 | |
081f75bb AH |
147 | #ifdef CONFIG_X86_64 |
148 | if (show_unhandled_signals && unhandled_signal(tsk, signr) && | |
149 | printk_ratelimit()) { | |
150 | printk(KERN_INFO | |
151 | "%s[%d] trap %s ip:%lx sp:%lx error:%lx", | |
152 | tsk->comm, tsk->pid, str, | |
153 | regs->ip, regs->sp, error_code); | |
154 | print_vma_addr(" in ", regs->ip); | |
155 | printk("\n"); | |
156 | } | |
157 | #endif | |
158 | ||
b5964405 IM |
159 | if (info) |
160 | force_sig_info(signr, info, tsk); | |
161 | else | |
162 | force_sig(signr, tsk); | |
163 | return; | |
1da177e4 | 164 | |
b5964405 IM |
165 | kernel_trap: |
166 | if (!fixup_exception(regs)) { | |
167 | tsk->thread.error_code = error_code; | |
168 | tsk->thread.trap_no = trapnr; | |
169 | die(str, regs, error_code); | |
1da177e4 | 170 | } |
b5964405 | 171 | return; |
1da177e4 | 172 | |
081f75bb | 173 | #ifdef CONFIG_X86_32 |
b5964405 IM |
174 | vm86_trap: |
175 | if (handle_vm86_trap((struct kernel_vm86_regs *) regs, | |
176 | error_code, trapnr)) | |
177 | goto trap_signal; | |
178 | return; | |
081f75bb | 179 | #endif |
1da177e4 LT |
180 | } |
181 | ||
b5964405 | 182 | #define DO_ERROR(trapnr, signr, str, name) \ |
e407d620 | 183 | dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ |
b5964405 IM |
184 | { \ |
185 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ | |
a8c1be9d | 186 | == NOTIFY_STOP) \ |
b5964405 | 187 | return; \ |
61aef7d2 | 188 | conditional_sti(regs); \ |
3c1326f8 | 189 | do_trap(trapnr, signr, str, regs, error_code, NULL); \ |
1da177e4 LT |
190 | } |
191 | ||
3c1326f8 | 192 | #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ |
e407d620 | 193 | dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ |
b5964405 IM |
194 | { \ |
195 | siginfo_t info; \ | |
196 | info.si_signo = signr; \ | |
197 | info.si_errno = 0; \ | |
198 | info.si_code = sicode; \ | |
199 | info.si_addr = (void __user *)siaddr; \ | |
b5964405 | 200 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ |
a8c1be9d | 201 | == NOTIFY_STOP) \ |
b5964405 | 202 | return; \ |
61aef7d2 | 203 | conditional_sti(regs); \ |
3c1326f8 | 204 | do_trap(trapnr, signr, str, regs, error_code, &info); \ |
1da177e4 LT |
205 | } |
206 | ||
3c1326f8 AH |
207 | DO_ERROR_INFO(0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip) |
208 | DO_ERROR(4, SIGSEGV, "overflow", overflow) | |
209 | DO_ERROR(5, SIGSEGV, "bounds", bounds) | |
210 | DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip) | |
51bc1ed6 | 211 | DO_ERROR(9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun) |
6bf77bf9 | 212 | DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS) |
36d936c7 | 213 | DO_ERROR(11, SIGBUS, "segment not present", segment_not_present) |
081f75bb | 214 | #ifdef CONFIG_X86_32 |
f5ca8187 | 215 | DO_ERROR(12, SIGBUS, "stack segment", stack_segment) |
081f75bb | 216 | #endif |
3c1326f8 | 217 | DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0) |
1da177e4 | 218 | |
081f75bb AH |
219 | #ifdef CONFIG_X86_64 |
220 | /* Runs on IST stack */ | |
221 | dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code) | |
222 | { | |
223 | if (notify_die(DIE_TRAP, "stack segment", regs, error_code, | |
224 | 12, SIGBUS) == NOTIFY_STOP) | |
225 | return; | |
226 | preempt_conditional_sti(regs); | |
227 | do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL); | |
228 | preempt_conditional_cli(regs); | |
229 | } | |
230 | ||
231 | dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) | |
232 | { | |
233 | static const char str[] = "double fault"; | |
234 | struct task_struct *tsk = current; | |
235 | ||
236 | /* Return not checked because double check cannot be ignored */ | |
237 | notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV); | |
238 | ||
239 | tsk->thread.error_code = error_code; | |
240 | tsk->thread.trap_no = 8; | |
241 | ||
bd8b96df IM |
242 | /* |
243 | * This is always a kernel trap and never fixable (and thus must | |
244 | * never return). | |
245 | */ | |
081f75bb AH |
246 | for (;;) |
247 | die(str, regs, error_code); | |
248 | } | |
249 | #endif | |
250 | ||
e407d620 | 251 | dotraplinkage void __kprobes |
13485ab5 | 252 | do_general_protection(struct pt_regs *regs, long error_code) |
1da177e4 | 253 | { |
13485ab5 | 254 | struct task_struct *tsk; |
b5964405 | 255 | |
c6df0d71 AH |
256 | conditional_sti(regs); |
257 | ||
081f75bb | 258 | #ifdef CONFIG_X86_32 |
6b6891f9 | 259 | if (regs->flags & X86_VM_MASK) |
1da177e4 | 260 | goto gp_in_vm86; |
081f75bb | 261 | #endif |
1da177e4 | 262 | |
13485ab5 | 263 | tsk = current; |
717b594a | 264 | if (!user_mode(regs)) |
1da177e4 LT |
265 | goto gp_in_kernel; |
266 | ||
13485ab5 AH |
267 | tsk->thread.error_code = error_code; |
268 | tsk->thread.trap_no = 13; | |
b5964405 | 269 | |
13485ab5 AH |
270 | if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && |
271 | printk_ratelimit()) { | |
abd4f750 | 272 | printk(KERN_INFO |
13485ab5 AH |
273 | "%s[%d] general protection ip:%lx sp:%lx error:%lx", |
274 | tsk->comm, task_pid_nr(tsk), | |
275 | regs->ip, regs->sp, error_code); | |
03252919 AK |
276 | print_vma_addr(" in ", regs->ip); |
277 | printk("\n"); | |
278 | } | |
abd4f750 | 279 | |
13485ab5 | 280 | force_sig(SIGSEGV, tsk); |
1da177e4 LT |
281 | return; |
282 | ||
081f75bb | 283 | #ifdef CONFIG_X86_32 |
1da177e4 LT |
284 | gp_in_vm86: |
285 | local_irq_enable(); | |
286 | handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); | |
287 | return; | |
081f75bb | 288 | #endif |
1da177e4 LT |
289 | |
290 | gp_in_kernel: | |
13485ab5 AH |
291 | if (fixup_exception(regs)) |
292 | return; | |
293 | ||
294 | tsk->thread.error_code = error_code; | |
295 | tsk->thread.trap_no = 13; | |
296 | if (notify_die(DIE_GPF, "general protection fault", regs, | |
1da177e4 | 297 | error_code, 13, SIGSEGV) == NOTIFY_STOP) |
13485ab5 AH |
298 | return; |
299 | die("general protection fault", regs, error_code); | |
1da177e4 LT |
300 | } |
301 | ||
c1d518c8 | 302 | /* May run on IST stack. */ |
e407d620 | 303 | dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) |
1da177e4 | 304 | { |
f503b5ae JW |
305 | #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP |
306 | if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) | |
307 | == NOTIFY_STOP) | |
308 | return; | |
309 | #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ | |
cc3a1bf5 | 310 | |
1da177e4 LT |
311 | if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) |
312 | == NOTIFY_STOP) | |
48c88211 | 313 | return; |
b5964405 | 314 | |
42181186 SR |
315 | /* |
316 | * Let others (NMI) know that the debug stack is in use | |
317 | * as we may switch to the interrupt stack. | |
318 | */ | |
319 | debug_stack_usage_inc(); | |
4915a35e | 320 | preempt_conditional_sti(regs); |
3c1326f8 | 321 | do_trap(3, SIGTRAP, "int3", regs, error_code, NULL); |
4915a35e | 322 | preempt_conditional_cli(regs); |
42181186 | 323 | debug_stack_usage_dec(); |
1da177e4 | 324 | } |
1da177e4 | 325 | |
081f75bb | 326 | #ifdef CONFIG_X86_64 |
bd8b96df IM |
327 | /* |
328 | * Help handler running on IST stack to switch back to user stack | |
329 | * for scheduling or signal handling. The actual stack switch is done in | |
330 | * entry.S | |
331 | */ | |
081f75bb AH |
332 | asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) |
333 | { | |
334 | struct pt_regs *regs = eregs; | |
335 | /* Did already sync */ | |
336 | if (eregs == (struct pt_regs *)eregs->sp) | |
337 | ; | |
338 | /* Exception from user space */ | |
339 | else if (user_mode(eregs)) | |
340 | regs = task_pt_regs(current); | |
bd8b96df IM |
341 | /* |
342 | * Exception from kernel and interrupts are enabled. Move to | |
343 | * kernel process stack. | |
344 | */ | |
081f75bb AH |
345 | else if (eregs->flags & X86_EFLAGS_IF) |
346 | regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs)); | |
347 | if (eregs != regs) | |
348 | *regs = *eregs; | |
349 | return regs; | |
350 | } | |
351 | #endif | |
352 | ||
1da177e4 LT |
353 | /* |
354 | * Our handling of the processor debug registers is non-trivial. | |
355 | * We do not clear them on entry and exit from the kernel. Therefore | |
356 | * it is possible to get a watchpoint trap here from inside the kernel. | |
357 | * However, the code in ./ptrace.c has ensured that the user can | |
358 | * only set watchpoints on userspace addresses. Therefore the in-kernel | |
359 | * watchpoint trap can only occur in code which is reading/writing | |
360 | * from user space. Such code must not hold kernel locks (since it | |
361 | * can equally take a page fault), therefore it is safe to call | |
362 | * force_sig_info even though that claims and releases locks. | |
b5964405 | 363 | * |
1da177e4 LT |
364 | * Code in ./signal.c ensures that the debug control register |
365 | * is restored before we deliver any signal, and therefore that | |
366 | * user code runs with the correct debug control register even though | |
367 | * we clear it here. | |
368 | * | |
369 | * Being careful here means that we don't have to be as careful in a | |
370 | * lot of more complicated places (task switching can be a bit lazy | |
371 | * about restoring all the debug state, and ptrace doesn't have to | |
372 | * find every occurrence of the TF bit that could be saved away even | |
373 | * by user code) | |
c1d518c8 AH |
374 | * |
375 | * May run on IST stack. | |
1da177e4 | 376 | */ |
e407d620 | 377 | dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) |
1da177e4 | 378 | { |
1da177e4 | 379 | struct task_struct *tsk = current; |
a1e80faf | 380 | int user_icebp = 0; |
08d68323 | 381 | unsigned long dr6; |
da654b74 | 382 | int si_code; |
1da177e4 | 383 | |
08d68323 | 384 | get_debugreg(dr6, 6); |
1da177e4 | 385 | |
40f9249a P |
386 | /* Filter out all the reserved bits which are preset to 1 */ |
387 | dr6 &= ~DR6_RESERVED; | |
388 | ||
a1e80faf FW |
389 | /* |
390 | * If dr6 has no reason to give us about the origin of this trap, | |
391 | * then it's very likely the result of an icebp/int01 trap. | |
392 | * User wants a sigtrap for that. | |
393 | */ | |
394 | if (!dr6 && user_mode(regs)) | |
395 | user_icebp = 1; | |
396 | ||
f8561296 | 397 | /* Catch kmemcheck conditions first of all! */ |
eadb8a09 | 398 | if ((dr6 & DR_STEP) && kmemcheck_trap(regs)) |
f8561296 VN |
399 | return; |
400 | ||
08d68323 P |
401 | /* DR6 may or may not be cleared by the CPU */ |
402 | set_debugreg(0, 6); | |
10faa81e | 403 | |
ea8e61b7 PZ |
404 | /* |
405 | * The processor cleared BTF, so don't mark that we need it set. | |
406 | */ | |
407 | clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP); | |
408 | ||
08d68323 P |
409 | /* Store the virtualized DR6 value */ |
410 | tsk->thread.debugreg6 = dr6; | |
411 | ||
62edab90 P |
412 | if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code, |
413 | SIGTRAP) == NOTIFY_STOP) | |
1da177e4 | 414 | return; |
3d2a71a5 | 415 | |
42181186 SR |
416 | /* |
417 | * Let others (NMI) know that the debug stack is in use | |
418 | * as we may switch to the interrupt stack. | |
419 | */ | |
420 | debug_stack_usage_inc(); | |
421 | ||
1da177e4 | 422 | /* It's safe to allow irq's after DR6 has been saved */ |
3d2a71a5 | 423 | preempt_conditional_sti(regs); |
1da177e4 | 424 | |
08d68323 P |
425 | if (regs->flags & X86_VM_MASK) { |
426 | handle_vm86_trap((struct kernel_vm86_regs *) regs, | |
427 | error_code, 1); | |
6554287b | 428 | preempt_conditional_cli(regs); |
42181186 | 429 | debug_stack_usage_dec(); |
08d68323 | 430 | return; |
1da177e4 LT |
431 | } |
432 | ||
1da177e4 | 433 | /* |
08d68323 P |
434 | * Single-stepping through system calls: ignore any exceptions in |
435 | * kernel space, but re-enable TF when returning to user mode. | |
436 | * | |
437 | * We already checked v86 mode above, so we can check for kernel mode | |
438 | * by just checking the CPL of CS. | |
1da177e4 | 439 | */ |
08d68323 P |
440 | if ((dr6 & DR_STEP) && !user_mode(regs)) { |
441 | tsk->thread.debugreg6 &= ~DR_STEP; | |
442 | set_tsk_thread_flag(tsk, TIF_SINGLESTEP); | |
443 | regs->flags &= ~X86_EFLAGS_TF; | |
1da177e4 | 444 | } |
08d68323 | 445 | si_code = get_si_code(tsk->thread.debugreg6); |
a1e80faf | 446 | if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp) |
08d68323 | 447 | send_sigtrap(tsk, regs, error_code, si_code); |
3d2a71a5 | 448 | preempt_conditional_cli(regs); |
42181186 | 449 | debug_stack_usage_dec(); |
1da177e4 | 450 | |
1da177e4 LT |
451 | return; |
452 | } | |
453 | ||
454 | /* | |
455 | * Note that we play around with the 'TS' bit in an attempt to get | |
456 | * the correct behaviour even in the presence of the asynchronous | |
457 | * IRQ13 behaviour | |
458 | */ | |
9b6dba9e | 459 | void math_error(struct pt_regs *regs, int error_code, int trapnr) |
1da177e4 | 460 | { |
e2e75c91 | 461 | struct task_struct *task = current; |
1da177e4 | 462 | siginfo_t info; |
9b6dba9e | 463 | unsigned short err; |
e2e75c91 BG |
464 | char *str = (trapnr == 16) ? "fpu exception" : "simd exception"; |
465 | ||
466 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP) | |
467 | return; | |
468 | conditional_sti(regs); | |
469 | ||
470 | if (!user_mode_vm(regs)) | |
471 | { | |
472 | if (!fixup_exception(regs)) { | |
473 | task->thread.error_code = error_code; | |
474 | task->thread.trap_no = trapnr; | |
475 | die(str, regs, error_code); | |
476 | } | |
477 | return; | |
478 | } | |
1da177e4 LT |
479 | |
480 | /* | |
481 | * Save the info for the exception handler and clear the error. | |
482 | */ | |
1da177e4 | 483 | save_init_fpu(task); |
9b6dba9e BG |
484 | task->thread.trap_no = trapnr; |
485 | task->thread.error_code = error_code; | |
1da177e4 LT |
486 | info.si_signo = SIGFPE; |
487 | info.si_errno = 0; | |
9b6dba9e BG |
488 | info.si_addr = (void __user *)regs->ip; |
489 | if (trapnr == 16) { | |
490 | unsigned short cwd, swd; | |
491 | /* | |
492 | * (~cwd & swd) will mask out exceptions that are not set to unmasked | |
493 | * status. 0x3f is the exception bits in these regs, 0x200 is the | |
494 | * C1 reg you need in case of a stack fault, 0x040 is the stack | |
495 | * fault bit. We should only be taking one exception at a time, | |
496 | * so if this combination doesn't produce any single exception, | |
497 | * then we have a bad program that isn't synchronizing its FPU usage | |
498 | * and it will suffer the consequences since we won't be able to | |
499 | * fully reproduce the context of the exception | |
500 | */ | |
501 | cwd = get_fpu_cwd(task); | |
502 | swd = get_fpu_swd(task); | |
adf77bac | 503 | |
9b6dba9e BG |
504 | err = swd & ~cwd; |
505 | } else { | |
506 | /* | |
507 | * The SIMD FPU exceptions are handled a little differently, as there | |
508 | * is only a single status/control register. Thus, to determine which | |
509 | * unmasked exception was caught we must mask the exception mask bits | |
510 | * at 0x1f80, and then use these to mask the exception bits at 0x3f. | |
511 | */ | |
512 | unsigned short mxcsr = get_fpu_mxcsr(task); | |
513 | err = ~(mxcsr >> 7) & mxcsr; | |
514 | } | |
adf77bac PA |
515 | |
516 | if (err & 0x001) { /* Invalid op */ | |
b5964405 IM |
517 | /* |
518 | * swd & 0x240 == 0x040: Stack Underflow | |
519 | * swd & 0x240 == 0x240: Stack Overflow | |
520 | * User must clear the SF bit (0x40) if set | |
521 | */ | |
522 | info.si_code = FPE_FLTINV; | |
adf77bac | 523 | } else if (err & 0x004) { /* Divide by Zero */ |
b5964405 | 524 | info.si_code = FPE_FLTDIV; |
adf77bac | 525 | } else if (err & 0x008) { /* Overflow */ |
b5964405 | 526 | info.si_code = FPE_FLTOVF; |
adf77bac PA |
527 | } else if (err & 0x012) { /* Denormal, Underflow */ |
528 | info.si_code = FPE_FLTUND; | |
529 | } else if (err & 0x020) { /* Precision */ | |
b5964405 | 530 | info.si_code = FPE_FLTRES; |
adf77bac | 531 | } else { |
bd8b96df IM |
532 | /* |
533 | * If we're using IRQ 13, or supposedly even some trap 16 | |
534 | * implementations, it's possible we get a spurious trap... | |
535 | */ | |
a73ad333 | 536 | return; /* Spurious trap, no error */ |
1da177e4 LT |
537 | } |
538 | force_sig_info(SIGFPE, &info, task); | |
539 | } | |
540 | ||
e407d620 | 541 | dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) |
1da177e4 | 542 | { |
081f75bb | 543 | #ifdef CONFIG_X86_32 |
1da177e4 | 544 | ignore_fpu_irq = 1; |
081f75bb AH |
545 | #endif |
546 | ||
9b6dba9e | 547 | math_error(regs, error_code, 16); |
1da177e4 LT |
548 | } |
549 | ||
e407d620 AH |
550 | dotraplinkage void |
551 | do_simd_coprocessor_error(struct pt_regs *regs, long error_code) | |
1da177e4 | 552 | { |
9b6dba9e | 553 | math_error(regs, error_code, 19); |
1da177e4 LT |
554 | } |
555 | ||
e407d620 AH |
556 | dotraplinkage void |
557 | do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) | |
1da177e4 | 558 | { |
cf81978d | 559 | conditional_sti(regs); |
1da177e4 LT |
560 | #if 0 |
561 | /* No need to warn about this any longer. */ | |
b5964405 | 562 | printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); |
1da177e4 LT |
563 | #endif |
564 | } | |
565 | ||
081f75bb | 566 | asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) |
1da177e4 | 567 | { |
1da177e4 | 568 | } |
4efc0670 | 569 | |
7856f6cc | 570 | asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void) |
081f75bb AH |
571 | { |
572 | } | |
573 | ||
1da177e4 | 574 | /* |
b5964405 | 575 | * 'math_state_restore()' saves the current math information in the |
1da177e4 LT |
576 | * old math state array, and gets the new ones from the current task |
577 | * | |
578 | * Careful.. There are problems with IBM-designed IRQ13 behaviour. | |
579 | * Don't touch unless you *really* know how it works. | |
580 | * | |
be98c2cd LT |
581 | * Must be called with kernel preemption disabled (eg with local |
582 | * local interrupts as in the case of do_device_not_available). | |
1da177e4 | 583 | */ |
be98c2cd | 584 | void math_state_restore(void) |
1da177e4 | 585 | { |
f94edacf | 586 | struct task_struct *tsk = current; |
1da177e4 | 587 | |
aa283f49 SS |
588 | if (!tsk_used_math(tsk)) { |
589 | local_irq_enable(); | |
590 | /* | |
591 | * does a slab alloc which can sleep | |
592 | */ | |
593 | if (init_fpu(tsk)) { | |
594 | /* | |
595 | * ran out of memory! | |
596 | */ | |
597 | do_group_exit(SIGKILL); | |
598 | return; | |
599 | } | |
600 | local_irq_disable(); | |
601 | } | |
602 | ||
f94edacf | 603 | __thread_fpu_begin(tsk); |
80ab6f1e LT |
604 | /* |
605 | * Paranoid restore. send a SIGSEGV if we fail to restore the state. | |
606 | */ | |
607 | if (unlikely(restore_fpu_checking(tsk))) { | |
608 | __thread_fpu_end(tsk); | |
609 | force_sig(SIGSEGV, tsk); | |
610 | return; | |
611 | } | |
b3b0870e LT |
612 | |
613 | tsk->fpu_counter++; | |
1da177e4 | 614 | } |
5992b6da | 615 | EXPORT_SYMBOL_GPL(math_state_restore); |
1da177e4 | 616 | |
e407d620 | 617 | dotraplinkage void __kprobes |
aa78bcfa | 618 | do_device_not_available(struct pt_regs *regs, long error_code) |
7643e9b9 | 619 | { |
a334fe43 | 620 | #ifdef CONFIG_MATH_EMULATION |
7643e9b9 | 621 | if (read_cr0() & X86_CR0_EM) { |
d315760f TH |
622 | struct math_emu_info info = { }; |
623 | ||
7643e9b9 | 624 | conditional_sti(regs); |
d315760f | 625 | |
aa78bcfa | 626 | info.regs = regs; |
d315760f | 627 | math_emulate(&info); |
a334fe43 | 628 | return; |
7643e9b9 | 629 | } |
a334fe43 BG |
630 | #endif |
631 | math_state_restore(); /* interrupts still off */ | |
632 | #ifdef CONFIG_X86_32 | |
633 | conditional_sti(regs); | |
081f75bb | 634 | #endif |
7643e9b9 AH |
635 | } |
636 | ||
081f75bb | 637 | #ifdef CONFIG_X86_32 |
e407d620 | 638 | dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) |
f8e0870f AH |
639 | { |
640 | siginfo_t info; | |
641 | local_irq_enable(); | |
642 | ||
643 | info.si_signo = SIGILL; | |
644 | info.si_errno = 0; | |
645 | info.si_code = ILL_BADSTK; | |
fc6fcdfb | 646 | info.si_addr = NULL; |
f8e0870f AH |
647 | if (notify_die(DIE_TRAP, "iret exception", |
648 | regs, error_code, 32, SIGILL) == NOTIFY_STOP) | |
649 | return; | |
3c1326f8 | 650 | do_trap(32, SIGILL, "iret exception", regs, error_code, &info); |
f8e0870f | 651 | } |
081f75bb | 652 | #endif |
f8e0870f | 653 | |
29c84391 JK |
654 | /* Set of traps needed for early debugging. */ |
655 | void __init early_trap_init(void) | |
656 | { | |
657 | set_intr_gate_ist(1, &debug, DEBUG_STACK); | |
658 | /* int3 can be called from all */ | |
659 | set_system_intr_gate_ist(3, &int3, DEBUG_STACK); | |
660 | set_intr_gate(14, &page_fault); | |
661 | load_idt(&idt_descr); | |
662 | } | |
663 | ||
1da177e4 LT |
664 | void __init trap_init(void) |
665 | { | |
dbeb2be2 RR |
666 | int i; |
667 | ||
1da177e4 | 668 | #ifdef CONFIG_EISA |
927222b1 | 669 | void __iomem *p = early_ioremap(0x0FFFD9, 4); |
b5964405 IM |
670 | |
671 | if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24)) | |
1da177e4 | 672 | EISA_bus = 1; |
927222b1 | 673 | early_iounmap(p, 4); |
1da177e4 LT |
674 | #endif |
675 | ||
976382dc | 676 | set_intr_gate(0, ÷_error); |
699d2937 | 677 | set_intr_gate_ist(2, &nmi, NMI_STACK); |
699d2937 AH |
678 | /* int4 can be called from all */ |
679 | set_system_intr_gate(4, &overflow); | |
64f644c0 | 680 | set_intr_gate(5, &bounds); |
12394cf5 | 681 | set_intr_gate(6, &invalid_op); |
7643e9b9 | 682 | set_intr_gate(7, &device_not_available); |
081f75bb | 683 | #ifdef CONFIG_X86_32 |
a8c1be9d | 684 | set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS); |
081f75bb AH |
685 | #else |
686 | set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK); | |
687 | #endif | |
51bc1ed6 | 688 | set_intr_gate(9, &coprocessor_segment_overrun); |
6bf77bf9 | 689 | set_intr_gate(10, &invalid_TSS); |
36d936c7 | 690 | set_intr_gate(11, &segment_not_present); |
699d2937 | 691 | set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK); |
c6df0d71 | 692 | set_intr_gate(13, &general_protection); |
cf81978d | 693 | set_intr_gate(15, &spurious_interrupt_bug); |
252d28fe | 694 | set_intr_gate(16, &coprocessor_error); |
5feedfd4 | 695 | set_intr_gate(17, &alignment_check); |
1da177e4 | 696 | #ifdef CONFIG_X86_MCE |
699d2937 | 697 | set_intr_gate_ist(18, &machine_check, MCE_STACK); |
1da177e4 | 698 | #endif |
b939bde2 | 699 | set_intr_gate(19, &simd_coprocessor_error); |
1da177e4 | 700 | |
bb3f0b59 YL |
701 | /* Reserve all the builtin and the syscall vector: */ |
702 | for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) | |
703 | set_bit(i, used_vectors); | |
704 | ||
081f75bb AH |
705 | #ifdef CONFIG_IA32_EMULATION |
706 | set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall); | |
bb3f0b59 | 707 | set_bit(IA32_SYSCALL_VECTOR, used_vectors); |
081f75bb AH |
708 | #endif |
709 | ||
710 | #ifdef CONFIG_X86_32 | |
699d2937 | 711 | set_system_trap_gate(SYSCALL_VECTOR, &system_call); |
dbeb2be2 | 712 | set_bit(SYSCALL_VECTOR, used_vectors); |
081f75bb | 713 | #endif |
bb3f0b59 | 714 | |
1da177e4 | 715 | /* |
b5964405 | 716 | * Should be a barrier for any external CPU state: |
1da177e4 LT |
717 | */ |
718 | cpu_init(); | |
719 | ||
428cf902 | 720 | x86_init.irqs.trap_init(); |
228bdaa9 SR |
721 | |
722 | #ifdef CONFIG_X86_64 | |
723 | memcpy(&nmi_idt_table, &idt_table, IDT_ENTRIES * 16); | |
724 | set_nmi_gate(1, &debug); | |
725 | set_nmi_gate(3, &int3); | |
726 | #endif | |
1da177e4 | 727 | } |