Commit | Line | Data |
---|---|---|
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> |
91d1aa43 | 58 | #include <asm/context_tracking.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 | ||
c416ddf5 FW |
111 | static int __kprobes |
112 | do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, | |
113 | struct pt_regs *regs, long error_code) | |
1da177e4 | 114 | { |
081f75bb | 115 | #ifdef CONFIG_X86_32 |
6b6891f9 | 116 | if (regs->flags & X86_VM_MASK) { |
3c1326f8 | 117 | /* |
c416ddf5 | 118 | * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86. |
3c1326f8 AH |
119 | * On nmi (interrupt 2), do_trap should not be called. |
120 | */ | |
c416ddf5 FW |
121 | if (trapnr < X86_TRAP_UD) { |
122 | if (!handle_vm86_trap((struct kernel_vm86_regs *) regs, | |
123 | error_code, trapnr)) | |
124 | return 0; | |
125 | } | |
126 | return -1; | |
1da177e4 | 127 | } |
081f75bb | 128 | #endif |
c416ddf5 FW |
129 | if (!user_mode(regs)) { |
130 | if (!fixup_exception(regs)) { | |
131 | tsk->thread.error_code = error_code; | |
132 | tsk->thread.trap_nr = trapnr; | |
133 | die(str, regs, error_code); | |
134 | } | |
135 | return 0; | |
136 | } | |
1da177e4 | 137 | |
c416ddf5 FW |
138 | return -1; |
139 | } | |
1da177e4 | 140 | |
c416ddf5 FW |
141 | static void __kprobes |
142 | do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, | |
143 | long error_code, siginfo_t *info) | |
144 | { | |
145 | struct task_struct *tsk = current; | |
146 | ||
147 | ||
148 | if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code)) | |
149 | return; | |
b5964405 | 150 | /* |
51e7dc70 | 151 | * We want error_code and trap_nr set for userspace faults and |
b5964405 IM |
152 | * kernelspace faults which result in die(), but not |
153 | * kernelspace faults which are fixed up. die() gives the | |
154 | * process no chance to handle the signal and notice the | |
155 | * kernel fault information, so that won't result in polluting | |
156 | * the information about previously queued, but not yet | |
157 | * delivered, faults. See also do_general_protection below. | |
158 | */ | |
159 | tsk->thread.error_code = error_code; | |
51e7dc70 | 160 | tsk->thread.trap_nr = trapnr; |
d1895183 | 161 | |
081f75bb AH |
162 | #ifdef CONFIG_X86_64 |
163 | if (show_unhandled_signals && unhandled_signal(tsk, signr) && | |
164 | printk_ratelimit()) { | |
c767a54b JP |
165 | pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx", |
166 | tsk->comm, tsk->pid, str, | |
167 | regs->ip, regs->sp, error_code); | |
081f75bb | 168 | print_vma_addr(" in ", regs->ip); |
c767a54b | 169 | pr_cont("\n"); |
081f75bb AH |
170 | } |
171 | #endif | |
172 | ||
b5964405 IM |
173 | if (info) |
174 | force_sig_info(signr, info, tsk); | |
175 | else | |
176 | force_sig(signr, tsk); | |
1da177e4 LT |
177 | } |
178 | ||
b5964405 | 179 | #define DO_ERROR(trapnr, signr, str, name) \ |
e407d620 | 180 | dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ |
b5964405 | 181 | { \ |
6ba3c97a FW |
182 | exception_enter(regs); \ |
183 | if (notify_die(DIE_TRAP, str, regs, error_code, \ | |
184 | trapnr, signr) == NOTIFY_STOP) { \ | |
185 | exception_exit(regs); \ | |
b5964405 | 186 | return; \ |
6ba3c97a | 187 | } \ |
61aef7d2 | 188 | conditional_sti(regs); \ |
3c1326f8 | 189 | do_trap(trapnr, signr, str, regs, error_code, NULL); \ |
6ba3c97a | 190 | exception_exit(regs); \ |
1da177e4 LT |
191 | } |
192 | ||
3c1326f8 | 193 | #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ |
e407d620 | 194 | dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ |
b5964405 IM |
195 | { \ |
196 | siginfo_t info; \ | |
197 | info.si_signo = signr; \ | |
198 | info.si_errno = 0; \ | |
199 | info.si_code = sicode; \ | |
200 | info.si_addr = (void __user *)siaddr; \ | |
6ba3c97a FW |
201 | exception_enter(regs); \ |
202 | if (notify_die(DIE_TRAP, str, regs, error_code, \ | |
203 | trapnr, signr) == NOTIFY_STOP) { \ | |
204 | exception_exit(regs); \ | |
b5964405 | 205 | return; \ |
6ba3c97a | 206 | } \ |
61aef7d2 | 207 | conditional_sti(regs); \ |
3c1326f8 | 208 | do_trap(trapnr, signr, str, regs, error_code, &info); \ |
6ba3c97a | 209 | exception_exit(regs); \ |
1da177e4 LT |
210 | } |
211 | ||
c9408265 KC |
212 | DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV, |
213 | regs->ip) | |
214 | DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow) | |
215 | DO_ERROR(X86_TRAP_BR, SIGSEGV, "bounds", bounds) | |
216 | DO_ERROR_INFO(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, | |
217 | regs->ip) | |
218 | DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun", | |
219 | coprocessor_segment_overrun) | |
220 | DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS) | |
221 | DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present) | |
081f75bb | 222 | #ifdef CONFIG_X86_32 |
c9408265 | 223 | DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment) |
081f75bb | 224 | #endif |
c9408265 KC |
225 | DO_ERROR_INFO(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check, |
226 | BUS_ADRALN, 0) | |
1da177e4 | 227 | |
081f75bb AH |
228 | #ifdef CONFIG_X86_64 |
229 | /* Runs on IST stack */ | |
230 | dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code) | |
231 | { | |
6ba3c97a | 232 | exception_enter(regs); |
081f75bb | 233 | if (notify_die(DIE_TRAP, "stack segment", regs, error_code, |
6ba3c97a FW |
234 | X86_TRAP_SS, SIGBUS) != NOTIFY_STOP) { |
235 | preempt_conditional_sti(regs); | |
236 | do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL); | |
237 | preempt_conditional_cli(regs); | |
238 | } | |
239 | exception_exit(regs); | |
081f75bb AH |
240 | } |
241 | ||
242 | dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) | |
243 | { | |
244 | static const char str[] = "double fault"; | |
245 | struct task_struct *tsk = current; | |
246 | ||
6ba3c97a | 247 | exception_enter(regs); |
081f75bb | 248 | /* Return not checked because double check cannot be ignored */ |
c9408265 | 249 | notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); |
081f75bb AH |
250 | |
251 | tsk->thread.error_code = error_code; | |
51e7dc70 | 252 | tsk->thread.trap_nr = X86_TRAP_DF; |
081f75bb | 253 | |
bd8b96df IM |
254 | /* |
255 | * This is always a kernel trap and never fixable (and thus must | |
256 | * never return). | |
257 | */ | |
081f75bb AH |
258 | for (;;) |
259 | die(str, regs, error_code); | |
260 | } | |
261 | #endif | |
262 | ||
e407d620 | 263 | dotraplinkage void __kprobes |
13485ab5 | 264 | do_general_protection(struct pt_regs *regs, long error_code) |
1da177e4 | 265 | { |
13485ab5 | 266 | struct task_struct *tsk; |
b5964405 | 267 | |
6ba3c97a | 268 | exception_enter(regs); |
c6df0d71 AH |
269 | conditional_sti(regs); |
270 | ||
081f75bb | 271 | #ifdef CONFIG_X86_32 |
ef3f6288 FW |
272 | if (regs->flags & X86_VM_MASK) { |
273 | local_irq_enable(); | |
274 | handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); | |
6ba3c97a | 275 | goto exit; |
ef3f6288 | 276 | } |
081f75bb | 277 | #endif |
1da177e4 | 278 | |
13485ab5 | 279 | tsk = current; |
ef3f6288 FW |
280 | if (!user_mode(regs)) { |
281 | if (fixup_exception(regs)) | |
6ba3c97a | 282 | goto exit; |
ef3f6288 FW |
283 | |
284 | tsk->thread.error_code = error_code; | |
285 | tsk->thread.trap_nr = X86_TRAP_GP; | |
6ba3c97a FW |
286 | if (notify_die(DIE_GPF, "general protection fault", regs, error_code, |
287 | X86_TRAP_GP, SIGSEGV) != NOTIFY_STOP) | |
ef3f6288 | 288 | die("general protection fault", regs, error_code); |
6ba3c97a | 289 | goto exit; |
ef3f6288 | 290 | } |
1da177e4 | 291 | |
13485ab5 | 292 | tsk->thread.error_code = error_code; |
51e7dc70 | 293 | tsk->thread.trap_nr = X86_TRAP_GP; |
b5964405 | 294 | |
13485ab5 AH |
295 | if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && |
296 | printk_ratelimit()) { | |
c767a54b | 297 | pr_info("%s[%d] general protection ip:%lx sp:%lx error:%lx", |
13485ab5 AH |
298 | tsk->comm, task_pid_nr(tsk), |
299 | regs->ip, regs->sp, error_code); | |
03252919 | 300 | print_vma_addr(" in ", regs->ip); |
c767a54b | 301 | pr_cont("\n"); |
03252919 | 302 | } |
abd4f750 | 303 | |
13485ab5 | 304 | force_sig(SIGSEGV, tsk); |
6ba3c97a FW |
305 | exit: |
306 | exception_exit(regs); | |
1da177e4 LT |
307 | } |
308 | ||
c1d518c8 | 309 | /* May run on IST stack. */ |
08d636b6 | 310 | dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_code) |
1da177e4 | 311 | { |
08d636b6 | 312 | #ifdef CONFIG_DYNAMIC_FTRACE |
a192cd04 SR |
313 | /* |
314 | * ftrace must be first, everything else may cause a recursive crash. | |
315 | * See note by declaration of modifying_ftrace_code in ftrace.c | |
316 | */ | |
317 | if (unlikely(atomic_read(&modifying_ftrace_code)) && | |
318 | ftrace_int3_handler(regs)) | |
08d636b6 SR |
319 | return; |
320 | #endif | |
6ba3c97a | 321 | exception_enter(regs); |
f503b5ae | 322 | #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP |
c9408265 KC |
323 | if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, |
324 | SIGTRAP) == NOTIFY_STOP) | |
6ba3c97a | 325 | goto exit; |
f503b5ae | 326 | #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ |
cc3a1bf5 | 327 | |
c9408265 KC |
328 | if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, |
329 | SIGTRAP) == NOTIFY_STOP) | |
6ba3c97a | 330 | goto exit; |
b5964405 | 331 | |
42181186 SR |
332 | /* |
333 | * Let others (NMI) know that the debug stack is in use | |
334 | * as we may switch to the interrupt stack. | |
335 | */ | |
336 | debug_stack_usage_inc(); | |
4915a35e | 337 | preempt_conditional_sti(regs); |
c9408265 | 338 | do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL); |
4915a35e | 339 | preempt_conditional_cli(regs); |
42181186 | 340 | debug_stack_usage_dec(); |
6ba3c97a FW |
341 | exit: |
342 | exception_exit(regs); | |
1da177e4 | 343 | } |
1da177e4 | 344 | |
081f75bb | 345 | #ifdef CONFIG_X86_64 |
bd8b96df IM |
346 | /* |
347 | * Help handler running on IST stack to switch back to user stack | |
348 | * for scheduling or signal handling. The actual stack switch is done in | |
349 | * entry.S | |
350 | */ | |
081f75bb AH |
351 | asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) |
352 | { | |
353 | struct pt_regs *regs = eregs; | |
354 | /* Did already sync */ | |
355 | if (eregs == (struct pt_regs *)eregs->sp) | |
356 | ; | |
357 | /* Exception from user space */ | |
358 | else if (user_mode(eregs)) | |
359 | regs = task_pt_regs(current); | |
bd8b96df IM |
360 | /* |
361 | * Exception from kernel and interrupts are enabled. Move to | |
362 | * kernel process stack. | |
363 | */ | |
081f75bb AH |
364 | else if (eregs->flags & X86_EFLAGS_IF) |
365 | regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs)); | |
366 | if (eregs != regs) | |
367 | *regs = *eregs; | |
368 | return regs; | |
369 | } | |
370 | #endif | |
371 | ||
1da177e4 LT |
372 | /* |
373 | * Our handling of the processor debug registers is non-trivial. | |
374 | * We do not clear them on entry and exit from the kernel. Therefore | |
375 | * it is possible to get a watchpoint trap here from inside the kernel. | |
376 | * However, the code in ./ptrace.c has ensured that the user can | |
377 | * only set watchpoints on userspace addresses. Therefore the in-kernel | |
378 | * watchpoint trap can only occur in code which is reading/writing | |
379 | * from user space. Such code must not hold kernel locks (since it | |
380 | * can equally take a page fault), therefore it is safe to call | |
381 | * force_sig_info even though that claims and releases locks. | |
b5964405 | 382 | * |
1da177e4 LT |
383 | * Code in ./signal.c ensures that the debug control register |
384 | * is restored before we deliver any signal, and therefore that | |
385 | * user code runs with the correct debug control register even though | |
386 | * we clear it here. | |
387 | * | |
388 | * Being careful here means that we don't have to be as careful in a | |
389 | * lot of more complicated places (task switching can be a bit lazy | |
390 | * about restoring all the debug state, and ptrace doesn't have to | |
391 | * find every occurrence of the TF bit that could be saved away even | |
392 | * by user code) | |
c1d518c8 AH |
393 | * |
394 | * May run on IST stack. | |
1da177e4 | 395 | */ |
e407d620 | 396 | dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) |
1da177e4 | 397 | { |
1da177e4 | 398 | struct task_struct *tsk = current; |
a1e80faf | 399 | int user_icebp = 0; |
08d68323 | 400 | unsigned long dr6; |
da654b74 | 401 | int si_code; |
1da177e4 | 402 | |
6ba3c97a FW |
403 | exception_enter(regs); |
404 | ||
08d68323 | 405 | get_debugreg(dr6, 6); |
1da177e4 | 406 | |
40f9249a P |
407 | /* Filter out all the reserved bits which are preset to 1 */ |
408 | dr6 &= ~DR6_RESERVED; | |
409 | ||
a1e80faf FW |
410 | /* |
411 | * If dr6 has no reason to give us about the origin of this trap, | |
412 | * then it's very likely the result of an icebp/int01 trap. | |
413 | * User wants a sigtrap for that. | |
414 | */ | |
415 | if (!dr6 && user_mode(regs)) | |
416 | user_icebp = 1; | |
417 | ||
f8561296 | 418 | /* Catch kmemcheck conditions first of all! */ |
eadb8a09 | 419 | if ((dr6 & DR_STEP) && kmemcheck_trap(regs)) |
6ba3c97a | 420 | goto exit; |
f8561296 | 421 | |
08d68323 P |
422 | /* DR6 may or may not be cleared by the CPU */ |
423 | set_debugreg(0, 6); | |
10faa81e | 424 | |
ea8e61b7 PZ |
425 | /* |
426 | * The processor cleared BTF, so don't mark that we need it set. | |
427 | */ | |
428 | clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP); | |
429 | ||
08d68323 P |
430 | /* Store the virtualized DR6 value */ |
431 | tsk->thread.debugreg6 = dr6; | |
432 | ||
62edab90 P |
433 | if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code, |
434 | SIGTRAP) == NOTIFY_STOP) | |
6ba3c97a | 435 | goto exit; |
3d2a71a5 | 436 | |
42181186 SR |
437 | /* |
438 | * Let others (NMI) know that the debug stack is in use | |
439 | * as we may switch to the interrupt stack. | |
440 | */ | |
441 | debug_stack_usage_inc(); | |
442 | ||
1da177e4 | 443 | /* It's safe to allow irq's after DR6 has been saved */ |
3d2a71a5 | 444 | preempt_conditional_sti(regs); |
1da177e4 | 445 | |
08d68323 | 446 | if (regs->flags & X86_VM_MASK) { |
c9408265 KC |
447 | handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, |
448 | X86_TRAP_DB); | |
6554287b | 449 | preempt_conditional_cli(regs); |
42181186 | 450 | debug_stack_usage_dec(); |
6ba3c97a | 451 | goto exit; |
1da177e4 LT |
452 | } |
453 | ||
1da177e4 | 454 | /* |
08d68323 P |
455 | * Single-stepping through system calls: ignore any exceptions in |
456 | * kernel space, but re-enable TF when returning to user mode. | |
457 | * | |
458 | * We already checked v86 mode above, so we can check for kernel mode | |
459 | * by just checking the CPL of CS. | |
1da177e4 | 460 | */ |
08d68323 P |
461 | if ((dr6 & DR_STEP) && !user_mode(regs)) { |
462 | tsk->thread.debugreg6 &= ~DR_STEP; | |
463 | set_tsk_thread_flag(tsk, TIF_SINGLESTEP); | |
464 | regs->flags &= ~X86_EFLAGS_TF; | |
1da177e4 | 465 | } |
08d68323 | 466 | si_code = get_si_code(tsk->thread.debugreg6); |
a1e80faf | 467 | if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp) |
08d68323 | 468 | send_sigtrap(tsk, regs, error_code, si_code); |
3d2a71a5 | 469 | preempt_conditional_cli(regs); |
42181186 | 470 | debug_stack_usage_dec(); |
1da177e4 | 471 | |
6ba3c97a FW |
472 | exit: |
473 | exception_exit(regs); | |
1da177e4 LT |
474 | } |
475 | ||
476 | /* | |
477 | * Note that we play around with the 'TS' bit in an attempt to get | |
478 | * the correct behaviour even in the presence of the asynchronous | |
479 | * IRQ13 behaviour | |
480 | */ | |
9b6dba9e | 481 | void math_error(struct pt_regs *regs, int error_code, int trapnr) |
1da177e4 | 482 | { |
e2e75c91 | 483 | struct task_struct *task = current; |
1da177e4 | 484 | siginfo_t info; |
9b6dba9e | 485 | unsigned short err; |
c9408265 KC |
486 | char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" : |
487 | "simd exception"; | |
e2e75c91 BG |
488 | |
489 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP) | |
490 | return; | |
491 | conditional_sti(regs); | |
492 | ||
493 | if (!user_mode_vm(regs)) | |
494 | { | |
495 | if (!fixup_exception(regs)) { | |
496 | task->thread.error_code = error_code; | |
51e7dc70 | 497 | task->thread.trap_nr = trapnr; |
e2e75c91 BG |
498 | die(str, regs, error_code); |
499 | } | |
500 | return; | |
501 | } | |
1da177e4 LT |
502 | |
503 | /* | |
504 | * Save the info for the exception handler and clear the error. | |
505 | */ | |
1da177e4 | 506 | save_init_fpu(task); |
51e7dc70 | 507 | task->thread.trap_nr = trapnr; |
9b6dba9e | 508 | task->thread.error_code = error_code; |
1da177e4 LT |
509 | info.si_signo = SIGFPE; |
510 | info.si_errno = 0; | |
9b6dba9e | 511 | info.si_addr = (void __user *)regs->ip; |
c9408265 | 512 | if (trapnr == X86_TRAP_MF) { |
9b6dba9e BG |
513 | unsigned short cwd, swd; |
514 | /* | |
515 | * (~cwd & swd) will mask out exceptions that are not set to unmasked | |
516 | * status. 0x3f is the exception bits in these regs, 0x200 is the | |
517 | * C1 reg you need in case of a stack fault, 0x040 is the stack | |
518 | * fault bit. We should only be taking one exception at a time, | |
519 | * so if this combination doesn't produce any single exception, | |
520 | * then we have a bad program that isn't synchronizing its FPU usage | |
521 | * and it will suffer the consequences since we won't be able to | |
522 | * fully reproduce the context of the exception | |
523 | */ | |
524 | cwd = get_fpu_cwd(task); | |
525 | swd = get_fpu_swd(task); | |
adf77bac | 526 | |
9b6dba9e BG |
527 | err = swd & ~cwd; |
528 | } else { | |
529 | /* | |
530 | * The SIMD FPU exceptions are handled a little differently, as there | |
531 | * is only a single status/control register. Thus, to determine which | |
532 | * unmasked exception was caught we must mask the exception mask bits | |
533 | * at 0x1f80, and then use these to mask the exception bits at 0x3f. | |
534 | */ | |
535 | unsigned short mxcsr = get_fpu_mxcsr(task); | |
536 | err = ~(mxcsr >> 7) & mxcsr; | |
537 | } | |
adf77bac PA |
538 | |
539 | if (err & 0x001) { /* Invalid op */ | |
b5964405 IM |
540 | /* |
541 | * swd & 0x240 == 0x040: Stack Underflow | |
542 | * swd & 0x240 == 0x240: Stack Overflow | |
543 | * User must clear the SF bit (0x40) if set | |
544 | */ | |
545 | info.si_code = FPE_FLTINV; | |
adf77bac | 546 | } else if (err & 0x004) { /* Divide by Zero */ |
b5964405 | 547 | info.si_code = FPE_FLTDIV; |
adf77bac | 548 | } else if (err & 0x008) { /* Overflow */ |
b5964405 | 549 | info.si_code = FPE_FLTOVF; |
adf77bac PA |
550 | } else if (err & 0x012) { /* Denormal, Underflow */ |
551 | info.si_code = FPE_FLTUND; | |
552 | } else if (err & 0x020) { /* Precision */ | |
b5964405 | 553 | info.si_code = FPE_FLTRES; |
adf77bac | 554 | } else { |
bd8b96df | 555 | /* |
c9408265 KC |
556 | * If we're using IRQ 13, or supposedly even some trap |
557 | * X86_TRAP_MF implementations, it's possible | |
558 | * we get a spurious trap, which is not an error. | |
bd8b96df | 559 | */ |
c9408265 | 560 | return; |
1da177e4 LT |
561 | } |
562 | force_sig_info(SIGFPE, &info, task); | |
563 | } | |
564 | ||
e407d620 | 565 | dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) |
1da177e4 | 566 | { |
081f75bb | 567 | #ifdef CONFIG_X86_32 |
1da177e4 | 568 | ignore_fpu_irq = 1; |
081f75bb | 569 | #endif |
6ba3c97a | 570 | exception_enter(regs); |
c9408265 | 571 | math_error(regs, error_code, X86_TRAP_MF); |
6ba3c97a | 572 | exception_exit(regs); |
1da177e4 LT |
573 | } |
574 | ||
e407d620 AH |
575 | dotraplinkage void |
576 | do_simd_coprocessor_error(struct pt_regs *regs, long error_code) | |
1da177e4 | 577 | { |
6ba3c97a | 578 | exception_enter(regs); |
c9408265 | 579 | math_error(regs, error_code, X86_TRAP_XF); |
6ba3c97a | 580 | exception_exit(regs); |
1da177e4 LT |
581 | } |
582 | ||
e407d620 AH |
583 | dotraplinkage void |
584 | do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) | |
1da177e4 | 585 | { |
cf81978d | 586 | conditional_sti(regs); |
1da177e4 LT |
587 | #if 0 |
588 | /* No need to warn about this any longer. */ | |
c767a54b | 589 | pr_info("Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); |
1da177e4 LT |
590 | #endif |
591 | } | |
592 | ||
081f75bb | 593 | asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) |
1da177e4 | 594 | { |
1da177e4 | 595 | } |
4efc0670 | 596 | |
7856f6cc | 597 | asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void) |
081f75bb AH |
598 | { |
599 | } | |
600 | ||
1da177e4 | 601 | /* |
b5964405 | 602 | * 'math_state_restore()' saves the current math information in the |
1da177e4 LT |
603 | * old math state array, and gets the new ones from the current task |
604 | * | |
605 | * Careful.. There are problems with IBM-designed IRQ13 behaviour. | |
606 | * Don't touch unless you *really* know how it works. | |
607 | * | |
be98c2cd LT |
608 | * Must be called with kernel preemption disabled (eg with local |
609 | * local interrupts as in the case of do_device_not_available). | |
1da177e4 | 610 | */ |
be98c2cd | 611 | void math_state_restore(void) |
1da177e4 | 612 | { |
f94edacf | 613 | struct task_struct *tsk = current; |
1da177e4 | 614 | |
aa283f49 SS |
615 | if (!tsk_used_math(tsk)) { |
616 | local_irq_enable(); | |
617 | /* | |
618 | * does a slab alloc which can sleep | |
619 | */ | |
620 | if (init_fpu(tsk)) { | |
621 | /* | |
622 | * ran out of memory! | |
623 | */ | |
624 | do_group_exit(SIGKILL); | |
625 | return; | |
626 | } | |
627 | local_irq_disable(); | |
628 | } | |
629 | ||
f94edacf | 630 | __thread_fpu_begin(tsk); |
304bceda | 631 | |
80ab6f1e LT |
632 | /* |
633 | * Paranoid restore. send a SIGSEGV if we fail to restore the state. | |
634 | */ | |
635 | if (unlikely(restore_fpu_checking(tsk))) { | |
304bceda | 636 | drop_init_fpu(tsk); |
80ab6f1e LT |
637 | force_sig(SIGSEGV, tsk); |
638 | return; | |
639 | } | |
b3b0870e LT |
640 | |
641 | tsk->fpu_counter++; | |
1da177e4 | 642 | } |
5992b6da | 643 | EXPORT_SYMBOL_GPL(math_state_restore); |
1da177e4 | 644 | |
e407d620 | 645 | dotraplinkage void __kprobes |
aa78bcfa | 646 | do_device_not_available(struct pt_regs *regs, long error_code) |
7643e9b9 | 647 | { |
6ba3c97a | 648 | exception_enter(regs); |
5d2bd700 | 649 | BUG_ON(use_eager_fpu()); |
304bceda | 650 | |
a334fe43 | 651 | #ifdef CONFIG_MATH_EMULATION |
7643e9b9 | 652 | if (read_cr0() & X86_CR0_EM) { |
d315760f TH |
653 | struct math_emu_info info = { }; |
654 | ||
7643e9b9 | 655 | conditional_sti(regs); |
d315760f | 656 | |
aa78bcfa | 657 | info.regs = regs; |
d315760f | 658 | math_emulate(&info); |
6ba3c97a | 659 | exception_exit(regs); |
a334fe43 | 660 | return; |
7643e9b9 | 661 | } |
a334fe43 BG |
662 | #endif |
663 | math_state_restore(); /* interrupts still off */ | |
664 | #ifdef CONFIG_X86_32 | |
665 | conditional_sti(regs); | |
081f75bb | 666 | #endif |
6ba3c97a | 667 | exception_exit(regs); |
7643e9b9 AH |
668 | } |
669 | ||
081f75bb | 670 | #ifdef CONFIG_X86_32 |
e407d620 | 671 | dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) |
f8e0870f AH |
672 | { |
673 | siginfo_t info; | |
6ba3c97a FW |
674 | |
675 | exception_enter(regs); | |
f8e0870f AH |
676 | local_irq_enable(); |
677 | ||
678 | info.si_signo = SIGILL; | |
679 | info.si_errno = 0; | |
680 | info.si_code = ILL_BADSTK; | |
fc6fcdfb | 681 | info.si_addr = NULL; |
c9408265 | 682 | if (notify_die(DIE_TRAP, "iret exception", regs, error_code, |
6ba3c97a FW |
683 | X86_TRAP_IRET, SIGILL) != NOTIFY_STOP) { |
684 | do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code, | |
685 | &info); | |
686 | } | |
687 | exception_exit(regs); | |
f8e0870f | 688 | } |
081f75bb | 689 | #endif |
f8e0870f | 690 | |
29c84391 JK |
691 | /* Set of traps needed for early debugging. */ |
692 | void __init early_trap_init(void) | |
693 | { | |
c9408265 | 694 | set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK); |
29c84391 | 695 | /* int3 can be called from all */ |
c9408265 KC |
696 | set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK); |
697 | set_intr_gate(X86_TRAP_PF, &page_fault); | |
29c84391 JK |
698 | load_idt(&idt_descr); |
699 | } | |
700 | ||
1da177e4 LT |
701 | void __init trap_init(void) |
702 | { | |
dbeb2be2 RR |
703 | int i; |
704 | ||
1da177e4 | 705 | #ifdef CONFIG_EISA |
927222b1 | 706 | void __iomem *p = early_ioremap(0x0FFFD9, 4); |
b5964405 IM |
707 | |
708 | if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24)) | |
1da177e4 | 709 | EISA_bus = 1; |
927222b1 | 710 | early_iounmap(p, 4); |
1da177e4 LT |
711 | #endif |
712 | ||
c9408265 KC |
713 | set_intr_gate(X86_TRAP_DE, ÷_error); |
714 | set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK); | |
699d2937 | 715 | /* int4 can be called from all */ |
c9408265 KC |
716 | set_system_intr_gate(X86_TRAP_OF, &overflow); |
717 | set_intr_gate(X86_TRAP_BR, &bounds); | |
718 | set_intr_gate(X86_TRAP_UD, &invalid_op); | |
719 | set_intr_gate(X86_TRAP_NM, &device_not_available); | |
081f75bb | 720 | #ifdef CONFIG_X86_32 |
c9408265 | 721 | set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS); |
081f75bb | 722 | #else |
c9408265 | 723 | set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK); |
081f75bb | 724 | #endif |
c9408265 KC |
725 | set_intr_gate(X86_TRAP_OLD_MF, &coprocessor_segment_overrun); |
726 | set_intr_gate(X86_TRAP_TS, &invalid_TSS); | |
727 | set_intr_gate(X86_TRAP_NP, &segment_not_present); | |
728 | set_intr_gate_ist(X86_TRAP_SS, &stack_segment, STACKFAULT_STACK); | |
729 | set_intr_gate(X86_TRAP_GP, &general_protection); | |
730 | set_intr_gate(X86_TRAP_SPURIOUS, &spurious_interrupt_bug); | |
731 | set_intr_gate(X86_TRAP_MF, &coprocessor_error); | |
732 | set_intr_gate(X86_TRAP_AC, &alignment_check); | |
1da177e4 | 733 | #ifdef CONFIG_X86_MCE |
c9408265 | 734 | set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK); |
1da177e4 | 735 | #endif |
c9408265 | 736 | set_intr_gate(X86_TRAP_XF, &simd_coprocessor_error); |
1da177e4 | 737 | |
bb3f0b59 YL |
738 | /* Reserve all the builtin and the syscall vector: */ |
739 | for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) | |
740 | set_bit(i, used_vectors); | |
741 | ||
081f75bb AH |
742 | #ifdef CONFIG_IA32_EMULATION |
743 | set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall); | |
bb3f0b59 | 744 | set_bit(IA32_SYSCALL_VECTOR, used_vectors); |
081f75bb AH |
745 | #endif |
746 | ||
747 | #ifdef CONFIG_X86_32 | |
699d2937 | 748 | set_system_trap_gate(SYSCALL_VECTOR, &system_call); |
dbeb2be2 | 749 | set_bit(SYSCALL_VECTOR, used_vectors); |
081f75bb | 750 | #endif |
bb3f0b59 | 751 | |
1da177e4 | 752 | /* |
b5964405 | 753 | * Should be a barrier for any external CPU state: |
1da177e4 LT |
754 | */ |
755 | cpu_init(); | |
756 | ||
428cf902 | 757 | x86_init.irqs.trap_init(); |
228bdaa9 SR |
758 | |
759 | #ifdef CONFIG_X86_64 | |
760 | memcpy(&nmi_idt_table, &idt_table, IDT_ENTRIES * 16); | |
c9408265 KC |
761 | set_nmi_gate(X86_TRAP_DB, &debug); |
762 | set_nmi_gate(X86_TRAP_BP, &int3); | |
228bdaa9 | 763 | #endif |
1da177e4 | 764 | } |