| blob | 7b784f4ef1e483876ad98e432283d1ba82c890a1 |
1 /*
2 *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 */
6 /*
7 * entry.S contains the system-call and fault low-level handling routines.
8 * This also contains the timer-interrupt handler, as well as all interrupts
9 * and faults that can result in a task-switch.
10 *
11 * NOTE: This code handles signal-recognition, which happens every time
12 * after a timer-interrupt and after each system call.
13 *
14 * I changed all the .align's to 4 (16 byte alignment), as that's faster
15 * on a 486.
16 *
17 * Stack layout in 'syscall_exit':
18 * ptrace needs to have all regs on the stack.
19 * if the order here is changed, it needs to be
20 * updated in fork.c:copy_process, signal.c:do_signal,
21 * ptrace.c and ptrace.h
22 *
23 * 0(%esp) - %ebx
24 * 4(%esp) - %ecx
25 * 8(%esp) - %edx
26 * C(%esp) - %esi
27 * 10(%esp) - %edi
28 * 14(%esp) - %ebp
29 * 18(%esp) - %eax
30 * 1C(%esp) - %ds
31 * 20(%esp) - %es
32 * 24(%esp) - %fs
33 * 28(%esp) - %gs saved iff !CONFIG_X86_32_LAZY_GS
34 * 2C(%esp) - orig_eax
35 * 30(%esp) - %eip
36 * 34(%esp) - %cs
37 * 38(%esp) - %eflags
38 * 3C(%esp) - %oldesp
39 * 40(%esp) - %oldss
40 *
41 * "current" is in register %ebx during any slow entries.
42 */
44 #include <linux/linkage.h>
45 #include <linux/err.h>
46 #include <asm/thread_info.h>
47 #include <asm/irqflags.h>
48 #include <asm/errno.h>
49 #include <asm/segment.h>
50 #include <asm/smp.h>
51 #include <asm/page_types.h>
52 #include <asm/percpu.h>
53 #include <asm/dwarf2.h>
54 #include <asm/processor-flags.h>
55 #include <asm/ftrace.h>
56 #include <asm/irq_vectors.h>
57 #include <asm/cpufeature.h>
58 #include <asm/alternative-asm.h>
60 /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
61 #include <linux/elf-em.h>
62 #define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE)
63 #define __AUDIT_ARCH_LE 0x40000000
65 #ifndef CONFIG_AUDITSYSCALL
66 #define sysenter_audit syscall_trace_entry
67 #define sysexit_audit syscall_exit_work
68 #endif
70 .section .entry.text, "ax"
72 /*
73 * We use macros for low-level operations which need to be overridden
74 * for paravirtualization. The following will never clobber any registers:
75 * INTERRUPT_RETURN (aka. "iret")
76 * GET_CR0_INTO_EAX (aka. "movl %cr0, %eax")
77 * ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit").
78 *
79 * For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must
80 * specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY).
81 * Allowing a register to be clobbered can shrink the paravirt replacement
82 * enough to patch inline, increasing performance.
83 */
85 #ifdef CONFIG_PREEMPT
86 #define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
87 #else
88 #define preempt_stop(clobbers)
89 #define resume_kernel restore_all
90 #endif
92 .macro TRACE_IRQS_IRET
93 #ifdef CONFIG_TRACE_IRQFLAGS
94 testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off?
95 jz 1f
96 TRACE_IRQS_ON
97 1:
98 #endif
99 .endm
101 /*
102 * User gs save/restore
103 *
104 * %gs is used for userland TLS and kernel only uses it for stack
105 * canary which is required to be at %gs:20 by gcc. Read the comment
106 * at the top of stackprotector.h for more info.
107 *
108 * Local labels 98 and 99 are used.
109 */
110 #ifdef CONFIG_X86_32_LAZY_GS
112 /* unfortunately push/pop can't be no-op */
113 .macro PUSH_GS
114 pushl_cfi $0
115 .endm
116 .macro POP_GS pop=0
117 addl $(4 + \pop), %esp
118 CFI_ADJUST_CFA_OFFSET -(4 + \pop)
119 .endm
120 .macro POP_GS_EX
121 .endm
123 /* all the rest are no-op */
124 .macro PTGS_TO_GS
125 .endm
126 .macro PTGS_TO_GS_EX
127 .endm
128 .macro GS_TO_REG reg
129 .endm
130 .macro REG_TO_PTGS reg
131 .endm
132 .macro SET_KERNEL_GS reg
133 .endm
135 #else /* CONFIG_X86_32_LAZY_GS */
137 .macro PUSH_GS
138 pushl_cfi %gs
139 /*CFI_REL_OFFSET gs, 0*/
140 .endm
142 .macro POP_GS pop=0
143 98: popl_cfi %gs
144 /*CFI_RESTORE gs*/
145 .if \pop <> 0
146 add $\pop, %esp
147 CFI_ADJUST_CFA_OFFSET -\pop
148 .endif
149 .endm
150 .macro POP_GS_EX
151 .pushsection .fixup, "ax"
152 99: movl $0, (%esp)
153 jmp 98b
154 .section __ex_table, "a"
155 .align 4
156 .long 98b, 99b
157 .popsection
158 .endm
160 .macro PTGS_TO_GS
161 98: mov PT_GS(%esp), %gs
162 .endm
163 .macro PTGS_TO_GS_EX
164 .pushsection .fixup, "ax"
165 99: movl $0, PT_GS(%esp)
166 jmp 98b
167 .section __ex_table, "a"
168 .align 4
169 .long 98b, 99b
170 .popsection
171 .endm
173 .macro GS_TO_REG reg
174 movl %gs, \reg
175 /*CFI_REGISTER gs, \reg*/
176 .endm
177 .macro REG_TO_PTGS reg
178 movl \reg, PT_GS(%esp)
179 /*CFI_REL_OFFSET gs, PT_GS*/
180 .endm
181 .macro SET_KERNEL_GS reg
182 movl $(__KERNEL_STACK_CANARY), \reg
183 movl \reg, %gs
184 .endm
186 #endif /* CONFIG_X86_32_LAZY_GS */
188 .macro SAVE_ALL
189 cld
190 PUSH_GS
191 pushl_cfi %fs
192 /*CFI_REL_OFFSET fs, 0;*/
193 pushl_cfi %es
194 /*CFI_REL_OFFSET es, 0;*/
195 pushl_cfi %ds
196 /*CFI_REL_OFFSET ds, 0;*/
197 pushl_cfi %eax
198 CFI_REL_OFFSET eax, 0
199 pushl_cfi %ebp
200 CFI_REL_OFFSET ebp, 0
201 pushl_cfi %edi
202 CFI_REL_OFFSET edi, 0
203 pushl_cfi %esi
204 CFI_REL_OFFSET esi, 0
205 pushl_cfi %edx
206 CFI_REL_OFFSET edx, 0
207 pushl_cfi %ecx
208 CFI_REL_OFFSET ecx, 0
209 pushl_cfi %ebx
210 CFI_REL_OFFSET ebx, 0
211 movl $(__USER_DS), %edx
212 movl %edx, %ds
213 movl %edx, %es
214 movl $(__KERNEL_PERCPU), %edx
215 movl %edx, %fs
216 SET_KERNEL_GS %edx
217 .endm
219 .macro RESTORE_INT_REGS
220 popl_cfi %ebx
221 CFI_RESTORE ebx
222 popl_cfi %ecx
223 CFI_RESTORE ecx
224 popl_cfi %edx
225 CFI_RESTORE edx
226 popl_cfi %esi
227 CFI_RESTORE esi
228 popl_cfi %edi
229 CFI_RESTORE edi
230 popl_cfi %ebp
231 CFI_RESTORE ebp
232 popl_cfi %eax
233 CFI_RESTORE eax
234 .endm
236 .macro RESTORE_REGS pop=0
237 RESTORE_INT_REGS
238 1: popl_cfi %ds
239 /*CFI_RESTORE ds;*/
240 2: popl_cfi %es
241 /*CFI_RESTORE es;*/
242 3: popl_cfi %fs
243 /*CFI_RESTORE fs;*/
244 POP_GS \pop
245 .pushsection .fixup, "ax"
246 4: movl $0, (%esp)
247 jmp 1b
248 5: movl $0, (%esp)
249 jmp 2b
250 6: movl $0, (%esp)
251 jmp 3b
252 .section __ex_table, "a"
253 .align 4
254 .long 1b, 4b
255 .long 2b, 5b
256 .long 3b, 6b
257 .popsection
258 POP_GS_EX
259 .endm
261 .macro RING0_INT_FRAME
262 CFI_STARTPROC simple
263 CFI_SIGNAL_FRAME
264 CFI_DEF_CFA esp, 3*4
265 /*CFI_OFFSET cs, -2*4;*/
266 CFI_OFFSET eip, -3*4
267 .endm
269 .macro RING0_EC_FRAME
270 CFI_STARTPROC simple
271 CFI_SIGNAL_FRAME
272 CFI_DEF_CFA esp, 4*4
273 /*CFI_OFFSET cs, -2*4;*/
274 CFI_OFFSET eip, -3*4
275 .endm
277 .macro RING0_PTREGS_FRAME
278 CFI_STARTPROC simple
279 CFI_SIGNAL_FRAME
280 CFI_DEF_CFA esp, PT_OLDESP-PT_EBX
281 /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/
282 CFI_OFFSET eip, PT_EIP-PT_OLDESP
283 /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/
284 /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/
285 CFI_OFFSET eax, PT_EAX-PT_OLDESP
286 CFI_OFFSET ebp, PT_EBP-PT_OLDESP
287 CFI_OFFSET edi, PT_EDI-PT_OLDESP
288 CFI_OFFSET esi, PT_ESI-PT_OLDESP
289 CFI_OFFSET edx, PT_EDX-PT_OLDESP
290 CFI_OFFSET ecx, PT_ECX-PT_OLDESP
291 CFI_OFFSET ebx, PT_EBX-PT_OLDESP
292 .endm
294 ENTRY(ret_from_fork)
295 CFI_STARTPROC
296 pushl_cfi %eax
297 call schedule_tail
298 GET_THREAD_INFO(%ebp)
299 popl_cfi %eax
300 pushl_cfi $0x0202 # Reset kernel eflags
301 popfl_cfi
302 jmp syscall_exit
303 CFI_ENDPROC
304 END(ret_from_fork)
306 /*
307 * Interrupt exit functions should be protected against kprobes
308 */
309 .pushsection .kprobes.text, "ax"
310 /*
311 * Return to user mode is not as complex as all this looks,
312 * but we want the default path for a system call return to
313 * go as quickly as possible which is why some of this is
314 * less clear than it otherwise should be.
315 */
317 # userspace resumption stub bypassing syscall exit tracing
318 ALIGN
319 RING0_PTREGS_FRAME
320 ret_from_exception:
321 preempt_stop(CLBR_ANY)
322 ret_from_intr:
323 GET_THREAD_INFO(%ebp)
324 resume_userspace_sig:
325 #ifdef CONFIG_VM86
326 movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS
327 movb PT_CS(%esp), %al
328 andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax
329 #else
330 /*
331 * We can be coming here from a syscall done in the kernel space,
332 * e.g. a failed kernel_execve().
333 */
334 movl PT_CS(%esp), %eax
335 andl $SEGMENT_RPL_MASK, %eax
336 #endif
337 cmpl $USER_RPL, %eax
338 jb resume_kernel # not returning to v8086 or userspace
340 ENTRY(resume_userspace)
341 LOCKDEP_SYS_EXIT
342 DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
343 # setting need_resched or sigpending
344 # between sampling and the iret
345 TRACE_IRQS_OFF
346 movl TI_flags(%ebp), %ecx
347 andl $_TIF_WORK_MASK, %ecx # is there any work to be done on
348 # int/exception return?
349 jne work_pending
350 jmp restore_all
351 END(ret_from_exception)
353 #ifdef CONFIG_PREEMPT
354 ENTRY(resume_kernel)
355 DISABLE_INTERRUPTS(CLBR_ANY)
356 cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
357 jnz restore_all
358 need_resched:
359 movl TI_flags(%ebp), %ecx # need_resched set ?
360 testb $_TIF_NEED_RESCHED, %cl
361 jz restore_all
362 testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ?
363 jz restore_all
364 call preempt_schedule_irq
365 jmp need_resched
366 END(resume_kernel)
367 #endif
368 CFI_ENDPROC
369 /*
370 * End of kprobes section
371 */
372 .popsection
374 /* SYSENTER_RETURN points to after the "sysenter" instruction in
375 the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */
377 # sysenter call handler stub
378 ENTRY(ia32_sysenter_target)
379 CFI_STARTPROC simple
380 CFI_SIGNAL_FRAME
381 CFI_DEF_CFA esp, 0
382 CFI_REGISTER esp, ebp
383 movl TSS_sysenter_sp0(%esp),%esp
384 sysenter_past_esp:
385 /*
386 * Interrupts are disabled here, but we can't trace it until
387 * enough kernel state to call TRACE_IRQS_OFF can be called - but
388 * we immediately enable interrupts at that point anyway.
389 */
390 pushl_cfi $__USER_DS
391 /*CFI_REL_OFFSET ss, 0*/
392 pushl_cfi %ebp
393 CFI_REL_OFFSET esp, 0
394 pushfl_cfi
395 orl $X86_EFLAGS_IF, (%esp)
396 pushl_cfi $__USER_CS
397 /*CFI_REL_OFFSET cs, 0*/
398 /*
399 * Push current_thread_info()->sysenter_return to the stack.
400 * A tiny bit of offset fixup is necessary - 4*4 means the 4 words
401 * pushed above; +8 corresponds to copy_thread's esp0 setting.
402 */
403 pushl_cfi ((TI_sysenter_return)-THREAD_SIZE+8+4*4)(%esp)
404 CFI_REL_OFFSET eip, 0
406 pushl_cfi %eax
407 SAVE_ALL
408 ENABLE_INTERRUPTS(CLBR_NONE)
410 /*
411 * Load the potential sixth argument from user stack.
412 * Careful about security.
413 */
414 cmpl $__PAGE_OFFSET-3,%ebp
415 jae syscall_fault
416 1: movl (%ebp),%ebp
417 movl %ebp,PT_EBP(%esp)
418 .section __ex_table,"a"
419 .align 4
420 .long 1b,syscall_fault
421 .previous
423 GET_THREAD_INFO(%ebp)
425 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp)
426 jnz sysenter_audit
427 sysenter_do_call:
428 cmpl $(NR_syscalls), %eax
429 jae syscall_badsys
430 call *sys_call_table(,%eax,4)
431 movl %eax,PT_EAX(%esp)
432 LOCKDEP_SYS_EXIT
433 DISABLE_INTERRUPTS(CLBR_ANY)
434 TRACE_IRQS_OFF
435 movl TI_flags(%ebp), %ecx
436 testl $_TIF_ALLWORK_MASK, %ecx
437 jne sysexit_audit
438 sysenter_exit:
439 /* if something modifies registers it must also disable sysexit */
440 movl PT_EIP(%esp), %edx
441 movl PT_OLDESP(%esp), %ecx
442 xorl %ebp,%ebp
443 TRACE_IRQS_ON
444 1: mov PT_FS(%esp), %fs
445 PTGS_TO_GS
446 ENABLE_INTERRUPTS_SYSEXIT
448 #ifdef CONFIG_AUDITSYSCALL
449 sysenter_audit:
450 testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
451 jnz syscall_trace_entry
452 addl $4,%esp
453 CFI_ADJUST_CFA_OFFSET -4
454 /* %esi already in 8(%esp) 6th arg: 4th syscall arg */
455 /* %edx already in 4(%esp) 5th arg: 3rd syscall arg */
456 /* %ecx already in 0(%esp) 4th arg: 2nd syscall arg */
457 movl %ebx,%ecx /* 3rd arg: 1st syscall arg */
458 movl %eax,%edx /* 2nd arg: syscall number */
459 movl $AUDIT_ARCH_I386,%eax /* 1st arg: audit arch */
460 call __audit_syscall_entry
461 pushl_cfi %ebx
462 movl PT_EAX(%esp),%eax /* reload syscall number */
463 jmp sysenter_do_call
465 sysexit_audit:
466 testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
467 jne syscall_exit_work
468 TRACE_IRQS_ON
469 ENABLE_INTERRUPTS(CLBR_ANY)
470 movl %eax,%edx /* second arg, syscall return value */
471 cmpl $-MAX_ERRNO,%eax /* is it an error ? */
472 setbe %al /* 1 if so, 0 if not */
473 movzbl %al,%eax /* zero-extend that */
474 call __audit_syscall_exit
475 DISABLE_INTERRUPTS(CLBR_ANY)
476 TRACE_IRQS_OFF
477 movl TI_flags(%ebp), %ecx
478 testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
479 jne syscall_exit_work
480 movl PT_EAX(%esp),%eax /* reload syscall return value */
481 jmp sysenter_exit
482 #endif
484 CFI_ENDPROC
485 .pushsection .fixup,"ax"
486 2: movl $0,PT_FS(%esp)
487 jmp 1b
488 .section __ex_table,"a"
489 .align 4
490 .long 1b,2b
491 .popsection
492 PTGS_TO_GS_EX
493 ENDPROC(ia32_sysenter_target)
495 /*
496 * syscall stub including irq exit should be protected against kprobes
497 */
498 .pushsection .kprobes.text, "ax"
499 # system call handler stub
500 ENTRY(system_call)
501 RING0_INT_FRAME # can't unwind into user space anyway
502 pushl_cfi %eax # save orig_eax
503 SAVE_ALL
504 GET_THREAD_INFO(%ebp)
505 # system call tracing in operation / emulation
506 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp)
507 jnz syscall_trace_entry
508 cmpl $(NR_syscalls), %eax
509 jae syscall_badsys
510 syscall_call:
511 call *sys_call_table(,%eax,4)
512 movl %eax,PT_EAX(%esp) # store the return value
513 syscall_exit:
514 LOCKDEP_SYS_EXIT
515 DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
516 # setting need_resched or sigpending
517 # between sampling and the iret
518 TRACE_IRQS_OFF
519 movl TI_flags(%ebp), %ecx
520 testl $_TIF_ALLWORK_MASK, %ecx # current->work
521 jne syscall_exit_work
523 restore_all:
524 TRACE_IRQS_IRET
525 restore_all_notrace:
526 movl PT_EFLAGS(%esp), %eax # mix EFLAGS, SS and CS
527 # Warning: PT_OLDSS(%esp) contains the wrong/random values if we
528 # are returning to the kernel.
529 # See comments in process.c:copy_thread() for details.
530 movb PT_OLDSS(%esp), %ah
531 movb PT_CS(%esp), %al
532 andl $(X86_EFLAGS_VM | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
533 cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
534 CFI_REMEMBER_STATE
535 je ldt_ss # returning to user-space with LDT SS
536 restore_nocheck:
537 RESTORE_REGS 4 # skip orig_eax/error_code
538 irq_return:
539 INTERRUPT_RETURN
540 .section .fixup,"ax"
541 ENTRY(iret_exc)
542 pushl $0 # no error code
543 pushl $do_iret_error
544 jmp error_code
545 .previous
546 .section __ex_table,"a"
547 .align 4
548 .long irq_return,iret_exc
549 .previous
551 CFI_RESTORE_STATE
552 ldt_ss:
553 larl PT_OLDSS(%esp), %eax
554 jnz restore_nocheck
555 testl $0x00400000, %eax # returning to 32bit stack?
556 jnz restore_nocheck # allright, normal return
558 #ifdef CONFIG_PARAVIRT
559 /*
560 * The kernel can't run on a non-flat stack if paravirt mode
561 * is active. Rather than try to fixup the high bits of
562 * ESP, bypass this code entirely. This may break DOSemu
563 * and/or Wine support in a paravirt VM, although the option
564 * is still available to implement the setting of the high
565 * 16-bits in the INTERRUPT_RETURN paravirt-op.
566 */
567 cmpl $0, pv_info+PARAVIRT_enabled
568 jne restore_nocheck
569 #endif
571 /*
572 * Setup and switch to ESPFIX stack
573 *
574 * We're returning to userspace with a 16 bit stack. The CPU will not
575 * restore the high word of ESP for us on executing iret... This is an
576 * "official" bug of all the x86-compatible CPUs, which we can work
577 * around to make dosemu and wine happy. We do this by preloading the
578 * high word of ESP with the high word of the userspace ESP while
579 * compensating for the offset by changing to the ESPFIX segment with
580 * a base address that matches for the difference.
581 */
582 #define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8)
583 mov %esp, %edx /* load kernel esp */
584 mov PT_OLDESP(%esp), %eax /* load userspace esp */
585 mov %dx, %ax /* eax: new kernel esp */
586 sub %eax, %edx /* offset (low word is 0) */
587 shr $16, %edx
588 mov %dl, GDT_ESPFIX_SS + 4 /* bits 16..23 */
589 mov %dh, GDT_ESPFIX_SS + 7 /* bits 24..31 */
590 pushl_cfi $__ESPFIX_SS
591 pushl_cfi %eax /* new kernel esp */
592 /* Disable interrupts, but do not irqtrace this section: we
593 * will soon execute iret and the tracer was already set to
594 * the irqstate after the iret */
595 DISABLE_INTERRUPTS(CLBR_EAX)
596 lss (%esp), %esp /* switch to espfix segment */
597 CFI_ADJUST_CFA_OFFSET -8
598 jmp restore_nocheck
599 CFI_ENDPROC
600 ENDPROC(system_call)
602 # perform work that needs to be done immediately before resumption
603 ALIGN
604 RING0_PTREGS_FRAME # can't unwind into user space anyway
605 work_pending:
606 testb $_TIF_NEED_RESCHED, %cl
607 jz work_notifysig
608 work_resched:
609 call schedule
610 LOCKDEP_SYS_EXIT
611 DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
612 # setting need_resched or sigpending
613 # between sampling and the iret
614 TRACE_IRQS_OFF
615 movl TI_flags(%ebp), %ecx
616 andl $_TIF_WORK_MASK, %ecx # is there any work to be done other
617 # than syscall tracing?
618 jz restore_all
619 testb $_TIF_NEED_RESCHED, %cl
620 jnz work_resched
622 work_notifysig: # deal with pending signals and
623 # notify-resume requests
624 #ifdef CONFIG_VM86
625 testl $X86_EFLAGS_VM, PT_EFLAGS(%esp)
626 movl %esp, %eax
627 jne work_notifysig_v86 # returning to kernel-space or
628 # vm86-space
629 TRACE_IRQS_ON
630 ENABLE_INTERRUPTS(CLBR_NONE)
631 xorl %edx, %edx
632 call do_notify_resume
633 jmp resume_userspace_sig
635 ALIGN
636 work_notifysig_v86:
637 pushl_cfi %ecx # save ti_flags for do_notify_resume
638 call save_v86_state # %eax contains pt_regs pointer
639 popl_cfi %ecx
640 movl %eax, %esp
641 #else
642 movl %esp, %eax
643 #endif
644 TRACE_IRQS_ON
645 ENABLE_INTERRUPTS(CLBR_NONE)
646 xorl %edx, %edx
647 call do_notify_resume
648 jmp resume_userspace_sig
649 END(work_pending)
651 # perform syscall exit tracing
652 ALIGN
653 syscall_trace_entry:
654 movl $-ENOSYS,PT_EAX(%esp)
655 movl %esp, %eax
656 call syscall_trace_enter
657 /* What it returned is what we'll actually use. */
658 cmpl $(NR_syscalls), %eax
659 jnae syscall_call
660 jmp syscall_exit
661 END(syscall_trace_entry)
663 # perform syscall exit tracing
664 ALIGN
665 syscall_exit_work:
666 testl $_TIF_WORK_SYSCALL_EXIT, %ecx
667 jz work_pending
668 TRACE_IRQS_ON
669 ENABLE_INTERRUPTS(CLBR_ANY) # could let syscall_trace_leave() call
670 # schedule() instead
671 movl %esp, %eax
672 call syscall_trace_leave
673 jmp resume_userspace
674 END(syscall_exit_work)
675 CFI_ENDPROC
677 RING0_INT_FRAME # can't unwind into user space anyway
678 syscall_fault:
679 GET_THREAD_INFO(%ebp)
680 movl $-EFAULT,PT_EAX(%esp)
681 jmp resume_userspace
682 END(syscall_fault)
684 syscall_badsys:
685 movl $-ENOSYS,PT_EAX(%esp)
686 jmp resume_userspace
687 END(syscall_badsys)
688 CFI_ENDPROC
689 /*
690 * End of kprobes section
691 */
692 .popsection
694 /*
695 * System calls that need a pt_regs pointer.
696 */
697 #define PTREGSCALL0(name) \
698 ENTRY(ptregs_##name) ; \
699 leal 4(%esp),%eax; \
700 jmp sys_##name; \
701 ENDPROC(ptregs_##name)
703 #define PTREGSCALL1(name) \
704 ENTRY(ptregs_##name) ; \
705 leal 4(%esp),%edx; \
706 movl (PT_EBX+4)(%esp),%eax; \
707 jmp sys_##name; \
708 ENDPROC(ptregs_##name)
710 #define PTREGSCALL2(name) \
711 ENTRY(ptregs_##name) ; \
712 leal 4(%esp),%ecx; \
713 movl (PT_ECX+4)(%esp),%edx; \
714 movl (PT_EBX+4)(%esp),%eax; \
715 jmp sys_##name; \
716 ENDPROC(ptregs_##name)
718 #define PTREGSCALL3(name) \
719 ENTRY(ptregs_##name) ; \
720 CFI_STARTPROC; \
721 leal 4(%esp),%eax; \
722 pushl_cfi %eax; \
723 movl PT_EDX(%eax),%ecx; \
724 movl PT_ECX(%eax),%edx; \
725 movl PT_EBX(%eax),%eax; \
726 call sys_##name; \
727 addl $4,%esp; \
728 CFI_ADJUST_CFA_OFFSET -4; \
729 ret; \
730 CFI_ENDPROC; \
731 ENDPROC(ptregs_##name)
733 PTREGSCALL1(iopl)
734 PTREGSCALL0(fork)
735 PTREGSCALL0(vfork)
736 PTREGSCALL3(execve)
737 PTREGSCALL2(sigaltstack)
738 PTREGSCALL0(sigreturn)
739 PTREGSCALL0(rt_sigreturn)
740 PTREGSCALL2(vm86)
741 PTREGSCALL1(vm86old)
743 /* Clone is an oddball. The 4th arg is in %edi */
744 ENTRY(ptregs_clone)
745 CFI_STARTPROC
746 leal 4(%esp),%eax
747 pushl_cfi %eax
748 pushl_cfi PT_EDI(%eax)
749 movl PT_EDX(%eax),%ecx
750 movl PT_ECX(%eax),%edx
751 movl PT_EBX(%eax),%eax
752 call sys_clone
753 addl $8,%esp
754 CFI_ADJUST_CFA_OFFSET -8
755 ret
756 CFI_ENDPROC
757 ENDPROC(ptregs_clone)
759 .macro FIXUP_ESPFIX_STACK
760 /*
761 * Switch back for ESPFIX stack to the normal zerobased stack
762 *
763 * We can't call C functions using the ESPFIX stack. This code reads
764 * the high word of the segment base from the GDT and swiches to the
765 * normal stack and adjusts ESP with the matching offset.
766 */
767 /* fixup the stack */
768 mov GDT_ESPFIX_SS + 4, %al /* bits 16..23 */
769 mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */
770 shl $16, %eax
771 addl %esp, %eax /* the adjusted stack pointer */
772 pushl_cfi $__KERNEL_DS
773 pushl_cfi %eax
774 lss (%esp), %esp /* switch to the normal stack segment */
775 CFI_ADJUST_CFA_OFFSET -8
776 .endm
777 .macro UNWIND_ESPFIX_STACK
778 movl %ss, %eax
779 /* see if on espfix stack */
780 cmpw $__ESPFIX_SS, %ax
781 jne 27f
782 movl $__KERNEL_DS, %eax
783 movl %eax, %ds
784 movl %eax, %es
785 /* switch to normal stack */
786 FIXUP_ESPFIX_STACK
787 27:
788 .endm
790 /*
791 * Build the entry stubs and pointer table with some assembler magic.
792 * We pack 7 stubs into a single 32-byte chunk, which will fit in a
793 * single cache line on all modern x86 implementations.
794 */
795 .section .init.rodata,"a"
796 ENTRY(interrupt)
797 .section .entry.text, "ax"
798 .p2align 5
799 .p2align CONFIG_X86_L1_CACHE_SHIFT
800 ENTRY(irq_entries_start)
801 RING0_INT_FRAME
802 vector=FIRST_EXTERNAL_VECTOR
803 .rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7
804 .balign 32
805 .rept 7
806 .if vector < NR_VECTORS
807 .if vector <> FIRST_EXTERNAL_VECTOR
808 CFI_ADJUST_CFA_OFFSET -4
809 .endif
810 1: pushl_cfi $(~vector+0x80) /* Note: always in signed byte range */
811 .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6
812 jmp 2f
813 .endif
814 .previous
815 .long 1b
816 .section .entry.text, "ax"
817 vector=vector+1
818 .endif
819 .endr
820 2: jmp common_interrupt
821 .endr
822 END(irq_entries_start)
824 .previous
825 END(interrupt)
826 .previous
828 /*
829 * the CPU automatically disables interrupts when executing an IRQ vector,
830 * so IRQ-flags tracing has to follow that:
831 */
832 .p2align CONFIG_X86_L1_CACHE_SHIFT
833 common_interrupt:
834 addl $-0x80,(%esp) /* Adjust vector into the [-256,-1] range */
835 SAVE_ALL
836 TRACE_IRQS_OFF
837 movl %esp,%eax
838 call do_IRQ
839 jmp ret_from_intr
840 ENDPROC(common_interrupt)
841 CFI_ENDPROC
843 /*
844 * Irq entries should be protected against kprobes
845 */
846 .pushsection .kprobes.text, "ax"
847 #define BUILD_INTERRUPT3(name, nr, fn) \
848 ENTRY(name) \
849 RING0_INT_FRAME; \
850 pushl_cfi $~(nr); \
851 SAVE_ALL; \
852 TRACE_IRQS_OFF \
853 movl %esp,%eax; \
854 call fn; \
855 jmp ret_from_intr; \
856 CFI_ENDPROC; \
857 ENDPROC(name)
859 #define BUILD_INTERRUPT(name, nr) BUILD_INTERRUPT3(name, nr, smp_##name)
861 /* The include is where all of the SMP etc. interrupts come from */
862 #include <asm/entry_arch.h>
864 ENTRY(coprocessor_error)
865 RING0_INT_FRAME
866 pushl_cfi $0
867 pushl_cfi $do_coprocessor_error
868 jmp error_code
869 CFI_ENDPROC
870 END(coprocessor_error)
872 ENTRY(simd_coprocessor_error)
873 RING0_INT_FRAME
874 pushl_cfi $0
875 #ifdef CONFIG_X86_INVD_BUG
876 /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
877 661: pushl_cfi $do_general_protection
878 662:
879 .section .altinstructions,"a"
880 altinstruction_entry 661b, 663f, X86_FEATURE_XMM, 662b-661b, 664f-663f
881 .previous
882 .section .altinstr_replacement,"ax"
883 663: pushl $do_simd_coprocessor_error
884 664:
885 .previous
886 #else
887 pushl_cfi $do_simd_coprocessor_error
888 #endif
889 jmp error_code
890 CFI_ENDPROC
891 END(simd_coprocessor_error)
893 ENTRY(device_not_available)
894 RING0_INT_FRAME
895 pushl_cfi $-1 # mark this as an int
896 pushl_cfi $do_device_not_available
897 jmp error_code
898 CFI_ENDPROC
899 END(device_not_available)
901 #ifdef CONFIG_PARAVIRT
902 ENTRY(native_iret)
903 iret
904 .section __ex_table,"a"
905 .align 4
906 .long native_iret, iret_exc
907 .previous
908 END(native_iret)
910 ENTRY(native_irq_enable_sysexit)
911 sti
912 sysexit
913 END(native_irq_enable_sysexit)
914 #endif
916 ENTRY(overflow)
917 RING0_INT_FRAME
918 pushl_cfi $0
919 pushl_cfi $do_overflow
920 jmp error_code
921 CFI_ENDPROC
922 END(overflow)
924 ENTRY(bounds)
925 RING0_INT_FRAME
926 pushl_cfi $0
927 pushl_cfi $do_bounds
928 jmp error_code
929 CFI_ENDPROC
930 END(bounds)
932 ENTRY(invalid_op)
933 RING0_INT_FRAME
934 pushl_cfi $0
935 pushl_cfi $do_invalid_op
936 jmp error_code
937 CFI_ENDPROC
938 END(invalid_op)
940 ENTRY(coprocessor_segment_overrun)
941 RING0_INT_FRAME
942 pushl_cfi $0
943 pushl_cfi $do_coprocessor_segment_overrun
944 jmp error_code
945 CFI_ENDPROC
946 END(coprocessor_segment_overrun)
948 ENTRY(invalid_TSS)
949 RING0_EC_FRAME
950 pushl_cfi $do_invalid_TSS
951 jmp error_code
952 CFI_ENDPROC
953 END(invalid_TSS)
955 ENTRY(segment_not_present)
956 RING0_EC_FRAME
957 pushl_cfi $do_segment_not_present
958 jmp error_code
959 CFI_ENDPROC
960 END(segment_not_present)
962 ENTRY(stack_segment)
963 RING0_EC_FRAME
964 pushl_cfi $do_stack_segment
965 jmp error_code
966 CFI_ENDPROC
967 END(stack_segment)
969 ENTRY(alignment_check)
970 RING0_EC_FRAME
971 pushl_cfi $do_alignment_check
972 jmp error_code
973 CFI_ENDPROC
974 END(alignment_check)
976 ENTRY(divide_error)
977 RING0_INT_FRAME
978 pushl_cfi $0 # no error code
979 pushl_cfi $do_divide_error
980 jmp error_code
981 CFI_ENDPROC
982 END(divide_error)
984 #ifdef CONFIG_X86_MCE
985 ENTRY(machine_check)
986 RING0_INT_FRAME
987 pushl_cfi $0
988 pushl_cfi machine_check_vector
989 jmp error_code
990 CFI_ENDPROC
991 END(machine_check)
992 #endif
994 ENTRY(spurious_interrupt_bug)
995 RING0_INT_FRAME
996 pushl_cfi $0
997 pushl_cfi $do_spurious_interrupt_bug
998 jmp error_code
999 CFI_ENDPROC
1000 END(spurious_interrupt_bug)
1001 /*
1002 * End of kprobes section
1003 */
1004 .popsection
1006 ENTRY(kernel_thread_helper)
1007 pushl $0 # fake return address for unwinder
1008 CFI_STARTPROC
1009 movl %edi,%eax
1010 call *%esi
1011 call do_exit
1012 ud2 # padding for call trace
1013 CFI_ENDPROC
1014 ENDPROC(kernel_thread_helper)
1016 #ifdef CONFIG_XEN
1017 /* Xen doesn't set %esp to be precisely what the normal sysenter
1018 entrypoint expects, so fix it up before using the normal path. */
1019 ENTRY(xen_sysenter_target)
1020 RING0_INT_FRAME
1021 addl $5*4, %esp /* remove xen-provided frame */
1022 CFI_ADJUST_CFA_OFFSET -5*4
1023 jmp sysenter_past_esp
1024 CFI_ENDPROC
1026 ENTRY(xen_hypervisor_callback)
1027 CFI_STARTPROC
1028 pushl_cfi $0
1029 SAVE_ALL
1030 TRACE_IRQS_OFF
1032 /* Check to see if we got the event in the critical
1033 region in xen_iret_direct, after we've reenabled
1034 events and checked for pending events. This simulates
1035 iret instruction's behaviour where it delivers a
1036 pending interrupt when enabling interrupts. */
1037 movl PT_EIP(%esp),%eax
1038 cmpl $xen_iret_start_crit,%eax
1039 jb 1f
1040 cmpl $xen_iret_end_crit,%eax
1041 jae 1f
1043 jmp xen_iret_crit_fixup
1045 ENTRY(xen_do_upcall)
1046 1: mov %esp, %eax
1047 call xen_evtchn_do_upcall
1048 jmp ret_from_intr
1049 CFI_ENDPROC
1050 ENDPROC(xen_hypervisor_callback)
1052 # Hypervisor uses this for application faults while it executes.
1053 # We get here for two reasons:
1054 # 1. Fault while reloading DS, ES, FS or GS
1055 # 2. Fault while executing IRET
1056 # Category 1 we fix up by reattempting the load, and zeroing the segment
1057 # register if the load fails.
1058 # Category 2 we fix up by jumping to do_iret_error. We cannot use the
1059 # normal Linux return path in this case because if we use the IRET hypercall
1060 # to pop the stack frame we end up in an infinite loop of failsafe callbacks.
1061 # We distinguish between categories by maintaining a status value in EAX.
1062 ENTRY(xen_failsafe_callback)
1063 CFI_STARTPROC
1064 pushl_cfi %eax
1065 movl $1,%eax
1066 1: mov 4(%esp),%ds
1067 2: mov 8(%esp),%es
1068 3: mov 12(%esp),%fs
1069 4: mov 16(%esp),%gs
1070 testl %eax,%eax
1071 popl_cfi %eax
1072 lea 16(%esp),%esp
1073 CFI_ADJUST_CFA_OFFSET -16
1074 jz 5f
1075 addl $16,%esp
1076 jmp iret_exc # EAX != 0 => Category 2 (Bad IRET)
1077 5: pushl_cfi $0 # EAX == 0 => Category 1 (Bad segment)
1078 SAVE_ALL
1079 jmp ret_from_exception
1080 CFI_ENDPROC
1082 .section .fixup,"ax"
1083 6: xorl %eax,%eax
1084 movl %eax,4(%esp)
1085 jmp 1b
1086 7: xorl %eax,%eax
1087 movl %eax,8(%esp)
1088 jmp 2b
1089 8: xorl %eax,%eax
1090 movl %eax,12(%esp)
1091 jmp 3b
1092 9: xorl %eax,%eax
1093 movl %eax,16(%esp)
1094 jmp 4b
1095 .previous
1096 .section __ex_table,"a"
1097 .align 4
1098 .long 1b,6b
1099 .long 2b,7b
1100 .long 3b,8b
1101 .long 4b,9b
1102 .previous
1103 ENDPROC(xen_failsafe_callback)
1105 BUILD_INTERRUPT3(xen_hvm_callback_vector, XEN_HVM_EVTCHN_CALLBACK,
1106 xen_evtchn_do_upcall)
1108 #endif /* CONFIG_XEN */
1110 #ifdef CONFIG_FUNCTION_TRACER
1111 #ifdef CONFIG_DYNAMIC_FTRACE
1113 ENTRY(mcount)
1114 ret
1115 END(mcount)
1117 ENTRY(ftrace_caller)
1118 cmpl $0, function_trace_stop
1119 jne ftrace_stub
1121 pushl %eax
1122 pushl %ecx
1123 pushl %edx
1124 movl 0xc(%esp), %eax
1125 movl 0x4(%ebp), %edx
1126 subl $MCOUNT_INSN_SIZE, %eax
1128 .globl ftrace_call
1129 ftrace_call:
1130 call ftrace_stub
1132 popl %edx
1133 popl %ecx
1134 popl %eax
1135 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1136 .globl ftrace_graph_call
1137 ftrace_graph_call:
1138 jmp ftrace_stub
1139 #endif
1141 .globl ftrace_stub
1142 ftrace_stub:
1143 ret
1144 END(ftrace_caller)
1146 #else /* ! CONFIG_DYNAMIC_FTRACE */
1148 ENTRY(mcount)
1149 cmpl $0, function_trace_stop
1150 jne ftrace_stub
1152 cmpl $ftrace_stub, ftrace_trace_function
1153 jnz trace
1154 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1155 cmpl $ftrace_stub, ftrace_graph_return
1156 jnz ftrace_graph_caller
1158 cmpl $ftrace_graph_entry_stub, ftrace_graph_entry
1159 jnz ftrace_graph_caller
1160 #endif
1161 .globl ftrace_stub
1162 ftrace_stub:
1163 ret
1165 /* taken from glibc */
1166 trace:
1167 pushl %eax
1168 pushl %ecx
1169 pushl %edx
1170 movl 0xc(%esp), %eax
1171 movl 0x4(%ebp), %edx
1172 subl $MCOUNT_INSN_SIZE, %eax
1174 call *ftrace_trace_function
1176 popl %edx
1177 popl %ecx
1178 popl %eax
1179 jmp ftrace_stub
1180 END(mcount)
1181 #endif /* CONFIG_DYNAMIC_FTRACE */
1182 #endif /* CONFIG_FUNCTION_TRACER */
1184 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1185 ENTRY(ftrace_graph_caller)
1186 cmpl $0, function_trace_stop
1187 jne ftrace_stub
1189 pushl %eax
1190 pushl %ecx
1191 pushl %edx
1192 movl 0xc(%esp), %edx
1193 lea 0x4(%ebp), %eax
1194 movl (%ebp), %ecx
1195 subl $MCOUNT_INSN_SIZE, %edx
1196 call prepare_ftrace_return
1197 popl %edx
1198 popl %ecx
1199 popl %eax
1200 ret
1201 END(ftrace_graph_caller)
1203 .globl return_to_handler
1204 return_to_handler:
1205 pushl %eax
1206 pushl %edx
1207 movl %ebp, %eax
1208 call ftrace_return_to_handler
1209 movl %eax, %ecx
1210 popl %edx
1211 popl %eax
1212 jmp *%ecx
1213 #endif
1215 /*
1216 * Some functions should be protected against kprobes
1217 */
1218 .pushsection .kprobes.text, "ax"
1220 ENTRY(page_fault)
1221 RING0_EC_FRAME
1222 pushl_cfi $do_page_fault
1223 ALIGN
1224 error_code:
1225 /* the function address is in %gs's slot on the stack */
1226 pushl_cfi %fs
1227 /*CFI_REL_OFFSET fs, 0*/
1228 pushl_cfi %es
1229 /*CFI_REL_OFFSET es, 0*/
1230 pushl_cfi %ds
1231 /*CFI_REL_OFFSET ds, 0*/
1232 pushl_cfi %eax
1233 CFI_REL_OFFSET eax, 0
1234 pushl_cfi %ebp
1235 CFI_REL_OFFSET ebp, 0
1236 pushl_cfi %edi
1237 CFI_REL_OFFSET edi, 0
1238 pushl_cfi %esi
1239 CFI_REL_OFFSET esi, 0
1240 pushl_cfi %edx
1241 CFI_REL_OFFSET edx, 0
1242 pushl_cfi %ecx
1243 CFI_REL_OFFSET ecx, 0
1244 pushl_cfi %ebx
1245 CFI_REL_OFFSET ebx, 0
1246 cld
1247 movl $(__KERNEL_PERCPU), %ecx
1248 movl %ecx, %fs
1249 UNWIND_ESPFIX_STACK
1250 GS_TO_REG %ecx
1251 movl PT_GS(%esp), %edi # get the function address
1252 movl PT_ORIG_EAX(%esp), %edx # get the error code
1253 movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart
1254 REG_TO_PTGS %ecx
1255 SET_KERNEL_GS %ecx
1256 movl $(__USER_DS), %ecx
1257 movl %ecx, %ds
1258 movl %ecx, %es
1259 TRACE_IRQS_OFF
1260 movl %esp,%eax # pt_regs pointer
1261 call *%edi
1262 jmp ret_from_exception
1263 CFI_ENDPROC
1264 END(page_fault)
1266 /*
1267 * Debug traps and NMI can happen at the one SYSENTER instruction
1268 * that sets up the real kernel stack. Check here, since we can't
1269 * allow the wrong stack to be used.
1270 *
1271 * "TSS_sysenter_sp0+12" is because the NMI/debug handler will have
1272 * already pushed 3 words if it hits on the sysenter instruction:
1273 * eflags, cs and eip.
1274 *
1275 * We just load the right stack, and push the three (known) values
1276 * by hand onto the new stack - while updating the return eip past
1277 * the instruction that would have done it for sysenter.
1278 */
1279 .macro FIX_STACK offset ok label
1280 cmpw $__KERNEL_CS, 4(%esp)
1281 jne \ok
1282 \label:
1283 movl TSS_sysenter_sp0 + \offset(%esp), %esp
1284 CFI_DEF_CFA esp, 0
1285 CFI_UNDEFINED eip
1286 pushfl_cfi
1287 pushl_cfi $__KERNEL_CS
1288 pushl_cfi $sysenter_past_esp
1289 CFI_REL_OFFSET eip, 0
1290 .endm
1292 ENTRY(debug)
1293 RING0_INT_FRAME
1294 cmpl $ia32_sysenter_target,(%esp)
1295 jne debug_stack_correct
1296 FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn
1297 debug_stack_correct:
1298 pushl_cfi $-1 # mark this as an int
1299 SAVE_ALL
1300 TRACE_IRQS_OFF
1301 xorl %edx,%edx # error code 0
1302 movl %esp,%eax # pt_regs pointer
1303 call do_debug
1304 jmp ret_from_exception
1305 CFI_ENDPROC
1306 END(debug)
1308 /*
1309 * NMI is doubly nasty. It can happen _while_ we're handling
1310 * a debug fault, and the debug fault hasn't yet been able to
1311 * clear up the stack. So we first check whether we got an
1312 * NMI on the sysenter entry path, but after that we need to
1313 * check whether we got an NMI on the debug path where the debug
1314 * fault happened on the sysenter path.
1315 */
1316 ENTRY(nmi)
1317 RING0_INT_FRAME
1318 pushl_cfi %eax
1319 movl %ss, %eax
1320 cmpw $__ESPFIX_SS, %ax
1321 popl_cfi %eax
1322 je nmi_espfix_stack
1323 cmpl $ia32_sysenter_target,(%esp)
1324 je nmi_stack_fixup
1325 pushl_cfi %eax
1326 movl %esp,%eax
1327 /* Do not access memory above the end of our stack page,
1328 * it might not exist.
1329 */
1330 andl $(THREAD_SIZE-1),%eax
1331 cmpl $(THREAD_SIZE-20),%eax
1332 popl_cfi %eax
1333 jae nmi_stack_correct
1334 cmpl $ia32_sysenter_target,12(%esp)
1335 je nmi_debug_stack_check
1336 nmi_stack_correct:
1337 /* We have a RING0_INT_FRAME here */
1338 pushl_cfi %eax
1339 SAVE_ALL
1340 xorl %edx,%edx # zero error code
1341 movl %esp,%eax # pt_regs pointer
1342 call do_nmi
1343 jmp restore_all_notrace
1344 CFI_ENDPROC
1346 nmi_stack_fixup:
1347 RING0_INT_FRAME
1348 FIX_STACK 12, nmi_stack_correct, 1
1349 jmp nmi_stack_correct
1351 nmi_debug_stack_check:
1352 /* We have a RING0_INT_FRAME here */
1353 cmpw $__KERNEL_CS,16(%esp)
1354 jne nmi_stack_correct
1355 cmpl $debug,(%esp)
1356 jb nmi_stack_correct
1357 cmpl $debug_esp_fix_insn,(%esp)
1358 ja nmi_stack_correct
1359 FIX_STACK 24, nmi_stack_correct, 1
1360 jmp nmi_stack_correct
1362 nmi_espfix_stack:
1363 /* We have a RING0_INT_FRAME here.
1364 *
1365 * create the pointer to lss back
1366 */
1367 pushl_cfi %ss
1368 pushl_cfi %esp
1369 addl $4, (%esp)
1370 /* copy the iret frame of 12 bytes */
1371 .rept 3
1372 pushl_cfi 16(%esp)
1373 .endr
1374 pushl_cfi %eax
1375 SAVE_ALL
1376 FIXUP_ESPFIX_STACK # %eax == %esp
1377 xorl %edx,%edx # zero error code
1378 call do_nmi
1379 RESTORE_REGS
1380 lss 12+4(%esp), %esp # back to espfix stack
1381 CFI_ADJUST_CFA_OFFSET -24
1382 jmp irq_return
1383 CFI_ENDPROC
1384 END(nmi)
1386 ENTRY(int3)
1387 RING0_INT_FRAME
1388 pushl_cfi $-1 # mark this as an int
1389 SAVE_ALL
1390 TRACE_IRQS_OFF
1391 xorl %edx,%edx # zero error code
1392 movl %esp,%eax # pt_regs pointer
1393 call do_int3
1394 jmp ret_from_exception
1395 CFI_ENDPROC
1396 END(int3)
1398 ENTRY(general_protection)
1399 RING0_EC_FRAME
1400 pushl_cfi $do_general_protection
1401 jmp error_code
1402 CFI_ENDPROC
1403 END(general_protection)
1405 #ifdef CONFIG_KVM_GUEST
1406 ENTRY(async_page_fault)
1407 RING0_EC_FRAME
1408 pushl_cfi $do_async_page_fault
1409 jmp error_code
1410 CFI_ENDPROC
1411 END(async_page_fault)
1412 #endif
1414 /*
1415 * End of kprobes section
1416 */
1417 .popsection