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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 */
5
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 *
Andi Kleen889f21c2007-05-02 19:27:19 +020017 * Stack layout in 'syscall_exit':
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 * 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
Jeremy Fitzhardinge464d1a72007-02-13 13:26:20 +010032 * 24(%esp) - %fs
Tejun Heoccbeed32009-02-09 22:17:40 +090033 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 *
41 * "current" is in register %ebx during any slow entries.
42 */
43
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#include <linux/linkage.h>
45#include <asm/thread_info.h>
Ingo Molnar55f327f2006-07-03 00:24:43 -070046#include <asm/irqflags.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <asm/errno.h>
48#include <asm/segment.h>
49#include <asm/smp.h>
Jeremy Fitzhardinge0341c142009-02-13 11:14:01 -080050#include <asm/page_types.h>
Stas Sergeevbe44d2a2006-12-07 02:14:01 +010051#include <asm/percpu.h>
Jan Beulichfe7cacc2006-06-26 13:57:44 +020052#include <asm/dwarf2.h>
Cyrill Gorcunovab68ed92008-03-25 22:16:32 +030053#include <asm/processor-flags.h>
Abhishek Sagar395a59d2008-06-21 23:47:27 +053054#include <asm/ftrace.h>
Thomas Gleixner9b7dc562008-05-02 20:10:09 +020055#include <asm/irq_vectors.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
Roland McGrathaf0575b2008-06-24 04:16:52 -070057/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
58#include <linux/elf-em.h>
59#define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE)
60#define __AUDIT_ARCH_LE 0x40000000
61
62#ifndef CONFIG_AUDITSYSCALL
63#define sysenter_audit syscall_trace_entry
64#define sysexit_audit syscall_exit_work
65#endif
66
Rusty Russell139ec7c2006-12-07 02:14:08 +010067/*
68 * We use macros for low-level operations which need to be overridden
69 * for paravirtualization. The following will never clobber any registers:
70 * INTERRUPT_RETURN (aka. "iret")
71 * GET_CR0_INTO_EAX (aka. "movl %cr0, %eax")
Jeremy Fitzhardinged75cd222008-06-25 00:19:26 -040072 * ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit").
Rusty Russell139ec7c2006-12-07 02:14:08 +010073 *
74 * For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must
75 * specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY).
76 * Allowing a register to be clobbered can shrink the paravirt replacement
77 * enough to patch inline, increasing performance.
78 */
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080#define nr_syscalls ((syscall_table_size)/4)
81
Linus Torvalds1da177e2005-04-16 15:20:36 -070082#ifdef CONFIG_PREEMPT
Rusty Russell139ec7c2006-12-07 02:14:08 +010083#define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -070084#else
Rusty Russell139ec7c2006-12-07 02:14:08 +010085#define preempt_stop(clobbers)
Alexander van Heukelum2e04bc72009-06-18 00:35:57 +020086#define resume_kernel restore_all
Linus Torvalds1da177e2005-04-16 15:20:36 -070087#endif
88
Ingo Molnar55f327f2006-07-03 00:24:43 -070089.macro TRACE_IRQS_IRET
90#ifdef CONFIG_TRACE_IRQFLAGS
Cyrill Gorcunovab68ed92008-03-25 22:16:32 +030091 testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off?
Ingo Molnar55f327f2006-07-03 00:24:43 -070092 jz 1f
93 TRACE_IRQS_ON
941:
95#endif
96.endm
97
Aleksey Gorelov4031ff32006-06-27 02:53:48 -070098#ifdef CONFIG_VM86
99#define resume_userspace_sig check_userspace
100#else
101#define resume_userspace_sig resume_userspace
102#endif
103
Tejun Heoccbeed32009-02-09 22:17:40 +0900104/*
105 * User gs save/restore
106 *
107 * %gs is used for userland TLS and kernel only uses it for stack
108 * canary which is required to be at %gs:20 by gcc. Read the comment
109 * at the top of stackprotector.h for more info.
110 *
111 * Local labels 98 and 99 are used.
112 */
113#ifdef CONFIG_X86_32_LAZY_GS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
Tejun Heoccbeed32009-02-09 22:17:40 +0900115 /* unfortunately push/pop can't be no-op */
116.macro PUSH_GS
117 pushl $0
118 CFI_ADJUST_CFA_OFFSET 4
119.endm
120.macro POP_GS pop=0
121 addl $(4 + \pop), %esp
122 CFI_ADJUST_CFA_OFFSET -(4 + \pop)
123.endm
124.macro POP_GS_EX
125.endm
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
Tejun Heoccbeed32009-02-09 22:17:40 +0900127 /* all the rest are no-op */
128.macro PTGS_TO_GS
129.endm
130.macro PTGS_TO_GS_EX
131.endm
132.macro GS_TO_REG reg
133.endm
134.macro REG_TO_PTGS reg
135.endm
136.macro SET_KERNEL_GS reg
137.endm
138
139#else /* CONFIG_X86_32_LAZY_GS */
140
141.macro PUSH_GS
142 pushl %gs
143 CFI_ADJUST_CFA_OFFSET 4
144 /*CFI_REL_OFFSET gs, 0*/
145.endm
146
147.macro POP_GS pop=0
14898: popl %gs
149 CFI_ADJUST_CFA_OFFSET -4
150 /*CFI_RESTORE gs*/
151 .if \pop <> 0
152 add $\pop, %esp
153 CFI_ADJUST_CFA_OFFSET -\pop
154 .endif
155.endm
156.macro POP_GS_EX
157.pushsection .fixup, "ax"
15899: movl $0, (%esp)
159 jmp 98b
160.section __ex_table, "a"
161 .align 4
162 .long 98b, 99b
Jeremy Fitzhardingef95d47c2006-12-07 02:14:02 +0100163.popsection
Tejun Heoccbeed32009-02-09 22:17:40 +0900164.endm
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Tejun Heoccbeed32009-02-09 22:17:40 +0900166.macro PTGS_TO_GS
16798: mov PT_GS(%esp), %gs
168.endm
169.macro PTGS_TO_GS_EX
170.pushsection .fixup, "ax"
17199: movl $0, PT_GS(%esp)
172 jmp 98b
173.section __ex_table, "a"
174 .align 4
175 .long 98b, 99b
176.popsection
177.endm
178
179.macro GS_TO_REG reg
180 movl %gs, \reg
181 /*CFI_REGISTER gs, \reg*/
182.endm
183.macro REG_TO_PTGS reg
184 movl \reg, PT_GS(%esp)
185 /*CFI_REL_OFFSET gs, PT_GS*/
186.endm
187.macro SET_KERNEL_GS reg
Tejun Heo60a53172009-02-09 22:17:40 +0900188 movl $(__KERNEL_STACK_CANARY), \reg
Tejun Heoccbeed32009-02-09 22:17:40 +0900189 movl \reg, %gs
190.endm
191
192#endif /* CONFIG_X86_32_LAZY_GS */
193
Tejun Heof0d96112009-02-09 22:17:40 +0900194.macro SAVE_ALL
195 cld
Tejun Heoccbeed32009-02-09 22:17:40 +0900196 PUSH_GS
Tejun Heof0d96112009-02-09 22:17:40 +0900197 pushl %fs
198 CFI_ADJUST_CFA_OFFSET 4
199 /*CFI_REL_OFFSET fs, 0;*/
200 pushl %es
201 CFI_ADJUST_CFA_OFFSET 4
202 /*CFI_REL_OFFSET es, 0;*/
203 pushl %ds
204 CFI_ADJUST_CFA_OFFSET 4
205 /*CFI_REL_OFFSET ds, 0;*/
206 pushl %eax
207 CFI_ADJUST_CFA_OFFSET 4
208 CFI_REL_OFFSET eax, 0
209 pushl %ebp
210 CFI_ADJUST_CFA_OFFSET 4
211 CFI_REL_OFFSET ebp, 0
212 pushl %edi
213 CFI_ADJUST_CFA_OFFSET 4
214 CFI_REL_OFFSET edi, 0
215 pushl %esi
216 CFI_ADJUST_CFA_OFFSET 4
217 CFI_REL_OFFSET esi, 0
218 pushl %edx
219 CFI_ADJUST_CFA_OFFSET 4
220 CFI_REL_OFFSET edx, 0
221 pushl %ecx
222 CFI_ADJUST_CFA_OFFSET 4
223 CFI_REL_OFFSET ecx, 0
224 pushl %ebx
225 CFI_ADJUST_CFA_OFFSET 4
226 CFI_REL_OFFSET ebx, 0
227 movl $(__USER_DS), %edx
228 movl %edx, %ds
229 movl %edx, %es
230 movl $(__KERNEL_PERCPU), %edx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 movl %edx, %fs
Tejun Heoccbeed32009-02-09 22:17:40 +0900232 SET_KERNEL_GS %edx
Tejun Heof0d96112009-02-09 22:17:40 +0900233.endm
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Tejun Heof0d96112009-02-09 22:17:40 +0900235.macro RESTORE_INT_REGS
236 popl %ebx
237 CFI_ADJUST_CFA_OFFSET -4
238 CFI_RESTORE ebx
239 popl %ecx
240 CFI_ADJUST_CFA_OFFSET -4
241 CFI_RESTORE ecx
242 popl %edx
243 CFI_ADJUST_CFA_OFFSET -4
244 CFI_RESTORE edx
245 popl %esi
246 CFI_ADJUST_CFA_OFFSET -4
247 CFI_RESTORE esi
248 popl %edi
249 CFI_ADJUST_CFA_OFFSET -4
250 CFI_RESTORE edi
251 popl %ebp
252 CFI_ADJUST_CFA_OFFSET -4
253 CFI_RESTORE ebp
254 popl %eax
255 CFI_ADJUST_CFA_OFFSET -4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 CFI_RESTORE eax
Tejun Heof0d96112009-02-09 22:17:40 +0900257.endm
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
Tejun Heoccbeed32009-02-09 22:17:40 +0900259.macro RESTORE_REGS pop=0
Tejun Heof0d96112009-02-09 22:17:40 +0900260 RESTORE_INT_REGS
2611: popl %ds
262 CFI_ADJUST_CFA_OFFSET -4
263 /*CFI_RESTORE ds;*/
2642: popl %es
265 CFI_ADJUST_CFA_OFFSET -4
266 /*CFI_RESTORE es;*/
2673: popl %fs
268 CFI_ADJUST_CFA_OFFSET -4
269 /*CFI_RESTORE fs;*/
Tejun Heoccbeed32009-02-09 22:17:40 +0900270 POP_GS \pop
Tejun Heof0d96112009-02-09 22:17:40 +0900271.pushsection .fixup, "ax"
2724: movl $0, (%esp)
273 jmp 1b
2745: movl $0, (%esp)
275 jmp 2b
2766: movl $0, (%esp)
277 jmp 3b
278.section __ex_table, "a"
279 .align 4
280 .long 1b, 4b
281 .long 2b, 5b
282 .long 3b, 6b
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283.popsection
Tejun Heoccbeed32009-02-09 22:17:40 +0900284 POP_GS_EX
Tejun Heof0d96112009-02-09 22:17:40 +0900285.endm
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286
Tejun Heof0d96112009-02-09 22:17:40 +0900287.macro RING0_INT_FRAME
288 CFI_STARTPROC simple
289 CFI_SIGNAL_FRAME
290 CFI_DEF_CFA esp, 3*4
291 /*CFI_OFFSET cs, -2*4;*/
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200292 CFI_OFFSET eip, -3*4
Tejun Heof0d96112009-02-09 22:17:40 +0900293.endm
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200294
Tejun Heof0d96112009-02-09 22:17:40 +0900295.macro RING0_EC_FRAME
296 CFI_STARTPROC simple
297 CFI_SIGNAL_FRAME
298 CFI_DEF_CFA esp, 4*4
299 /*CFI_OFFSET cs, -2*4;*/
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200300 CFI_OFFSET eip, -3*4
Tejun Heof0d96112009-02-09 22:17:40 +0900301.endm
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200302
Tejun Heof0d96112009-02-09 22:17:40 +0900303.macro RING0_PTREGS_FRAME
304 CFI_STARTPROC simple
305 CFI_SIGNAL_FRAME
306 CFI_DEF_CFA esp, PT_OLDESP-PT_EBX
307 /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/
308 CFI_OFFSET eip, PT_EIP-PT_OLDESP
309 /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/
310 /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/
311 CFI_OFFSET eax, PT_EAX-PT_OLDESP
312 CFI_OFFSET ebp, PT_EBP-PT_OLDESP
313 CFI_OFFSET edi, PT_EDI-PT_OLDESP
314 CFI_OFFSET esi, PT_ESI-PT_OLDESP
315 CFI_OFFSET edx, PT_EDX-PT_OLDESP
316 CFI_OFFSET ecx, PT_ECX-PT_OLDESP
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100317 CFI_OFFSET ebx, PT_EBX-PT_OLDESP
Tejun Heof0d96112009-02-09 22:17:40 +0900318.endm
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319
320ENTRY(ret_from_fork)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200321 CFI_STARTPROC
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 pushl %eax
Markus Armbruster25d7dfd2006-07-30 03:04:08 -0700323 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 call schedule_tail
325 GET_THREAD_INFO(%ebp)
326 popl %eax
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200327 CFI_ADJUST_CFA_OFFSET -4
Linus Torvalds47a5c6f2006-09-18 16:20:40 -0700328 pushl $0x0202 # Reset kernel eflags
329 CFI_ADJUST_CFA_OFFSET 4
330 popfl
331 CFI_ADJUST_CFA_OFFSET -4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 jmp syscall_exit
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200333 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100334END(ret_from_fork)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
336/*
Masami Hiramatsua00e8172009-09-08 12:47:55 -0400337 * Interrupt exit functions should be protected against kprobes
338 */
339 .pushsection .kprobes.text, "ax"
340/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 * Return to user mode is not as complex as all this looks,
342 * but we want the default path for a system call return to
343 * go as quickly as possible which is why some of this is
344 * less clear than it otherwise should be.
345 */
346
347 # userspace resumption stub bypassing syscall exit tracing
348 ALIGN
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200349 RING0_PTREGS_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350ret_from_exception:
Rusty Russell139ec7c2006-12-07 02:14:08 +0100351 preempt_stop(CLBR_ANY)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352ret_from_intr:
353 GET_THREAD_INFO(%ebp)
Aleksey Gorelov4031ff32006-06-27 02:53:48 -0700354check_userspace:
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100355 movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS
356 movb PT_CS(%esp), %al
Cyrill Gorcunovab68ed92008-03-25 22:16:32 +0300357 andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax
Rusty Russell78be3702006-09-26 10:52:39 +0200358 cmpl $USER_RPL, %eax
359 jb resume_kernel # not returning to v8086 or userspace
Jeremy Fitzhardingef95d47c2006-12-07 02:14:02 +0100360
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361ENTRY(resume_userspace)
Peter Zijlstrac7e872e2007-10-11 22:11:12 +0200362 LOCKDEP_SYS_EXIT
Rusty Russell139ec7c2006-12-07 02:14:08 +0100363 DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 # setting need_resched or sigpending
365 # between sampling and the iret
Peter Zijlstrae32e58a2008-06-06 10:14:08 +0200366 TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 movl TI_flags(%ebp), %ecx
368 andl $_TIF_WORK_MASK, %ecx # is there any work to be done on
369 # int/exception return?
370 jne work_pending
371 jmp restore_all
Jan Beulich47a55cd2007-02-13 13:26:24 +0100372END(ret_from_exception)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373
374#ifdef CONFIG_PREEMPT
375ENTRY(resume_kernel)
Rusty Russell139ec7c2006-12-07 02:14:08 +0100376 DISABLE_INTERRUPTS(CLBR_ANY)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
Alexander van Heukelum2e04bc72009-06-18 00:35:57 +0200378 jnz restore_all
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379need_resched:
380 movl TI_flags(%ebp), %ecx # need_resched set ?
381 testb $_TIF_NEED_RESCHED, %cl
382 jz restore_all
Cyrill Gorcunovab68ed92008-03-25 22:16:32 +0300383 testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ?
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 jz restore_all
385 call preempt_schedule_irq
386 jmp need_resched
Jan Beulich47a55cd2007-02-13 13:26:24 +0100387END(resume_kernel)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388#endif
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200389 CFI_ENDPROC
Masami Hiramatsua00e8172009-09-08 12:47:55 -0400390/*
391 * End of kprobes section
392 */
393 .popsection
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395/* SYSENTER_RETURN points to after the "sysenter" instruction in
396 the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */
397
398 # sysenter call handler stub
Roland McGrath0aa97fb2008-01-30 13:30:43 +0100399ENTRY(ia32_sysenter_target)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200400 CFI_STARTPROC simple
Jan Beulichadf14232006-09-26 10:52:41 +0200401 CFI_SIGNAL_FRAME
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200402 CFI_DEF_CFA esp, 0
403 CFI_REGISTER esp, ebp
H. Peter Anvinfaca6222008-01-30 13:31:02 +0100404 movl TSS_sysenter_sp0(%esp),%esp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405sysenter_past_esp:
Ingo Molnar55f327f2006-07-03 00:24:43 -0700406 /*
Jeremy Fitzhardinged93c8702008-03-24 16:43:21 -0700407 * Interrupts are disabled here, but we can't trace it until
408 * enough kernel state to call TRACE_IRQS_OFF can be called - but
409 * we immediately enable interrupts at that point anyway.
Ingo Molnar55f327f2006-07-03 00:24:43 -0700410 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 pushl $(__USER_DS)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200412 CFI_ADJUST_CFA_OFFSET 4
413 /*CFI_REL_OFFSET ss, 0*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 pushl %ebp
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200415 CFI_ADJUST_CFA_OFFSET 4
416 CFI_REL_OFFSET esp, 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 pushfl
Jeremy Fitzhardinged93c8702008-03-24 16:43:21 -0700418 orl $X86_EFLAGS_IF, (%esp)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200419 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 pushl $(__USER_CS)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200421 CFI_ADJUST_CFA_OFFSET 4
422 /*CFI_REL_OFFSET cs, 0*/
Ingo Molnare6e54942006-06-27 02:53:50 -0700423 /*
424 * Push current_thread_info()->sysenter_return to the stack.
425 * A tiny bit of offset fixup is necessary - 4*4 means the 4 words
426 * pushed above; +8 corresponds to copy_thread's esp0 setting.
427 */
428 pushl (TI_sysenter_return-THREAD_SIZE+8+4*4)(%esp)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200429 CFI_ADJUST_CFA_OFFSET 4
430 CFI_REL_OFFSET eip, 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
Jeremy Fitzhardinged93c8702008-03-24 16:43:21 -0700432 pushl %eax
433 CFI_ADJUST_CFA_OFFSET 4
434 SAVE_ALL
435 ENABLE_INTERRUPTS(CLBR_NONE)
436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437/*
438 * Load the potential sixth argument from user stack.
439 * Careful about security.
440 */
441 cmpl $__PAGE_OFFSET-3,%ebp
442 jae syscall_fault
4431: movl (%ebp),%ebp
Jeremy Fitzhardinged93c8702008-03-24 16:43:21 -0700444 movl %ebp,PT_EBP(%esp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445.section __ex_table,"a"
446 .align 4
447 .long 1b,syscall_fault
448.previous
449
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 GET_THREAD_INFO(%ebp)
451
Jaswinder Singh Rajput88200bc2009-03-14 12:08:13 +0530452 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp)
Roland McGrathaf0575b2008-06-24 04:16:52 -0700453 jnz sysenter_audit
454sysenter_do_call:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 cmpl $(nr_syscalls), %eax
456 jae syscall_badsys
457 call *sys_call_table(,%eax,4)
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100458 movl %eax,PT_EAX(%esp)
Peter Zijlstrac7e872e2007-10-11 22:11:12 +0200459 LOCKDEP_SYS_EXIT
Jeremy Fitzhardinge42c24fa2007-05-02 19:27:14 +0200460 DISABLE_INTERRUPTS(CLBR_ANY)
Ingo Molnar55f327f2006-07-03 00:24:43 -0700461 TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 movl TI_flags(%ebp), %ecx
Jaswinder Singh Rajput88200bc2009-03-14 12:08:13 +0530463 testl $_TIF_ALLWORK_MASK, %ecx
Roland McGrathaf0575b2008-06-24 04:16:52 -0700464 jne sysexit_audit
465sysenter_exit:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466/* if something modifies registers it must also disable sysexit */
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100467 movl PT_EIP(%esp), %edx
468 movl PT_OLDESP(%esp), %ecx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 xorl %ebp,%ebp
Ingo Molnar55f327f2006-07-03 00:24:43 -0700470 TRACE_IRQS_ON
Jeremy Fitzhardinge464d1a72007-02-13 13:26:20 +01004711: mov PT_FS(%esp), %fs
Tejun Heoccbeed32009-02-09 22:17:40 +0900472 PTGS_TO_GS
Jeremy Fitzhardinged75cd222008-06-25 00:19:26 -0400473 ENABLE_INTERRUPTS_SYSEXIT
Roland McGrathaf0575b2008-06-24 04:16:52 -0700474
475#ifdef CONFIG_AUDITSYSCALL
476sysenter_audit:
Jaswinder Singh Rajput88200bc2009-03-14 12:08:13 +0530477 testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
Roland McGrathaf0575b2008-06-24 04:16:52 -0700478 jnz syscall_trace_entry
479 addl $4,%esp
480 CFI_ADJUST_CFA_OFFSET -4
481 /* %esi already in 8(%esp) 6th arg: 4th syscall arg */
482 /* %edx already in 4(%esp) 5th arg: 3rd syscall arg */
483 /* %ecx already in 0(%esp) 4th arg: 2nd syscall arg */
484 movl %ebx,%ecx /* 3rd arg: 1st syscall arg */
485 movl %eax,%edx /* 2nd arg: syscall number */
486 movl $AUDIT_ARCH_I386,%eax /* 1st arg: audit arch */
487 call audit_syscall_entry
488 pushl %ebx
489 CFI_ADJUST_CFA_OFFSET 4
490 movl PT_EAX(%esp),%eax /* reload syscall number */
491 jmp sysenter_do_call
492
493sysexit_audit:
Jaswinder Singh Rajput88200bc2009-03-14 12:08:13 +0530494 testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
Roland McGrathaf0575b2008-06-24 04:16:52 -0700495 jne syscall_exit_work
496 TRACE_IRQS_ON
497 ENABLE_INTERRUPTS(CLBR_ANY)
498 movl %eax,%edx /* second arg, syscall return value */
499 cmpl $0,%eax /* is it < 0? */
500 setl %al /* 1 if so, 0 if not */
501 movzbl %al,%eax /* zero-extend that */
502 inc %eax /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */
503 call audit_syscall_exit
504 DISABLE_INTERRUPTS(CLBR_ANY)
505 TRACE_IRQS_OFF
506 movl TI_flags(%ebp), %ecx
Jaswinder Singh Rajput88200bc2009-03-14 12:08:13 +0530507 testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
Roland McGrathaf0575b2008-06-24 04:16:52 -0700508 jne syscall_exit_work
509 movl PT_EAX(%esp),%eax /* reload syscall return value */
510 jmp sysenter_exit
511#endif
512
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200513 CFI_ENDPROC
Jeremy Fitzhardingef95d47c2006-12-07 02:14:02 +0100514.pushsection .fixup,"ax"
Jeremy Fitzhardinge464d1a72007-02-13 13:26:20 +01005152: movl $0,PT_FS(%esp)
Jeremy Fitzhardingef95d47c2006-12-07 02:14:02 +0100516 jmp 1b
517.section __ex_table,"a"
518 .align 4
519 .long 1b,2b
520.popsection
Tejun Heoccbeed32009-02-09 22:17:40 +0900521 PTGS_TO_GS_EX
Roland McGrath0aa97fb2008-01-30 13:30:43 +0100522ENDPROC(ia32_sysenter_target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523
Masami Hiramatsua00e8172009-09-08 12:47:55 -0400524/*
525 * syscall stub including irq exit should be protected against kprobes
526 */
527 .pushsection .kprobes.text, "ax"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 # system call handler stub
529ENTRY(system_call)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200530 RING0_INT_FRAME # can't unwind into user space anyway
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 pushl %eax # save orig_eax
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200532 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 SAVE_ALL
534 GET_THREAD_INFO(%ebp)
Laurent Viviered75e8d2005-09-03 15:57:18 -0700535 # system call tracing in operation / emulation
Jaswinder Singh Rajput88200bc2009-03-14 12:08:13 +0530536 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 jnz syscall_trace_entry
538 cmpl $(nr_syscalls), %eax
539 jae syscall_badsys
540syscall_call:
541 call *sys_call_table(,%eax,4)
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100542 movl %eax,PT_EAX(%esp) # store the return value
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543syscall_exit:
Peter Zijlstrac7e872e2007-10-11 22:11:12 +0200544 LOCKDEP_SYS_EXIT
Rusty Russell139ec7c2006-12-07 02:14:08 +0100545 DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 # setting need_resched or sigpending
547 # between sampling and the iret
Ingo Molnar55f327f2006-07-03 00:24:43 -0700548 TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 movl TI_flags(%ebp), %ecx
Jaswinder Singh Rajput88200bc2009-03-14 12:08:13 +0530550 testl $_TIF_ALLWORK_MASK, %ecx # current->work
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 jne syscall_exit_work
552
553restore_all:
Alexander van Heukelum2e04bc72009-06-18 00:35:57 +0200554 TRACE_IRQS_IRET
555restore_all_notrace:
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100556 movl PT_EFLAGS(%esp), %eax # mix EFLAGS, SS and CS
557 # Warning: PT_OLDSS(%esp) contains the wrong/random values if we
Stas Sergeev5df24082005-04-16 15:24:01 -0700558 # are returning to the kernel.
559 # See comments in process.c:copy_thread() for details.
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100560 movb PT_OLDSS(%esp), %ah
561 movb PT_CS(%esp), %al
Cyrill Gorcunovab68ed92008-03-25 22:16:32 +0300562 andl $(X86_EFLAGS_VM | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
Rusty Russell78be3702006-09-26 10:52:39 +0200563 cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200564 CFI_REMEMBER_STATE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 je ldt_ss # returning to user-space with LDT SS
566restore_nocheck:
Tejun Heoccbeed32009-02-09 22:17:40 +0900567 RESTORE_REGS 4 # skip orig_eax/error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200568 CFI_ADJUST_CFA_OFFSET -4
Adrian Bunkf7f3d792008-02-13 23:29:53 +0200569irq_return:
Ingo Molnar3701d8632008-02-09 23:24:08 +0100570 INTERRUPT_RETURN
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571.section .fixup,"ax"
Jeremy Fitzhardinge90e9f532008-03-17 16:37:12 -0700572ENTRY(iret_exc)
Linus Torvaldsa879cbb2005-04-29 09:38:44 -0700573 pushl $0 # no error code
574 pushl $do_iret_error
575 jmp error_code
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576.previous
577.section __ex_table,"a"
578 .align 4
Ingo Molnar3701d8632008-02-09 23:24:08 +0100579 .long irq_return,iret_exc
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580.previous
581
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200582 CFI_RESTORE_STATE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583ldt_ss:
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100584 larl PT_OLDSS(%esp), %eax
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 jnz restore_nocheck
586 testl $0x00400000, %eax # returning to 32bit stack?
587 jnz restore_nocheck # allright, normal return
Rusty Russelld3561b72006-12-07 02:14:07 +0100588
589#ifdef CONFIG_PARAVIRT
590 /*
591 * The kernel can't run on a non-flat stack if paravirt mode
592 * is active. Rather than try to fixup the high bits of
593 * ESP, bypass this code entirely. This may break DOSemu
594 * and/or Wine support in a paravirt VM, although the option
595 * is still available to implement the setting of the high
596 * 16-bits in the INTERRUPT_RETURN paravirt-op.
597 */
Jeremy Fitzhardinge93b1eab2007-10-16 11:51:29 -0700598 cmpl $0, pv_info+PARAVIRT_enabled
Rusty Russelld3561b72006-12-07 02:14:07 +0100599 jne restore_nocheck
600#endif
601
Alexander van Heukelumdc4c2a02009-06-18 00:35:58 +0200602/*
603 * Setup and switch to ESPFIX stack
604 *
605 * We're returning to userspace with a 16 bit stack. The CPU will not
606 * restore the high word of ESP for us on executing iret... This is an
607 * "official" bug of all the x86-compatible CPUs, which we can work
608 * around to make dosemu and wine happy. We do this by preloading the
609 * high word of ESP with the high word of the userspace ESP while
610 * compensating for the offset by changing to the ESPFIX segment with
611 * a base address that matches for the difference.
612 */
613 mov %esp, %edx /* load kernel esp */
614 mov PT_OLDESP(%esp), %eax /* load userspace esp */
615 mov %dx, %ax /* eax: new kernel esp */
616 sub %eax, %edx /* offset (low word is 0) */
617 PER_CPU(gdt_page, %ebx)
618 shr $16, %edx
619 mov %dl, GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx) /* bits 16..23 */
620 mov %dh, GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx) /* bits 24..31 */
Stas Sergeevbe44d2a2006-12-07 02:14:01 +0100621 pushl $__ESPFIX_SS
622 CFI_ADJUST_CFA_OFFSET 4
Alexander van Heukelumdc4c2a02009-06-18 00:35:58 +0200623 push %eax /* new kernel esp */
Stas Sergeevbe44d2a2006-12-07 02:14:01 +0100624 CFI_ADJUST_CFA_OFFSET 4
Alexander van Heukelum2e04bc72009-06-18 00:35:57 +0200625 /* Disable interrupts, but do not irqtrace this section: we
626 * will soon execute iret and the tracer was already set to
627 * the irqstate after the iret */
Rusty Russell139ec7c2006-12-07 02:14:08 +0100628 DISABLE_INTERRUPTS(CLBR_EAX)
Alexander van Heukelumdc4c2a02009-06-18 00:35:58 +0200629 lss (%esp), %esp /* switch to espfix segment */
Stas Sergeevbe44d2a2006-12-07 02:14:01 +0100630 CFI_ADJUST_CFA_OFFSET -8
631 jmp restore_nocheck
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200632 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100633ENDPROC(system_call)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
635 # perform work that needs to be done immediately before resumption
636 ALIGN
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200637 RING0_PTREGS_FRAME # can't unwind into user space anyway
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638work_pending:
639 testb $_TIF_NEED_RESCHED, %cl
640 jz work_notifysig
641work_resched:
642 call schedule
Peter Zijlstrac7e872e2007-10-11 22:11:12 +0200643 LOCKDEP_SYS_EXIT
Rusty Russell139ec7c2006-12-07 02:14:08 +0100644 DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 # setting need_resched or sigpending
646 # between sampling and the iret
Ingo Molnar55f327f2006-07-03 00:24:43 -0700647 TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 movl TI_flags(%ebp), %ecx
649 andl $_TIF_WORK_MASK, %ecx # is there any work to be done other
650 # than syscall tracing?
651 jz restore_all
652 testb $_TIF_NEED_RESCHED, %cl
653 jnz work_resched
654
655work_notifysig: # deal with pending signals and
656 # notify-resume requests
Joe Korty74b47a72006-12-07 02:14:04 +0100657#ifdef CONFIG_VM86
Cyrill Gorcunovab68ed92008-03-25 22:16:32 +0300658 testl $X86_EFLAGS_VM, PT_EFLAGS(%esp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 movl %esp, %eax
660 jne work_notifysig_v86 # returning to kernel-space or
661 # vm86-space
662 xorl %edx, %edx
663 call do_notify_resume
Aleksey Gorelov4031ff32006-06-27 02:53:48 -0700664 jmp resume_userspace_sig
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665
666 ALIGN
667work_notifysig_v86:
668 pushl %ecx # save ti_flags for do_notify_resume
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200669 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 call save_v86_state # %eax contains pt_regs pointer
671 popl %ecx
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200672 CFI_ADJUST_CFA_OFFSET -4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 movl %eax, %esp
Joe Korty74b47a72006-12-07 02:14:04 +0100674#else
675 movl %esp, %eax
676#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 xorl %edx, %edx
678 call do_notify_resume
Aleksey Gorelov4031ff32006-06-27 02:53:48 -0700679 jmp resume_userspace_sig
Jan Beulich47a55cd2007-02-13 13:26:24 +0100680END(work_pending)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681
682 # perform syscall exit tracing
683 ALIGN
684syscall_trace_entry:
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100685 movl $-ENOSYS,PT_EAX(%esp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 movl %esp, %eax
Roland McGrathd4d67152008-07-09 02:38:07 -0700687 call syscall_trace_enter
688 /* What it returned is what we'll actually use. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 cmpl $(nr_syscalls), %eax
690 jnae syscall_call
691 jmp syscall_exit
Jan Beulich47a55cd2007-02-13 13:26:24 +0100692END(syscall_trace_entry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
694 # perform syscall exit tracing
695 ALIGN
696syscall_exit_work:
Jaswinder Singh Rajput88200bc2009-03-14 12:08:13 +0530697 testl $_TIF_WORK_SYSCALL_EXIT, %ecx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 jz work_pending
Ingo Molnar55f327f2006-07-03 00:24:43 -0700699 TRACE_IRQS_ON
Roland McGrathd4d67152008-07-09 02:38:07 -0700700 ENABLE_INTERRUPTS(CLBR_ANY) # could let syscall_trace_leave() call
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 # schedule() instead
702 movl %esp, %eax
Roland McGrathd4d67152008-07-09 02:38:07 -0700703 call syscall_trace_leave
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 jmp resume_userspace
Jan Beulich47a55cd2007-02-13 13:26:24 +0100705END(syscall_exit_work)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200706 CFI_ENDPROC
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200708 RING0_INT_FRAME # can't unwind into user space anyway
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709syscall_fault:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 GET_THREAD_INFO(%ebp)
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100711 movl $-EFAULT,PT_EAX(%esp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 jmp resume_userspace
Jan Beulich47a55cd2007-02-13 13:26:24 +0100713END(syscall_fault)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715syscall_badsys:
Jeremy Fitzhardingeeb5b7b92006-12-07 02:14:02 +0100716 movl $-ENOSYS,PT_EAX(%esp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 jmp resume_userspace
Jan Beulich47a55cd2007-02-13 13:26:24 +0100718END(syscall_badsys)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200719 CFI_ENDPROC
Masami Hiramatsua00e8172009-09-08 12:47:55 -0400720/*
721 * End of kprobes section
722 */
723 .popsection
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
Brian Gerst253f29a2009-02-10 09:51:46 -0500725/*
726 * System calls that need a pt_regs pointer.
727 */
Brian Gerste258e4e2009-12-09 19:01:51 -0500728#define PTREGSCALL0(name) \
Brian Gerst253f29a2009-02-10 09:51:46 -0500729 ALIGN; \
730ptregs_##name: \
731 leal 4(%esp),%eax; \
732 jmp sys_##name;
733
Brian Gerste258e4e2009-12-09 19:01:51 -0500734#define PTREGSCALL1(name) \
735 ALIGN; \
736ptregs_##name: \
737 leal 4(%esp),%edx; \
738 movl PT_EBX(%edx),%eax; \
739 jmp sys_##name;
740
741#define PTREGSCALL2(name) \
742 ALIGN; \
743ptregs_##name: \
744 leal 4(%esp),%ecx; \
745 movl PT_ECX(%ecx),%edx; \
746 movl PT_EBX(%ecx),%eax; \
747 jmp sys_##name;
748
749#define PTREGSCALL3(name) \
750 ALIGN; \
751ptregs_##name: \
752 leal 4(%esp),%eax; \
753 pushl %eax; \
754 movl PT_EDX(%eax),%ecx; \
755 movl PT_ECX(%eax),%edx; \
756 movl PT_EBX(%eax),%eax; \
757 call sys_##name; \
758 addl $4,%esp; \
759 ret
760
Brian Gerst27f59552009-12-09 19:01:52 -0500761PTREGSCALL1(iopl)
Brian Gerste258e4e2009-12-09 19:01:51 -0500762PTREGSCALL0(fork)
763PTREGSCALL0(clone)
764PTREGSCALL0(vfork)
765PTREGSCALL0(execve)
766PTREGSCALL0(sigaltstack)
767PTREGSCALL0(sigreturn)
768PTREGSCALL0(rt_sigreturn)
769PTREGSCALL0(vm86)
770PTREGSCALL0(vm86old)
Brian Gerst253f29a2009-02-10 09:51:46 -0500771
Tejun Heof0d96112009-02-09 22:17:40 +0900772.macro FIXUP_ESPFIX_STACK
Alexander van Heukelumdc4c2a02009-06-18 00:35:58 +0200773/*
774 * Switch back for ESPFIX stack to the normal zerobased stack
775 *
776 * We can't call C functions using the ESPFIX stack. This code reads
777 * the high word of the segment base from the GDT and swiches to the
778 * normal stack and adjusts ESP with the matching offset.
779 */
780 /* fixup the stack */
Tejun Heof0d96112009-02-09 22:17:40 +0900781 PER_CPU(gdt_page, %ebx)
Alexander van Heukelumdc4c2a02009-06-18 00:35:58 +0200782 mov GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx), %al /* bits 16..23 */
783 mov GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx), %ah /* bits 24..31 */
784 shl $16, %eax
785 addl %esp, %eax /* the adjusted stack pointer */
Tejun Heof0d96112009-02-09 22:17:40 +0900786 pushl $__KERNEL_DS
787 CFI_ADJUST_CFA_OFFSET 4
788 pushl %eax
789 CFI_ADJUST_CFA_OFFSET 4
Alexander van Heukelumdc4c2a02009-06-18 00:35:58 +0200790 lss (%esp), %esp /* switch to the normal stack segment */
Tejun Heof0d96112009-02-09 22:17:40 +0900791 CFI_ADJUST_CFA_OFFSET -8
792.endm
793.macro UNWIND_ESPFIX_STACK
794 movl %ss, %eax
795 /* see if on espfix stack */
796 cmpw $__ESPFIX_SS, %ax
797 jne 27f
798 movl $__KERNEL_DS, %eax
799 movl %eax, %ds
800 movl %eax, %es
801 /* switch to normal stack */
802 FIXUP_ESPFIX_STACK
80327:
804.endm
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805
806/*
H. Peter Anvinb7c62442008-11-11 13:24:58 -0800807 * Build the entry stubs and pointer table with some assembler magic.
808 * We pack 7 stubs into a single 32-byte chunk, which will fit in a
809 * single cache line on all modern x86 implementations.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 */
H. Peter Anvin46875182008-11-11 13:03:07 -0800811.section .init.rodata,"a"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812ENTRY(interrupt)
813.text
H. Peter Anvinb7c62442008-11-11 13:24:58 -0800814 .p2align 5
815 .p2align CONFIG_X86_L1_CACHE_SHIFT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816ENTRY(irq_entries_start)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200817 RING0_INT_FRAME
H. Peter Anvin46875182008-11-11 13:03:07 -0800818vector=FIRST_EXTERNAL_VECTOR
H. Peter Anvinb7c62442008-11-11 13:24:58 -0800819.rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7
820 .balign 32
821 .rept 7
822 .if vector < NR_VECTORS
H. Peter Anvin86655962008-11-12 10:27:35 -0800823 .if vector <> FIRST_EXTERNAL_VECTOR
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200824 CFI_ADJUST_CFA_OFFSET -4
H. Peter Anvinb7c62442008-11-11 13:24:58 -0800825 .endif
8261: pushl $(~vector+0x80) /* Note: always in signed byte range */
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200827 CFI_ADJUST_CFA_OFFSET 4
H. Peter Anvin86655962008-11-12 10:27:35 -0800828 .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6
H. Peter Anvinb7c62442008-11-11 13:24:58 -0800829 jmp 2f
830 .endif
831 .previous
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 .long 1b
H. Peter Anvinb7c62442008-11-11 13:24:58 -0800833 .text
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834vector=vector+1
H. Peter Anvinb7c62442008-11-11 13:24:58 -0800835 .endif
836 .endr
8372: jmp common_interrupt
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838.endr
Jan Beulich47a55cd2007-02-13 13:26:24 +0100839END(irq_entries_start)
840
841.previous
842END(interrupt)
843.previous
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844
Ingo Molnar55f327f2006-07-03 00:24:43 -0700845/*
846 * the CPU automatically disables interrupts when executing an IRQ vector,
847 * so IRQ-flags tracing has to follow that:
848 */
H. Peter Anvinb7c62442008-11-11 13:24:58 -0800849 .p2align CONFIG_X86_L1_CACHE_SHIFT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850common_interrupt:
H. Peter Anvinb7c62442008-11-11 13:24:58 -0800851 addl $-0x80,(%esp) /* Adjust vector into the [-256,-1] range */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 SAVE_ALL
Ingo Molnar55f327f2006-07-03 00:24:43 -0700853 TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 movl %esp,%eax
855 call do_IRQ
856 jmp ret_from_intr
Jan Beulich47a55cd2007-02-13 13:26:24 +0100857ENDPROC(common_interrupt)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200858 CFI_ENDPROC
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859
Masami Hiramatsua00e8172009-09-08 12:47:55 -0400860/*
861 * Irq entries should be protected against kprobes
862 */
863 .pushsection .kprobes.text, "ax"
Tejun Heo02cf94c2009-01-21 17:26:06 +0900864#define BUILD_INTERRUPT3(name, nr, fn) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865ENTRY(name) \
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200866 RING0_INT_FRAME; \
Rusty Russell19eadf92006-06-27 02:53:44 -0700867 pushl $~(nr); \
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200868 CFI_ADJUST_CFA_OFFSET 4; \
869 SAVE_ALL; \
Ingo Molnar55f327f2006-07-03 00:24:43 -0700870 TRACE_IRQS_OFF \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 movl %esp,%eax; \
Tejun Heo02cf94c2009-01-21 17:26:06 +0900872 call fn; \
Ingo Molnar55f327f2006-07-03 00:24:43 -0700873 jmp ret_from_intr; \
Jan Beulich47a55cd2007-02-13 13:26:24 +0100874 CFI_ENDPROC; \
875ENDPROC(name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876
Tejun Heo02cf94c2009-01-21 17:26:06 +0900877#define BUILD_INTERRUPT(name, nr) BUILD_INTERRUPT3(name, nr, smp_##name)
878
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879/* The include is where all of the SMP etc. interrupts come from */
Ingo Molnar1164dd02009-01-28 19:34:09 +0100880#include <asm/entry_arch.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882ENTRY(coprocessor_error)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200883 RING0_INT_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 pushl $0
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200885 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 pushl $do_coprocessor_error
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200887 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200889 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100890END(coprocessor_error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
892ENTRY(simd_coprocessor_error)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200893 RING0_INT_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 pushl $0
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200895 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 pushl $do_simd_coprocessor_error
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200897 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200899 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100900END(simd_coprocessor_error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901
902ENTRY(device_not_available)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200903 RING0_INT_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 pushl $-1 # mark this as an int
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200905 CFI_ADJUST_CFA_OFFSET 4
Alexander van Heukelum7643e9b2008-09-09 21:56:02 +0200906 pushl $do_device_not_available
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200907 CFI_ADJUST_CFA_OFFSET 4
Alexander van Heukelum7643e9b2008-09-09 21:56:02 +0200908 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200909 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100910END(device_not_available)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911
Rusty Russelld3561b72006-12-07 02:14:07 +0100912#ifdef CONFIG_PARAVIRT
913ENTRY(native_iret)
Ingo Molnar3701d8632008-02-09 23:24:08 +0100914 iret
Rusty Russelld3561b72006-12-07 02:14:07 +0100915.section __ex_table,"a"
916 .align 4
Ingo Molnar3701d8632008-02-09 23:24:08 +0100917 .long native_iret, iret_exc
Rusty Russelld3561b72006-12-07 02:14:07 +0100918.previous
Jan Beulich47a55cd2007-02-13 13:26:24 +0100919END(native_iret)
Rusty Russelld3561b72006-12-07 02:14:07 +0100920
Jeremy Fitzhardinged75cd222008-06-25 00:19:26 -0400921ENTRY(native_irq_enable_sysexit)
Rusty Russelld3561b72006-12-07 02:14:07 +0100922 sti
923 sysexit
Jeremy Fitzhardinged75cd222008-06-25 00:19:26 -0400924END(native_irq_enable_sysexit)
Rusty Russelld3561b72006-12-07 02:14:07 +0100925#endif
926
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927ENTRY(overflow)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200928 RING0_INT_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 pushl $0
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200930 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 pushl $do_overflow
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200932 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200934 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100935END(overflow)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936
937ENTRY(bounds)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200938 RING0_INT_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 pushl $0
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200940 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 pushl $do_bounds
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200942 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200944 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100945END(bounds)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946
947ENTRY(invalid_op)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200948 RING0_INT_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 pushl $0
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200950 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 pushl $do_invalid_op
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200952 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200954 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100955END(invalid_op)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956
957ENTRY(coprocessor_segment_overrun)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200958 RING0_INT_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 pushl $0
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200960 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 pushl $do_coprocessor_segment_overrun
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200962 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200964 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100965END(coprocessor_segment_overrun)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966
967ENTRY(invalid_TSS)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200968 RING0_EC_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 pushl $do_invalid_TSS
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200970 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200972 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100973END(invalid_TSS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974
975ENTRY(segment_not_present)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200976 RING0_EC_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 pushl $do_segment_not_present
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200978 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200980 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100981END(segment_not_present)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982
983ENTRY(stack_segment)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200984 RING0_EC_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 pushl $do_stack_segment
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200986 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200988 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100989END(stack_segment)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991ENTRY(alignment_check)
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200992 RING0_EC_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 pushl $do_alignment_check
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200994 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +0200996 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +0100997END(alignment_check)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998
Prasanna S.Pd28c4392006-09-26 10:52:34 +0200999ENTRY(divide_error)
1000 RING0_INT_FRAME
1001 pushl $0 # no error code
1002 CFI_ADJUST_CFA_OFFSET 4
1003 pushl $do_divide_error
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001004 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001006 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +01001007END(divide_error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008
1009#ifdef CONFIG_X86_MCE
1010ENTRY(machine_check)
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001011 RING0_INT_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 pushl $0
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001013 CFI_ADJUST_CFA_OFFSET 4
Andi Kleend2f6f7a2008-10-21 22:45:22 +02001014 pushl machine_check_vector
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001015 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001017 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +01001018END(machine_check)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019#endif
1020
1021ENTRY(spurious_interrupt_bug)
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001022 RING0_INT_FRAME
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 pushl $0
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001024 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025 pushl $do_spurious_interrupt_bug
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001026 CFI_ADJUST_CFA_OFFSET 4
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 jmp error_code
Jan Beulichfe7cacc2006-06-26 13:57:44 +02001028 CFI_ENDPROC
Jan Beulich47a55cd2007-02-13 13:26:24 +01001029END(spurious_interrupt_bug)
Masami Hiramatsua00e8172009-09-08 12:47:55 -04001030/*
1031 * End of kprobes section
1032 */
1033 .popsection
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034
Andi Kleen02ba1a32006-09-26 10:52:35 +02001035ENTRY(kernel_thread_helper)
1036 pushl $0 # fake return address for unwinder
1037 CFI_STARTPROC
1038 movl %edx,%eax
1039 push %edx
1040 CFI_ADJUST_CFA_OFFSET 4
1041 call *%ebx
1042 push %eax
1043 CFI_ADJUST_CFA_OFFSET 4
1044 call do_exit
jia zhang5f5db592008-11-23 22:47:10 +08001045 ud2 # padding for call trace
Andi Kleen02ba1a32006-09-26 10:52:35 +02001046 CFI_ENDPROC
1047ENDPROC(kernel_thread_helper)
1048
Jeremy Fitzhardinge5ead97c2007-07-17 18:37:04 -07001049#ifdef CONFIG_XEN
Jeremy Fitzhardingee2a81ba2008-03-17 16:37:17 -07001050/* Xen doesn't set %esp to be precisely what the normal sysenter
1051 entrypoint expects, so fix it up before using the normal path. */
1052ENTRY(xen_sysenter_target)
1053 RING0_INT_FRAME
1054 addl $5*4, %esp /* remove xen-provided frame */
Jan Beulich2ddf9b72008-07-18 13:32:23 +01001055 CFI_ADJUST_CFA_OFFSET -5*4
Jeremy Fitzhardingee2a81ba2008-03-17 16:37:17 -07001056 jmp sysenter_past_esp
Glauber Costa557d7d42008-07-10 15:09:20 -03001057 CFI_ENDPROC
Jeremy Fitzhardingee2a81ba2008-03-17 16:37:17 -07001058
Jeremy Fitzhardinge5ead97c2007-07-17 18:37:04 -07001059ENTRY(xen_hypervisor_callback)
1060 CFI_STARTPROC
1061 pushl $0
1062 CFI_ADJUST_CFA_OFFSET 4
1063 SAVE_ALL
1064 TRACE_IRQS_OFF
Jeremy Fitzhardinge9ec2b802007-07-17 18:37:07 -07001065
1066 /* Check to see if we got the event in the critical
1067 region in xen_iret_direct, after we've reenabled
1068 events and checked for pending events. This simulates
1069 iret instruction's behaviour where it delivers a
1070 pending interrupt when enabling interrupts. */
1071 movl PT_EIP(%esp),%eax
1072 cmpl $xen_iret_start_crit,%eax
1073 jb 1f
1074 cmpl $xen_iret_end_crit,%eax
1075 jae 1f
1076
Jeremy Fitzhardinge0f2c8762008-03-17 16:37:22 -07001077 jmp xen_iret_crit_fixup
Jeremy Fitzhardinge9ec2b802007-07-17 18:37:07 -07001078
Jeremy Fitzhardingee2a81ba2008-03-17 16:37:17 -07001079ENTRY(xen_do_upcall)
Jeremy Fitzhardingeb77797f2008-04-02 10:54:11 -070010801: mov %esp, %eax
Jeremy Fitzhardinge5ead97c2007-07-17 18:37:04 -07001081 call xen_evtchn_do_upcall
1082 jmp ret_from_intr
1083 CFI_ENDPROC
1084ENDPROC(xen_hypervisor_callback)
1085
1086# Hypervisor uses this for application faults while it executes.
1087# We get here for two reasons:
1088# 1. Fault while reloading DS, ES, FS or GS
1089# 2. Fault while executing IRET
1090# Category 1 we fix up by reattempting the load, and zeroing the segment
1091# register if the load fails.
1092# Category 2 we fix up by jumping to do_iret_error. We cannot use the
1093# normal Linux return path in this case because if we use the IRET hypercall
1094# to pop the stack frame we end up in an infinite loop of failsafe callbacks.
1095# We distinguish between categories by maintaining a status value in EAX.
1096ENTRY(xen_failsafe_callback)
1097 CFI_STARTPROC
1098 pushl %eax
1099 CFI_ADJUST_CFA_OFFSET 4
1100 movl $1,%eax
11011: mov 4(%esp),%ds
11022: mov 8(%esp),%es
11033: mov 12(%esp),%fs
11044: mov 16(%esp),%gs
1105 testl %eax,%eax
1106 popl %eax
1107 CFI_ADJUST_CFA_OFFSET -4
1108 lea 16(%esp),%esp
1109 CFI_ADJUST_CFA_OFFSET -16
1110 jz 5f
1111 addl $16,%esp
1112 jmp iret_exc # EAX != 0 => Category 2 (Bad IRET)
11135: pushl $0 # EAX == 0 => Category 1 (Bad segment)
1114 CFI_ADJUST_CFA_OFFSET 4
1115 SAVE_ALL
1116 jmp ret_from_exception
1117 CFI_ENDPROC
1118
1119.section .fixup,"ax"
11206: xorl %eax,%eax
1121 movl %eax,4(%esp)
1122 jmp 1b
11237: xorl %eax,%eax
1124 movl %eax,8(%esp)
1125 jmp 2b
11268: xorl %eax,%eax
1127 movl %eax,12(%esp)
1128 jmp 3b
11299: xorl %eax,%eax
1130 movl %eax,16(%esp)
1131 jmp 4b
1132.previous
1133.section __ex_table,"a"
1134 .align 4
1135 .long 1b,6b
1136 .long 2b,7b
1137 .long 3b,8b
1138 .long 4b,9b
1139.previous
1140ENDPROC(xen_failsafe_callback)
1141
1142#endif /* CONFIG_XEN */
1143
Steven Rostedt606576c2008-10-06 19:06:12 -04001144#ifdef CONFIG_FUNCTION_TRACER
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001145#ifdef CONFIG_DYNAMIC_FTRACE
1146
1147ENTRY(mcount)
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001148 ret
1149END(mcount)
1150
1151ENTRY(ftrace_caller)
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05001152 cmpl $0, function_trace_stop
1153 jne ftrace_stub
1154
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001155 pushl %eax
1156 pushl %ecx
1157 pushl %edx
1158 movl 0xc(%esp), %eax
1159 movl 0x4(%ebp), %edx
Abhishek Sagar395a59d2008-06-21 23:47:27 +05301160 subl $MCOUNT_INSN_SIZE, %eax
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001161
1162.globl ftrace_call
1163ftrace_call:
1164 call ftrace_stub
1165
1166 popl %edx
1167 popl %ecx
1168 popl %eax
Steven Rostedt5a45cfe2008-11-26 00:16:24 -05001169#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1170.globl ftrace_graph_call
1171ftrace_graph_call:
1172 jmp ftrace_stub
1173#endif
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001174
1175.globl ftrace_stub
1176ftrace_stub:
1177 ret
1178END(ftrace_caller)
1179
1180#else /* ! CONFIG_DYNAMIC_FTRACE */
1181
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001182ENTRY(mcount)
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05001183 cmpl $0, function_trace_stop
1184 jne ftrace_stub
1185
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001186 cmpl $ftrace_stub, ftrace_trace_function
1187 jnz trace
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01001188#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Ingo Molnarc2324b62008-11-26 03:10:01 +01001189 cmpl $ftrace_stub, ftrace_graph_return
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01001190 jnz ftrace_graph_caller
Steven Rostedte49dc192008-12-02 23:50:05 -05001191
1192 cmpl $ftrace_graph_entry_stub, ftrace_graph_entry
1193 jnz ftrace_graph_caller
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001194#endif
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001195.globl ftrace_stub
1196ftrace_stub:
1197 ret
1198
1199 /* taken from glibc */
1200trace:
1201 pushl %eax
1202 pushl %ecx
1203 pushl %edx
1204 movl 0xc(%esp), %eax
1205 movl 0x4(%ebp), %edx
Abhishek Sagar395a59d2008-06-21 23:47:27 +05301206 subl $MCOUNT_INSN_SIZE, %eax
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001207
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001208 call *ftrace_trace_function
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001209
1210 popl %edx
1211 popl %ecx
1212 popl %eax
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001213 jmp ftrace_stub
1214END(mcount)
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001215#endif /* CONFIG_DYNAMIC_FTRACE */
Steven Rostedt606576c2008-10-06 19:06:12 -04001216#endif /* CONFIG_FUNCTION_TRACER */
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001217
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01001218#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1219ENTRY(ftrace_graph_caller)
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01001220 cmpl $0, function_trace_stop
1221 jne ftrace_stub
1222
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001223 pushl %eax
1224 pushl %ecx
1225 pushl %edx
Frederic Weisbecker1dc1c6a2008-11-12 22:49:23 +01001226 movl 0xc(%esp), %edx
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001227 lea 0x4(%ebp), %eax
Steven Rostedt71e308a2009-06-18 12:45:08 -04001228 movl (%ebp), %ecx
Steven Rostedtbb4304c2008-12-02 15:34:09 -05001229 subl $MCOUNT_INSN_SIZE, %edx
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001230 call prepare_ftrace_return
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001231 popl %edx
1232 popl %ecx
1233 popl %eax
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01001234 ret
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01001235END(ftrace_graph_caller)
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001236
1237.globl return_to_handler
1238return_to_handler:
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001239 pushl %eax
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001240 pushl %edx
Steven Rostedt71e308a2009-06-18 12:45:08 -04001241 movl %ebp, %eax
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001242 call ftrace_return_to_handler
Steven Rostedt194ec342009-10-13 16:33:50 -04001243 movl %eax, %ecx
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001244 popl %edx
Frederic Weisbeckercaf4b322008-11-11 07:03:45 +01001245 popl %eax
Steven Rostedt194ec342009-10-13 16:33:50 -04001246 jmp *%ecx
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01001247#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248
1249.section .rodata,"a"
1250#include "syscall_table_32.S"
1251
1252syscall_table_size=(.-sys_call_table)
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001253
1254/*
1255 * Some functions should be protected against kprobes
1256 */
1257 .pushsection .kprobes.text, "ax"
1258
1259ENTRY(page_fault)
1260 RING0_EC_FRAME
1261 pushl $do_page_fault
1262 CFI_ADJUST_CFA_OFFSET 4
1263 ALIGN
1264error_code:
Tejun Heoccbeed32009-02-09 22:17:40 +09001265 /* the function address is in %gs's slot on the stack */
1266 pushl %fs
1267 CFI_ADJUST_CFA_OFFSET 4
1268 /*CFI_REL_OFFSET fs, 0*/
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001269 pushl %es
1270 CFI_ADJUST_CFA_OFFSET 4
1271 /*CFI_REL_OFFSET es, 0*/
1272 pushl %ds
1273 CFI_ADJUST_CFA_OFFSET 4
1274 /*CFI_REL_OFFSET ds, 0*/
1275 pushl %eax
1276 CFI_ADJUST_CFA_OFFSET 4
1277 CFI_REL_OFFSET eax, 0
1278 pushl %ebp
1279 CFI_ADJUST_CFA_OFFSET 4
1280 CFI_REL_OFFSET ebp, 0
1281 pushl %edi
1282 CFI_ADJUST_CFA_OFFSET 4
1283 CFI_REL_OFFSET edi, 0
1284 pushl %esi
1285 CFI_ADJUST_CFA_OFFSET 4
1286 CFI_REL_OFFSET esi, 0
1287 pushl %edx
1288 CFI_ADJUST_CFA_OFFSET 4
1289 CFI_REL_OFFSET edx, 0
1290 pushl %ecx
1291 CFI_ADJUST_CFA_OFFSET 4
1292 CFI_REL_OFFSET ecx, 0
1293 pushl %ebx
1294 CFI_ADJUST_CFA_OFFSET 4
1295 CFI_REL_OFFSET ebx, 0
1296 cld
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001297 movl $(__KERNEL_PERCPU), %ecx
1298 movl %ecx, %fs
1299 UNWIND_ESPFIX_STACK
Tejun Heoccbeed32009-02-09 22:17:40 +09001300 GS_TO_REG %ecx
1301 movl PT_GS(%esp), %edi # get the function address
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001302 movl PT_ORIG_EAX(%esp), %edx # get the error code
1303 movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart
Tejun Heoccbeed32009-02-09 22:17:40 +09001304 REG_TO_PTGS %ecx
1305 SET_KERNEL_GS %ecx
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001306 movl $(__USER_DS), %ecx
1307 movl %ecx, %ds
1308 movl %ecx, %es
1309 TRACE_IRQS_OFF
1310 movl %esp,%eax # pt_regs pointer
1311 call *%edi
1312 jmp ret_from_exception
1313 CFI_ENDPROC
1314END(page_fault)
1315
1316/*
1317 * Debug traps and NMI can happen at the one SYSENTER instruction
1318 * that sets up the real kernel stack. Check here, since we can't
1319 * allow the wrong stack to be used.
1320 *
1321 * "TSS_sysenter_sp0+12" is because the NMI/debug handler will have
1322 * already pushed 3 words if it hits on the sysenter instruction:
1323 * eflags, cs and eip.
1324 *
1325 * We just load the right stack, and push the three (known) values
1326 * by hand onto the new stack - while updating the return eip past
1327 * the instruction that would have done it for sysenter.
1328 */
Tejun Heof0d96112009-02-09 22:17:40 +09001329.macro FIX_STACK offset ok label
1330 cmpw $__KERNEL_CS, 4(%esp)
1331 jne \ok
1332\label:
1333 movl TSS_sysenter_sp0 + \offset(%esp), %esp
1334 CFI_DEF_CFA esp, 0
1335 CFI_UNDEFINED eip
1336 pushfl
1337 CFI_ADJUST_CFA_OFFSET 4
1338 pushl $__KERNEL_CS
1339 CFI_ADJUST_CFA_OFFSET 4
1340 pushl $sysenter_past_esp
1341 CFI_ADJUST_CFA_OFFSET 4
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001342 CFI_REL_OFFSET eip, 0
Tejun Heof0d96112009-02-09 22:17:40 +09001343.endm
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001344
1345ENTRY(debug)
1346 RING0_INT_FRAME
1347 cmpl $ia32_sysenter_target,(%esp)
1348 jne debug_stack_correct
Tejun Heof0d96112009-02-09 22:17:40 +09001349 FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001350debug_stack_correct:
1351 pushl $-1 # mark this as an int
1352 CFI_ADJUST_CFA_OFFSET 4
1353 SAVE_ALL
1354 TRACE_IRQS_OFF
1355 xorl %edx,%edx # error code 0
1356 movl %esp,%eax # pt_regs pointer
1357 call do_debug
1358 jmp ret_from_exception
1359 CFI_ENDPROC
1360END(debug)
1361
1362/*
1363 * NMI is doubly nasty. It can happen _while_ we're handling
1364 * a debug fault, and the debug fault hasn't yet been able to
1365 * clear up the stack. So we first check whether we got an
1366 * NMI on the sysenter entry path, but after that we need to
1367 * check whether we got an NMI on the debug path where the debug
1368 * fault happened on the sysenter path.
1369 */
1370ENTRY(nmi)
1371 RING0_INT_FRAME
1372 pushl %eax
1373 CFI_ADJUST_CFA_OFFSET 4
1374 movl %ss, %eax
1375 cmpw $__ESPFIX_SS, %ax
1376 popl %eax
1377 CFI_ADJUST_CFA_OFFSET -4
1378 je nmi_espfix_stack
1379 cmpl $ia32_sysenter_target,(%esp)
1380 je nmi_stack_fixup
1381 pushl %eax
1382 CFI_ADJUST_CFA_OFFSET 4
1383 movl %esp,%eax
1384 /* Do not access memory above the end of our stack page,
1385 * it might not exist.
1386 */
1387 andl $(THREAD_SIZE-1),%eax
1388 cmpl $(THREAD_SIZE-20),%eax
1389 popl %eax
1390 CFI_ADJUST_CFA_OFFSET -4
1391 jae nmi_stack_correct
1392 cmpl $ia32_sysenter_target,12(%esp)
1393 je nmi_debug_stack_check
1394nmi_stack_correct:
1395 /* We have a RING0_INT_FRAME here */
1396 pushl %eax
1397 CFI_ADJUST_CFA_OFFSET 4
1398 SAVE_ALL
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001399 xorl %edx,%edx # zero error code
1400 movl %esp,%eax # pt_regs pointer
1401 call do_nmi
Alexander van Heukelum2e04bc72009-06-18 00:35:57 +02001402 jmp restore_all_notrace
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001403 CFI_ENDPROC
1404
1405nmi_stack_fixup:
1406 RING0_INT_FRAME
Tejun Heof0d96112009-02-09 22:17:40 +09001407 FIX_STACK 12, nmi_stack_correct, 1
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001408 jmp nmi_stack_correct
1409
1410nmi_debug_stack_check:
1411 /* We have a RING0_INT_FRAME here */
1412 cmpw $__KERNEL_CS,16(%esp)
1413 jne nmi_stack_correct
1414 cmpl $debug,(%esp)
1415 jb nmi_stack_correct
1416 cmpl $debug_esp_fix_insn,(%esp)
1417 ja nmi_stack_correct
Tejun Heof0d96112009-02-09 22:17:40 +09001418 FIX_STACK 24, nmi_stack_correct, 1
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001419 jmp nmi_stack_correct
1420
1421nmi_espfix_stack:
1422 /* We have a RING0_INT_FRAME here.
1423 *
1424 * create the pointer to lss back
1425 */
1426 pushl %ss
1427 CFI_ADJUST_CFA_OFFSET 4
1428 pushl %esp
1429 CFI_ADJUST_CFA_OFFSET 4
Stas Sergeevbda3a892009-02-23 19:13:07 +03001430 addl $4, (%esp)
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001431 /* copy the iret frame of 12 bytes */
1432 .rept 3
1433 pushl 16(%esp)
1434 CFI_ADJUST_CFA_OFFSET 4
1435 .endr
1436 pushl %eax
1437 CFI_ADJUST_CFA_OFFSET 4
1438 SAVE_ALL
Alexander van Heukelumd211af02008-11-24 15:38:45 +01001439 FIXUP_ESPFIX_STACK # %eax == %esp
1440 xorl %edx,%edx # zero error code
1441 call do_nmi
1442 RESTORE_REGS
1443 lss 12+4(%esp), %esp # back to espfix stack
1444 CFI_ADJUST_CFA_OFFSET -24
1445 jmp irq_return
1446 CFI_ENDPROC
1447END(nmi)
1448
1449ENTRY(int3)
1450 RING0_INT_FRAME
1451 pushl $-1 # mark this as an int
1452 CFI_ADJUST_CFA_OFFSET 4
1453 SAVE_ALL
1454 TRACE_IRQS_OFF
1455 xorl %edx,%edx # zero error code
1456 movl %esp,%eax # pt_regs pointer
1457 call do_int3
1458 jmp ret_from_exception
1459 CFI_ENDPROC
1460END(int3)
1461
1462ENTRY(general_protection)
1463 RING0_EC_FRAME
1464 pushl $do_general_protection
1465 CFI_ADJUST_CFA_OFFSET 4
1466 jmp error_code
1467 CFI_ENDPROC
1468END(general_protection)
1469
1470/*
1471 * End of kprobes section
1472 */
1473 .popsection