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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/x86_64/entry.S
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
6 * Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 */
8
9/*
10 * entry.S contains the system-call and fault low-level handling routines.
11 *
Andy Lutomirski8b4777a2011-06-05 13:50:18 -040012 * Some of this is documented in Documentation/x86/entry_64.txt
13 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070014 * NOTE: This code handles signal-recognition, which happens every time
15 * after an interrupt and after each system call.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +010016 *
17 * Normal syscalls and interrupts don't save a full stack frame, this is
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 * only done for syscall tracing, signals or fork/exec et.al.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +010019 *
20 * A note on terminology:
21 * - top of stack: Architecture defined interrupt frame from SS to RIP
22 * at the top of the kernel process stack.
Lucas De Marchi0d2eb442011-03-17 16:24:16 -030023 * - partial stack frame: partially saved registers up to R11.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +010024 * - full stack frame: Like partial stack frame, but all register saved.
Andi Kleen2e91a172006-09-26 10:52:29 +020025 *
26 * Some macro usage:
27 * - CFI macros are used to generate dwarf2 unwind information for better
28 * backtraces. They don't change any code.
29 * - SAVE_ALL/RESTORE_ALL - Save/restore all registers
30 * - SAVE_ARGS/RESTORE_ARGS - Save/restore registers that C functions modify.
31 * There are unfortunately lots of special cases where some registers
32 * not touched. The macro is a big mess that should be cleaned up.
33 * - SAVE_REST/RESTORE_REST - Handle the registers not saved by SAVE_ARGS.
34 * Gives a full stack frame.
35 * - ENTRY/END Define functions in the symbol table.
36 * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack
37 * frame that is otherwise undefined after a SYSCALL
38 * - TRACE_IRQ_* - Trace hard interrupt state for lock debugging.
39 * - errorentry/paranoidentry/zeroentry - Define exception entry points.
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 */
41
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <linux/linkage.h>
43#include <asm/segment.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#include <asm/cache.h>
45#include <asm/errno.h>
46#include <asm/dwarf2.h>
47#include <asm/calling.h>
Sam Ravnborge2d5df92005-09-09 21:28:48 +020048#include <asm/asm-offsets.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#include <asm/msr.h>
50#include <asm/unistd.h>
51#include <asm/thread_info.h>
52#include <asm/hw_irq.h>
Jeremy Fitzhardinge0341c142009-02-13 11:14:01 -080053#include <asm/page_types.h>
Ingo Molnar2601e642006-07-03 00:24:45 -070054#include <asm/irqflags.h>
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +010055#include <asm/paravirt.h>
Abhishek Sagar395a59d2008-06-21 23:47:27 +053056#include <asm/ftrace.h>
Tejun Heo9939dda2009-01-13 20:41:35 +090057#include <asm/percpu.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Roland McGrath86a1c342008-06-23 15:37:04 -070059/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
60#include <linux/elf-em.h>
61#define AUDIT_ARCH_X86_64 (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
62#define __AUDIT_ARCH_64BIT 0x80000000
63#define __AUDIT_ARCH_LE 0x40000000
64
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 .code64
Jiri Olsaea714542011-03-07 19:10:39 +010066 .section .entry.text, "ax"
67
Steven Rostedt606576c2008-10-06 19:06:12 -040068#ifdef CONFIG_FUNCTION_TRACER
Steven Rostedtd61f82d2008-05-12 21:20:43 +020069#ifdef CONFIG_DYNAMIC_FTRACE
70ENTRY(mcount)
Steven Rostedtd61f82d2008-05-12 21:20:43 +020071 retq
72END(mcount)
73
74ENTRY(ftrace_caller)
Steven Rostedt60a7ecf2008-11-05 16:05:44 -050075 cmpl $0, function_trace_stop
76 jne ftrace_stub
Steven Rostedtd61f82d2008-05-12 21:20:43 +020077
Cyrill Gorcunovd680fe42008-12-13 00:09:08 +030078 MCOUNT_SAVE_FRAME
Steven Rostedtd61f82d2008-05-12 21:20:43 +020079
80 movq 0x38(%rsp), %rdi
81 movq 8(%rbp), %rsi
Abhishek Sagar395a59d2008-06-21 23:47:27 +053082 subq $MCOUNT_INSN_SIZE, %rdi
Steven Rostedtd61f82d2008-05-12 21:20:43 +020083
Cyrill Gorcunovbc8b2b92009-02-23 22:57:01 +030084GLOBAL(ftrace_call)
Steven Rostedtd61f82d2008-05-12 21:20:43 +020085 call ftrace_stub
86
Cyrill Gorcunovd680fe42008-12-13 00:09:08 +030087 MCOUNT_RESTORE_FRAME
Steven Rostedtd61f82d2008-05-12 21:20:43 +020088
Frederic Weisbecker48d68b22008-12-02 00:20:39 +010089#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Cyrill Gorcunovbc8b2b92009-02-23 22:57:01 +030090GLOBAL(ftrace_graph_call)
Frederic Weisbecker48d68b22008-12-02 00:20:39 +010091 jmp ftrace_stub
92#endif
Steven Rostedtd61f82d2008-05-12 21:20:43 +020093
Cyrill Gorcunovbc8b2b92009-02-23 22:57:01 +030094GLOBAL(ftrace_stub)
Steven Rostedtd61f82d2008-05-12 21:20:43 +020095 retq
96END(ftrace_caller)
97
98#else /* ! CONFIG_DYNAMIC_FTRACE */
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +020099ENTRY(mcount)
Steven Rostedt60a7ecf2008-11-05 16:05:44 -0500100 cmpl $0, function_trace_stop
101 jne ftrace_stub
102
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200103 cmpq $ftrace_stub, ftrace_trace_function
104 jnz trace
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100105
106#ifdef CONFIG_FUNCTION_GRAPH_TRACER
107 cmpq $ftrace_stub, ftrace_graph_return
108 jnz ftrace_graph_caller
Steven Rostedte49dc192008-12-02 23:50:05 -0500109
110 cmpq $ftrace_graph_entry_stub, ftrace_graph_entry
111 jnz ftrace_graph_caller
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100112#endif
113
Cyrill Gorcunovbc8b2b92009-02-23 22:57:01 +0300114GLOBAL(ftrace_stub)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200115 retq
116
117trace:
Cyrill Gorcunovd680fe42008-12-13 00:09:08 +0300118 MCOUNT_SAVE_FRAME
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200119
120 movq 0x38(%rsp), %rdi
121 movq 8(%rbp), %rsi
Abhishek Sagar395a59d2008-06-21 23:47:27 +0530122 subq $MCOUNT_INSN_SIZE, %rdi
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200123
124 call *ftrace_trace_function
125
Cyrill Gorcunovd680fe42008-12-13 00:09:08 +0300126 MCOUNT_RESTORE_FRAME
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200127
128 jmp ftrace_stub
129END(mcount)
Steven Rostedtd61f82d2008-05-12 21:20:43 +0200130#endif /* CONFIG_DYNAMIC_FTRACE */
Steven Rostedt606576c2008-10-06 19:06:12 -0400131#endif /* CONFIG_FUNCTION_TRACER */
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200132
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100133#ifdef CONFIG_FUNCTION_GRAPH_TRACER
134ENTRY(ftrace_graph_caller)
135 cmpl $0, function_trace_stop
136 jne ftrace_stub
137
Cyrill Gorcunovd680fe42008-12-13 00:09:08 +0300138 MCOUNT_SAVE_FRAME
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100139
140 leaq 8(%rbp), %rdi
141 movq 0x38(%rsp), %rsi
Steven Rostedt71e308a2009-06-18 12:45:08 -0400142 movq (%rbp), %rdx
Steven Rostedtbb4304c2008-12-02 15:34:09 -0500143 subq $MCOUNT_INSN_SIZE, %rsi
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100144
145 call prepare_ftrace_return
146
Cyrill Gorcunovd680fe42008-12-13 00:09:08 +0300147 MCOUNT_RESTORE_FRAME
148
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100149 retq
150END(ftrace_graph_caller)
151
Cyrill Gorcunovbc8b2b92009-02-23 22:57:01 +0300152GLOBAL(return_to_handler)
Jiri Olsa4818d802009-07-29 10:58:37 +0200153 subq $24, %rsp
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100154
Steven Rostedte71e99c2009-03-25 14:30:04 -0400155 /* Save the return values */
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100156 movq %rax, (%rsp)
Steven Rostedte71e99c2009-03-25 14:30:04 -0400157 movq %rdx, 8(%rsp)
Steven Rostedt71e308a2009-06-18 12:45:08 -0400158 movq %rbp, %rdi
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100159
160 call ftrace_return_to_handler
161
Steven Rostedt194ec342009-10-13 16:33:50 -0400162 movq %rax, %rdi
Steven Rostedte71e99c2009-03-25 14:30:04 -0400163 movq 8(%rsp), %rdx
Jan Beulich7effaa82005-09-12 18:49:24 +0200164 movq (%rsp), %rax
Steven Rostedt194ec342009-10-13 16:33:50 -0400165 addq $24, %rsp
166 jmp *%rdi
Frederic Weisbecker48d68b22008-12-02 00:20:39 +0100167#endif
Jan Beulich7effaa82005-09-12 18:49:24 +0200168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170#ifndef CONFIG_PREEMPT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171#define retint_kernel retint_restore_args
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100172#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
174#ifdef CONFIG_PARAVIRT
175ENTRY(native_usergs_sysret64)
176 swapgs
177 sysretq
Cyrill Gorcunovb3baaa12009-02-23 22:57:00 +0300178ENDPROC(native_usergs_sysret64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179#endif /* CONFIG_PARAVIRT */
180
181
182.macro TRACE_IRQS_IRETQ offset=ARGOFFSET
183#ifdef CONFIG_TRACE_IRQFLAGS
184 bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */
185 jnc 1f
186 TRACE_IRQS_ON
1871:
188#endif
189.endm
190
191/*
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100192 * C code is not supposed to know about undefined top of stack. Every time
193 * a C function with an pt_regs argument is called from the SYSCALL based
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 * fast path FIXUP_TOP_OF_STACK is needed.
195 * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs
196 * manipulation.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100197 */
198
199 /* %rsp:at FRAMEEND */
Alexander van Heukelumc002a1e2008-11-21 16:41:55 +0100200 .macro FIXUP_TOP_OF_STACK tmp offset=0
Brian Gerst3d1e42a2009-01-19 00:38:58 +0900201 movq PER_CPU_VAR(old_rsp),\tmp
Alexander van Heukelumc002a1e2008-11-21 16:41:55 +0100202 movq \tmp,RSP+\offset(%rsp)
203 movq $__USER_DS,SS+\offset(%rsp)
204 movq $__USER_CS,CS+\offset(%rsp)
205 movq $-1,RCX+\offset(%rsp)
206 movq R11+\offset(%rsp),\tmp /* get eflags */
207 movq \tmp,EFLAGS+\offset(%rsp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 .endm
209
Alexander van Heukelumc002a1e2008-11-21 16:41:55 +0100210 .macro RESTORE_TOP_OF_STACK tmp offset=0
211 movq RSP+\offset(%rsp),\tmp
Brian Gerst3d1e42a2009-01-19 00:38:58 +0900212 movq \tmp,PER_CPU_VAR(old_rsp)
Alexander van Heukelumc002a1e2008-11-21 16:41:55 +0100213 movq EFLAGS+\offset(%rsp),\tmp
214 movq \tmp,R11+\offset(%rsp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 .endm
216
217 .macro FAKE_STACK_FRAME child_rip
218 /* push in order ss, rsp, eflags, cs, rip */
219 xorl %eax, %eax
Jan Beulichdf5d1872010-09-02 14:07:16 +0100220 pushq_cfi $__KERNEL_DS /* ss */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 /*CFI_REL_OFFSET ss,0*/
Jan Beulichdf5d1872010-09-02 14:07:16 +0100222 pushq_cfi %rax /* rsp */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 CFI_REL_OFFSET rsp,0
Jan Beulichdf5d1872010-09-02 14:07:16 +0100224 pushq_cfi $X86_EFLAGS_IF /* eflags - interrupts on */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 /*CFI_REL_OFFSET rflags,0*/
Jan Beulichdf5d1872010-09-02 14:07:16 +0100226 pushq_cfi $__KERNEL_CS /* cs */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 /*CFI_REL_OFFSET cs,0*/
Jan Beulichdf5d1872010-09-02 14:07:16 +0100228 pushq_cfi \child_rip /* rip */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 CFI_REL_OFFSET rip,0
Jan Beulichdf5d1872010-09-02 14:07:16 +0100230 pushq_cfi %rax /* orig rax */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 .endm
232
233 .macro UNFAKE_STACK_FRAME
234 addq $8*6, %rsp
235 CFI_ADJUST_CFA_OFFSET -(6*8)
236 .endm
237
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100238/*
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100239 * initial frame state for interrupts (and exceptions without error code)
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100240 */
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100241 .macro EMPTY_FRAME start=1 offset=0
242 .if \start
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100243 CFI_STARTPROC simple
244 CFI_SIGNAL_FRAME
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100245 CFI_DEF_CFA rsp,8+\offset
246 .else
247 CFI_DEF_CFA_OFFSET 8+\offset
248 .endif
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100249 .endm
250
251/*
252 * initial frame state for interrupts (and exceptions without error code)
253 */
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100254 .macro INTR_FRAME start=1 offset=0
Ingo Molnare8a0e272008-11-21 15:11:32 +0100255 EMPTY_FRAME \start, SS+8+\offset-RIP
256 /*CFI_REL_OFFSET ss, SS+\offset-RIP*/
257 CFI_REL_OFFSET rsp, RSP+\offset-RIP
258 /*CFI_REL_OFFSET rflags, EFLAGS+\offset-RIP*/
259 /*CFI_REL_OFFSET cs, CS+\offset-RIP*/
260 CFI_REL_OFFSET rip, RIP+\offset-RIP
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100261 .endm
262
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100263/*
264 * initial frame state for exceptions with error code (and interrupts
265 * with vector already pushed)
266 */
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100267 .macro XCPT_FRAME start=1 offset=0
Ingo Molnare8a0e272008-11-21 15:11:32 +0100268 INTR_FRAME \start, RIP+\offset-ORIG_RAX
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100269 /*CFI_REL_OFFSET orig_rax, ORIG_RAX-ORIG_RAX*/
270 .endm
271
272/*
273 * frame that enables calling into C.
274 */
275 .macro PARTIAL_FRAME start=1 offset=0
Ingo Molnare8a0e272008-11-21 15:11:32 +0100276 XCPT_FRAME \start, ORIG_RAX+\offset-ARGOFFSET
277 CFI_REL_OFFSET rdi, RDI+\offset-ARGOFFSET
278 CFI_REL_OFFSET rsi, RSI+\offset-ARGOFFSET
279 CFI_REL_OFFSET rdx, RDX+\offset-ARGOFFSET
280 CFI_REL_OFFSET rcx, RCX+\offset-ARGOFFSET
281 CFI_REL_OFFSET rax, RAX+\offset-ARGOFFSET
282 CFI_REL_OFFSET r8, R8+\offset-ARGOFFSET
283 CFI_REL_OFFSET r9, R9+\offset-ARGOFFSET
284 CFI_REL_OFFSET r10, R10+\offset-ARGOFFSET
285 CFI_REL_OFFSET r11, R11+\offset-ARGOFFSET
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100286 .endm
287
288/*
289 * frame that enables passing a complete pt_regs to a C function.
290 */
291 .macro DEFAULT_FRAME start=1 offset=0
Ingo Molnare8a0e272008-11-21 15:11:32 +0100292 PARTIAL_FRAME \start, R11+\offset-R15
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100293 CFI_REL_OFFSET rbx, RBX+\offset
294 CFI_REL_OFFSET rbp, RBP+\offset
295 CFI_REL_OFFSET r12, R12+\offset
296 CFI_REL_OFFSET r13, R13+\offset
297 CFI_REL_OFFSET r14, R14+\offset
298 CFI_REL_OFFSET r15, R15+\offset
299 .endm
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100300
301/* save partial stack frame */
Frederic Weisbecker18718532011-07-01 01:51:22 +0200302 .macro SAVE_ARGS_IRQ
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100303 cld
Frederic Weisbecker18718532011-07-01 01:51:22 +0200304 /* start from rbp in pt_regs and jump over */
305 movq_cfi rdi, RDI-RBP
306 movq_cfi rsi, RSI-RBP
307 movq_cfi rdx, RDX-RBP
308 movq_cfi rcx, RCX-RBP
309 movq_cfi rax, RAX-RBP
310 movq_cfi r8, R8-RBP
311 movq_cfi r9, R9-RBP
312 movq_cfi r10, R10-RBP
313 movq_cfi r11, R11-RBP
Ingo Molnar14ae22b2008-11-21 15:20:47 +0100314
Frederic Weisbeckera2bbe752011-07-02 16:52:45 +0200315 /* Save rbp so that we can unwind from get_irq_regs() */
316 movq_cfi rbp, 0
317
318 /* Save previous stack value */
319 movq %rsp, %rsi
Frederic Weisbecker3b99a3ef2011-07-01 02:25:17 +0200320
321 leaq -RBP(%rsp),%rdi /* arg1 for handler */
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100322 testl $3, CS(%rdi)
323 je 1f
324 SWAPGS
325 /*
Brian Gerst56895532009-01-19 00:38:58 +0900326 * irq_count is used to check if a CPU is already on an interrupt stack
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100327 * or not. While this is essentially redundant with preempt_count it is
328 * a little cheaper to use a separate counter in the PDA (short of
329 * moving irq_enter into assembly, which would be too much work)
330 */
Brian Gerst56895532009-01-19 00:38:58 +09003311: incl PER_CPU_VAR(irq_count)
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100332 jne 2f
Brian Gerst26f80bd2009-01-19 00:38:58 +0900333 mov PER_CPU_VAR(irq_stack_ptr),%rsp
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100334 EMPTY_FRAME 0
Frederic Weisbeckera2bbe752011-07-02 16:52:45 +0200335
3362: /* Store previous stack value */
337 pushq %rsi
338 /* We entered an interrupt context - irqs are off: */
339 TRACE_IRQS_OFF
Frederic Weisbecker18718532011-07-01 01:51:22 +0200340 .endm
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100341
Alexander van Heukelumc002a1e2008-11-21 16:41:55 +0100342ENTRY(save_rest)
343 PARTIAL_FRAME 1 REST_SKIP+8
344 movq 5*8+16(%rsp), %r11 /* save return address */
345 movq_cfi rbx, RBX+16
346 movq_cfi rbp, RBP+16
347 movq_cfi r12, R12+16
348 movq_cfi r13, R13+16
349 movq_cfi r14, R14+16
350 movq_cfi r15, R15+16
351 movq %r11, 8(%rsp) /* return address */
352 FIXUP_TOP_OF_STACK %r11, 16
353 ret
354 CFI_ENDPROC
355END(save_rest)
356
Alexander van Heukelume2f6bc22008-11-21 16:43:18 +0100357/* save complete stack frame */
Jan Beulichc2810182009-03-12 10:38:55 +0000358 .pushsection .kprobes.text, "ax"
Alexander van Heukelume2f6bc22008-11-21 16:43:18 +0100359ENTRY(save_paranoid)
360 XCPT_FRAME 1 RDI+8
361 cld
362 movq_cfi rdi, RDI+8
363 movq_cfi rsi, RSI+8
364 movq_cfi rdx, RDX+8
365 movq_cfi rcx, RCX+8
366 movq_cfi rax, RAX+8
367 movq_cfi r8, R8+8
368 movq_cfi r9, R9+8
369 movq_cfi r10, R10+8
370 movq_cfi r11, R11+8
371 movq_cfi rbx, RBX+8
372 movq_cfi rbp, RBP+8
373 movq_cfi r12, R12+8
374 movq_cfi r13, R13+8
375 movq_cfi r14, R14+8
376 movq_cfi r15, R15+8
377 movl $1,%ebx
378 movl $MSR_GS_BASE,%ecx
379 rdmsr
380 testl %edx,%edx
381 js 1f /* negative -> in kernel */
382 SWAPGS
383 xorl %ebx,%ebx
3841: ret
385 CFI_ENDPROC
386END(save_paranoid)
Jan Beulichc2810182009-03-12 10:38:55 +0000387 .popsection
Alexander van Heukelume2f6bc22008-11-21 16:43:18 +0100388
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389/*
Ingo Molnar5b3eec02008-11-27 14:41:21 +0100390 * A newly forked process directly context switches into this address.
391 *
392 * rdi: prev task we switched from
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100393 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394ENTRY(ret_from_fork)
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100395 DEFAULT_FRAME
Ingo Molnar5b3eec02008-11-27 14:41:21 +0100396
Benjamin LaHaise7106a5a2009-01-10 23:00:22 -0500397 LOCK ; btr $TIF_FORK,TI_flags(%r8)
398
Jan Beulichdf5d1872010-09-02 14:07:16 +0100399 pushq_cfi kernel_eflags(%rip)
400 popfq_cfi # reset kernel eflags
Ingo Molnar5b3eec02008-11-27 14:41:21 +0100401
402 call schedule_tail # rdi: 'prev' task parameter
403
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 GET_THREAD_INFO(%rcx)
Ingo Molnar5b3eec02008-11-27 14:41:21 +0100405
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 RESTORE_REST
Ingo Molnar5b3eec02008-11-27 14:41:21 +0100407
408 testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread?
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 je int_ret_from_sys_call
Ingo Molnar5b3eec02008-11-27 14:41:21 +0100410
411 testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 jnz int_ret_from_sys_call
Ingo Molnar5b3eec02008-11-27 14:41:21 +0100413
Alexander van Heukelumc002a1e2008-11-21 16:41:55 +0100414 RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET
Ingo Molnar5b3eec02008-11-27 14:41:21 +0100415 jmp ret_from_sys_call # go to the SYSRET fastpath
416
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 CFI_ENDPROC
Jan Beulich4b787e02006-06-26 13:56:55 +0200418END(ret_from_fork)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
420/*
Lucas De Marchi0d2eb442011-03-17 16:24:16 -0300421 * System call entry. Up to 6 arguments in registers are supported.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 *
423 * SYSCALL does not save anything on the stack and does not change the
424 * stack pointer.
425 */
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100426
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427/*
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100428 * Register setup:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 * rax system call number
430 * rdi arg0
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100431 * rcx return address for syscall/sysret, C arg3
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 * rsi arg1
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100433 * rdx arg2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 * r10 arg3 (--> moved to rcx for C)
435 * r8 arg4
436 * r9 arg5
437 * r11 eflags for syscall/sysret, temporary for C
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100438 * r12-r15,rbp,rbx saved by C code, not touched.
439 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 * Interrupts are off on entry.
441 * Only called from user space.
442 *
443 * XXX if we had a free scratch register we could save the RSP into the stack frame
444 * and report it properly in ps. Unfortunately we haven't.
Andi Kleen7bf36bb2006-04-07 19:50:00 +0200445 *
446 * When user can change the frames always force IRET. That is because
447 * it deals with uncanonical addresses better. SYSRET has trouble
448 * with them due to bugs in both AMD and Intel CPUs.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100449 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450
451ENTRY(system_call)
Jan Beulich7effaa82005-09-12 18:49:24 +0200452 CFI_STARTPROC simple
Jan Beulichadf14232006-09-26 10:52:41 +0200453 CFI_SIGNAL_FRAME
Brian Gerst9af45652009-01-19 00:38:58 +0900454 CFI_DEF_CFA rsp,KERNEL_STACK_OFFSET
Jan Beulich7effaa82005-09-12 18:49:24 +0200455 CFI_REGISTER rip,rcx
456 /*CFI_REGISTER rflags,r11*/
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100457 SWAPGS_UNSAFE_STACK
458 /*
459 * A hypervisor implementation might want to use a label
460 * after the swapgs, so that it can do the swapgs
461 * for the guest and jump here on syscall.
462 */
463ENTRY(system_call_after_swapgs)
464
Brian Gerst3d1e42a2009-01-19 00:38:58 +0900465 movq %rsp,PER_CPU_VAR(old_rsp)
Brian Gerst9af45652009-01-19 00:38:58 +0900466 movq PER_CPU_VAR(kernel_stack),%rsp
Ingo Molnar2601e642006-07-03 00:24:45 -0700467 /*
468 * No need to follow this irqs off/on section - it's straight
469 * and short:
470 */
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100471 ENABLE_INTERRUPTS(CLBR_NONE)
Borislav Petkovcac0e0a2011-05-31 22:21:52 +0200472 SAVE_ARGS 8,0
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100473 movq %rax,ORIG_RAX-ARGOFFSET(%rsp)
Jan Beulich7effaa82005-09-12 18:49:24 +0200474 movq %rcx,RIP-ARGOFFSET(%rsp)
475 CFI_REL_OFFSET rip,RIP-ARGOFFSET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 GET_THREAD_INFO(%rcx)
Roland McGrathd4d67152008-07-09 02:38:07 -0700477 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 jnz tracesys
Roland McGrath86a1c342008-06-23 15:37:04 -0700479system_call_fastpath:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 cmpq $__NR_syscall_max,%rax
481 ja badsys
482 movq %r10,%rcx
483 call *sys_call_table(,%rax,8) # XXX: rip relative
484 movq %rax,RAX-ARGOFFSET(%rsp)
485/*
486 * Syscall return path ending with SYSRET (fast path)
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100487 * Has incomplete stack frame and undefined top of stack.
488 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489ret_from_sys_call:
Andi Kleen11b854b2005-04-16 15:25:02 -0700490 movl $_TIF_ALLWORK_MASK,%edi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 /* edi: flagmask */
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100492sysret_check:
Peter Zijlstra10cd7062007-10-11 22:11:12 +0200493 LOCKDEP_SYS_EXIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 GET_THREAD_INFO(%rcx)
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100495 DISABLE_INTERRUPTS(CLBR_NONE)
Ingo Molnar2601e642006-07-03 00:24:45 -0700496 TRACE_IRQS_OFF
Glauber Costa26ccb8a2008-06-24 11:19:35 -0300497 movl TI_flags(%rcx),%edx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 andl %edi,%edx
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100499 jnz sysret_careful
Jan Beulichbcddc012006-12-07 02:14:02 +0100500 CFI_REMEMBER_STATE
Ingo Molnar2601e642006-07-03 00:24:45 -0700501 /*
502 * sysretq will re-enable interrupts:
503 */
504 TRACE_IRQS_ON
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 movq RIP-ARGOFFSET(%rsp),%rcx
Jan Beulich7effaa82005-09-12 18:49:24 +0200506 CFI_REGISTER rip,rcx
Borislav Petkov838feb42011-05-31 22:21:53 +0200507 RESTORE_ARGS 1,-ARG_SKIP,0
Jan Beulich7effaa82005-09-12 18:49:24 +0200508 /*CFI_REGISTER rflags,r11*/
Brian Gerst3d1e42a2009-01-19 00:38:58 +0900509 movq PER_CPU_VAR(old_rsp), %rsp
Jeremy Fitzhardinge2be29982008-06-25 00:19:28 -0400510 USERGS_SYSRET64
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511
Jan Beulichbcddc012006-12-07 02:14:02 +0100512 CFI_RESTORE_STATE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 /* Handle reschedules */
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100514 /* edx: work, edi: workmask */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515sysret_careful:
516 bt $TIF_NEED_RESCHED,%edx
517 jnc sysret_signal
Ingo Molnar2601e642006-07-03 00:24:45 -0700518 TRACE_IRQS_ON
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100519 ENABLE_INTERRUPTS(CLBR_NONE)
Jan Beulichdf5d1872010-09-02 14:07:16 +0100520 pushq_cfi %rdi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 call schedule
Jan Beulichdf5d1872010-09-02 14:07:16 +0100522 popq_cfi %rdi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 jmp sysret_check
524
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100525 /* Handle a signal */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526sysret_signal:
Ingo Molnar2601e642006-07-03 00:24:45 -0700527 TRACE_IRQS_ON
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100528 ENABLE_INTERRUPTS(CLBR_NONE)
Roland McGrath86a1c342008-06-23 15:37:04 -0700529#ifdef CONFIG_AUDITSYSCALL
530 bt $TIF_SYSCALL_AUDIT,%edx
531 jc sysret_audit
532#endif
Roland McGrathb60e7142009-09-22 16:46:34 -0700533 /*
534 * We have a signal, or exit tracing or single-step.
535 * These all wind up with the iret return path anyway,
536 * so just join that path right now.
537 */
538 FIXUP_TOP_OF_STACK %r11, -ARGOFFSET
539 jmp int_check_syscall_exit_work
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100540
Jan Beulich7effaa82005-09-12 18:49:24 +0200541badsys:
542 movq $-ENOSYS,RAX-ARGOFFSET(%rsp)
543 jmp ret_from_sys_call
544
Roland McGrath86a1c342008-06-23 15:37:04 -0700545#ifdef CONFIG_AUDITSYSCALL
546 /*
547 * Fast path for syscall audit without full syscall trace.
548 * We just call audit_syscall_entry() directly, and then
549 * jump back to the normal fast path.
550 */
551auditsys:
552 movq %r10,%r9 /* 6th arg: 4th syscall arg */
553 movq %rdx,%r8 /* 5th arg: 3rd syscall arg */
554 movq %rsi,%rcx /* 4th arg: 2nd syscall arg */
555 movq %rdi,%rdx /* 3rd arg: 1st syscall arg */
556 movq %rax,%rsi /* 2nd arg: syscall number */
557 movl $AUDIT_ARCH_X86_64,%edi /* 1st arg: audit arch */
558 call audit_syscall_entry
559 LOAD_ARGS 0 /* reload call-clobbered registers */
560 jmp system_call_fastpath
561
562 /*
563 * Return fast path for syscall audit. Call audit_syscall_exit()
564 * directly and then jump back to the fast path with TIF_SYSCALL_AUDIT
565 * masked off.
566 */
567sysret_audit:
Roland McGrath03275592010-07-21 17:44:12 -0700568 movq RAX-ARGOFFSET(%rsp),%rsi /* second arg, syscall return value */
569 cmpq $0,%rsi /* is it < 0? */
Roland McGrath86a1c342008-06-23 15:37:04 -0700570 setl %al /* 1 if so, 0 if not */
571 movzbl %al,%edi /* zero-extend that into %edi */
572 inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */
573 call audit_syscall_exit
574 movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
575 jmp sysret_check
576#endif /* CONFIG_AUDITSYSCALL */
577
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 /* Do syscall tracing */
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100579tracesys:
Roland McGrath86a1c342008-06-23 15:37:04 -0700580#ifdef CONFIG_AUDITSYSCALL
581 testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%rcx)
582 jz auditsys
583#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 SAVE_REST
Roland McGratha31f8dd2008-03-16 21:59:11 -0700585 movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 FIXUP_TOP_OF_STACK %rdi
587 movq %rsp,%rdi
588 call syscall_trace_enter
Roland McGrathd4d67152008-07-09 02:38:07 -0700589 /*
590 * Reload arg registers from stack in case ptrace changed them.
591 * We don't reload %rax because syscall_trace_enter() returned
592 * the value it wants us to use in the table lookup.
593 */
594 LOAD_ARGS ARGOFFSET, 1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 RESTORE_REST
596 cmpq $__NR_syscall_max,%rax
Roland McGratha31f8dd2008-03-16 21:59:11 -0700597 ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 movq %r10,%rcx /* fixup for C */
599 call *sys_call_table(,%rax,8)
Roland McGratha31f8dd2008-03-16 21:59:11 -0700600 movq %rax,RAX-ARGOFFSET(%rsp)
Andi Kleen7bf36bb2006-04-07 19:50:00 +0200601 /* Use IRET because user could have changed frame */
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100602
603/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 * Syscall return path ending with IRET.
605 * Has correct top of stack, but partial stack frame.
Jan Beulichbcddc012006-12-07 02:14:02 +0100606 */
Cyrill Gorcunovbc8b2b92009-02-23 22:57:01 +0300607GLOBAL(int_ret_from_sys_call)
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100608 DISABLE_INTERRUPTS(CLBR_NONE)
Ingo Molnar2601e642006-07-03 00:24:45 -0700609 TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 testl $3,CS-ARGOFFSET(%rsp)
611 je retint_restore_args
612 movl $_TIF_ALLWORK_MASK,%edi
613 /* edi: mask to check */
Cyrill Gorcunovbc8b2b92009-02-23 22:57:01 +0300614GLOBAL(int_with_check)
Peter Zijlstra10cd7062007-10-11 22:11:12 +0200615 LOCKDEP_SYS_EXIT_IRQ
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 GET_THREAD_INFO(%rcx)
Glauber Costa26ccb8a2008-06-24 11:19:35 -0300617 movl TI_flags(%rcx),%edx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 andl %edi,%edx
619 jnz int_careful
Glauber Costa26ccb8a2008-06-24 11:19:35 -0300620 andl $~TS_COMPAT,TI_status(%rcx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 jmp retint_swapgs
622
623 /* Either reschedule or signal or syscall exit tracking needed. */
624 /* First do a reschedule test. */
625 /* edx: work, edi: workmask */
626int_careful:
627 bt $TIF_NEED_RESCHED,%edx
628 jnc int_very_careful
Ingo Molnar2601e642006-07-03 00:24:45 -0700629 TRACE_IRQS_ON
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100630 ENABLE_INTERRUPTS(CLBR_NONE)
Jan Beulichdf5d1872010-09-02 14:07:16 +0100631 pushq_cfi %rdi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 call schedule
Jan Beulichdf5d1872010-09-02 14:07:16 +0100633 popq_cfi %rdi
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100634 DISABLE_INTERRUPTS(CLBR_NONE)
Ingo Molnar2601e642006-07-03 00:24:45 -0700635 TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 jmp int_with_check
637
638 /* handle signals and tracing -- both require a full stack frame */
639int_very_careful:
Ingo Molnar2601e642006-07-03 00:24:45 -0700640 TRACE_IRQS_ON
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100641 ENABLE_INTERRUPTS(CLBR_NONE)
Roland McGrathb60e7142009-09-22 16:46:34 -0700642int_check_syscall_exit_work:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 SAVE_REST
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100644 /* Check for syscall exit trace */
Roland McGrathd4d67152008-07-09 02:38:07 -0700645 testl $_TIF_WORK_SYSCALL_EXIT,%edx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 jz int_signal
Jan Beulichdf5d1872010-09-02 14:07:16 +0100647 pushq_cfi %rdi
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100648 leaq 8(%rsp),%rdi # &ptregs -> arg1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 call syscall_trace_leave
Jan Beulichdf5d1872010-09-02 14:07:16 +0100650 popq_cfi %rdi
Roland McGrathd4d67152008-07-09 02:38:07 -0700651 andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 jmp int_restore_rest
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100653
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654int_signal:
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +0100655 testl $_TIF_DO_NOTIFY_MASK,%edx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 jz 1f
657 movq %rsp,%rdi # &ptregs -> arg1
658 xorl %esi,%esi # oldset -> arg2
659 call do_notify_resume
Roland McGratheca91e72008-07-10 14:50:39 -07006601: movl $_TIF_WORK_MASK,%edi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661int_restore_rest:
662 RESTORE_REST
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100663 DISABLE_INTERRUPTS(CLBR_NONE)
Ingo Molnar2601e642006-07-03 00:24:45 -0700664 TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 jmp int_with_check
666 CFI_ENDPROC
Jan Beulichbcddc012006-12-07 02:14:02 +0100667END(system_call)
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100668
669/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 * Certain special system calls that need to save a complete full stack frame.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100671 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 .macro PTREGSCALL label,func,arg
Alexander van Heukelumc002a1e2008-11-21 16:41:55 +0100673ENTRY(\label)
674 PARTIAL_FRAME 1 8 /* offset 8: return address */
675 subq $REST_SKIP, %rsp
676 CFI_ADJUST_CFA_OFFSET REST_SKIP
677 call save_rest
678 DEFAULT_FRAME 0 8 /* offset 8: return address */
679 leaq 8(%rsp), \arg /* pt_regs pointer */
680 call \func
681 jmp ptregscall_common
682 CFI_ENDPROC
Jan Beulich4b787e02006-06-26 13:56:55 +0200683END(\label)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 .endm
685
686 PTREGSCALL stub_clone, sys_clone, %r8
687 PTREGSCALL stub_fork, sys_fork, %rdi
688 PTREGSCALL stub_vfork, sys_vfork, %rdi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx
690 PTREGSCALL stub_iopl, sys_iopl, %rsi
691
692ENTRY(ptregscall_common)
Alexander van Heukelumc002a1e2008-11-21 16:41:55 +0100693 DEFAULT_FRAME 1 8 /* offset 8: return address */
694 RESTORE_TOP_OF_STACK %r11, 8
695 movq_cfi_restore R15+8, r15
696 movq_cfi_restore R14+8, r14
697 movq_cfi_restore R13+8, r13
698 movq_cfi_restore R12+8, r12
699 movq_cfi_restore RBP+8, rbp
700 movq_cfi_restore RBX+8, rbx
701 ret $REST_SKIP /* pop extended registers */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 CFI_ENDPROC
Jan Beulich4b787e02006-06-26 13:56:55 +0200703END(ptregscall_common)
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100704
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705ENTRY(stub_execve)
706 CFI_STARTPROC
Jan Beuliche6b04b62010-09-02 13:52:45 +0100707 addq $8, %rsp
708 PARTIAL_FRAME 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 SAVE_REST
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 FIXUP_TOP_OF_STACK %r11
Ingo Molnar5d119b22008-02-26 12:55:57 +0100711 movq %rsp, %rcx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 call sys_execve
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 RESTORE_TOP_OF_STACK %r11
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 movq %rax,RAX(%rsp)
715 RESTORE_REST
716 jmp int_ret_from_sys_call
717 CFI_ENDPROC
Jan Beulich4b787e02006-06-26 13:56:55 +0200718END(stub_execve)
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100719
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720/*
721 * sigreturn is special because it needs to restore all registers on return.
722 * This cannot be done with SYSRET, so use the IRET return path instead.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100723 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724ENTRY(stub_rt_sigreturn)
725 CFI_STARTPROC
Jan Beulich7effaa82005-09-12 18:49:24 +0200726 addq $8, %rsp
Jan Beuliche6b04b62010-09-02 13:52:45 +0100727 PARTIAL_FRAME 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 SAVE_REST
729 movq %rsp,%rdi
730 FIXUP_TOP_OF_STACK %r11
731 call sys_rt_sigreturn
732 movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer
733 RESTORE_REST
734 jmp int_ret_from_sys_call
735 CFI_ENDPROC
Jan Beulich4b787e02006-06-26 13:56:55 +0200736END(stub_rt_sigreturn)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737
Jan Beulich7effaa82005-09-12 18:49:24 +0200738/*
H. Peter Anvin939b7872008-11-11 13:51:52 -0800739 * Build the entry stubs and pointer table with some assembler magic.
740 * We pack 7 stubs into a single 32-byte chunk, which will fit in a
741 * single cache line on all modern x86 implementations.
742 */
743 .section .init.rodata,"a"
744ENTRY(interrupt)
Jiri Olsaea714542011-03-07 19:10:39 +0100745 .section .entry.text
H. Peter Anvin939b7872008-11-11 13:51:52 -0800746 .p2align 5
747 .p2align CONFIG_X86_L1_CACHE_SHIFT
748ENTRY(irq_entries_start)
749 INTR_FRAME
750vector=FIRST_EXTERNAL_VECTOR
751.rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7
752 .balign 32
753 .rept 7
754 .if vector < NR_VECTORS
H. Peter Anvin86655962008-11-12 10:27:35 -0800755 .if vector <> FIRST_EXTERNAL_VECTOR
H. Peter Anvin939b7872008-11-11 13:51:52 -0800756 CFI_ADJUST_CFA_OFFSET -8
757 .endif
Jan Beulichdf5d1872010-09-02 14:07:16 +01007581: pushq_cfi $(~vector+0x80) /* Note: always in signed byte range */
H. Peter Anvin86655962008-11-12 10:27:35 -0800759 .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6
H. Peter Anvin939b7872008-11-11 13:51:52 -0800760 jmp 2f
761 .endif
762 .previous
763 .quad 1b
Jiri Olsaea714542011-03-07 19:10:39 +0100764 .section .entry.text
H. Peter Anvin939b7872008-11-11 13:51:52 -0800765vector=vector+1
766 .endif
767 .endr
7682: jmp common_interrupt
769.endr
770 CFI_ENDPROC
771END(irq_entries_start)
772
773.previous
774END(interrupt)
775.previous
776
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100777/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 * Interrupt entry/exit.
779 *
780 * Interrupt entry points save only callee clobbered registers in fast path.
Alexander van Heukelumd99015b2008-11-19 01:18:11 +0100781 *
782 * Entry runs with interrupts off.
783 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784
Alexander van Heukelum722024d2008-11-13 13:50:20 +0100785/* 0(%rsp): ~(interrupt number) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 .macro interrupt func
Frederic Weisbecker625dbc32011-01-06 15:22:47 +0100787 /* reserve pt_regs for scratch regs and rbp */
788 subq $ORIG_RAX-RBP, %rsp
789 CFI_ADJUST_CFA_OFFSET ORIG_RAX-RBP
Frederic Weisbecker18718532011-07-01 01:51:22 +0200790 SAVE_ARGS_IRQ
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +0100791 PARTIAL_FRAME 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 call \func
793 .endm
794
Masami Hiramatsu8222d712009-08-27 13:23:25 -0400795/*
796 * Interrupt entry/exit should be protected against kprobes
797 */
798 .pushsection .kprobes.text, "ax"
Alexander van Heukelum722024d2008-11-13 13:50:20 +0100799 /*
800 * The interrupt stubs push (~vector+0x80) onto the stack and
801 * then jump to common_interrupt.
802 */
H. Peter Anvin939b7872008-11-11 13:51:52 -0800803 .p2align CONFIG_X86_L1_CACHE_SHIFT
804common_interrupt:
Jan Beulich7effaa82005-09-12 18:49:24 +0200805 XCPT_FRAME
Alexander van Heukelum722024d2008-11-13 13:50:20 +0100806 addq $-0x80,(%rsp) /* Adjust vector to [-256,-1] range */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 interrupt do_IRQ
Brian Gerst3d1e42a2009-01-19 00:38:58 +0900808 /* 0(%rsp): old_rsp-ARGOFFSET */
Jan Beulich7effaa82005-09-12 18:49:24 +0200809ret_from_intr:
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100810 DISABLE_INTERRUPTS(CLBR_NONE)
Ingo Molnar2601e642006-07-03 00:24:45 -0700811 TRACE_IRQS_OFF
Brian Gerst56895532009-01-19 00:38:58 +0900812 decl PER_CPU_VAR(irq_count)
Frederic Weisbecker625dbc32011-01-06 15:22:47 +0100813
Frederic Weisbeckera2bbe752011-07-02 16:52:45 +0200814 /* Restore saved previous stack */
815 popq %rsi
816 leaq 16(%rsi), %rsp
817
Jan Beulich7effaa82005-09-12 18:49:24 +0200818 CFI_DEF_CFA_REGISTER rsp
Frederic Weisbeckera2bbe752011-07-02 16:52:45 +0200819 CFI_ADJUST_CFA_OFFSET -16
Frederic Weisbecker625dbc32011-01-06 15:22:47 +0100820
Jan Beulich7effaa82005-09-12 18:49:24 +0200821exit_intr:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822 GET_THREAD_INFO(%rcx)
823 testl $3,CS-ARGOFFSET(%rsp)
824 je retint_kernel
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100825
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 /* Interrupt came from user space */
827 /*
828 * Has a correct top of stack, but a partial stack frame
829 * %rcx: thread info. Interrupts off.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100830 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831retint_with_reschedule:
832 movl $_TIF_WORK_MASK,%edi
Jan Beulich7effaa82005-09-12 18:49:24 +0200833retint_check:
Peter Zijlstra10cd7062007-10-11 22:11:12 +0200834 LOCKDEP_SYS_EXIT_IRQ
Glauber Costa26ccb8a2008-06-24 11:19:35 -0300835 movl TI_flags(%rcx),%edx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 andl %edi,%edx
Jan Beulich7effaa82005-09-12 18:49:24 +0200837 CFI_REMEMBER_STATE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 jnz retint_careful
Peter Zijlstra10cd7062007-10-11 22:11:12 +0200839
840retint_swapgs: /* return to user-space */
Ingo Molnar2601e642006-07-03 00:24:45 -0700841 /*
842 * The iretq could re-enable interrupts:
843 */
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100844 DISABLE_INTERRUPTS(CLBR_ANY)
Ingo Molnar2601e642006-07-03 00:24:45 -0700845 TRACE_IRQS_IRETQ
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100846 SWAPGS
Ingo Molnar2601e642006-07-03 00:24:45 -0700847 jmp restore_args
848
Peter Zijlstra10cd7062007-10-11 22:11:12 +0200849retint_restore_args: /* return to kernel space */
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100850 DISABLE_INTERRUPTS(CLBR_ANY)
Ingo Molnar2601e642006-07-03 00:24:45 -0700851 /*
852 * The iretq could re-enable interrupts:
853 */
854 TRACE_IRQS_IRETQ
855restore_args:
Borislav Petkov838feb42011-05-31 22:21:53 +0200856 RESTORE_ARGS 1,8,1
Ingo Molnar3701d8632008-02-09 23:24:08 +0100857
Adrian Bunkf7f3d792008-02-13 23:29:53 +0200858irq_return:
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100859 INTERRUPT_RETURN
Ingo Molnar3701d8632008-02-09 23:24:08 +0100860
861 .section __ex_table, "a"
862 .quad irq_return, bad_iret
863 .previous
864
865#ifdef CONFIG_PARAVIRT
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100866ENTRY(native_iret)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 iretq
868
869 .section __ex_table,"a"
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100870 .quad native_iret, bad_iret
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 .previous
Ingo Molnar3701d8632008-02-09 23:24:08 +0100872#endif
873
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 .section .fixup,"ax"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875bad_iret:
Roland McGrath3aa4b372008-02-06 22:39:43 +0100876 /*
877 * The iret traps when the %cs or %ss being restored is bogus.
878 * We've lost the original trap vector and error code.
879 * #GPF is the most likely one to get for an invalid selector.
880 * So pretend we completed the iret and took the #GPF in user mode.
881 *
882 * We are now running with the kernel GS after exception recovery.
883 * But error_entry expects us to have user GS to match the user %cs,
884 * so swap back.
885 */
886 pushq $0
887
888 SWAPGS
889 jmp general_protection
890
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100891 .previous
892
Jan Beulich7effaa82005-09-12 18:49:24 +0200893 /* edi: workmask, edx: work */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894retint_careful:
Jan Beulich7effaa82005-09-12 18:49:24 +0200895 CFI_RESTORE_STATE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 bt $TIF_NEED_RESCHED,%edx
897 jnc retint_signal
Ingo Molnar2601e642006-07-03 00:24:45 -0700898 TRACE_IRQS_ON
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100899 ENABLE_INTERRUPTS(CLBR_NONE)
Jan Beulichdf5d1872010-09-02 14:07:16 +0100900 pushq_cfi %rdi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 call schedule
Jan Beulichdf5d1872010-09-02 14:07:16 +0100902 popq_cfi %rdi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 GET_THREAD_INFO(%rcx)
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100904 DISABLE_INTERRUPTS(CLBR_NONE)
Ingo Molnar2601e642006-07-03 00:24:45 -0700905 TRACE_IRQS_OFF
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 jmp retint_check
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100907
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908retint_signal:
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +0100909 testl $_TIF_DO_NOTIFY_MASK,%edx
Andi Kleen10ffdbb2005-05-16 21:53:19 -0700910 jz retint_swapgs
Ingo Molnar2601e642006-07-03 00:24:45 -0700911 TRACE_IRQS_ON
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100912 ENABLE_INTERRUPTS(CLBR_NONE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 SAVE_REST
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100914 movq $-1,ORIG_RAX(%rsp)
Andi Kleen3829ee62005-07-28 21:15:48 -0700915 xorl %esi,%esi # oldset
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 movq %rsp,%rdi # &pt_regs
917 call do_notify_resume
918 RESTORE_REST
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +0100919 DISABLE_INTERRUPTS(CLBR_NONE)
Ingo Molnar2601e642006-07-03 00:24:45 -0700920 TRACE_IRQS_OFF
Andi Kleenbe9e6872005-05-01 08:58:51 -0700921 GET_THREAD_INFO(%rcx)
Roland McGratheca91e72008-07-10 14:50:39 -0700922 jmp retint_with_reschedule
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923
924#ifdef CONFIG_PREEMPT
925 /* Returning to kernel space. Check if we need preemption */
926 /* rcx: threadinfo. interrupts off. */
Andi Kleenb06baba2006-09-26 10:52:29 +0200927ENTRY(retint_kernel)
Glauber Costa26ccb8a2008-06-24 11:19:35 -0300928 cmpl $0,TI_preempt_count(%rcx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 jnz retint_restore_args
Glauber Costa26ccb8a2008-06-24 11:19:35 -0300930 bt $TIF_NEED_RESCHED,TI_flags(%rcx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 jnc retint_restore_args
932 bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */
933 jnc retint_restore_args
934 call preempt_schedule_irq
935 jmp exit_intr
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100936#endif
Jan Beulich4b787e02006-06-26 13:56:55 +0200937
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 CFI_ENDPROC
Jan Beulich4b787e02006-06-26 13:56:55 +0200939END(common_interrupt)
Masami Hiramatsu8222d712009-08-27 13:23:25 -0400940/*
941 * End of kprobes section
942 */
943 .popsection
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100944
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945/*
946 * APIC interrupts.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100947 */
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100948.macro apicinterrupt num sym do_sym
949ENTRY(\sym)
Jan Beulich7effaa82005-09-12 18:49:24 +0200950 INTR_FRAME
Jan Beulichdf5d1872010-09-02 14:07:16 +0100951 pushq_cfi $~(\num)
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100952 interrupt \do_sym
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 jmp ret_from_intr
954 CFI_ENDPROC
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100955END(\sym)
956.endm
Jacob Shin89b831e2005-11-05 17:25:53 +0100957
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +0100958#ifdef CONFIG_SMP
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100959apicinterrupt IRQ_MOVE_CLEANUP_VECTOR \
960 irq_move_cleanup_interrupt smp_irq_move_cleanup_interrupt
Andi Kleen4ef702c2009-05-27 21:56:52 +0200961apicinterrupt REBOOT_VECTOR \
962 reboot_interrupt smp_reboot_interrupt
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963#endif
964
Nick Piggin03b48632009-01-20 04:36:04 +0100965#ifdef CONFIG_X86_UV
Cyrill Gorcunov5ae3a132008-11-27 00:02:10 +0300966apicinterrupt UV_BAU_MESSAGE \
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100967 uv_bau_message_intr1 uv_bau_message_interrupt
Nick Piggin03b48632009-01-20 04:36:04 +0100968#endif
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100969apicinterrupt LOCAL_TIMER_VECTOR \
970 apic_timer_interrupt smp_apic_timer_interrupt
Dimitri Sivanich4a4de9c2009-10-14 09:22:57 -0500971apicinterrupt X86_PLATFORM_IPI_VECTOR \
972 x86_platform_ipi smp_x86_platform_ipi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100974#ifdef CONFIG_SMP
Shaohua Li3a09fb42011-01-17 10:52:05 +0800975.irp idx,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15, \
976 16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
977.if NUM_INVALIDATE_TLB_VECTORS > \idx
Jan Beulich32342822010-10-19 14:52:26 +0100978apicinterrupt (INVALIDATE_TLB_VECTOR_START)+\idx \
979 invalidate_interrupt\idx smp_invalidate_interrupt
Shaohua Li3a09fb42011-01-17 10:52:05 +0800980.endif
Jan Beulich32342822010-10-19 14:52:26 +0100981.endr
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100982#endif
Cliff Wickman18129242008-06-02 08:56:14 -0500983
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100984apicinterrupt THRESHOLD_APIC_VECTOR \
Andi Kleen7856f6c2009-04-28 23:32:56 +0200985 threshold_interrupt smp_threshold_interrupt
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100986apicinterrupt THERMAL_APIC_VECTOR \
987 thermal_interrupt smp_thermal_interrupt
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988
Alexander van Heukelum322648d2008-11-23 10:08:28 +0100989#ifdef CONFIG_SMP
990apicinterrupt CALL_FUNCTION_SINGLE_VECTOR \
991 call_function_single_interrupt smp_call_function_single_interrupt
992apicinterrupt CALL_FUNCTION_VECTOR \
993 call_function_interrupt smp_call_function_interrupt
994apicinterrupt RESCHEDULE_VECTOR \
995 reschedule_interrupt smp_reschedule_interrupt
996#endif
997
998apicinterrupt ERROR_APIC_VECTOR \
999 error_interrupt smp_error_interrupt
1000apicinterrupt SPURIOUS_APIC_VECTOR \
1001 spurious_interrupt smp_spurious_interrupt
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +01001002
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001003#ifdef CONFIG_IRQ_WORK
1004apicinterrupt IRQ_WORK_VECTOR \
1005 irq_work_interrupt smp_irq_work_interrupt
Ingo Molnar241771e2008-12-03 10:39:53 +01001006#endif
1007
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008/*
1009 * Exception entry points.
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +01001010 */
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001011.macro zeroentry sym do_sym
1012ENTRY(\sym)
Jan Beulich7effaa82005-09-12 18:49:24 +02001013 INTR_FRAME
Jeremy Fitzhardingefab58422008-06-25 00:19:31 -04001014 PARAVIRT_ADJUST_EXCEPTION_FRAME
Ingo Molnar14ae22b2008-11-21 15:20:47 +01001015 pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
Jan Beulichb1cccb12010-09-02 13:55:11 +01001016 subq $ORIG_RAX-R15, %rsp
1017 CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
Alexander van Heukelumd99015b2008-11-19 01:18:11 +01001018 call error_entry
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +01001019 DEFAULT_FRAME 0
Alexander van Heukelumd99015b2008-11-19 01:18:11 +01001020 movq %rsp,%rdi /* pt_regs pointer */
1021 xorl %esi,%esi /* no error code */
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001022 call \do_sym
Alexander van Heukelumd99015b2008-11-19 01:18:11 +01001023 jmp error_exit /* %ebx: no swapgs flag */
Jan Beulich7effaa82005-09-12 18:49:24 +02001024 CFI_ENDPROC
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001025END(\sym)
1026.endm
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001028.macro paranoidzeroentry sym do_sym
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001029ENTRY(\sym)
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001030 INTR_FRAME
1031 PARAVIRT_ADJUST_EXCEPTION_FRAME
Jan Beulichb1cccb12010-09-02 13:55:11 +01001032 pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
1033 subq $ORIG_RAX-R15, %rsp
1034 CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001035 call save_paranoid
1036 TRACE_IRQS_OFF
1037 movq %rsp,%rdi /* pt_regs pointer */
1038 xorl %esi,%esi /* no error code */
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001039 call \do_sym
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001040 jmp paranoid_exit /* %ebx: no swapgs flag */
1041 CFI_ENDPROC
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001042END(\sym)
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001043.endm
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001044
Brian Gerstc15a5952010-07-31 12:48:22 -04001045#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001046.macro paranoidzeroentry_ist sym do_sym ist
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001047ENTRY(\sym)
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001048 INTR_FRAME
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001049 PARAVIRT_ADJUST_EXCEPTION_FRAME
Jan Beulichb1cccb12010-09-02 13:55:11 +01001050 pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
1051 subq $ORIG_RAX-R15, %rsp
1052 CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001053 call save_paranoid
1054 TRACE_IRQS_OFF
1055 movq %rsp,%rdi /* pt_regs pointer */
1056 xorl %esi,%esi /* no error code */
Brian Gerstc15a5952010-07-31 12:48:22 -04001057 subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001058 call \do_sym
Brian Gerstc15a5952010-07-31 12:48:22 -04001059 addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001060 jmp paranoid_exit /* %ebx: no swapgs flag */
1061 CFI_ENDPROC
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001062END(\sym)
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001063.endm
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001064
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001065.macro errorentry sym do_sym
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001066ENTRY(\sym)
Jan Beulich7effaa82005-09-12 18:49:24 +02001067 XCPT_FRAME
Jeremy Fitzhardingefab58422008-06-25 00:19:31 -04001068 PARAVIRT_ADJUST_EXCEPTION_FRAME
Jan Beulichb1cccb12010-09-02 13:55:11 +01001069 subq $ORIG_RAX-R15, %rsp
1070 CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
Alexander van Heukelumd99015b2008-11-19 01:18:11 +01001071 call error_entry
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +01001072 DEFAULT_FRAME 0
Alexander van Heukelumd99015b2008-11-19 01:18:11 +01001073 movq %rsp,%rdi /* pt_regs pointer */
1074 movq ORIG_RAX(%rsp),%rsi /* get error code */
1075 movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001076 call \do_sym
Alexander van Heukelumd99015b2008-11-19 01:18:11 +01001077 jmp error_exit /* %ebx: no swapgs flag */
Jan Beulich7effaa82005-09-12 18:49:24 +02001078 CFI_ENDPROC
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001079END(\sym)
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001080.endm
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081
1082 /* error code is on the stack already */
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001083.macro paranoiderrorentry sym do_sym
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001084ENTRY(\sym)
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001085 XCPT_FRAME
1086 PARAVIRT_ADJUST_EXCEPTION_FRAME
Jan Beulichb1cccb12010-09-02 13:55:11 +01001087 subq $ORIG_RAX-R15, %rsp
1088 CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
Alexander van Heukelume2f6bc22008-11-21 16:43:18 +01001089 call save_paranoid
1090 DEFAULT_FRAME 0
Alexander van Heukelum7e61a792008-09-26 14:03:03 +02001091 TRACE_IRQS_OFF
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001092 movq %rsp,%rdi /* pt_regs pointer */
1093 movq ORIG_RAX(%rsp),%rsi /* get error code */
1094 movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001095 call \do_sym
Alexander van Heukelumb8b1d082008-11-21 16:44:28 +01001096 jmp paranoid_exit /* %ebx: no swapgs flag */
1097 CFI_ENDPROC
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001098END(\sym)
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001099.endm
1100
1101zeroentry divide_error do_divide_error
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001102zeroentry overflow do_overflow
1103zeroentry bounds do_bounds
1104zeroentry invalid_op do_invalid_op
1105zeroentry device_not_available do_device_not_available
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001106paranoiderrorentry double_fault do_double_fault
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001107zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun
1108errorentry invalid_TSS do_invalid_TSS
1109errorentry segment_not_present do_segment_not_present
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001110zeroentry spurious_interrupt_bug do_spurious_interrupt_bug
1111zeroentry coprocessor_error do_coprocessor_error
1112errorentry alignment_check do_alignment_check
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001113zeroentry simd_coprocessor_error do_simd_coprocessor_error
Andy Lutomirski5cec93c2011-06-05 13:50:24 -04001114zeroentry emulate_vsyscall do_emulate_vsyscall
1115
Ingo Molnar2601e642006-07-03 00:24:45 -07001116
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001117 /* Reload gs selector with exception handling */
1118 /* edi: new selector */
Jeremy Fitzhardinge9f9d4892008-06-25 00:19:32 -04001119ENTRY(native_load_gs_index)
Jan Beulich7effaa82005-09-12 18:49:24 +02001120 CFI_STARTPROC
Jan Beulichdf5d1872010-09-02 14:07:16 +01001121 pushfq_cfi
Jeremy Fitzhardingeb8aa2872009-01-28 14:35:03 -08001122 DISABLE_INTERRUPTS(CLBR_ANY & ~CLBR_RDI)
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001123 SWAPGS
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +01001124gs_change:
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001125 movl %edi,%gs
Linus Torvalds1da177e2005-04-16 15:20:36 -070011262: mfence /* workaround */
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +01001127 SWAPGS
Jan Beulichdf5d1872010-09-02 14:07:16 +01001128 popfq_cfi
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001129 ret
Jan Beulich7effaa82005-09-12 18:49:24 +02001130 CFI_ENDPROC
Alexander van Heukelum6efdcfa2008-11-23 10:15:32 +01001131END(native_load_gs_index)
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +01001132
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001133 .section __ex_table,"a"
1134 .align 8
1135 .quad gs_change,bad_gs
1136 .previous
1137 .section .fixup,"ax"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 /* running with kernelgs */
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +01001139bad_gs:
Glauber de Oliveira Costa72fe4852008-01-30 13:32:08 +01001140 SWAPGS /* switch back to user gs */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 xorl %eax,%eax
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001142 movl %eax,%gs
1143 jmp 2b
1144 .previous
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +01001145
Brian Gerst3bd95df2009-12-09 12:34:40 -05001146ENTRY(kernel_thread_helper)
Andi Kleenc05991e2006-08-30 19:37:08 +02001147 pushq $0 # fake return address
1148 CFI_STARTPROC
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 /*
1150 * Here we are in the child and the registers are set as they were
1151 * at kernel_thread() invocation in the parent.
1152 */
Brian Gerst3bd95df2009-12-09 12:34:40 -05001153 call *%rsi
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 # exit
Andrey Mirkin1c5b5cf2007-10-17 18:04:33 +02001155 mov %eax, %edi
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 call do_exit
jia zhang5f5db592008-11-23 22:47:10 +08001157 ud2 # padding for call trace
Andi Kleenc05991e2006-08-30 19:37:08 +02001158 CFI_ENDPROC
Brian Gerst3bd95df2009-12-09 12:34:40 -05001159END(kernel_thread_helper)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160
1161/*
1162 * execve(). This function needs to use IRET, not SYSRET, to set up all state properly.
1163 *
1164 * C extern interface:
David Howellsc7887322010-08-11 11:26:22 +01001165 * extern long execve(const char *name, char **argv, char **envp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166 *
1167 * asm input arguments:
1168 * rdi: name, rsi: argv, rdx: envp
1169 *
1170 * We want to fallback into:
David Howellsc7887322010-08-11 11:26:22 +01001171 * extern long sys_execve(const char *name, char **argv,char **envp, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 *
1173 * do_sys_execve asm fallback arguments:
Ingo Molnar5d119b22008-02-26 12:55:57 +01001174 * rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack
Linus Torvalds1da177e2005-04-16 15:20:36 -07001175 */
Arnd Bergmann3db03b42006-10-02 02:18:31 -07001176ENTRY(kernel_execve)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 CFI_STARTPROC
1178 FAKE_STACK_FRAME $0
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +01001179 SAVE_ALL
Ingo Molnar5d119b22008-02-26 12:55:57 +01001180 movq %rsp,%rcx
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181 call sys_execve
Alexander van Heukelum0bd7b792008-11-16 15:29:00 +01001182 movq %rax, RAX(%rsp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 RESTORE_REST
1184 testq %rax,%rax
1185 je int_ret_from_sys_call
1186 RESTORE_ARGS
1187 UNFAKE_STACK_FRAME
1188 ret
1189 CFI_ENDPROC
Alexander van Heukelum6efdcfa2008-11-23 10:15:32 +01001190END(kernel_execve)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191
Andi Kleen26995002006-08-02 22:37:28 +02001192/* Call softirq on interrupt stack. Interrupts are off. */
Andi Kleened6b6762005-07-28 21:15:49 -07001193ENTRY(call_softirq)
Jan Beulich7effaa82005-09-12 18:49:24 +02001194 CFI_STARTPROC
Jan Beulichdf5d1872010-09-02 14:07:16 +01001195 pushq_cfi %rbp
Andi Kleen26995002006-08-02 22:37:28 +02001196 CFI_REL_OFFSET rbp,0
1197 mov %rsp,%rbp
1198 CFI_DEF_CFA_REGISTER rbp
Brian Gerst56895532009-01-19 00:38:58 +09001199 incl PER_CPU_VAR(irq_count)
Brian Gerst26f80bd2009-01-19 00:38:58 +09001200 cmove PER_CPU_VAR(irq_stack_ptr),%rsp
Andi Kleen26995002006-08-02 22:37:28 +02001201 push %rbp # backlink for old unwinder
Andi Kleened6b6762005-07-28 21:15:49 -07001202 call __do_softirq
Andi Kleen26995002006-08-02 22:37:28 +02001203 leaveq
Jan Beulichdf5d1872010-09-02 14:07:16 +01001204 CFI_RESTORE rbp
Jan Beulich7effaa82005-09-12 18:49:24 +02001205 CFI_DEF_CFA_REGISTER rsp
Andi Kleen26995002006-08-02 22:37:28 +02001206 CFI_ADJUST_CFA_OFFSET -8
Brian Gerst56895532009-01-19 00:38:58 +09001207 decl PER_CPU_VAR(irq_count)
Andi Kleened6b6762005-07-28 21:15:49 -07001208 ret
Jan Beulich7effaa82005-09-12 18:49:24 +02001209 CFI_ENDPROC
Alexander van Heukelum6efdcfa2008-11-23 10:15:32 +01001210END(call_softirq)
Andi Kleen75154f42007-06-23 02:29:25 +02001211
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001212#ifdef CONFIG_XEN
Alexander van Heukelum322648d2008-11-23 10:08:28 +01001213zeroentry xen_hypervisor_callback xen_do_hypervisor_callback
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001214
1215/*
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001216 * A note on the "critical region" in our callback handler.
1217 * We want to avoid stacking callback handlers due to events occurring
1218 * during handling of the last event. To do this, we keep events disabled
1219 * until we've done all processing. HOWEVER, we must enable events before
1220 * popping the stack frame (can't be done atomically) and so it would still
1221 * be possible to get enough handler activations to overflow the stack.
1222 * Although unlikely, bugs of that kind are hard to track down, so we'd
1223 * like to avoid the possibility.
1224 * So, on entry to the handler we detect whether we interrupted an
1225 * existing activation in its critical region -- if so, we pop the current
1226 * activation and restart the handler using the previous one.
1227 */
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001228ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
1229 CFI_STARTPROC
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001230/*
1231 * Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will
1232 * see the correct pointer to the pt_regs
1233 */
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001234 movq %rdi, %rsp # we don't return, adjust the stack frame
1235 CFI_ENDPROC
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +01001236 DEFAULT_FRAME
Brian Gerst56895532009-01-19 00:38:58 +0900123711: incl PER_CPU_VAR(irq_count)
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001238 movq %rsp,%rbp
1239 CFI_DEF_CFA_REGISTER rbp
Brian Gerst26f80bd2009-01-19 00:38:58 +09001240 cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001241 pushq %rbp # backlink for old unwinder
1242 call xen_evtchn_do_upcall
1243 popq %rsp
1244 CFI_DEF_CFA_REGISTER rsp
Brian Gerst56895532009-01-19 00:38:58 +09001245 decl PER_CPU_VAR(irq_count)
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001246 jmp error_exit
1247 CFI_ENDPROC
Alexander van Heukelum371c3942011-03-11 21:59:38 +01001248END(xen_do_hypervisor_callback)
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001249
1250/*
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001251 * Hypervisor uses this for application faults while it executes.
1252 * We get here for two reasons:
1253 * 1. Fault while reloading DS, ES, FS or GS
1254 * 2. Fault while executing IRET
1255 * Category 1 we do not need to fix up as Xen has already reloaded all segment
1256 * registers that could be reloaded and zeroed the others.
1257 * Category 2 we fix up by killing the current process. We cannot use the
1258 * normal Linux return path in this case because if we use the IRET hypercall
1259 * to pop the stack frame we end up in an infinite loop of failsafe callbacks.
1260 * We distinguish between categories by comparing each saved segment register
1261 * with its current contents: any discrepancy means we in category 1.
1262 */
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001263ENTRY(xen_failsafe_callback)
Alexander van Heukelumdcd072e2008-11-20 14:40:11 +01001264 INTR_FRAME 1 (6*8)
1265 /*CFI_REL_OFFSET gs,GS*/
1266 /*CFI_REL_OFFSET fs,FS*/
1267 /*CFI_REL_OFFSET es,ES*/
1268 /*CFI_REL_OFFSET ds,DS*/
1269 CFI_REL_OFFSET r11,8
1270 CFI_REL_OFFSET rcx,0
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001271 movw %ds,%cx
1272 cmpw %cx,0x10(%rsp)
1273 CFI_REMEMBER_STATE
1274 jne 1f
1275 movw %es,%cx
1276 cmpw %cx,0x18(%rsp)
1277 jne 1f
1278 movw %fs,%cx
1279 cmpw %cx,0x20(%rsp)
1280 jne 1f
1281 movw %gs,%cx
1282 cmpw %cx,0x28(%rsp)
1283 jne 1f
1284 /* All segments match their saved values => Category 2 (Bad IRET). */
1285 movq (%rsp),%rcx
1286 CFI_RESTORE rcx
1287 movq 8(%rsp),%r11
1288 CFI_RESTORE r11
1289 addq $0x30,%rsp
1290 CFI_ADJUST_CFA_OFFSET -0x30
Ingo Molnar14ae22b2008-11-21 15:20:47 +01001291 pushq_cfi $0 /* RIP */
1292 pushq_cfi %r11
1293 pushq_cfi %rcx
Jeremy Fitzhardinge4a5c3e72008-07-08 15:07:09 -07001294 jmp general_protection
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001295 CFI_RESTORE_STATE
12961: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */
1297 movq (%rsp),%rcx
1298 CFI_RESTORE rcx
1299 movq 8(%rsp),%r11
1300 CFI_RESTORE r11
1301 addq $0x30,%rsp
1302 CFI_ADJUST_CFA_OFFSET -0x30
Ingo Molnar14ae22b2008-11-21 15:20:47 +01001303 pushq_cfi $0
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001304 SAVE_ALL
1305 jmp error_exit
1306 CFI_ENDPROC
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001307END(xen_failsafe_callback)
1308
Sheng Yang38e20b02010-05-14 12:40:51 +01001309apicinterrupt XEN_HVM_EVTCHN_CALLBACK \
1310 xen_hvm_callback_vector xen_evtchn_do_upcall
1311
Jeremy Fitzhardinge3d75e1b2008-07-08 15:06:49 -07001312#endif /* CONFIG_XEN */
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001313
1314/*
1315 * Some functions should be protected against kprobes
1316 */
1317 .pushsection .kprobes.text, "ax"
1318
1319paranoidzeroentry_ist debug do_debug DEBUG_STACK
1320paranoidzeroentry_ist int3 do_int3 DEBUG_STACK
1321paranoiderrorentry stack_segment do_stack_segment
Jeremy Fitzhardinge6cac5a92009-03-29 19:56:29 -07001322#ifdef CONFIG_XEN
1323zeroentry xen_debug do_debug
1324zeroentry xen_int3 do_int3
1325errorentry xen_stack_segment do_stack_segment
1326#endif
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001327errorentry general_protection do_general_protection
1328errorentry page_fault do_page_fault
Gleb Natapov631bc482010-10-14 11:22:52 +02001329#ifdef CONFIG_KVM_GUEST
1330errorentry async_page_fault do_async_page_fault
1331#endif
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001332#ifdef CONFIG_X86_MCE
Andi Kleen5d727922009-04-27 19:25:48 +02001333paranoidzeroentry machine_check *machine_check_vector(%rip)
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001334#endif
1335
1336 /*
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001337 * "Paranoid" exit path from exception stack.
1338 * Paranoid because this is used by NMIs and cannot take
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001339 * any kernel state for granted.
1340 * We don't do kernel preemption checks here, because only
1341 * NMI should be common and it does not enable IRQs and
1342 * cannot get reschedule ticks.
1343 *
1344 * "trace" is 0 for the NMI handler only, because irq-tracing
1345 * is fundamentally NMI-unsafe. (we cannot change the soft and
1346 * hard flags at once, atomically)
1347 */
1348
1349 /* ebx: no swapgs flag */
1350ENTRY(paranoid_exit)
Jan Beulich1f130a72010-09-02 13:54:32 +01001351 DEFAULT_FRAME
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001352 DISABLE_INTERRUPTS(CLBR_NONE)
1353 TRACE_IRQS_OFF
1354 testl %ebx,%ebx /* swapgs needed? */
1355 jnz paranoid_restore
1356 testl $3,CS(%rsp)
1357 jnz paranoid_userspace
1358paranoid_swapgs:
1359 TRACE_IRQS_IRETQ 0
1360 SWAPGS_UNSAFE_STACK
Steven Rostedt0300e7f12009-04-17 08:33:52 -04001361 RESTORE_ALL 8
1362 jmp irq_return
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001363paranoid_restore:
Steven Rostedt0300e7f12009-04-17 08:33:52 -04001364 TRACE_IRQS_IRETQ 0
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001365 RESTORE_ALL 8
1366 jmp irq_return
1367paranoid_userspace:
1368 GET_THREAD_INFO(%rcx)
1369 movl TI_flags(%rcx),%ebx
1370 andl $_TIF_WORK_MASK,%ebx
1371 jz paranoid_swapgs
1372 movq %rsp,%rdi /* &pt_regs */
1373 call sync_regs
1374 movq %rax,%rsp /* switch stack for scheduling */
1375 testl $_TIF_NEED_RESCHED,%ebx
1376 jnz paranoid_schedule
1377 movl %ebx,%edx /* arg3: thread flags */
1378 TRACE_IRQS_ON
1379 ENABLE_INTERRUPTS(CLBR_NONE)
1380 xorl %esi,%esi /* arg2: oldset */
1381 movq %rsp,%rdi /* arg1: &pt_regs */
1382 call do_notify_resume
1383 DISABLE_INTERRUPTS(CLBR_NONE)
1384 TRACE_IRQS_OFF
1385 jmp paranoid_userspace
1386paranoid_schedule:
1387 TRACE_IRQS_ON
1388 ENABLE_INTERRUPTS(CLBR_ANY)
1389 call schedule
1390 DISABLE_INTERRUPTS(CLBR_ANY)
1391 TRACE_IRQS_OFF
1392 jmp paranoid_userspace
1393 CFI_ENDPROC
1394END(paranoid_exit)
1395
1396/*
1397 * Exception entry point. This expects an error code/orig_rax on the stack.
1398 * returns in "no swapgs flag" in %ebx.
1399 */
1400ENTRY(error_entry)
1401 XCPT_FRAME
1402 CFI_ADJUST_CFA_OFFSET 15*8
1403 /* oldrax contains error code */
1404 cld
1405 movq_cfi rdi, RDI+8
1406 movq_cfi rsi, RSI+8
1407 movq_cfi rdx, RDX+8
1408 movq_cfi rcx, RCX+8
1409 movq_cfi rax, RAX+8
1410 movq_cfi r8, R8+8
1411 movq_cfi r9, R9+8
1412 movq_cfi r10, R10+8
1413 movq_cfi r11, R11+8
1414 movq_cfi rbx, RBX+8
1415 movq_cfi rbp, RBP+8
1416 movq_cfi r12, R12+8
1417 movq_cfi r13, R13+8
1418 movq_cfi r14, R14+8
1419 movq_cfi r15, R15+8
1420 xorl %ebx,%ebx
1421 testl $3,CS+8(%rsp)
1422 je error_kernelspace
1423error_swapgs:
1424 SWAPGS
1425error_sti:
1426 TRACE_IRQS_OFF
1427 ret
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001428
1429/*
1430 * There are two places in the kernel that can potentially fault with
1431 * usergs. Handle them here. The exception handlers after iret run with
1432 * kernel gs again, so don't set the user space flag. B stepping K8s
1433 * sometimes report an truncated RIP for IRET exceptions returning to
1434 * compat mode. Check for these here too.
1435 */
1436error_kernelspace:
1437 incl %ebx
1438 leaq irq_return(%rip),%rcx
1439 cmpq %rcx,RIP+8(%rsp)
1440 je error_swapgs
Brian Gerstae24ffe2009-10-12 10:18:23 -04001441 movl %ecx,%eax /* zero extend */
1442 cmpq %rax,RIP+8(%rsp)
1443 je bstep_iret
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001444 cmpq $gs_change,RIP+8(%rsp)
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001445 je error_swapgs
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001446 jmp error_sti
Brian Gerstae24ffe2009-10-12 10:18:23 -04001447
1448bstep_iret:
1449 /* Fix truncated RIP */
1450 movq %rcx,RIP+8(%rsp)
Brian Gerst97829de2009-11-03 14:02:05 -05001451 jmp error_swapgs
Jan Beuliche6b04b62010-09-02 13:52:45 +01001452 CFI_ENDPROC
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001453END(error_entry)
1454
1455
1456/* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */
1457ENTRY(error_exit)
1458 DEFAULT_FRAME
1459 movl %ebx,%eax
1460 RESTORE_REST
1461 DISABLE_INTERRUPTS(CLBR_NONE)
1462 TRACE_IRQS_OFF
1463 GET_THREAD_INFO(%rcx)
1464 testl %eax,%eax
1465 jne retint_kernel
1466 LOCKDEP_SYS_EXIT_IRQ
1467 movl TI_flags(%rcx),%edx
1468 movl $_TIF_WORK_MASK,%edi
1469 andl %edi,%edx
1470 jnz retint_careful
1471 jmp retint_swapgs
1472 CFI_ENDPROC
1473END(error_exit)
1474
1475
1476 /* runs on exception stack */
1477ENTRY(nmi)
1478 INTR_FRAME
1479 PARAVIRT_ADJUST_EXCEPTION_FRAME
1480 pushq_cfi $-1
Jan Beulichb1cccb12010-09-02 13:55:11 +01001481 subq $ORIG_RAX-R15, %rsp
1482 CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001483 call save_paranoid
1484 DEFAULT_FRAME 0
1485 /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */
1486 movq %rsp,%rdi
1487 movq $-1,%rsi
1488 call do_nmi
1489#ifdef CONFIG_TRACE_IRQFLAGS
1490 /* paranoidexit; without TRACE_IRQS_OFF */
1491 /* ebx: no swapgs flag */
1492 DISABLE_INTERRUPTS(CLBR_NONE)
1493 testl %ebx,%ebx /* swapgs needed? */
1494 jnz nmi_restore
1495 testl $3,CS(%rsp)
1496 jnz nmi_userspace
1497nmi_swapgs:
1498 SWAPGS_UNSAFE_STACK
1499nmi_restore:
1500 RESTORE_ALL 8
1501 jmp irq_return
1502nmi_userspace:
1503 GET_THREAD_INFO(%rcx)
1504 movl TI_flags(%rcx),%ebx
1505 andl $_TIF_WORK_MASK,%ebx
1506 jz nmi_swapgs
1507 movq %rsp,%rdi /* &pt_regs */
1508 call sync_regs
1509 movq %rax,%rsp /* switch stack for scheduling */
1510 testl $_TIF_NEED_RESCHED,%ebx
1511 jnz nmi_schedule
1512 movl %ebx,%edx /* arg3: thread flags */
1513 ENABLE_INTERRUPTS(CLBR_NONE)
1514 xorl %esi,%esi /* arg2: oldset */
1515 movq %rsp,%rdi /* arg1: &pt_regs */
1516 call do_notify_resume
1517 DISABLE_INTERRUPTS(CLBR_NONE)
1518 jmp nmi_userspace
1519nmi_schedule:
1520 ENABLE_INTERRUPTS(CLBR_ANY)
1521 call schedule
1522 DISABLE_INTERRUPTS(CLBR_ANY)
1523 jmp nmi_userspace
1524 CFI_ENDPROC
1525#else
1526 jmp paranoid_exit
Cyrill Gorcunov9f1e87e2008-11-27 21:10:08 +03001527 CFI_ENDPROC
Alexander van Heukelumddeb8f22008-11-24 13:24:28 +01001528#endif
1529END(nmi)
1530
1531ENTRY(ignore_sysret)
1532 CFI_STARTPROC
1533 mov $-ENOSYS,%eax
1534 sysret
1535 CFI_ENDPROC
1536END(ignore_sysret)
1537
1538/*
1539 * End of kprobes section
1540 */
1541 .popsection