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1da177e4 LT |
1 | /* |
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> | |
1da177e4 LT |
7 | */ |
8 | ||
9 | /* | |
10 | * entry.S contains the system-call and fault low-level handling routines. | |
11 | * | |
12 | * NOTE: This code handles signal-recognition, which happens every time | |
13 | * after an interrupt and after each system call. | |
14 | * | |
15 | * Normal syscalls and interrupts don't save a full stack frame, this is | |
16 | * only done for syscall tracing, signals or fork/exec et.al. | |
17 | * | |
18 | * A note on terminology: | |
19 | * - top of stack: Architecture defined interrupt frame from SS to RIP | |
20 | * at the top of the kernel process stack. | |
21 | * - partial stack frame: partially saved registers upto R11. | |
22 | * - full stack frame: Like partial stack frame, but all register saved. | |
2e91a17b AK |
23 | * |
24 | * Some macro usage: | |
25 | * - CFI macros are used to generate dwarf2 unwind information for better | |
26 | * backtraces. They don't change any code. | |
27 | * - SAVE_ALL/RESTORE_ALL - Save/restore all registers | |
28 | * - SAVE_ARGS/RESTORE_ARGS - Save/restore registers that C functions modify. | |
29 | * There are unfortunately lots of special cases where some registers | |
30 | * not touched. The macro is a big mess that should be cleaned up. | |
31 | * - SAVE_REST/RESTORE_REST - Handle the registers not saved by SAVE_ARGS. | |
32 | * Gives a full stack frame. | |
33 | * - ENTRY/END Define functions in the symbol table. | |
34 | * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack | |
35 | * frame that is otherwise undefined after a SYSCALL | |
36 | * - TRACE_IRQ_* - Trace hard interrupt state for lock debugging. | |
37 | * - errorentry/paranoidentry/zeroentry - Define exception entry points. | |
1da177e4 LT |
38 | */ |
39 | ||
1da177e4 LT |
40 | #include <linux/linkage.h> |
41 | #include <asm/segment.h> | |
1da177e4 LT |
42 | #include <asm/cache.h> |
43 | #include <asm/errno.h> | |
44 | #include <asm/dwarf2.h> | |
45 | #include <asm/calling.h> | |
e2d5df93 | 46 | #include <asm/asm-offsets.h> |
1da177e4 LT |
47 | #include <asm/msr.h> |
48 | #include <asm/unistd.h> | |
49 | #include <asm/thread_info.h> | |
50 | #include <asm/hw_irq.h> | |
5f8efbb9 | 51 | #include <asm/page.h> |
2601e64d | 52 | #include <asm/irqflags.h> |
72fe4858 | 53 | #include <asm/paravirt.h> |
395a59d0 | 54 | #include <asm/ftrace.h> |
1da177e4 LT |
55 | |
56 | .code64 | |
57 | ||
16444a8a | 58 | #ifdef CONFIG_FTRACE |
d61f82d0 SR |
59 | #ifdef CONFIG_DYNAMIC_FTRACE |
60 | ENTRY(mcount) | |
61 | ||
62 | subq $0x38, %rsp | |
63 | movq %rax, (%rsp) | |
64 | movq %rcx, 8(%rsp) | |
65 | movq %rdx, 16(%rsp) | |
66 | movq %rsi, 24(%rsp) | |
67 | movq %rdi, 32(%rsp) | |
68 | movq %r8, 40(%rsp) | |
69 | movq %r9, 48(%rsp) | |
70 | ||
71 | movq 0x38(%rsp), %rdi | |
395a59d0 | 72 | subq $MCOUNT_INSN_SIZE, %rdi |
d61f82d0 SR |
73 | |
74 | .globl mcount_call | |
75 | mcount_call: | |
76 | call ftrace_stub | |
77 | ||
78 | movq 48(%rsp), %r9 | |
79 | movq 40(%rsp), %r8 | |
80 | movq 32(%rsp), %rdi | |
81 | movq 24(%rsp), %rsi | |
82 | movq 16(%rsp), %rdx | |
83 | movq 8(%rsp), %rcx | |
84 | movq (%rsp), %rax | |
85 | addq $0x38, %rsp | |
86 | ||
87 | retq | |
88 | END(mcount) | |
89 | ||
90 | ENTRY(ftrace_caller) | |
91 | ||
92 | /* taken from glibc */ | |
93 | subq $0x38, %rsp | |
94 | movq %rax, (%rsp) | |
95 | movq %rcx, 8(%rsp) | |
96 | movq %rdx, 16(%rsp) | |
97 | movq %rsi, 24(%rsp) | |
98 | movq %rdi, 32(%rsp) | |
99 | movq %r8, 40(%rsp) | |
100 | movq %r9, 48(%rsp) | |
101 | ||
102 | movq 0x38(%rsp), %rdi | |
103 | movq 8(%rbp), %rsi | |
395a59d0 | 104 | subq $MCOUNT_INSN_SIZE, %rdi |
d61f82d0 SR |
105 | |
106 | .globl ftrace_call | |
107 | ftrace_call: | |
108 | call ftrace_stub | |
109 | ||
110 | movq 48(%rsp), %r9 | |
111 | movq 40(%rsp), %r8 | |
112 | movq 32(%rsp), %rdi | |
113 | movq 24(%rsp), %rsi | |
114 | movq 16(%rsp), %rdx | |
115 | movq 8(%rsp), %rcx | |
116 | movq (%rsp), %rax | |
117 | addq $0x38, %rsp | |
118 | ||
119 | .globl ftrace_stub | |
120 | ftrace_stub: | |
121 | retq | |
122 | END(ftrace_caller) | |
123 | ||
124 | #else /* ! CONFIG_DYNAMIC_FTRACE */ | |
16444a8a ACM |
125 | ENTRY(mcount) |
126 | cmpq $ftrace_stub, ftrace_trace_function | |
127 | jnz trace | |
128 | .globl ftrace_stub | |
129 | ftrace_stub: | |
130 | retq | |
131 | ||
132 | trace: | |
133 | /* taken from glibc */ | |
134 | subq $0x38, %rsp | |
135 | movq %rax, (%rsp) | |
136 | movq %rcx, 8(%rsp) | |
137 | movq %rdx, 16(%rsp) | |
138 | movq %rsi, 24(%rsp) | |
139 | movq %rdi, 32(%rsp) | |
140 | movq %r8, 40(%rsp) | |
141 | movq %r9, 48(%rsp) | |
142 | ||
143 | movq 0x38(%rsp), %rdi | |
144 | movq 8(%rbp), %rsi | |
395a59d0 | 145 | subq $MCOUNT_INSN_SIZE, %rdi |
16444a8a ACM |
146 | |
147 | call *ftrace_trace_function | |
148 | ||
149 | movq 48(%rsp), %r9 | |
150 | movq 40(%rsp), %r8 | |
151 | movq 32(%rsp), %rdi | |
152 | movq 24(%rsp), %rsi | |
153 | movq 16(%rsp), %rdx | |
154 | movq 8(%rsp), %rcx | |
155 | movq (%rsp), %rax | |
156 | addq $0x38, %rsp | |
157 | ||
158 | jmp ftrace_stub | |
159 | END(mcount) | |
d61f82d0 SR |
160 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
161 | #endif /* CONFIG_FTRACE */ | |
16444a8a | 162 | |
dc37db4d | 163 | #ifndef CONFIG_PREEMPT |
1da177e4 LT |
164 | #define retint_kernel retint_restore_args |
165 | #endif | |
2601e64d | 166 | |
72fe4858 | 167 | #ifdef CONFIG_PARAVIRT |
2be29982 | 168 | ENTRY(native_usergs_sysret64) |
72fe4858 GOC |
169 | swapgs |
170 | sysretq | |
171 | #endif /* CONFIG_PARAVIRT */ | |
172 | ||
2601e64d IM |
173 | |
174 | .macro TRACE_IRQS_IRETQ offset=ARGOFFSET | |
175 | #ifdef CONFIG_TRACE_IRQFLAGS | |
176 | bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */ | |
177 | jnc 1f | |
178 | TRACE_IRQS_ON | |
179 | 1: | |
180 | #endif | |
181 | .endm | |
182 | ||
1da177e4 LT |
183 | /* |
184 | * C code is not supposed to know about undefined top of stack. Every time | |
185 | * a C function with an pt_regs argument is called from the SYSCALL based | |
186 | * fast path FIXUP_TOP_OF_STACK is needed. | |
187 | * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs | |
188 | * manipulation. | |
189 | */ | |
190 | ||
191 | /* %rsp:at FRAMEEND */ | |
192 | .macro FIXUP_TOP_OF_STACK tmp | |
193 | movq %gs:pda_oldrsp,\tmp | |
194 | movq \tmp,RSP(%rsp) | |
195 | movq $__USER_DS,SS(%rsp) | |
196 | movq $__USER_CS,CS(%rsp) | |
197 | movq $-1,RCX(%rsp) | |
198 | movq R11(%rsp),\tmp /* get eflags */ | |
199 | movq \tmp,EFLAGS(%rsp) | |
200 | .endm | |
201 | ||
202 | .macro RESTORE_TOP_OF_STACK tmp,offset=0 | |
203 | movq RSP-\offset(%rsp),\tmp | |
204 | movq \tmp,%gs:pda_oldrsp | |
205 | movq EFLAGS-\offset(%rsp),\tmp | |
206 | movq \tmp,R11-\offset(%rsp) | |
207 | .endm | |
208 | ||
209 | .macro FAKE_STACK_FRAME child_rip | |
210 | /* push in order ss, rsp, eflags, cs, rip */ | |
3829ee6b | 211 | xorl %eax, %eax |
e04e0a63 | 212 | pushq $__KERNEL_DS /* ss */ |
1da177e4 | 213 | CFI_ADJUST_CFA_OFFSET 8 |
7effaa88 | 214 | /*CFI_REL_OFFSET ss,0*/ |
1da177e4 LT |
215 | pushq %rax /* rsp */ |
216 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 217 | CFI_REL_OFFSET rsp,0 |
1da177e4 LT |
218 | pushq $(1<<9) /* eflags - interrupts on */ |
219 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 220 | /*CFI_REL_OFFSET rflags,0*/ |
1da177e4 LT |
221 | pushq $__KERNEL_CS /* cs */ |
222 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 223 | /*CFI_REL_OFFSET cs,0*/ |
1da177e4 LT |
224 | pushq \child_rip /* rip */ |
225 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 226 | CFI_REL_OFFSET rip,0 |
1da177e4 LT |
227 | pushq %rax /* orig rax */ |
228 | CFI_ADJUST_CFA_OFFSET 8 | |
229 | .endm | |
230 | ||
231 | .macro UNFAKE_STACK_FRAME | |
232 | addq $8*6, %rsp | |
233 | CFI_ADJUST_CFA_OFFSET -(6*8) | |
234 | .endm | |
235 | ||
7effaa88 JB |
236 | .macro CFI_DEFAULT_STACK start=1 |
237 | .if \start | |
238 | CFI_STARTPROC simple | |
adf14236 | 239 | CFI_SIGNAL_FRAME |
7effaa88 JB |
240 | CFI_DEF_CFA rsp,SS+8 |
241 | .else | |
242 | CFI_DEF_CFA_OFFSET SS+8 | |
243 | .endif | |
244 | CFI_REL_OFFSET r15,R15 | |
245 | CFI_REL_OFFSET r14,R14 | |
246 | CFI_REL_OFFSET r13,R13 | |
247 | CFI_REL_OFFSET r12,R12 | |
248 | CFI_REL_OFFSET rbp,RBP | |
249 | CFI_REL_OFFSET rbx,RBX | |
250 | CFI_REL_OFFSET r11,R11 | |
251 | CFI_REL_OFFSET r10,R10 | |
252 | CFI_REL_OFFSET r9,R9 | |
253 | CFI_REL_OFFSET r8,R8 | |
254 | CFI_REL_OFFSET rax,RAX | |
255 | CFI_REL_OFFSET rcx,RCX | |
256 | CFI_REL_OFFSET rdx,RDX | |
257 | CFI_REL_OFFSET rsi,RSI | |
258 | CFI_REL_OFFSET rdi,RDI | |
259 | CFI_REL_OFFSET rip,RIP | |
260 | /*CFI_REL_OFFSET cs,CS*/ | |
261 | /*CFI_REL_OFFSET rflags,EFLAGS*/ | |
262 | CFI_REL_OFFSET rsp,RSP | |
263 | /*CFI_REL_OFFSET ss,SS*/ | |
1da177e4 LT |
264 | .endm |
265 | /* | |
266 | * A newly forked process directly context switches into this. | |
267 | */ | |
268 | /* rdi: prev */ | |
269 | ENTRY(ret_from_fork) | |
1da177e4 | 270 | CFI_DEFAULT_STACK |
658fdbef AK |
271 | push kernel_eflags(%rip) |
272 | CFI_ADJUST_CFA_OFFSET 4 | |
273 | popf # reset kernel eflags | |
274 | CFI_ADJUST_CFA_OFFSET -4 | |
1da177e4 LT |
275 | call schedule_tail |
276 | GET_THREAD_INFO(%rcx) | |
26ccb8a7 | 277 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%rcx) |
1da177e4 LT |
278 | jnz rff_trace |
279 | rff_action: | |
280 | RESTORE_REST | |
281 | testl $3,CS-ARGOFFSET(%rsp) # from kernel_thread? | |
282 | je int_ret_from_sys_call | |
26ccb8a7 | 283 | testl $_TIF_IA32,TI_flags(%rcx) |
1da177e4 LT |
284 | jnz int_ret_from_sys_call |
285 | RESTORE_TOP_OF_STACK %rdi,ARGOFFSET | |
286 | jmp ret_from_sys_call | |
287 | rff_trace: | |
288 | movq %rsp,%rdi | |
289 | call syscall_trace_leave | |
290 | GET_THREAD_INFO(%rcx) | |
291 | jmp rff_action | |
292 | CFI_ENDPROC | |
4b787e0b | 293 | END(ret_from_fork) |
1da177e4 LT |
294 | |
295 | /* | |
296 | * System call entry. Upto 6 arguments in registers are supported. | |
297 | * | |
298 | * SYSCALL does not save anything on the stack and does not change the | |
299 | * stack pointer. | |
300 | */ | |
301 | ||
302 | /* | |
303 | * Register setup: | |
304 | * rax system call number | |
305 | * rdi arg0 | |
306 | * rcx return address for syscall/sysret, C arg3 | |
307 | * rsi arg1 | |
308 | * rdx arg2 | |
309 | * r10 arg3 (--> moved to rcx for C) | |
310 | * r8 arg4 | |
311 | * r9 arg5 | |
312 | * r11 eflags for syscall/sysret, temporary for C | |
313 | * r12-r15,rbp,rbx saved by C code, not touched. | |
314 | * | |
315 | * Interrupts are off on entry. | |
316 | * Only called from user space. | |
317 | * | |
318 | * XXX if we had a free scratch register we could save the RSP into the stack frame | |
319 | * and report it properly in ps. Unfortunately we haven't. | |
7bf36bbc AK |
320 | * |
321 | * When user can change the frames always force IRET. That is because | |
322 | * it deals with uncanonical addresses better. SYSRET has trouble | |
323 | * with them due to bugs in both AMD and Intel CPUs. | |
1da177e4 LT |
324 | */ |
325 | ||
326 | ENTRY(system_call) | |
7effaa88 | 327 | CFI_STARTPROC simple |
adf14236 | 328 | CFI_SIGNAL_FRAME |
dffead4e | 329 | CFI_DEF_CFA rsp,PDA_STACKOFFSET |
7effaa88 JB |
330 | CFI_REGISTER rip,rcx |
331 | /*CFI_REGISTER rflags,r11*/ | |
72fe4858 GOC |
332 | SWAPGS_UNSAFE_STACK |
333 | /* | |
334 | * A hypervisor implementation might want to use a label | |
335 | * after the swapgs, so that it can do the swapgs | |
336 | * for the guest and jump here on syscall. | |
337 | */ | |
338 | ENTRY(system_call_after_swapgs) | |
339 | ||
1da177e4 LT |
340 | movq %rsp,%gs:pda_oldrsp |
341 | movq %gs:pda_kernelstack,%rsp | |
2601e64d IM |
342 | /* |
343 | * No need to follow this irqs off/on section - it's straight | |
344 | * and short: | |
345 | */ | |
72fe4858 | 346 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 LT |
347 | SAVE_ARGS 8,1 |
348 | movq %rax,ORIG_RAX-ARGOFFSET(%rsp) | |
7effaa88 JB |
349 | movq %rcx,RIP-ARGOFFSET(%rsp) |
350 | CFI_REL_OFFSET rip,RIP-ARGOFFSET | |
1da177e4 | 351 | GET_THREAD_INFO(%rcx) |
26ccb8a7 GC |
352 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP), \ |
353 | TI_flags(%rcx) | |
1da177e4 LT |
354 | jnz tracesys |
355 | cmpq $__NR_syscall_max,%rax | |
356 | ja badsys | |
357 | movq %r10,%rcx | |
358 | call *sys_call_table(,%rax,8) # XXX: rip relative | |
359 | movq %rax,RAX-ARGOFFSET(%rsp) | |
360 | /* | |
361 | * Syscall return path ending with SYSRET (fast path) | |
362 | * Has incomplete stack frame and undefined top of stack. | |
363 | */ | |
1da177e4 | 364 | ret_from_sys_call: |
11b854b2 | 365 | movl $_TIF_ALLWORK_MASK,%edi |
1da177e4 LT |
366 | /* edi: flagmask */ |
367 | sysret_check: | |
10cd706d | 368 | LOCKDEP_SYS_EXIT |
1da177e4 | 369 | GET_THREAD_INFO(%rcx) |
72fe4858 | 370 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 371 | TRACE_IRQS_OFF |
26ccb8a7 | 372 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
373 | andl %edi,%edx |
374 | jnz sysret_careful | |
bcddc015 | 375 | CFI_REMEMBER_STATE |
2601e64d IM |
376 | /* |
377 | * sysretq will re-enable interrupts: | |
378 | */ | |
379 | TRACE_IRQS_ON | |
1da177e4 | 380 | movq RIP-ARGOFFSET(%rsp),%rcx |
7effaa88 | 381 | CFI_REGISTER rip,rcx |
1da177e4 | 382 | RESTORE_ARGS 0,-ARG_SKIP,1 |
7effaa88 | 383 | /*CFI_REGISTER rflags,r11*/ |
c7245da6 | 384 | movq %gs:pda_oldrsp, %rsp |
2be29982 | 385 | USERGS_SYSRET64 |
1da177e4 | 386 | |
bcddc015 | 387 | CFI_RESTORE_STATE |
1da177e4 LT |
388 | /* Handle reschedules */ |
389 | /* edx: work, edi: workmask */ | |
390 | sysret_careful: | |
391 | bt $TIF_NEED_RESCHED,%edx | |
392 | jnc sysret_signal | |
2601e64d | 393 | TRACE_IRQS_ON |
72fe4858 | 394 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 395 | pushq %rdi |
7effaa88 | 396 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
397 | call schedule |
398 | popq %rdi | |
7effaa88 | 399 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 LT |
400 | jmp sysret_check |
401 | ||
402 | /* Handle a signal */ | |
403 | sysret_signal: | |
2601e64d | 404 | TRACE_IRQS_ON |
72fe4858 | 405 | ENABLE_INTERRUPTS(CLBR_NONE) |
8f4d37ec | 406 | testl $_TIF_DO_NOTIFY_MASK,%edx |
10ffdbb8 AK |
407 | jz 1f |
408 | ||
409 | /* Really a signal */ | |
410 | /* edx: work flags (arg3) */ | |
1da177e4 LT |
411 | leaq do_notify_resume(%rip),%rax |
412 | leaq -ARGOFFSET(%rsp),%rdi # &pt_regs -> arg1 | |
413 | xorl %esi,%esi # oldset -> arg2 | |
414 | call ptregscall_common | |
eca91e78 | 415 | 1: movl $_TIF_WORK_MASK,%edi |
7bf36bbc AK |
416 | /* Use IRET because user could have changed frame. This |
417 | works because ptregscall_common has called FIXUP_TOP_OF_STACK. */ | |
72fe4858 | 418 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 419 | TRACE_IRQS_OFF |
7bf36bbc | 420 | jmp int_with_check |
1da177e4 | 421 | |
7effaa88 JB |
422 | badsys: |
423 | movq $-ENOSYS,RAX-ARGOFFSET(%rsp) | |
424 | jmp ret_from_sys_call | |
425 | ||
1da177e4 LT |
426 | /* Do syscall tracing */ |
427 | tracesys: | |
428 | SAVE_REST | |
a31f8dd7 | 429 | movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ |
1da177e4 LT |
430 | FIXUP_TOP_OF_STACK %rdi |
431 | movq %rsp,%rdi | |
432 | call syscall_trace_enter | |
433 | LOAD_ARGS ARGOFFSET /* reload args from stack in case ptrace changed it */ | |
434 | RESTORE_REST | |
435 | cmpq $__NR_syscall_max,%rax | |
a31f8dd7 | 436 | ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */ |
1da177e4 LT |
437 | movq %r10,%rcx /* fixup for C */ |
438 | call *sys_call_table(,%rax,8) | |
a31f8dd7 | 439 | movq %rax,RAX-ARGOFFSET(%rsp) |
7bf36bbc | 440 | /* Use IRET because user could have changed frame */ |
1da177e4 | 441 | |
1da177e4 LT |
442 | /* |
443 | * Syscall return path ending with IRET. | |
444 | * Has correct top of stack, but partial stack frame. | |
bcddc015 JB |
445 | */ |
446 | .globl int_ret_from_sys_call | |
447 | int_ret_from_sys_call: | |
72fe4858 | 448 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 449 | TRACE_IRQS_OFF |
1da177e4 LT |
450 | testl $3,CS-ARGOFFSET(%rsp) |
451 | je retint_restore_args | |
452 | movl $_TIF_ALLWORK_MASK,%edi | |
453 | /* edi: mask to check */ | |
454 | int_with_check: | |
10cd706d | 455 | LOCKDEP_SYS_EXIT_IRQ |
1da177e4 | 456 | GET_THREAD_INFO(%rcx) |
26ccb8a7 | 457 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
458 | andl %edi,%edx |
459 | jnz int_careful | |
26ccb8a7 | 460 | andl $~TS_COMPAT,TI_status(%rcx) |
1da177e4 LT |
461 | jmp retint_swapgs |
462 | ||
463 | /* Either reschedule or signal or syscall exit tracking needed. */ | |
464 | /* First do a reschedule test. */ | |
465 | /* edx: work, edi: workmask */ | |
466 | int_careful: | |
467 | bt $TIF_NEED_RESCHED,%edx | |
468 | jnc int_very_careful | |
2601e64d | 469 | TRACE_IRQS_ON |
72fe4858 | 470 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 471 | pushq %rdi |
7effaa88 | 472 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
473 | call schedule |
474 | popq %rdi | |
7effaa88 | 475 | CFI_ADJUST_CFA_OFFSET -8 |
72fe4858 | 476 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 477 | TRACE_IRQS_OFF |
1da177e4 LT |
478 | jmp int_with_check |
479 | ||
480 | /* handle signals and tracing -- both require a full stack frame */ | |
481 | int_very_careful: | |
2601e64d | 482 | TRACE_IRQS_ON |
72fe4858 | 483 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 LT |
484 | SAVE_REST |
485 | /* Check for syscall exit trace */ | |
486 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edx | |
487 | jz int_signal | |
488 | pushq %rdi | |
7effaa88 | 489 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
490 | leaq 8(%rsp),%rdi # &ptregs -> arg1 |
491 | call syscall_trace_leave | |
492 | popq %rdi | |
7effaa88 | 493 | CFI_ADJUST_CFA_OFFSET -8 |
36c1104e | 494 | andl $~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edi |
1da177e4 LT |
495 | jmp int_restore_rest |
496 | ||
497 | int_signal: | |
8f4d37ec | 498 | testl $_TIF_DO_NOTIFY_MASK,%edx |
1da177e4 LT |
499 | jz 1f |
500 | movq %rsp,%rdi # &ptregs -> arg1 | |
501 | xorl %esi,%esi # oldset -> arg2 | |
502 | call do_notify_resume | |
eca91e78 | 503 | 1: movl $_TIF_WORK_MASK,%edi |
1da177e4 LT |
504 | int_restore_rest: |
505 | RESTORE_REST | |
72fe4858 | 506 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 507 | TRACE_IRQS_OFF |
1da177e4 LT |
508 | jmp int_with_check |
509 | CFI_ENDPROC | |
bcddc015 | 510 | END(system_call) |
1da177e4 LT |
511 | |
512 | /* | |
513 | * Certain special system calls that need to save a complete full stack frame. | |
514 | */ | |
515 | ||
516 | .macro PTREGSCALL label,func,arg | |
517 | .globl \label | |
518 | \label: | |
519 | leaq \func(%rip),%rax | |
520 | leaq -ARGOFFSET+8(%rsp),\arg /* 8 for return address */ | |
521 | jmp ptregscall_common | |
4b787e0b | 522 | END(\label) |
1da177e4 LT |
523 | .endm |
524 | ||
7effaa88 JB |
525 | CFI_STARTPROC |
526 | ||
1da177e4 LT |
527 | PTREGSCALL stub_clone, sys_clone, %r8 |
528 | PTREGSCALL stub_fork, sys_fork, %rdi | |
529 | PTREGSCALL stub_vfork, sys_vfork, %rdi | |
1da177e4 LT |
530 | PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx |
531 | PTREGSCALL stub_iopl, sys_iopl, %rsi | |
532 | ||
533 | ENTRY(ptregscall_common) | |
1da177e4 | 534 | popq %r11 |
7effaa88 JB |
535 | CFI_ADJUST_CFA_OFFSET -8 |
536 | CFI_REGISTER rip, r11 | |
1da177e4 LT |
537 | SAVE_REST |
538 | movq %r11, %r15 | |
7effaa88 | 539 | CFI_REGISTER rip, r15 |
1da177e4 LT |
540 | FIXUP_TOP_OF_STACK %r11 |
541 | call *%rax | |
542 | RESTORE_TOP_OF_STACK %r11 | |
543 | movq %r15, %r11 | |
7effaa88 | 544 | CFI_REGISTER rip, r11 |
1da177e4 LT |
545 | RESTORE_REST |
546 | pushq %r11 | |
7effaa88 JB |
547 | CFI_ADJUST_CFA_OFFSET 8 |
548 | CFI_REL_OFFSET rip, 0 | |
1da177e4 LT |
549 | ret |
550 | CFI_ENDPROC | |
4b787e0b | 551 | END(ptregscall_common) |
1da177e4 LT |
552 | |
553 | ENTRY(stub_execve) | |
554 | CFI_STARTPROC | |
555 | popq %r11 | |
7effaa88 JB |
556 | CFI_ADJUST_CFA_OFFSET -8 |
557 | CFI_REGISTER rip, r11 | |
1da177e4 | 558 | SAVE_REST |
1da177e4 | 559 | FIXUP_TOP_OF_STACK %r11 |
5d119b2c | 560 | movq %rsp, %rcx |
1da177e4 | 561 | call sys_execve |
1da177e4 | 562 | RESTORE_TOP_OF_STACK %r11 |
1da177e4 LT |
563 | movq %rax,RAX(%rsp) |
564 | RESTORE_REST | |
565 | jmp int_ret_from_sys_call | |
566 | CFI_ENDPROC | |
4b787e0b | 567 | END(stub_execve) |
1da177e4 LT |
568 | |
569 | /* | |
570 | * sigreturn is special because it needs to restore all registers on return. | |
571 | * This cannot be done with SYSRET, so use the IRET return path instead. | |
572 | */ | |
573 | ENTRY(stub_rt_sigreturn) | |
574 | CFI_STARTPROC | |
7effaa88 JB |
575 | addq $8, %rsp |
576 | CFI_ADJUST_CFA_OFFSET -8 | |
1da177e4 LT |
577 | SAVE_REST |
578 | movq %rsp,%rdi | |
579 | FIXUP_TOP_OF_STACK %r11 | |
580 | call sys_rt_sigreturn | |
581 | movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer | |
582 | RESTORE_REST | |
583 | jmp int_ret_from_sys_call | |
584 | CFI_ENDPROC | |
4b787e0b | 585 | END(stub_rt_sigreturn) |
1da177e4 | 586 | |
7effaa88 JB |
587 | /* |
588 | * initial frame state for interrupts and exceptions | |
589 | */ | |
590 | .macro _frame ref | |
591 | CFI_STARTPROC simple | |
adf14236 | 592 | CFI_SIGNAL_FRAME |
7effaa88 JB |
593 | CFI_DEF_CFA rsp,SS+8-\ref |
594 | /*CFI_REL_OFFSET ss,SS-\ref*/ | |
595 | CFI_REL_OFFSET rsp,RSP-\ref | |
596 | /*CFI_REL_OFFSET rflags,EFLAGS-\ref*/ | |
597 | /*CFI_REL_OFFSET cs,CS-\ref*/ | |
598 | CFI_REL_OFFSET rip,RIP-\ref | |
599 | .endm | |
600 | ||
601 | /* initial frame state for interrupts (and exceptions without error code) */ | |
602 | #define INTR_FRAME _frame RIP | |
603 | /* initial frame state for exceptions with error code (and interrupts with | |
604 | vector already pushed) */ | |
605 | #define XCPT_FRAME _frame ORIG_RAX | |
606 | ||
1da177e4 LT |
607 | /* |
608 | * Interrupt entry/exit. | |
609 | * | |
610 | * Interrupt entry points save only callee clobbered registers in fast path. | |
611 | * | |
612 | * Entry runs with interrupts off. | |
613 | */ | |
614 | ||
615 | /* 0(%rsp): interrupt number */ | |
616 | .macro interrupt func | |
1da177e4 | 617 | cld |
1da177e4 LT |
618 | SAVE_ARGS |
619 | leaq -ARGOFFSET(%rsp),%rdi # arg1 for handler | |
1de9c3f6 JB |
620 | pushq %rbp |
621 | CFI_ADJUST_CFA_OFFSET 8 | |
622 | CFI_REL_OFFSET rbp, 0 | |
623 | movq %rsp,%rbp | |
624 | CFI_DEF_CFA_REGISTER rbp | |
1da177e4 LT |
625 | testl $3,CS(%rdi) |
626 | je 1f | |
72fe4858 | 627 | SWAPGS |
96e54049 AK |
628 | /* irqcount is used to check if a CPU is already on an interrupt |
629 | stack or not. While this is essentially redundant with preempt_count | |
630 | it is a little cheaper to use a separate counter in the PDA | |
631 | (short of moving irq_enter into assembly, which would be too | |
632 | much work) */ | |
633 | 1: incl %gs:pda_irqcount | |
1de9c3f6 | 634 | cmoveq %gs:pda_irqstackptr,%rsp |
2699500b | 635 | push %rbp # backlink for old unwinder |
2601e64d IM |
636 | /* |
637 | * We entered an interrupt context - irqs are off: | |
638 | */ | |
639 | TRACE_IRQS_OFF | |
1da177e4 LT |
640 | call \func |
641 | .endm | |
642 | ||
643 | ENTRY(common_interrupt) | |
7effaa88 | 644 | XCPT_FRAME |
1da177e4 LT |
645 | interrupt do_IRQ |
646 | /* 0(%rsp): oldrsp-ARGOFFSET */ | |
7effaa88 | 647 | ret_from_intr: |
72fe4858 | 648 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 649 | TRACE_IRQS_OFF |
3829ee6b | 650 | decl %gs:pda_irqcount |
1de9c3f6 | 651 | leaveq |
7effaa88 | 652 | CFI_DEF_CFA_REGISTER rsp |
1de9c3f6 | 653 | CFI_ADJUST_CFA_OFFSET -8 |
7effaa88 | 654 | exit_intr: |
1da177e4 LT |
655 | GET_THREAD_INFO(%rcx) |
656 | testl $3,CS-ARGOFFSET(%rsp) | |
657 | je retint_kernel | |
658 | ||
659 | /* Interrupt came from user space */ | |
660 | /* | |
661 | * Has a correct top of stack, but a partial stack frame | |
662 | * %rcx: thread info. Interrupts off. | |
663 | */ | |
664 | retint_with_reschedule: | |
665 | movl $_TIF_WORK_MASK,%edi | |
7effaa88 | 666 | retint_check: |
10cd706d | 667 | LOCKDEP_SYS_EXIT_IRQ |
26ccb8a7 | 668 | movl TI_flags(%rcx),%edx |
1da177e4 | 669 | andl %edi,%edx |
7effaa88 | 670 | CFI_REMEMBER_STATE |
1da177e4 | 671 | jnz retint_careful |
10cd706d PZ |
672 | |
673 | retint_swapgs: /* return to user-space */ | |
2601e64d IM |
674 | /* |
675 | * The iretq could re-enable interrupts: | |
676 | */ | |
72fe4858 | 677 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 678 | TRACE_IRQS_IRETQ |
72fe4858 | 679 | SWAPGS |
2601e64d IM |
680 | jmp restore_args |
681 | ||
10cd706d | 682 | retint_restore_args: /* return to kernel space */ |
72fe4858 | 683 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
684 | /* |
685 | * The iretq could re-enable interrupts: | |
686 | */ | |
687 | TRACE_IRQS_IRETQ | |
688 | restore_args: | |
3701d863 IM |
689 | RESTORE_ARGS 0,8,0 |
690 | ||
f7f3d791 | 691 | irq_return: |
72fe4858 | 692 | INTERRUPT_RETURN |
3701d863 IM |
693 | |
694 | .section __ex_table, "a" | |
695 | .quad irq_return, bad_iret | |
696 | .previous | |
697 | ||
698 | #ifdef CONFIG_PARAVIRT | |
72fe4858 | 699 | ENTRY(native_iret) |
1da177e4 LT |
700 | iretq |
701 | ||
702 | .section __ex_table,"a" | |
72fe4858 | 703 | .quad native_iret, bad_iret |
1da177e4 | 704 | .previous |
3701d863 IM |
705 | #endif |
706 | ||
1da177e4 | 707 | .section .fixup,"ax" |
1da177e4 | 708 | bad_iret: |
3aa4b37d RM |
709 | /* |
710 | * The iret traps when the %cs or %ss being restored is bogus. | |
711 | * We've lost the original trap vector and error code. | |
712 | * #GPF is the most likely one to get for an invalid selector. | |
713 | * So pretend we completed the iret and took the #GPF in user mode. | |
714 | * | |
715 | * We are now running with the kernel GS after exception recovery. | |
716 | * But error_entry expects us to have user GS to match the user %cs, | |
717 | * so swap back. | |
718 | */ | |
719 | pushq $0 | |
720 | ||
721 | SWAPGS | |
722 | jmp general_protection | |
723 | ||
72fe4858 GOC |
724 | .previous |
725 | ||
7effaa88 | 726 | /* edi: workmask, edx: work */ |
1da177e4 | 727 | retint_careful: |
7effaa88 | 728 | CFI_RESTORE_STATE |
1da177e4 LT |
729 | bt $TIF_NEED_RESCHED,%edx |
730 | jnc retint_signal | |
2601e64d | 731 | TRACE_IRQS_ON |
72fe4858 | 732 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 733 | pushq %rdi |
7effaa88 | 734 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
735 | call schedule |
736 | popq %rdi | |
7effaa88 | 737 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 | 738 | GET_THREAD_INFO(%rcx) |
72fe4858 | 739 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 740 | TRACE_IRQS_OFF |
1da177e4 LT |
741 | jmp retint_check |
742 | ||
743 | retint_signal: | |
8f4d37ec | 744 | testl $_TIF_DO_NOTIFY_MASK,%edx |
10ffdbb8 | 745 | jz retint_swapgs |
2601e64d | 746 | TRACE_IRQS_ON |
72fe4858 | 747 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 LT |
748 | SAVE_REST |
749 | movq $-1,ORIG_RAX(%rsp) | |
3829ee6b | 750 | xorl %esi,%esi # oldset |
1da177e4 LT |
751 | movq %rsp,%rdi # &pt_regs |
752 | call do_notify_resume | |
753 | RESTORE_REST | |
72fe4858 | 754 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 755 | TRACE_IRQS_OFF |
be9e6870 | 756 | GET_THREAD_INFO(%rcx) |
eca91e78 | 757 | jmp retint_with_reschedule |
1da177e4 LT |
758 | |
759 | #ifdef CONFIG_PREEMPT | |
760 | /* Returning to kernel space. Check if we need preemption */ | |
761 | /* rcx: threadinfo. interrupts off. */ | |
b06babac | 762 | ENTRY(retint_kernel) |
26ccb8a7 | 763 | cmpl $0,TI_preempt_count(%rcx) |
1da177e4 | 764 | jnz retint_restore_args |
26ccb8a7 | 765 | bt $TIF_NEED_RESCHED,TI_flags(%rcx) |
1da177e4 LT |
766 | jnc retint_restore_args |
767 | bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */ | |
768 | jnc retint_restore_args | |
769 | call preempt_schedule_irq | |
770 | jmp exit_intr | |
771 | #endif | |
4b787e0b | 772 | |
1da177e4 | 773 | CFI_ENDPROC |
4b787e0b | 774 | END(common_interrupt) |
1da177e4 LT |
775 | |
776 | /* | |
777 | * APIC interrupts. | |
778 | */ | |
779 | .macro apicinterrupt num,func | |
7effaa88 | 780 | INTR_FRAME |
19eadf98 | 781 | pushq $~(\num) |
7effaa88 | 782 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
783 | interrupt \func |
784 | jmp ret_from_intr | |
785 | CFI_ENDPROC | |
786 | .endm | |
787 | ||
788 | ENTRY(thermal_interrupt) | |
789 | apicinterrupt THERMAL_APIC_VECTOR,smp_thermal_interrupt | |
4b787e0b | 790 | END(thermal_interrupt) |
1da177e4 | 791 | |
89b831ef JS |
792 | ENTRY(threshold_interrupt) |
793 | apicinterrupt THRESHOLD_APIC_VECTOR,mce_threshold_interrupt | |
4b787e0b | 794 | END(threshold_interrupt) |
89b831ef | 795 | |
1da177e4 LT |
796 | #ifdef CONFIG_SMP |
797 | ENTRY(reschedule_interrupt) | |
798 | apicinterrupt RESCHEDULE_VECTOR,smp_reschedule_interrupt | |
4b787e0b | 799 | END(reschedule_interrupt) |
1da177e4 | 800 | |
e5bc8b6b AK |
801 | .macro INVALIDATE_ENTRY num |
802 | ENTRY(invalidate_interrupt\num) | |
803 | apicinterrupt INVALIDATE_TLB_VECTOR_START+\num,smp_invalidate_interrupt | |
4b787e0b | 804 | END(invalidate_interrupt\num) |
e5bc8b6b AK |
805 | .endm |
806 | ||
807 | INVALIDATE_ENTRY 0 | |
808 | INVALIDATE_ENTRY 1 | |
809 | INVALIDATE_ENTRY 2 | |
810 | INVALIDATE_ENTRY 3 | |
811 | INVALIDATE_ENTRY 4 | |
812 | INVALIDATE_ENTRY 5 | |
813 | INVALIDATE_ENTRY 6 | |
814 | INVALIDATE_ENTRY 7 | |
1da177e4 LT |
815 | |
816 | ENTRY(call_function_interrupt) | |
817 | apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt | |
4b787e0b | 818 | END(call_function_interrupt) |
3b16cf87 JA |
819 | ENTRY(call_function_single_interrupt) |
820 | apicinterrupt CALL_FUNCTION_SINGLE_VECTOR,smp_call_function_single_interrupt | |
821 | END(call_function_single_interrupt) | |
61014292 EB |
822 | ENTRY(irq_move_cleanup_interrupt) |
823 | apicinterrupt IRQ_MOVE_CLEANUP_VECTOR,smp_irq_move_cleanup_interrupt | |
824 | END(irq_move_cleanup_interrupt) | |
1da177e4 LT |
825 | #endif |
826 | ||
1da177e4 LT |
827 | ENTRY(apic_timer_interrupt) |
828 | apicinterrupt LOCAL_TIMER_VECTOR,smp_apic_timer_interrupt | |
4b787e0b | 829 | END(apic_timer_interrupt) |
1da177e4 | 830 | |
1812924b CW |
831 | ENTRY(uv_bau_message_intr1) |
832 | apicinterrupt 220,uv_bau_message_interrupt | |
833 | END(uv_bau_message_intr1) | |
834 | ||
1da177e4 LT |
835 | ENTRY(error_interrupt) |
836 | apicinterrupt ERROR_APIC_VECTOR,smp_error_interrupt | |
4b787e0b | 837 | END(error_interrupt) |
1da177e4 LT |
838 | |
839 | ENTRY(spurious_interrupt) | |
840 | apicinterrupt SPURIOUS_APIC_VECTOR,smp_spurious_interrupt | |
4b787e0b | 841 | END(spurious_interrupt) |
1da177e4 LT |
842 | |
843 | /* | |
844 | * Exception entry points. | |
845 | */ | |
846 | .macro zeroentry sym | |
7effaa88 | 847 | INTR_FRAME |
fab58420 | 848 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1da177e4 | 849 | pushq $0 /* push error code/oldrax */ |
7effaa88 | 850 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 | 851 | pushq %rax /* push real oldrax to the rdi slot */ |
7effaa88 | 852 | CFI_ADJUST_CFA_OFFSET 8 |
37550907 | 853 | CFI_REL_OFFSET rax,0 |
1da177e4 LT |
854 | leaq \sym(%rip),%rax |
855 | jmp error_entry | |
7effaa88 | 856 | CFI_ENDPROC |
1da177e4 LT |
857 | .endm |
858 | ||
859 | .macro errorentry sym | |
7effaa88 | 860 | XCPT_FRAME |
fab58420 | 861 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1da177e4 | 862 | pushq %rax |
7effaa88 | 863 | CFI_ADJUST_CFA_OFFSET 8 |
37550907 | 864 | CFI_REL_OFFSET rax,0 |
1da177e4 LT |
865 | leaq \sym(%rip),%rax |
866 | jmp error_entry | |
7effaa88 | 867 | CFI_ENDPROC |
1da177e4 LT |
868 | .endm |
869 | ||
870 | /* error code is on the stack already */ | |
871 | /* handle NMI like exceptions that can happen everywhere */ | |
2601e64d | 872 | .macro paranoidentry sym, ist=0, irqtrace=1 |
1da177e4 LT |
873 | SAVE_ALL |
874 | cld | |
875 | movl $1,%ebx | |
876 | movl $MSR_GS_BASE,%ecx | |
877 | rdmsr | |
878 | testl %edx,%edx | |
879 | js 1f | |
72fe4858 | 880 | SWAPGS |
1da177e4 | 881 | xorl %ebx,%ebx |
b556b35e JB |
882 | 1: |
883 | .if \ist | |
884 | movq %gs:pda_data_offset, %rbp | |
885 | .endif | |
886 | movq %rsp,%rdi | |
1da177e4 LT |
887 | movq ORIG_RAX(%rsp),%rsi |
888 | movq $-1,ORIG_RAX(%rsp) | |
b556b35e | 889 | .if \ist |
5f8efbb9 | 890 | subq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) |
b556b35e | 891 | .endif |
1da177e4 | 892 | call \sym |
b556b35e | 893 | .if \ist |
5f8efbb9 | 894 | addq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) |
b556b35e | 895 | .endif |
72fe4858 | 896 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d IM |
897 | .if \irqtrace |
898 | TRACE_IRQS_OFF | |
899 | .endif | |
1da177e4 | 900 | .endm |
2601e64d IM |
901 | |
902 | /* | |
903 | * "Paranoid" exit path from exception stack. | |
904 | * Paranoid because this is used by NMIs and cannot take | |
905 | * any kernel state for granted. | |
906 | * We don't do kernel preemption checks here, because only | |
907 | * NMI should be common and it does not enable IRQs and | |
908 | * cannot get reschedule ticks. | |
909 | * | |
910 | * "trace" is 0 for the NMI handler only, because irq-tracing | |
911 | * is fundamentally NMI-unsafe. (we cannot change the soft and | |
912 | * hard flags at once, atomically) | |
913 | */ | |
914 | .macro paranoidexit trace=1 | |
915 | /* ebx: no swapgs flag */ | |
916 | paranoid_exit\trace: | |
917 | testl %ebx,%ebx /* swapgs needed? */ | |
918 | jnz paranoid_restore\trace | |
919 | testl $3,CS(%rsp) | |
920 | jnz paranoid_userspace\trace | |
921 | paranoid_swapgs\trace: | |
7a0a2dff | 922 | .if \trace |
2601e64d | 923 | TRACE_IRQS_IRETQ 0 |
7a0a2dff | 924 | .endif |
72fe4858 | 925 | SWAPGS_UNSAFE_STACK |
2601e64d IM |
926 | paranoid_restore\trace: |
927 | RESTORE_ALL 8 | |
3701d863 | 928 | jmp irq_return |
2601e64d IM |
929 | paranoid_userspace\trace: |
930 | GET_THREAD_INFO(%rcx) | |
26ccb8a7 | 931 | movl TI_flags(%rcx),%ebx |
2601e64d IM |
932 | andl $_TIF_WORK_MASK,%ebx |
933 | jz paranoid_swapgs\trace | |
934 | movq %rsp,%rdi /* &pt_regs */ | |
935 | call sync_regs | |
936 | movq %rax,%rsp /* switch stack for scheduling */ | |
937 | testl $_TIF_NEED_RESCHED,%ebx | |
938 | jnz paranoid_schedule\trace | |
939 | movl %ebx,%edx /* arg3: thread flags */ | |
940 | .if \trace | |
941 | TRACE_IRQS_ON | |
942 | .endif | |
72fe4858 | 943 | ENABLE_INTERRUPTS(CLBR_NONE) |
2601e64d IM |
944 | xorl %esi,%esi /* arg2: oldset */ |
945 | movq %rsp,%rdi /* arg1: &pt_regs */ | |
946 | call do_notify_resume | |
72fe4858 | 947 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d IM |
948 | .if \trace |
949 | TRACE_IRQS_OFF | |
950 | .endif | |
951 | jmp paranoid_userspace\trace | |
952 | paranoid_schedule\trace: | |
953 | .if \trace | |
954 | TRACE_IRQS_ON | |
955 | .endif | |
72fe4858 | 956 | ENABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 957 | call schedule |
72fe4858 | 958 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
959 | .if \trace |
960 | TRACE_IRQS_OFF | |
961 | .endif | |
962 | jmp paranoid_userspace\trace | |
963 | CFI_ENDPROC | |
964 | .endm | |
965 | ||
1da177e4 LT |
966 | /* |
967 | * Exception entry point. This expects an error code/orig_rax on the stack | |
968 | * and the exception handler in %rax. | |
969 | */ | |
d28c4393 | 970 | KPROBE_ENTRY(error_entry) |
7effaa88 | 971 | _frame RDI |
37550907 | 972 | CFI_REL_OFFSET rax,0 |
1da177e4 LT |
973 | /* rdi slot contains rax, oldrax contains error code */ |
974 | cld | |
975 | subq $14*8,%rsp | |
976 | CFI_ADJUST_CFA_OFFSET (14*8) | |
977 | movq %rsi,13*8(%rsp) | |
978 | CFI_REL_OFFSET rsi,RSI | |
979 | movq 14*8(%rsp),%rsi /* load rax from rdi slot */ | |
37550907 | 980 | CFI_REGISTER rax,rsi |
1da177e4 LT |
981 | movq %rdx,12*8(%rsp) |
982 | CFI_REL_OFFSET rdx,RDX | |
983 | movq %rcx,11*8(%rsp) | |
984 | CFI_REL_OFFSET rcx,RCX | |
985 | movq %rsi,10*8(%rsp) /* store rax */ | |
986 | CFI_REL_OFFSET rax,RAX | |
987 | movq %r8, 9*8(%rsp) | |
988 | CFI_REL_OFFSET r8,R8 | |
989 | movq %r9, 8*8(%rsp) | |
990 | CFI_REL_OFFSET r9,R9 | |
991 | movq %r10,7*8(%rsp) | |
992 | CFI_REL_OFFSET r10,R10 | |
993 | movq %r11,6*8(%rsp) | |
994 | CFI_REL_OFFSET r11,R11 | |
995 | movq %rbx,5*8(%rsp) | |
996 | CFI_REL_OFFSET rbx,RBX | |
997 | movq %rbp,4*8(%rsp) | |
998 | CFI_REL_OFFSET rbp,RBP | |
999 | movq %r12,3*8(%rsp) | |
1000 | CFI_REL_OFFSET r12,R12 | |
1001 | movq %r13,2*8(%rsp) | |
1002 | CFI_REL_OFFSET r13,R13 | |
1003 | movq %r14,1*8(%rsp) | |
1004 | CFI_REL_OFFSET r14,R14 | |
1005 | movq %r15,(%rsp) | |
1006 | CFI_REL_OFFSET r15,R15 | |
1007 | xorl %ebx,%ebx | |
1008 | testl $3,CS(%rsp) | |
1009 | je error_kernelspace | |
1010 | error_swapgs: | |
72fe4858 | 1011 | SWAPGS |
1da177e4 LT |
1012 | error_sti: |
1013 | movq %rdi,RDI(%rsp) | |
37550907 | 1014 | CFI_REL_OFFSET rdi,RDI |
1da177e4 LT |
1015 | movq %rsp,%rdi |
1016 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1017 | movq $-1,ORIG_RAX(%rsp) | |
1018 | call *%rax | |
10cd706d PZ |
1019 | /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ |
1020 | error_exit: | |
1021 | movl %ebx,%eax | |
1da177e4 | 1022 | RESTORE_REST |
72fe4858 | 1023 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 1024 | TRACE_IRQS_OFF |
1da177e4 LT |
1025 | GET_THREAD_INFO(%rcx) |
1026 | testl %eax,%eax | |
1027 | jne retint_kernel | |
10cd706d | 1028 | LOCKDEP_SYS_EXIT_IRQ |
26ccb8a7 | 1029 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
1030 | movl $_TIF_WORK_MASK,%edi |
1031 | andl %edi,%edx | |
1032 | jnz retint_careful | |
10cd706d | 1033 | jmp retint_swapgs |
1da177e4 LT |
1034 | CFI_ENDPROC |
1035 | ||
1036 | error_kernelspace: | |
1037 | incl %ebx | |
1038 | /* There are two places in the kernel that can potentially fault with | |
1039 | usergs. Handle them here. The exception handlers after | |
1040 | iret run with kernel gs again, so don't set the user space flag. | |
1041 | B stepping K8s sometimes report an truncated RIP for IRET | |
1042 | exceptions returning to compat mode. Check for these here too. */ | |
9d8ad5d6 VN |
1043 | leaq irq_return(%rip),%rcx |
1044 | cmpq %rcx,RIP(%rsp) | |
1da177e4 | 1045 | je error_swapgs |
9d8ad5d6 VN |
1046 | movl %ecx,%ecx /* zero extend */ |
1047 | cmpq %rcx,RIP(%rsp) | |
1da177e4 LT |
1048 | je error_swapgs |
1049 | cmpq $gs_change,RIP(%rsp) | |
1050 | je error_swapgs | |
1051 | jmp error_sti | |
d28c4393 | 1052 | KPROBE_END(error_entry) |
1da177e4 LT |
1053 | |
1054 | /* Reload gs selector with exception handling */ | |
1055 | /* edi: new selector */ | |
9f9d489a | 1056 | ENTRY(native_load_gs_index) |
7effaa88 | 1057 | CFI_STARTPROC |
1da177e4 | 1058 | pushf |
7effaa88 | 1059 | CFI_ADJUST_CFA_OFFSET 8 |
72fe4858 GOC |
1060 | DISABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI)) |
1061 | SWAPGS | |
1da177e4 LT |
1062 | gs_change: |
1063 | movl %edi,%gs | |
1064 | 2: mfence /* workaround */ | |
72fe4858 | 1065 | SWAPGS |
1da177e4 | 1066 | popf |
7effaa88 | 1067 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 | 1068 | ret |
7effaa88 | 1069 | CFI_ENDPROC |
9f9d489a | 1070 | ENDPROC(native_load_gs_index) |
1da177e4 LT |
1071 | |
1072 | .section __ex_table,"a" | |
1073 | .align 8 | |
1074 | .quad gs_change,bad_gs | |
1075 | .previous | |
1076 | .section .fixup,"ax" | |
1077 | /* running with kernelgs */ | |
1078 | bad_gs: | |
72fe4858 | 1079 | SWAPGS /* switch back to user gs */ |
1da177e4 LT |
1080 | xorl %eax,%eax |
1081 | movl %eax,%gs | |
1082 | jmp 2b | |
1083 | .previous | |
1084 | ||
1085 | /* | |
1086 | * Create a kernel thread. | |
1087 | * | |
1088 | * C extern interface: | |
1089 | * extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
1090 | * | |
1091 | * asm input arguments: | |
1092 | * rdi: fn, rsi: arg, rdx: flags | |
1093 | */ | |
1094 | ENTRY(kernel_thread) | |
1095 | CFI_STARTPROC | |
1096 | FAKE_STACK_FRAME $child_rip | |
1097 | SAVE_ALL | |
1098 | ||
1099 | # rdi: flags, rsi: usp, rdx: will be &pt_regs | |
1100 | movq %rdx,%rdi | |
1101 | orq kernel_thread_flags(%rip),%rdi | |
1102 | movq $-1, %rsi | |
1103 | movq %rsp, %rdx | |
1104 | ||
1105 | xorl %r8d,%r8d | |
1106 | xorl %r9d,%r9d | |
1107 | ||
1108 | # clone now | |
1109 | call do_fork | |
1110 | movq %rax,RAX(%rsp) | |
1111 | xorl %edi,%edi | |
1112 | ||
1113 | /* | |
1114 | * It isn't worth to check for reschedule here, | |
1115 | * so internally to the x86_64 port you can rely on kernel_thread() | |
1116 | * not to reschedule the child before returning, this avoids the need | |
1117 | * of hacks for example to fork off the per-CPU idle tasks. | |
1118 | * [Hopefully no generic code relies on the reschedule -AK] | |
1119 | */ | |
1120 | RESTORE_ALL | |
1121 | UNFAKE_STACK_FRAME | |
1122 | ret | |
1123 | CFI_ENDPROC | |
4b787e0b | 1124 | ENDPROC(kernel_thread) |
1da177e4 LT |
1125 | |
1126 | child_rip: | |
c05991ed AK |
1127 | pushq $0 # fake return address |
1128 | CFI_STARTPROC | |
1da177e4 LT |
1129 | /* |
1130 | * Here we are in the child and the registers are set as they were | |
1131 | * at kernel_thread() invocation in the parent. | |
1132 | */ | |
1133 | movq %rdi, %rax | |
1134 | movq %rsi, %rdi | |
1135 | call *%rax | |
1136 | # exit | |
1c5b5cfd | 1137 | mov %eax, %edi |
1da177e4 | 1138 | call do_exit |
c05991ed | 1139 | CFI_ENDPROC |
4b787e0b | 1140 | ENDPROC(child_rip) |
1da177e4 LT |
1141 | |
1142 | /* | |
1143 | * execve(). This function needs to use IRET, not SYSRET, to set up all state properly. | |
1144 | * | |
1145 | * C extern interface: | |
1146 | * extern long execve(char *name, char **argv, char **envp) | |
1147 | * | |
1148 | * asm input arguments: | |
1149 | * rdi: name, rsi: argv, rdx: envp | |
1150 | * | |
1151 | * We want to fallback into: | |
5d119b2c | 1152 | * extern long sys_execve(char *name, char **argv,char **envp, struct pt_regs *regs) |
1da177e4 LT |
1153 | * |
1154 | * do_sys_execve asm fallback arguments: | |
5d119b2c | 1155 | * rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack |
1da177e4 | 1156 | */ |
3db03b4a | 1157 | ENTRY(kernel_execve) |
1da177e4 LT |
1158 | CFI_STARTPROC |
1159 | FAKE_STACK_FRAME $0 | |
1160 | SAVE_ALL | |
5d119b2c | 1161 | movq %rsp,%rcx |
1da177e4 LT |
1162 | call sys_execve |
1163 | movq %rax, RAX(%rsp) | |
1164 | RESTORE_REST | |
1165 | testq %rax,%rax | |
1166 | je int_ret_from_sys_call | |
1167 | RESTORE_ARGS | |
1168 | UNFAKE_STACK_FRAME | |
1169 | ret | |
1170 | CFI_ENDPROC | |
3db03b4a | 1171 | ENDPROC(kernel_execve) |
1da177e4 | 1172 | |
0f2fbdcb | 1173 | KPROBE_ENTRY(page_fault) |
1da177e4 | 1174 | errorentry do_page_fault |
d28c4393 | 1175 | KPROBE_END(page_fault) |
1da177e4 LT |
1176 | |
1177 | ENTRY(coprocessor_error) | |
1178 | zeroentry do_coprocessor_error | |
4b787e0b | 1179 | END(coprocessor_error) |
1da177e4 LT |
1180 | |
1181 | ENTRY(simd_coprocessor_error) | |
1182 | zeroentry do_simd_coprocessor_error | |
4b787e0b | 1183 | END(simd_coprocessor_error) |
1da177e4 LT |
1184 | |
1185 | ENTRY(device_not_available) | |
1186 | zeroentry math_state_restore | |
4b787e0b | 1187 | END(device_not_available) |
1da177e4 LT |
1188 | |
1189 | /* runs on exception stack */ | |
0f2fbdcb | 1190 | KPROBE_ENTRY(debug) |
7effaa88 | 1191 | INTR_FRAME |
1da177e4 LT |
1192 | pushq $0 |
1193 | CFI_ADJUST_CFA_OFFSET 8 | |
5f8efbb9 | 1194 | paranoidentry do_debug, DEBUG_STACK |
2601e64d | 1195 | paranoidexit |
d28c4393 | 1196 | KPROBE_END(debug) |
1da177e4 LT |
1197 | |
1198 | /* runs on exception stack */ | |
eddb6fb9 | 1199 | KPROBE_ENTRY(nmi) |
7effaa88 | 1200 | INTR_FRAME |
1da177e4 | 1201 | pushq $-1 |
7effaa88 | 1202 | CFI_ADJUST_CFA_OFFSET 8 |
2601e64d IM |
1203 | paranoidentry do_nmi, 0, 0 |
1204 | #ifdef CONFIG_TRACE_IRQFLAGS | |
1205 | paranoidexit 0 | |
1206 | #else | |
1207 | jmp paranoid_exit1 | |
1208 | CFI_ENDPROC | |
1209 | #endif | |
d28c4393 | 1210 | KPROBE_END(nmi) |
6fefb0d1 | 1211 | |
0f2fbdcb | 1212 | KPROBE_ENTRY(int3) |
b556b35e JB |
1213 | INTR_FRAME |
1214 | pushq $0 | |
1215 | CFI_ADJUST_CFA_OFFSET 8 | |
5f8efbb9 | 1216 | paranoidentry do_int3, DEBUG_STACK |
2601e64d | 1217 | jmp paranoid_exit1 |
b556b35e | 1218 | CFI_ENDPROC |
d28c4393 | 1219 | KPROBE_END(int3) |
1da177e4 LT |
1220 | |
1221 | ENTRY(overflow) | |
1222 | zeroentry do_overflow | |
4b787e0b | 1223 | END(overflow) |
1da177e4 LT |
1224 | |
1225 | ENTRY(bounds) | |
1226 | zeroentry do_bounds | |
4b787e0b | 1227 | END(bounds) |
1da177e4 LT |
1228 | |
1229 | ENTRY(invalid_op) | |
1230 | zeroentry do_invalid_op | |
4b787e0b | 1231 | END(invalid_op) |
1da177e4 LT |
1232 | |
1233 | ENTRY(coprocessor_segment_overrun) | |
1234 | zeroentry do_coprocessor_segment_overrun | |
4b787e0b | 1235 | END(coprocessor_segment_overrun) |
1da177e4 | 1236 | |
1da177e4 LT |
1237 | /* runs on exception stack */ |
1238 | ENTRY(double_fault) | |
7effaa88 | 1239 | XCPT_FRAME |
1da177e4 | 1240 | paranoidentry do_double_fault |
2601e64d | 1241 | jmp paranoid_exit1 |
1da177e4 | 1242 | CFI_ENDPROC |
4b787e0b | 1243 | END(double_fault) |
1da177e4 LT |
1244 | |
1245 | ENTRY(invalid_TSS) | |
1246 | errorentry do_invalid_TSS | |
4b787e0b | 1247 | END(invalid_TSS) |
1da177e4 LT |
1248 | |
1249 | ENTRY(segment_not_present) | |
1250 | errorentry do_segment_not_present | |
4b787e0b | 1251 | END(segment_not_present) |
1da177e4 LT |
1252 | |
1253 | /* runs on exception stack */ | |
1254 | ENTRY(stack_segment) | |
7effaa88 | 1255 | XCPT_FRAME |
1da177e4 | 1256 | paranoidentry do_stack_segment |
2601e64d | 1257 | jmp paranoid_exit1 |
1da177e4 | 1258 | CFI_ENDPROC |
4b787e0b | 1259 | END(stack_segment) |
1da177e4 | 1260 | |
0f2fbdcb | 1261 | KPROBE_ENTRY(general_protection) |
1da177e4 | 1262 | errorentry do_general_protection |
d28c4393 | 1263 | KPROBE_END(general_protection) |
1da177e4 LT |
1264 | |
1265 | ENTRY(alignment_check) | |
1266 | errorentry do_alignment_check | |
4b787e0b | 1267 | END(alignment_check) |
1da177e4 LT |
1268 | |
1269 | ENTRY(divide_error) | |
1270 | zeroentry do_divide_error | |
4b787e0b | 1271 | END(divide_error) |
1da177e4 LT |
1272 | |
1273 | ENTRY(spurious_interrupt_bug) | |
1274 | zeroentry do_spurious_interrupt_bug | |
4b787e0b | 1275 | END(spurious_interrupt_bug) |
1da177e4 LT |
1276 | |
1277 | #ifdef CONFIG_X86_MCE | |
1278 | /* runs on exception stack */ | |
1279 | ENTRY(machine_check) | |
7effaa88 | 1280 | INTR_FRAME |
1da177e4 LT |
1281 | pushq $0 |
1282 | CFI_ADJUST_CFA_OFFSET 8 | |
1283 | paranoidentry do_machine_check | |
2601e64d | 1284 | jmp paranoid_exit1 |
1da177e4 | 1285 | CFI_ENDPROC |
4b787e0b | 1286 | END(machine_check) |
1da177e4 LT |
1287 | #endif |
1288 | ||
2699500b | 1289 | /* Call softirq on interrupt stack. Interrupts are off. */ |
ed6b676c | 1290 | ENTRY(call_softirq) |
7effaa88 | 1291 | CFI_STARTPROC |
2699500b AK |
1292 | push %rbp |
1293 | CFI_ADJUST_CFA_OFFSET 8 | |
1294 | CFI_REL_OFFSET rbp,0 | |
1295 | mov %rsp,%rbp | |
1296 | CFI_DEF_CFA_REGISTER rbp | |
ed6b676c | 1297 | incl %gs:pda_irqcount |
2699500b AK |
1298 | cmove %gs:pda_irqstackptr,%rsp |
1299 | push %rbp # backlink for old unwinder | |
ed6b676c | 1300 | call __do_softirq |
2699500b | 1301 | leaveq |
7effaa88 | 1302 | CFI_DEF_CFA_REGISTER rsp |
2699500b | 1303 | CFI_ADJUST_CFA_OFFSET -8 |
ed6b676c | 1304 | decl %gs:pda_irqcount |
ed6b676c | 1305 | ret |
7effaa88 | 1306 | CFI_ENDPROC |
4b787e0b | 1307 | ENDPROC(call_softirq) |
75154f40 AK |
1308 | |
1309 | KPROBE_ENTRY(ignore_sysret) | |
1310 | CFI_STARTPROC | |
1311 | mov $-ENOSYS,%eax | |
1312 | sysret | |
1313 | CFI_ENDPROC | |
1314 | ENDPROC(ignore_sysret) | |
3d75e1b8 JF |
1315 | |
1316 | #ifdef CONFIG_XEN | |
1317 | ENTRY(xen_hypervisor_callback) | |
1318 | zeroentry xen_do_hypervisor_callback | |
1319 | END(xen_hypervisor_callback) | |
1320 | ||
1321 | /* | |
1322 | # A note on the "critical region" in our callback handler. | |
1323 | # We want to avoid stacking callback handlers due to events occurring | |
1324 | # during handling of the last event. To do this, we keep events disabled | |
1325 | # until we've done all processing. HOWEVER, we must enable events before | |
1326 | # popping the stack frame (can't be done atomically) and so it would still | |
1327 | # be possible to get enough handler activations to overflow the stack. | |
1328 | # Although unlikely, bugs of that kind are hard to track down, so we'd | |
1329 | # like to avoid the possibility. | |
1330 | # So, on entry to the handler we detect whether we interrupted an | |
1331 | # existing activation in its critical region -- if so, we pop the current | |
1332 | # activation and restart the handler using the previous one. | |
1333 | */ | |
1334 | ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs) | |
1335 | CFI_STARTPROC | |
1336 | /* Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will | |
1337 | see the correct pointer to the pt_regs */ | |
1338 | movq %rdi, %rsp # we don't return, adjust the stack frame | |
1339 | CFI_ENDPROC | |
1340 | CFI_DEFAULT_STACK | |
1341 | 11: incl %gs:pda_irqcount | |
1342 | movq %rsp,%rbp | |
1343 | CFI_DEF_CFA_REGISTER rbp | |
1344 | cmovzq %gs:pda_irqstackptr,%rsp | |
1345 | pushq %rbp # backlink for old unwinder | |
1346 | call xen_evtchn_do_upcall | |
1347 | popq %rsp | |
1348 | CFI_DEF_CFA_REGISTER rsp | |
1349 | decl %gs:pda_irqcount | |
1350 | jmp error_exit | |
1351 | CFI_ENDPROC | |
1352 | END(do_hypervisor_callback) | |
1353 | ||
1354 | /* | |
1355 | # Hypervisor uses this for application faults while it executes. | |
1356 | # We get here for two reasons: | |
1357 | # 1. Fault while reloading DS, ES, FS or GS | |
1358 | # 2. Fault while executing IRET | |
1359 | # Category 1 we do not need to fix up as Xen has already reloaded all segment | |
1360 | # registers that could be reloaded and zeroed the others. | |
1361 | # Category 2 we fix up by killing the current process. We cannot use the | |
1362 | # normal Linux return path in this case because if we use the IRET hypercall | |
1363 | # to pop the stack frame we end up in an infinite loop of failsafe callbacks. | |
1364 | # We distinguish between categories by comparing each saved segment register | |
1365 | # with its current contents: any discrepancy means we in category 1. | |
1366 | */ | |
1367 | ENTRY(xen_failsafe_callback) | |
4a5c3e77 JF |
1368 | framesz = (RIP-0x30) /* workaround buggy gas */ |
1369 | _frame framesz | |
3d75e1b8 JF |
1370 | CFI_REL_OFFSET rcx, 0 |
1371 | CFI_REL_OFFSET r11, 8 | |
1372 | movw %ds,%cx | |
1373 | cmpw %cx,0x10(%rsp) | |
1374 | CFI_REMEMBER_STATE | |
1375 | jne 1f | |
1376 | movw %es,%cx | |
1377 | cmpw %cx,0x18(%rsp) | |
1378 | jne 1f | |
1379 | movw %fs,%cx | |
1380 | cmpw %cx,0x20(%rsp) | |
1381 | jne 1f | |
1382 | movw %gs,%cx | |
1383 | cmpw %cx,0x28(%rsp) | |
1384 | jne 1f | |
1385 | /* All segments match their saved values => Category 2 (Bad IRET). */ | |
1386 | movq (%rsp),%rcx | |
1387 | CFI_RESTORE rcx | |
1388 | movq 8(%rsp),%r11 | |
1389 | CFI_RESTORE r11 | |
1390 | addq $0x30,%rsp | |
1391 | CFI_ADJUST_CFA_OFFSET -0x30 | |
4a5c3e77 JF |
1392 | pushq $0 |
1393 | CFI_ADJUST_CFA_OFFSET 8 | |
1394 | pushq %r11 | |
1395 | CFI_ADJUST_CFA_OFFSET 8 | |
1396 | pushq %rcx | |
1397 | CFI_ADJUST_CFA_OFFSET 8 | |
1398 | jmp general_protection | |
3d75e1b8 JF |
1399 | CFI_RESTORE_STATE |
1400 | 1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */ | |
1401 | movq (%rsp),%rcx | |
1402 | CFI_RESTORE rcx | |
1403 | movq 8(%rsp),%r11 | |
1404 | CFI_RESTORE r11 | |
1405 | addq $0x30,%rsp | |
1406 | CFI_ADJUST_CFA_OFFSET -0x30 | |
1407 | pushq $0 | |
1408 | CFI_ADJUST_CFA_OFFSET 8 | |
1409 | SAVE_ALL | |
1410 | jmp error_exit | |
1411 | CFI_ENDPROC | |
3d75e1b8 JF |
1412 | END(xen_failsafe_callback) |
1413 | ||
1414 | #endif /* CONFIG_XEN */ |