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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> | |
7 | * | |
8 | * $Id$ | |
9 | */ | |
10 | ||
11 | /* | |
12 | * entry.S contains the system-call and fault low-level handling routines. | |
13 | * | |
14 | * NOTE: This code handles signal-recognition, which happens every time | |
15 | * after an interrupt and after each system call. | |
16 | * | |
17 | * Normal syscalls and interrupts don't save a full stack frame, this is | |
18 | * only done for syscall tracing, signals or fork/exec et.al. | |
19 | * | |
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. | |
23 | * - partial stack frame: partially saved registers upto R11. | |
24 | * - full stack frame: Like partial stack frame, but all register saved. | |
25 | * | |
26 | * TODO: | |
27 | * - schedule it carefully for the final hardware. | |
28 | */ | |
29 | ||
30 | #define ASSEMBLY 1 | |
31 | #include <linux/config.h> | |
32 | #include <linux/linkage.h> | |
33 | #include <asm/segment.h> | |
34 | #include <asm/smp.h> | |
35 | #include <asm/cache.h> | |
36 | #include <asm/errno.h> | |
37 | #include <asm/dwarf2.h> | |
38 | #include <asm/calling.h> | |
39 | #include <asm/offset.h> | |
40 | #include <asm/msr.h> | |
41 | #include <asm/unistd.h> | |
42 | #include <asm/thread_info.h> | |
43 | #include <asm/hw_irq.h> | |
44 | ||
45 | .code64 | |
46 | ||
47 | #ifdef CONFIG_PREEMPT | |
48 | #define preempt_stop cli | |
49 | #else | |
50 | #define preempt_stop | |
51 | #define retint_kernel retint_restore_args | |
52 | #endif | |
53 | ||
54 | /* | |
55 | * C code is not supposed to know about undefined top of stack. Every time | |
56 | * a C function with an pt_regs argument is called from the SYSCALL based | |
57 | * fast path FIXUP_TOP_OF_STACK is needed. | |
58 | * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs | |
59 | * manipulation. | |
60 | */ | |
61 | ||
62 | /* %rsp:at FRAMEEND */ | |
63 | .macro FIXUP_TOP_OF_STACK tmp | |
64 | movq %gs:pda_oldrsp,\tmp | |
65 | movq \tmp,RSP(%rsp) | |
66 | movq $__USER_DS,SS(%rsp) | |
67 | movq $__USER_CS,CS(%rsp) | |
68 | movq $-1,RCX(%rsp) | |
69 | movq R11(%rsp),\tmp /* get eflags */ | |
70 | movq \tmp,EFLAGS(%rsp) | |
71 | .endm | |
72 | ||
73 | .macro RESTORE_TOP_OF_STACK tmp,offset=0 | |
74 | movq RSP-\offset(%rsp),\tmp | |
75 | movq \tmp,%gs:pda_oldrsp | |
76 | movq EFLAGS-\offset(%rsp),\tmp | |
77 | movq \tmp,R11-\offset(%rsp) | |
78 | .endm | |
79 | ||
80 | .macro FAKE_STACK_FRAME child_rip | |
81 | /* push in order ss, rsp, eflags, cs, rip */ | |
82 | xorq %rax, %rax | |
83 | pushq %rax /* ss */ | |
84 | CFI_ADJUST_CFA_OFFSET 8 | |
85 | pushq %rax /* rsp */ | |
86 | CFI_ADJUST_CFA_OFFSET 8 | |
87 | CFI_OFFSET rip,0 | |
88 | pushq $(1<<9) /* eflags - interrupts on */ | |
89 | CFI_ADJUST_CFA_OFFSET 8 | |
90 | pushq $__KERNEL_CS /* cs */ | |
91 | CFI_ADJUST_CFA_OFFSET 8 | |
92 | pushq \child_rip /* rip */ | |
93 | CFI_ADJUST_CFA_OFFSET 8 | |
94 | CFI_OFFSET rip,0 | |
95 | pushq %rax /* orig rax */ | |
96 | CFI_ADJUST_CFA_OFFSET 8 | |
97 | .endm | |
98 | ||
99 | .macro UNFAKE_STACK_FRAME | |
100 | addq $8*6, %rsp | |
101 | CFI_ADJUST_CFA_OFFSET -(6*8) | |
102 | .endm | |
103 | ||
104 | .macro CFI_DEFAULT_STACK | |
105 | CFI_ADJUST_CFA_OFFSET (SS) | |
106 | CFI_OFFSET r15,R15-SS | |
107 | CFI_OFFSET r14,R14-SS | |
108 | CFI_OFFSET r13,R13-SS | |
109 | CFI_OFFSET r12,R12-SS | |
110 | CFI_OFFSET rbp,RBP-SS | |
111 | CFI_OFFSET rbx,RBX-SS | |
112 | CFI_OFFSET r11,R11-SS | |
113 | CFI_OFFSET r10,R10-SS | |
114 | CFI_OFFSET r9,R9-SS | |
115 | CFI_OFFSET r8,R8-SS | |
116 | CFI_OFFSET rax,RAX-SS | |
117 | CFI_OFFSET rcx,RCX-SS | |
118 | CFI_OFFSET rdx,RDX-SS | |
119 | CFI_OFFSET rsi,RSI-SS | |
120 | CFI_OFFSET rdi,RDI-SS | |
121 | CFI_OFFSET rsp,RSP-SS | |
122 | CFI_OFFSET rip,RIP-SS | |
123 | .endm | |
124 | /* | |
125 | * A newly forked process directly context switches into this. | |
126 | */ | |
127 | /* rdi: prev */ | |
128 | ENTRY(ret_from_fork) | |
129 | CFI_STARTPROC | |
130 | CFI_DEFAULT_STACK | |
131 | call schedule_tail | |
132 | GET_THREAD_INFO(%rcx) | |
133 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),threadinfo_flags(%rcx) | |
134 | jnz rff_trace | |
135 | rff_action: | |
136 | RESTORE_REST | |
137 | testl $3,CS-ARGOFFSET(%rsp) # from kernel_thread? | |
138 | je int_ret_from_sys_call | |
139 | testl $_TIF_IA32,threadinfo_flags(%rcx) | |
140 | jnz int_ret_from_sys_call | |
141 | RESTORE_TOP_OF_STACK %rdi,ARGOFFSET | |
142 | jmp ret_from_sys_call | |
143 | rff_trace: | |
144 | movq %rsp,%rdi | |
145 | call syscall_trace_leave | |
146 | GET_THREAD_INFO(%rcx) | |
147 | jmp rff_action | |
148 | CFI_ENDPROC | |
149 | ||
150 | /* | |
151 | * System call entry. Upto 6 arguments in registers are supported. | |
152 | * | |
153 | * SYSCALL does not save anything on the stack and does not change the | |
154 | * stack pointer. | |
155 | */ | |
156 | ||
157 | /* | |
158 | * Register setup: | |
159 | * rax system call number | |
160 | * rdi arg0 | |
161 | * rcx return address for syscall/sysret, C arg3 | |
162 | * rsi arg1 | |
163 | * rdx arg2 | |
164 | * r10 arg3 (--> moved to rcx for C) | |
165 | * r8 arg4 | |
166 | * r9 arg5 | |
167 | * r11 eflags for syscall/sysret, temporary for C | |
168 | * r12-r15,rbp,rbx saved by C code, not touched. | |
169 | * | |
170 | * Interrupts are off on entry. | |
171 | * Only called from user space. | |
172 | * | |
173 | * XXX if we had a free scratch register we could save the RSP into the stack frame | |
174 | * and report it properly in ps. Unfortunately we haven't. | |
175 | */ | |
176 | ||
177 | ENTRY(system_call) | |
178 | CFI_STARTPROC | |
179 | swapgs | |
180 | movq %rsp,%gs:pda_oldrsp | |
181 | movq %gs:pda_kernelstack,%rsp | |
182 | sti | |
183 | SAVE_ARGS 8,1 | |
184 | movq %rax,ORIG_RAX-ARGOFFSET(%rsp) | |
185 | movq %rcx,RIP-ARGOFFSET(%rsp) | |
186 | GET_THREAD_INFO(%rcx) | |
187 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%rcx) | |
188 | jnz tracesys | |
189 | cmpq $__NR_syscall_max,%rax | |
190 | ja badsys | |
191 | movq %r10,%rcx | |
192 | call *sys_call_table(,%rax,8) # XXX: rip relative | |
193 | movq %rax,RAX-ARGOFFSET(%rsp) | |
194 | /* | |
195 | * Syscall return path ending with SYSRET (fast path) | |
196 | * Has incomplete stack frame and undefined top of stack. | |
197 | */ | |
198 | .globl ret_from_sys_call | |
199 | ret_from_sys_call: | |
11b854b2 | 200 | movl $_TIF_ALLWORK_MASK,%edi |
1da177e4 LT |
201 | /* edi: flagmask */ |
202 | sysret_check: | |
203 | GET_THREAD_INFO(%rcx) | |
204 | cli | |
205 | movl threadinfo_flags(%rcx),%edx | |
206 | andl %edi,%edx | |
207 | jnz sysret_careful | |
208 | movq RIP-ARGOFFSET(%rsp),%rcx | |
209 | RESTORE_ARGS 0,-ARG_SKIP,1 | |
210 | movq %gs:pda_oldrsp,%rsp | |
211 | swapgs | |
212 | sysretq | |
213 | ||
214 | /* Handle reschedules */ | |
215 | /* edx: work, edi: workmask */ | |
216 | sysret_careful: | |
217 | bt $TIF_NEED_RESCHED,%edx | |
218 | jnc sysret_signal | |
219 | sti | |
220 | pushq %rdi | |
221 | call schedule | |
222 | popq %rdi | |
223 | jmp sysret_check | |
224 | ||
225 | /* Handle a signal */ | |
11b854b2 | 226 | /* edx: work flags (arg3) */ |
1da177e4 LT |
227 | sysret_signal: |
228 | sti | |
1da177e4 LT |
229 | leaq do_notify_resume(%rip),%rax |
230 | leaq -ARGOFFSET(%rsp),%rdi # &pt_regs -> arg1 | |
231 | xorl %esi,%esi # oldset -> arg2 | |
232 | call ptregscall_common | |
1da177e4 LT |
233 | jmp sysret_check |
234 | ||
235 | /* Do syscall tracing */ | |
236 | tracesys: | |
237 | SAVE_REST | |
238 | movq $-ENOSYS,RAX(%rsp) | |
239 | FIXUP_TOP_OF_STACK %rdi | |
240 | movq %rsp,%rdi | |
241 | call syscall_trace_enter | |
242 | LOAD_ARGS ARGOFFSET /* reload args from stack in case ptrace changed it */ | |
243 | RESTORE_REST | |
244 | cmpq $__NR_syscall_max,%rax | |
245 | ja 1f | |
246 | movq %r10,%rcx /* fixup for C */ | |
247 | call *sys_call_table(,%rax,8) | |
248 | movq %rax,RAX-ARGOFFSET(%rsp) | |
249 | 1: SAVE_REST | |
250 | movq %rsp,%rdi | |
251 | call syscall_trace_leave | |
252 | RESTORE_TOP_OF_STACK %rbx | |
253 | RESTORE_REST | |
254 | jmp ret_from_sys_call | |
255 | ||
256 | badsys: | |
257 | movq $-ENOSYS,RAX-ARGOFFSET(%rsp) | |
258 | jmp ret_from_sys_call | |
259 | ||
260 | /* | |
261 | * Syscall return path ending with IRET. | |
262 | * Has correct top of stack, but partial stack frame. | |
263 | */ | |
264 | ENTRY(int_ret_from_sys_call) | |
265 | cli | |
266 | testl $3,CS-ARGOFFSET(%rsp) | |
267 | je retint_restore_args | |
268 | movl $_TIF_ALLWORK_MASK,%edi | |
269 | /* edi: mask to check */ | |
270 | int_with_check: | |
271 | GET_THREAD_INFO(%rcx) | |
272 | movl threadinfo_flags(%rcx),%edx | |
273 | andl %edi,%edx | |
274 | jnz int_careful | |
275 | jmp retint_swapgs | |
276 | ||
277 | /* Either reschedule or signal or syscall exit tracking needed. */ | |
278 | /* First do a reschedule test. */ | |
279 | /* edx: work, edi: workmask */ | |
280 | int_careful: | |
281 | bt $TIF_NEED_RESCHED,%edx | |
282 | jnc int_very_careful | |
283 | sti | |
284 | pushq %rdi | |
285 | call schedule | |
286 | popq %rdi | |
cdd219cd | 287 | cli |
1da177e4 LT |
288 | jmp int_with_check |
289 | ||
290 | /* handle signals and tracing -- both require a full stack frame */ | |
291 | int_very_careful: | |
292 | sti | |
293 | SAVE_REST | |
294 | /* Check for syscall exit trace */ | |
295 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edx | |
296 | jz int_signal | |
297 | pushq %rdi | |
298 | leaq 8(%rsp),%rdi # &ptregs -> arg1 | |
299 | call syscall_trace_leave | |
300 | popq %rdi | |
36c1104e | 301 | andl $~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edi |
1da177e4 LT |
302 | jmp int_restore_rest |
303 | ||
304 | int_signal: | |
305 | testl $(_TIF_NOTIFY_RESUME|_TIF_SIGPENDING|_TIF_SINGLESTEP),%edx | |
306 | jz 1f | |
307 | movq %rsp,%rdi # &ptregs -> arg1 | |
308 | xorl %esi,%esi # oldset -> arg2 | |
309 | call do_notify_resume | |
310 | 1: movl $_TIF_NEED_RESCHED,%edi | |
311 | int_restore_rest: | |
312 | RESTORE_REST | |
313 | jmp int_with_check | |
314 | CFI_ENDPROC | |
315 | ||
316 | /* | |
317 | * Certain special system calls that need to save a complete full stack frame. | |
318 | */ | |
319 | ||
320 | .macro PTREGSCALL label,func,arg | |
321 | .globl \label | |
322 | \label: | |
323 | leaq \func(%rip),%rax | |
324 | leaq -ARGOFFSET+8(%rsp),\arg /* 8 for return address */ | |
325 | jmp ptregscall_common | |
326 | .endm | |
327 | ||
328 | PTREGSCALL stub_clone, sys_clone, %r8 | |
329 | PTREGSCALL stub_fork, sys_fork, %rdi | |
330 | PTREGSCALL stub_vfork, sys_vfork, %rdi | |
331 | PTREGSCALL stub_rt_sigsuspend, sys_rt_sigsuspend, %rdx | |
332 | PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx | |
333 | PTREGSCALL stub_iopl, sys_iopl, %rsi | |
334 | ||
335 | ENTRY(ptregscall_common) | |
336 | CFI_STARTPROC | |
337 | popq %r11 | |
338 | CFI_ADJUST_CFA_OFFSET -8 | |
339 | SAVE_REST | |
340 | movq %r11, %r15 | |
341 | FIXUP_TOP_OF_STACK %r11 | |
342 | call *%rax | |
343 | RESTORE_TOP_OF_STACK %r11 | |
344 | movq %r15, %r11 | |
345 | RESTORE_REST | |
346 | pushq %r11 | |
347 | CFI_ADJUST_CFA_OFFSET 8 | |
348 | ret | |
349 | CFI_ENDPROC | |
350 | ||
351 | ENTRY(stub_execve) | |
352 | CFI_STARTPROC | |
353 | popq %r11 | |
354 | CFI_ADJUST_CFA_OFFSET -8 | |
355 | SAVE_REST | |
356 | movq %r11, %r15 | |
357 | FIXUP_TOP_OF_STACK %r11 | |
358 | call sys_execve | |
359 | GET_THREAD_INFO(%rcx) | |
360 | bt $TIF_IA32,threadinfo_flags(%rcx) | |
361 | jc exec_32bit | |
362 | RESTORE_TOP_OF_STACK %r11 | |
363 | movq %r15, %r11 | |
364 | RESTORE_REST | |
365 | push %r11 | |
366 | ret | |
367 | ||
368 | exec_32bit: | |
369 | CFI_ADJUST_CFA_OFFSET REST_SKIP | |
370 | movq %rax,RAX(%rsp) | |
371 | RESTORE_REST | |
372 | jmp int_ret_from_sys_call | |
373 | CFI_ENDPROC | |
374 | ||
375 | /* | |
376 | * sigreturn is special because it needs to restore all registers on return. | |
377 | * This cannot be done with SYSRET, so use the IRET return path instead. | |
378 | */ | |
379 | ENTRY(stub_rt_sigreturn) | |
380 | CFI_STARTPROC | |
381 | addq $8, %rsp | |
382 | SAVE_REST | |
383 | movq %rsp,%rdi | |
384 | FIXUP_TOP_OF_STACK %r11 | |
385 | call sys_rt_sigreturn | |
386 | movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer | |
387 | RESTORE_REST | |
388 | jmp int_ret_from_sys_call | |
389 | CFI_ENDPROC | |
390 | ||
391 | /* | |
392 | * Interrupt entry/exit. | |
393 | * | |
394 | * Interrupt entry points save only callee clobbered registers in fast path. | |
395 | * | |
396 | * Entry runs with interrupts off. | |
397 | */ | |
398 | ||
399 | /* 0(%rsp): interrupt number */ | |
400 | .macro interrupt func | |
401 | CFI_STARTPROC simple | |
402 | CFI_DEF_CFA rsp,(SS-RDI) | |
403 | CFI_REL_OFFSET rsp,(RSP-ORIG_RAX) | |
404 | CFI_REL_OFFSET rip,(RIP-ORIG_RAX) | |
405 | cld | |
406 | #ifdef CONFIG_DEBUG_INFO | |
407 | SAVE_ALL | |
408 | movq %rsp,%rdi | |
409 | /* | |
410 | * Setup a stack frame pointer. This allows gdb to trace | |
411 | * back to the original stack. | |
412 | */ | |
413 | movq %rsp,%rbp | |
414 | CFI_DEF_CFA_REGISTER rbp | |
415 | #else | |
416 | SAVE_ARGS | |
417 | leaq -ARGOFFSET(%rsp),%rdi # arg1 for handler | |
418 | #endif | |
419 | testl $3,CS(%rdi) | |
420 | je 1f | |
421 | swapgs | |
422 | 1: addl $1,%gs:pda_irqcount # RED-PEN should check preempt count | |
423 | movq %gs:pda_irqstackptr,%rax | |
424 | cmoveq %rax,%rsp | |
425 | pushq %rdi # save old stack | |
426 | call \func | |
427 | .endm | |
428 | ||
429 | ENTRY(common_interrupt) | |
430 | interrupt do_IRQ | |
431 | /* 0(%rsp): oldrsp-ARGOFFSET */ | |
432 | ret_from_intr: | |
433 | popq %rdi | |
434 | cli | |
435 | subl $1,%gs:pda_irqcount | |
436 | #ifdef CONFIG_DEBUG_INFO | |
437 | movq RBP(%rdi),%rbp | |
438 | #endif | |
439 | leaq ARGOFFSET(%rdi),%rsp | |
440 | exit_intr: | |
441 | GET_THREAD_INFO(%rcx) | |
442 | testl $3,CS-ARGOFFSET(%rsp) | |
443 | je retint_kernel | |
444 | ||
445 | /* Interrupt came from user space */ | |
446 | /* | |
447 | * Has a correct top of stack, but a partial stack frame | |
448 | * %rcx: thread info. Interrupts off. | |
449 | */ | |
450 | retint_with_reschedule: | |
451 | movl $_TIF_WORK_MASK,%edi | |
452 | retint_check: | |
453 | movl threadinfo_flags(%rcx),%edx | |
454 | andl %edi,%edx | |
455 | jnz retint_careful | |
456 | retint_swapgs: | |
1da177e4 LT |
457 | swapgs |
458 | retint_restore_args: | |
459 | cli | |
460 | RESTORE_ARGS 0,8,0 | |
461 | iret_label: | |
462 | iretq | |
463 | ||
464 | .section __ex_table,"a" | |
465 | .quad iret_label,bad_iret | |
466 | .previous | |
467 | .section .fixup,"ax" | |
468 | /* force a signal here? this matches i386 behaviour */ | |
469 | /* running with kernel gs */ | |
470 | bad_iret: | |
471 | movq $-9999,%rdi /* better code? */ | |
472 | jmp do_exit | |
473 | .previous | |
474 | ||
475 | /* edi: workmask, edx: work */ | |
476 | retint_careful: | |
477 | bt $TIF_NEED_RESCHED,%edx | |
478 | jnc retint_signal | |
479 | sti | |
480 | pushq %rdi | |
481 | call schedule | |
482 | popq %rdi | |
483 | GET_THREAD_INFO(%rcx) | |
484 | cli | |
485 | jmp retint_check | |
486 | ||
487 | retint_signal: | |
1da177e4 LT |
488 | sti |
489 | SAVE_REST | |
490 | movq $-1,ORIG_RAX(%rsp) | |
491 | xorq %rsi,%rsi # oldset | |
492 | movq %rsp,%rdi # &pt_regs | |
493 | call do_notify_resume | |
494 | RESTORE_REST | |
495 | cli | |
1da177e4 LT |
496 | GET_THREAD_INFO(%rcx) |
497 | jmp retint_check | |
498 | ||
499 | #ifdef CONFIG_PREEMPT | |
500 | /* Returning to kernel space. Check if we need preemption */ | |
501 | /* rcx: threadinfo. interrupts off. */ | |
502 | .p2align | |
503 | retint_kernel: | |
504 | cmpl $0,threadinfo_preempt_count(%rcx) | |
505 | jnz retint_restore_args | |
506 | bt $TIF_NEED_RESCHED,threadinfo_flags(%rcx) | |
507 | jnc retint_restore_args | |
508 | bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */ | |
509 | jnc retint_restore_args | |
510 | call preempt_schedule_irq | |
511 | jmp exit_intr | |
512 | #endif | |
513 | CFI_ENDPROC | |
514 | ||
515 | /* | |
516 | * APIC interrupts. | |
517 | */ | |
518 | .macro apicinterrupt num,func | |
519 | pushq $\num-256 | |
520 | interrupt \func | |
521 | jmp ret_from_intr | |
522 | CFI_ENDPROC | |
523 | .endm | |
524 | ||
525 | ENTRY(thermal_interrupt) | |
526 | apicinterrupt THERMAL_APIC_VECTOR,smp_thermal_interrupt | |
527 | ||
528 | #ifdef CONFIG_SMP | |
529 | ENTRY(reschedule_interrupt) | |
530 | apicinterrupt RESCHEDULE_VECTOR,smp_reschedule_interrupt | |
531 | ||
532 | ENTRY(invalidate_interrupt) | |
533 | apicinterrupt INVALIDATE_TLB_VECTOR,smp_invalidate_interrupt | |
534 | ||
535 | ENTRY(call_function_interrupt) | |
536 | apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt | |
537 | #endif | |
538 | ||
539 | #ifdef CONFIG_X86_LOCAL_APIC | |
540 | ENTRY(apic_timer_interrupt) | |
541 | apicinterrupt LOCAL_TIMER_VECTOR,smp_apic_timer_interrupt | |
542 | ||
543 | ENTRY(error_interrupt) | |
544 | apicinterrupt ERROR_APIC_VECTOR,smp_error_interrupt | |
545 | ||
546 | ENTRY(spurious_interrupt) | |
547 | apicinterrupt SPURIOUS_APIC_VECTOR,smp_spurious_interrupt | |
548 | #endif | |
549 | ||
550 | /* | |
551 | * Exception entry points. | |
552 | */ | |
553 | .macro zeroentry sym | |
554 | pushq $0 /* push error code/oldrax */ | |
555 | pushq %rax /* push real oldrax to the rdi slot */ | |
556 | leaq \sym(%rip),%rax | |
557 | jmp error_entry | |
558 | .endm | |
559 | ||
560 | .macro errorentry sym | |
561 | pushq %rax | |
562 | leaq \sym(%rip),%rax | |
563 | jmp error_entry | |
564 | .endm | |
565 | ||
566 | /* error code is on the stack already */ | |
567 | /* handle NMI like exceptions that can happen everywhere */ | |
568 | .macro paranoidentry sym | |
569 | SAVE_ALL | |
570 | cld | |
571 | movl $1,%ebx | |
572 | movl $MSR_GS_BASE,%ecx | |
573 | rdmsr | |
574 | testl %edx,%edx | |
575 | js 1f | |
576 | swapgs | |
577 | xorl %ebx,%ebx | |
578 | 1: movq %rsp,%rdi | |
579 | movq ORIG_RAX(%rsp),%rsi | |
580 | movq $-1,ORIG_RAX(%rsp) | |
581 | call \sym | |
6fefb0d1 | 582 | cli |
1da177e4 LT |
583 | .endm |
584 | ||
585 | /* | |
586 | * Exception entry point. This expects an error code/orig_rax on the stack | |
587 | * and the exception handler in %rax. | |
588 | */ | |
589 | ENTRY(error_entry) | |
590 | CFI_STARTPROC simple | |
591 | CFI_DEF_CFA rsp,(SS-RDI) | |
592 | CFI_REL_OFFSET rsp,(RSP-RDI) | |
593 | CFI_REL_OFFSET rip,(RIP-RDI) | |
594 | /* rdi slot contains rax, oldrax contains error code */ | |
595 | cld | |
596 | subq $14*8,%rsp | |
597 | CFI_ADJUST_CFA_OFFSET (14*8) | |
598 | movq %rsi,13*8(%rsp) | |
599 | CFI_REL_OFFSET rsi,RSI | |
600 | movq 14*8(%rsp),%rsi /* load rax from rdi slot */ | |
601 | movq %rdx,12*8(%rsp) | |
602 | CFI_REL_OFFSET rdx,RDX | |
603 | movq %rcx,11*8(%rsp) | |
604 | CFI_REL_OFFSET rcx,RCX | |
605 | movq %rsi,10*8(%rsp) /* store rax */ | |
606 | CFI_REL_OFFSET rax,RAX | |
607 | movq %r8, 9*8(%rsp) | |
608 | CFI_REL_OFFSET r8,R8 | |
609 | movq %r9, 8*8(%rsp) | |
610 | CFI_REL_OFFSET r9,R9 | |
611 | movq %r10,7*8(%rsp) | |
612 | CFI_REL_OFFSET r10,R10 | |
613 | movq %r11,6*8(%rsp) | |
614 | CFI_REL_OFFSET r11,R11 | |
615 | movq %rbx,5*8(%rsp) | |
616 | CFI_REL_OFFSET rbx,RBX | |
617 | movq %rbp,4*8(%rsp) | |
618 | CFI_REL_OFFSET rbp,RBP | |
619 | movq %r12,3*8(%rsp) | |
620 | CFI_REL_OFFSET r12,R12 | |
621 | movq %r13,2*8(%rsp) | |
622 | CFI_REL_OFFSET r13,R13 | |
623 | movq %r14,1*8(%rsp) | |
624 | CFI_REL_OFFSET r14,R14 | |
625 | movq %r15,(%rsp) | |
626 | CFI_REL_OFFSET r15,R15 | |
627 | xorl %ebx,%ebx | |
628 | testl $3,CS(%rsp) | |
629 | je error_kernelspace | |
630 | error_swapgs: | |
631 | swapgs | |
632 | error_sti: | |
633 | movq %rdi,RDI(%rsp) | |
634 | movq %rsp,%rdi | |
635 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
636 | movq $-1,ORIG_RAX(%rsp) | |
637 | call *%rax | |
638 | /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ | |
639 | error_exit: | |
640 | movl %ebx,%eax | |
641 | RESTORE_REST | |
642 | cli | |
643 | GET_THREAD_INFO(%rcx) | |
644 | testl %eax,%eax | |
645 | jne retint_kernel | |
646 | movl threadinfo_flags(%rcx),%edx | |
647 | movl $_TIF_WORK_MASK,%edi | |
648 | andl %edi,%edx | |
649 | jnz retint_careful | |
650 | swapgs | |
651 | RESTORE_ARGS 0,8,0 | |
652 | iretq | |
653 | CFI_ENDPROC | |
654 | ||
655 | error_kernelspace: | |
656 | incl %ebx | |
657 | /* There are two places in the kernel that can potentially fault with | |
658 | usergs. Handle them here. The exception handlers after | |
659 | iret run with kernel gs again, so don't set the user space flag. | |
660 | B stepping K8s sometimes report an truncated RIP for IRET | |
661 | exceptions returning to compat mode. Check for these here too. */ | |
662 | leaq iret_label(%rip),%rbp | |
663 | cmpq %rbp,RIP(%rsp) | |
664 | je error_swapgs | |
665 | movl %ebp,%ebp /* zero extend */ | |
666 | cmpq %rbp,RIP(%rsp) | |
667 | je error_swapgs | |
668 | cmpq $gs_change,RIP(%rsp) | |
669 | je error_swapgs | |
670 | jmp error_sti | |
671 | ||
672 | /* Reload gs selector with exception handling */ | |
673 | /* edi: new selector */ | |
674 | ENTRY(load_gs_index) | |
675 | pushf | |
676 | cli | |
677 | swapgs | |
678 | gs_change: | |
679 | movl %edi,%gs | |
680 | 2: mfence /* workaround */ | |
681 | swapgs | |
682 | popf | |
683 | ret | |
684 | ||
685 | .section __ex_table,"a" | |
686 | .align 8 | |
687 | .quad gs_change,bad_gs | |
688 | .previous | |
689 | .section .fixup,"ax" | |
690 | /* running with kernelgs */ | |
691 | bad_gs: | |
692 | swapgs /* switch back to user gs */ | |
693 | xorl %eax,%eax | |
694 | movl %eax,%gs | |
695 | jmp 2b | |
696 | .previous | |
697 | ||
698 | /* | |
699 | * Create a kernel thread. | |
700 | * | |
701 | * C extern interface: | |
702 | * extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
703 | * | |
704 | * asm input arguments: | |
705 | * rdi: fn, rsi: arg, rdx: flags | |
706 | */ | |
707 | ENTRY(kernel_thread) | |
708 | CFI_STARTPROC | |
709 | FAKE_STACK_FRAME $child_rip | |
710 | SAVE_ALL | |
711 | ||
712 | # rdi: flags, rsi: usp, rdx: will be &pt_regs | |
713 | movq %rdx,%rdi | |
714 | orq kernel_thread_flags(%rip),%rdi | |
715 | movq $-1, %rsi | |
716 | movq %rsp, %rdx | |
717 | ||
718 | xorl %r8d,%r8d | |
719 | xorl %r9d,%r9d | |
720 | ||
721 | # clone now | |
722 | call do_fork | |
723 | movq %rax,RAX(%rsp) | |
724 | xorl %edi,%edi | |
725 | ||
726 | /* | |
727 | * It isn't worth to check for reschedule here, | |
728 | * so internally to the x86_64 port you can rely on kernel_thread() | |
729 | * not to reschedule the child before returning, this avoids the need | |
730 | * of hacks for example to fork off the per-CPU idle tasks. | |
731 | * [Hopefully no generic code relies on the reschedule -AK] | |
732 | */ | |
733 | RESTORE_ALL | |
734 | UNFAKE_STACK_FRAME | |
735 | ret | |
736 | CFI_ENDPROC | |
737 | ||
738 | ||
739 | child_rip: | |
740 | /* | |
741 | * Here we are in the child and the registers are set as they were | |
742 | * at kernel_thread() invocation in the parent. | |
743 | */ | |
744 | movq %rdi, %rax | |
745 | movq %rsi, %rdi | |
746 | call *%rax | |
747 | # exit | |
748 | xorq %rdi, %rdi | |
749 | call do_exit | |
750 | ||
751 | /* | |
752 | * execve(). This function needs to use IRET, not SYSRET, to set up all state properly. | |
753 | * | |
754 | * C extern interface: | |
755 | * extern long execve(char *name, char **argv, char **envp) | |
756 | * | |
757 | * asm input arguments: | |
758 | * rdi: name, rsi: argv, rdx: envp | |
759 | * | |
760 | * We want to fallback into: | |
761 | * extern long sys_execve(char *name, char **argv,char **envp, struct pt_regs regs) | |
762 | * | |
763 | * do_sys_execve asm fallback arguments: | |
764 | * rdi: name, rsi: argv, rdx: envp, fake frame on the stack | |
765 | */ | |
766 | ENTRY(execve) | |
767 | CFI_STARTPROC | |
768 | FAKE_STACK_FRAME $0 | |
769 | SAVE_ALL | |
770 | call sys_execve | |
771 | movq %rax, RAX(%rsp) | |
772 | RESTORE_REST | |
773 | testq %rax,%rax | |
774 | je int_ret_from_sys_call | |
775 | RESTORE_ARGS | |
776 | UNFAKE_STACK_FRAME | |
777 | ret | |
778 | CFI_ENDPROC | |
779 | ||
780 | ENTRY(page_fault) | |
781 | errorentry do_page_fault | |
782 | ||
783 | ENTRY(coprocessor_error) | |
784 | zeroentry do_coprocessor_error | |
785 | ||
786 | ENTRY(simd_coprocessor_error) | |
787 | zeroentry do_simd_coprocessor_error | |
788 | ||
789 | ENTRY(device_not_available) | |
790 | zeroentry math_state_restore | |
791 | ||
792 | /* runs on exception stack */ | |
793 | ENTRY(debug) | |
794 | CFI_STARTPROC | |
795 | pushq $0 | |
796 | CFI_ADJUST_CFA_OFFSET 8 | |
797 | paranoidentry do_debug | |
1da177e4 LT |
798 | jmp paranoid_exit |
799 | CFI_ENDPROC | |
800 | ||
801 | /* runs on exception stack */ | |
802 | ENTRY(nmi) | |
803 | CFI_STARTPROC | |
804 | pushq $-1 | |
805 | CFI_ADJUST_CFA_OFFSET 8 | |
806 | paranoidentry do_nmi | |
6fefb0d1 AK |
807 | /* |
808 | * "Paranoid" exit path from exception stack. | |
809 | * Paranoid because this is used by NMIs and cannot take | |
810 | * any kernel state for granted. | |
811 | * We don't do kernel preemption checks here, because only | |
812 | * NMI should be common and it does not enable IRQs and | |
813 | * cannot get reschedule ticks. | |
814 | */ | |
1da177e4 LT |
815 | /* ebx: no swapgs flag */ |
816 | paranoid_exit: | |
817 | testl %ebx,%ebx /* swapgs needed? */ | |
818 | jnz paranoid_restore | |
6fefb0d1 AK |
819 | testl $3,CS(%rsp) |
820 | jnz paranoid_userspace | |
1da177e4 | 821 | paranoid_swapgs: |
1da177e4 LT |
822 | swapgs |
823 | paranoid_restore: | |
824 | RESTORE_ALL 8 | |
825 | iretq | |
826 | paranoid_userspace: | |
1da177e4 | 827 | GET_THREAD_INFO(%rcx) |
6fefb0d1 AK |
828 | movl threadinfo_flags(%rcx),%ebx |
829 | andl $_TIF_WORK_MASK,%ebx | |
11b854b2 | 830 | jz paranoid_swapgs |
6fefb0d1 AK |
831 | movq %rsp,%rdi /* &pt_regs */ |
832 | call sync_regs | |
833 | movq %rax,%rsp /* switch stack for scheduling */ | |
834 | testl $_TIF_NEED_RESCHED,%ebx | |
835 | jnz paranoid_schedule | |
836 | movl %ebx,%edx /* arg3: thread flags */ | |
1da177e4 | 837 | sti |
6fefb0d1 AK |
838 | xorl %esi,%esi /* arg2: oldset */ |
839 | movq %rsp,%rdi /* arg1: &pt_regs */ | |
1da177e4 | 840 | call do_notify_resume |
6fefb0d1 AK |
841 | cli |
842 | jmp paranoid_userspace | |
843 | paranoid_schedule: | |
11b854b2 AK |
844 | sti |
845 | call schedule | |
6fefb0d1 AK |
846 | cli |
847 | jmp paranoid_userspace | |
1da177e4 | 848 | CFI_ENDPROC |
6fefb0d1 | 849 | |
1da177e4 LT |
850 | ENTRY(int3) |
851 | zeroentry do_int3 | |
852 | ||
853 | ENTRY(overflow) | |
854 | zeroentry do_overflow | |
855 | ||
856 | ENTRY(bounds) | |
857 | zeroentry do_bounds | |
858 | ||
859 | ENTRY(invalid_op) | |
860 | zeroentry do_invalid_op | |
861 | ||
862 | ENTRY(coprocessor_segment_overrun) | |
863 | zeroentry do_coprocessor_segment_overrun | |
864 | ||
865 | ENTRY(reserved) | |
866 | zeroentry do_reserved | |
867 | ||
868 | /* runs on exception stack */ | |
869 | ENTRY(double_fault) | |
870 | CFI_STARTPROC | |
871 | paranoidentry do_double_fault | |
1da177e4 LT |
872 | jmp paranoid_exit |
873 | CFI_ENDPROC | |
874 | ||
875 | ENTRY(invalid_TSS) | |
876 | errorentry do_invalid_TSS | |
877 | ||
878 | ENTRY(segment_not_present) | |
879 | errorentry do_segment_not_present | |
880 | ||
881 | /* runs on exception stack */ | |
882 | ENTRY(stack_segment) | |
883 | CFI_STARTPROC | |
884 | paranoidentry do_stack_segment | |
1da177e4 LT |
885 | jmp paranoid_exit |
886 | CFI_ENDPROC | |
887 | ||
888 | ENTRY(general_protection) | |
889 | errorentry do_general_protection | |
890 | ||
891 | ENTRY(alignment_check) | |
892 | errorentry do_alignment_check | |
893 | ||
894 | ENTRY(divide_error) | |
895 | zeroentry do_divide_error | |
896 | ||
897 | ENTRY(spurious_interrupt_bug) | |
898 | zeroentry do_spurious_interrupt_bug | |
899 | ||
900 | #ifdef CONFIG_X86_MCE | |
901 | /* runs on exception stack */ | |
902 | ENTRY(machine_check) | |
903 | CFI_STARTPROC | |
904 | pushq $0 | |
905 | CFI_ADJUST_CFA_OFFSET 8 | |
906 | paranoidentry do_machine_check | |
907 | jmp paranoid_exit | |
908 | CFI_ENDPROC | |
909 | #endif | |
910 | ||
911 | ENTRY(call_debug) | |
912 | zeroentry do_call_debug | |
913 |