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Commit | Line | Data |
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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> |
1da177e4 LT |
54 | |
55 | .code64 | |
56 | ||
dc37db4d | 57 | #ifndef CONFIG_PREEMPT |
1da177e4 LT |
58 | #define retint_kernel retint_restore_args |
59 | #endif | |
2601e64d | 60 | |
72fe4858 | 61 | #ifdef CONFIG_PARAVIRT |
2be29982 | 62 | ENTRY(native_usergs_sysret64) |
72fe4858 GOC |
63 | swapgs |
64 | sysretq | |
65 | #endif /* CONFIG_PARAVIRT */ | |
66 | ||
2601e64d IM |
67 | |
68 | .macro TRACE_IRQS_IRETQ offset=ARGOFFSET | |
69 | #ifdef CONFIG_TRACE_IRQFLAGS | |
70 | bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */ | |
71 | jnc 1f | |
72 | TRACE_IRQS_ON | |
73 | 1: | |
74 | #endif | |
75 | .endm | |
76 | ||
1da177e4 LT |
77 | /* |
78 | * C code is not supposed to know about undefined top of stack. Every time | |
79 | * a C function with an pt_regs argument is called from the SYSCALL based | |
80 | * fast path FIXUP_TOP_OF_STACK is needed. | |
81 | * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs | |
82 | * manipulation. | |
83 | */ | |
84 | ||
85 | /* %rsp:at FRAMEEND */ | |
86 | .macro FIXUP_TOP_OF_STACK tmp | |
87 | movq %gs:pda_oldrsp,\tmp | |
88 | movq \tmp,RSP(%rsp) | |
89 | movq $__USER_DS,SS(%rsp) | |
90 | movq $__USER_CS,CS(%rsp) | |
91 | movq $-1,RCX(%rsp) | |
92 | movq R11(%rsp),\tmp /* get eflags */ | |
93 | movq \tmp,EFLAGS(%rsp) | |
94 | .endm | |
95 | ||
96 | .macro RESTORE_TOP_OF_STACK tmp,offset=0 | |
97 | movq RSP-\offset(%rsp),\tmp | |
98 | movq \tmp,%gs:pda_oldrsp | |
99 | movq EFLAGS-\offset(%rsp),\tmp | |
100 | movq \tmp,R11-\offset(%rsp) | |
101 | .endm | |
102 | ||
103 | .macro FAKE_STACK_FRAME child_rip | |
104 | /* push in order ss, rsp, eflags, cs, rip */ | |
3829ee6b | 105 | xorl %eax, %eax |
e04e0a63 | 106 | pushq $__KERNEL_DS /* ss */ |
1da177e4 | 107 | CFI_ADJUST_CFA_OFFSET 8 |
7effaa88 | 108 | /*CFI_REL_OFFSET ss,0*/ |
1da177e4 LT |
109 | pushq %rax /* rsp */ |
110 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 111 | CFI_REL_OFFSET rsp,0 |
1da177e4 LT |
112 | pushq $(1<<9) /* eflags - interrupts on */ |
113 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 114 | /*CFI_REL_OFFSET rflags,0*/ |
1da177e4 LT |
115 | pushq $__KERNEL_CS /* cs */ |
116 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 117 | /*CFI_REL_OFFSET cs,0*/ |
1da177e4 LT |
118 | pushq \child_rip /* rip */ |
119 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 120 | CFI_REL_OFFSET rip,0 |
1da177e4 LT |
121 | pushq %rax /* orig rax */ |
122 | CFI_ADJUST_CFA_OFFSET 8 | |
123 | .endm | |
124 | ||
125 | .macro UNFAKE_STACK_FRAME | |
126 | addq $8*6, %rsp | |
127 | CFI_ADJUST_CFA_OFFSET -(6*8) | |
128 | .endm | |
129 | ||
7effaa88 JB |
130 | .macro CFI_DEFAULT_STACK start=1 |
131 | .if \start | |
132 | CFI_STARTPROC simple | |
adf14236 | 133 | CFI_SIGNAL_FRAME |
7effaa88 JB |
134 | CFI_DEF_CFA rsp,SS+8 |
135 | .else | |
136 | CFI_DEF_CFA_OFFSET SS+8 | |
137 | .endif | |
138 | CFI_REL_OFFSET r15,R15 | |
139 | CFI_REL_OFFSET r14,R14 | |
140 | CFI_REL_OFFSET r13,R13 | |
141 | CFI_REL_OFFSET r12,R12 | |
142 | CFI_REL_OFFSET rbp,RBP | |
143 | CFI_REL_OFFSET rbx,RBX | |
144 | CFI_REL_OFFSET r11,R11 | |
145 | CFI_REL_OFFSET r10,R10 | |
146 | CFI_REL_OFFSET r9,R9 | |
147 | CFI_REL_OFFSET r8,R8 | |
148 | CFI_REL_OFFSET rax,RAX | |
149 | CFI_REL_OFFSET rcx,RCX | |
150 | CFI_REL_OFFSET rdx,RDX | |
151 | CFI_REL_OFFSET rsi,RSI | |
152 | CFI_REL_OFFSET rdi,RDI | |
153 | CFI_REL_OFFSET rip,RIP | |
154 | /*CFI_REL_OFFSET cs,CS*/ | |
155 | /*CFI_REL_OFFSET rflags,EFLAGS*/ | |
156 | CFI_REL_OFFSET rsp,RSP | |
157 | /*CFI_REL_OFFSET ss,SS*/ | |
1da177e4 LT |
158 | .endm |
159 | /* | |
160 | * A newly forked process directly context switches into this. | |
161 | */ | |
162 | /* rdi: prev */ | |
163 | ENTRY(ret_from_fork) | |
1da177e4 | 164 | CFI_DEFAULT_STACK |
658fdbef AK |
165 | push kernel_eflags(%rip) |
166 | CFI_ADJUST_CFA_OFFSET 4 | |
167 | popf # reset kernel eflags | |
168 | CFI_ADJUST_CFA_OFFSET -4 | |
1da177e4 LT |
169 | call schedule_tail |
170 | GET_THREAD_INFO(%rcx) | |
171 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),threadinfo_flags(%rcx) | |
172 | jnz rff_trace | |
173 | rff_action: | |
174 | RESTORE_REST | |
175 | testl $3,CS-ARGOFFSET(%rsp) # from kernel_thread? | |
176 | je int_ret_from_sys_call | |
177 | testl $_TIF_IA32,threadinfo_flags(%rcx) | |
178 | jnz int_ret_from_sys_call | |
179 | RESTORE_TOP_OF_STACK %rdi,ARGOFFSET | |
180 | jmp ret_from_sys_call | |
181 | rff_trace: | |
182 | movq %rsp,%rdi | |
183 | call syscall_trace_leave | |
184 | GET_THREAD_INFO(%rcx) | |
185 | jmp rff_action | |
186 | CFI_ENDPROC | |
4b787e0b | 187 | END(ret_from_fork) |
1da177e4 LT |
188 | |
189 | /* | |
190 | * System call entry. Upto 6 arguments in registers are supported. | |
191 | * | |
192 | * SYSCALL does not save anything on the stack and does not change the | |
193 | * stack pointer. | |
194 | */ | |
195 | ||
196 | /* | |
197 | * Register setup: | |
198 | * rax system call number | |
199 | * rdi arg0 | |
200 | * rcx return address for syscall/sysret, C arg3 | |
201 | * rsi arg1 | |
202 | * rdx arg2 | |
203 | * r10 arg3 (--> moved to rcx for C) | |
204 | * r8 arg4 | |
205 | * r9 arg5 | |
206 | * r11 eflags for syscall/sysret, temporary for C | |
207 | * r12-r15,rbp,rbx saved by C code, not touched. | |
208 | * | |
209 | * Interrupts are off on entry. | |
210 | * Only called from user space. | |
211 | * | |
212 | * XXX if we had a free scratch register we could save the RSP into the stack frame | |
213 | * and report it properly in ps. Unfortunately we haven't. | |
7bf36bbc AK |
214 | * |
215 | * When user can change the frames always force IRET. That is because | |
216 | * it deals with uncanonical addresses better. SYSRET has trouble | |
217 | * with them due to bugs in both AMD and Intel CPUs. | |
1da177e4 LT |
218 | */ |
219 | ||
220 | ENTRY(system_call) | |
7effaa88 | 221 | CFI_STARTPROC simple |
adf14236 | 222 | CFI_SIGNAL_FRAME |
dffead4e | 223 | CFI_DEF_CFA rsp,PDA_STACKOFFSET |
7effaa88 JB |
224 | CFI_REGISTER rip,rcx |
225 | /*CFI_REGISTER rflags,r11*/ | |
72fe4858 GOC |
226 | SWAPGS_UNSAFE_STACK |
227 | /* | |
228 | * A hypervisor implementation might want to use a label | |
229 | * after the swapgs, so that it can do the swapgs | |
230 | * for the guest and jump here on syscall. | |
231 | */ | |
232 | ENTRY(system_call_after_swapgs) | |
233 | ||
1da177e4 LT |
234 | movq %rsp,%gs:pda_oldrsp |
235 | movq %gs:pda_kernelstack,%rsp | |
2601e64d IM |
236 | /* |
237 | * No need to follow this irqs off/on section - it's straight | |
238 | * and short: | |
239 | */ | |
72fe4858 | 240 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 LT |
241 | SAVE_ARGS 8,1 |
242 | movq %rax,ORIG_RAX-ARGOFFSET(%rsp) | |
7effaa88 JB |
243 | movq %rcx,RIP-ARGOFFSET(%rsp) |
244 | CFI_REL_OFFSET rip,RIP-ARGOFFSET | |
1da177e4 LT |
245 | GET_THREAD_INFO(%rcx) |
246 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%rcx) | |
247 | jnz tracesys | |
248 | cmpq $__NR_syscall_max,%rax | |
249 | ja badsys | |
250 | movq %r10,%rcx | |
251 | call *sys_call_table(,%rax,8) # XXX: rip relative | |
252 | movq %rax,RAX-ARGOFFSET(%rsp) | |
253 | /* | |
254 | * Syscall return path ending with SYSRET (fast path) | |
255 | * Has incomplete stack frame and undefined top of stack. | |
256 | */ | |
1da177e4 | 257 | ret_from_sys_call: |
11b854b2 | 258 | movl $_TIF_ALLWORK_MASK,%edi |
1da177e4 LT |
259 | /* edi: flagmask */ |
260 | sysret_check: | |
10cd706d | 261 | LOCKDEP_SYS_EXIT |
1da177e4 | 262 | GET_THREAD_INFO(%rcx) |
72fe4858 | 263 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 264 | TRACE_IRQS_OFF |
1da177e4 LT |
265 | movl threadinfo_flags(%rcx),%edx |
266 | andl %edi,%edx | |
267 | jnz sysret_careful | |
bcddc015 | 268 | CFI_REMEMBER_STATE |
2601e64d IM |
269 | /* |
270 | * sysretq will re-enable interrupts: | |
271 | */ | |
272 | TRACE_IRQS_ON | |
1da177e4 | 273 | movq RIP-ARGOFFSET(%rsp),%rcx |
7effaa88 | 274 | CFI_REGISTER rip,rcx |
1da177e4 | 275 | RESTORE_ARGS 0,-ARG_SKIP,1 |
7effaa88 | 276 | /*CFI_REGISTER rflags,r11*/ |
c7245da6 | 277 | movq %gs:pda_oldrsp, %rsp |
2be29982 | 278 | USERGS_SYSRET64 |
1da177e4 | 279 | |
bcddc015 | 280 | CFI_RESTORE_STATE |
1da177e4 LT |
281 | /* Handle reschedules */ |
282 | /* edx: work, edi: workmask */ | |
283 | sysret_careful: | |
284 | bt $TIF_NEED_RESCHED,%edx | |
285 | jnc sysret_signal | |
2601e64d | 286 | TRACE_IRQS_ON |
72fe4858 | 287 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 288 | pushq %rdi |
7effaa88 | 289 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
290 | call schedule |
291 | popq %rdi | |
7effaa88 | 292 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 LT |
293 | jmp sysret_check |
294 | ||
295 | /* Handle a signal */ | |
296 | sysret_signal: | |
2601e64d | 297 | TRACE_IRQS_ON |
72fe4858 | 298 | ENABLE_INTERRUPTS(CLBR_NONE) |
8f4d37ec | 299 | testl $_TIF_DO_NOTIFY_MASK,%edx |
10ffdbb8 AK |
300 | jz 1f |
301 | ||
302 | /* Really a signal */ | |
303 | /* edx: work flags (arg3) */ | |
1da177e4 LT |
304 | leaq do_notify_resume(%rip),%rax |
305 | leaq -ARGOFFSET(%rsp),%rdi # &pt_regs -> arg1 | |
306 | xorl %esi,%esi # oldset -> arg2 | |
307 | call ptregscall_common | |
10ffdbb8 | 308 | 1: movl $_TIF_NEED_RESCHED,%edi |
7bf36bbc AK |
309 | /* Use IRET because user could have changed frame. This |
310 | works because ptregscall_common has called FIXUP_TOP_OF_STACK. */ | |
72fe4858 | 311 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 312 | TRACE_IRQS_OFF |
7bf36bbc | 313 | jmp int_with_check |
1da177e4 | 314 | |
7effaa88 JB |
315 | badsys: |
316 | movq $-ENOSYS,RAX-ARGOFFSET(%rsp) | |
317 | jmp ret_from_sys_call | |
318 | ||
1da177e4 LT |
319 | /* Do syscall tracing */ |
320 | tracesys: | |
321 | SAVE_REST | |
a31f8dd7 | 322 | movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ |
1da177e4 LT |
323 | FIXUP_TOP_OF_STACK %rdi |
324 | movq %rsp,%rdi | |
325 | call syscall_trace_enter | |
326 | LOAD_ARGS ARGOFFSET /* reload args from stack in case ptrace changed it */ | |
327 | RESTORE_REST | |
328 | cmpq $__NR_syscall_max,%rax | |
a31f8dd7 | 329 | ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */ |
1da177e4 LT |
330 | movq %r10,%rcx /* fixup for C */ |
331 | call *sys_call_table(,%rax,8) | |
a31f8dd7 | 332 | movq %rax,RAX-ARGOFFSET(%rsp) |
7bf36bbc | 333 | /* Use IRET because user could have changed frame */ |
1da177e4 | 334 | |
1da177e4 LT |
335 | /* |
336 | * Syscall return path ending with IRET. | |
337 | * Has correct top of stack, but partial stack frame. | |
bcddc015 JB |
338 | */ |
339 | .globl int_ret_from_sys_call | |
340 | int_ret_from_sys_call: | |
72fe4858 | 341 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 342 | TRACE_IRQS_OFF |
1da177e4 LT |
343 | testl $3,CS-ARGOFFSET(%rsp) |
344 | je retint_restore_args | |
345 | movl $_TIF_ALLWORK_MASK,%edi | |
346 | /* edi: mask to check */ | |
347 | int_with_check: | |
10cd706d | 348 | LOCKDEP_SYS_EXIT_IRQ |
1da177e4 LT |
349 | GET_THREAD_INFO(%rcx) |
350 | movl threadinfo_flags(%rcx),%edx | |
351 | andl %edi,%edx | |
352 | jnz int_careful | |
bf2fcc6f | 353 | andl $~TS_COMPAT,threadinfo_status(%rcx) |
1da177e4 LT |
354 | jmp retint_swapgs |
355 | ||
356 | /* Either reschedule or signal or syscall exit tracking needed. */ | |
357 | /* First do a reschedule test. */ | |
358 | /* edx: work, edi: workmask */ | |
359 | int_careful: | |
360 | bt $TIF_NEED_RESCHED,%edx | |
361 | jnc int_very_careful | |
2601e64d | 362 | TRACE_IRQS_ON |
72fe4858 | 363 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 364 | pushq %rdi |
7effaa88 | 365 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
366 | call schedule |
367 | popq %rdi | |
7effaa88 | 368 | CFI_ADJUST_CFA_OFFSET -8 |
72fe4858 | 369 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 370 | TRACE_IRQS_OFF |
1da177e4 LT |
371 | jmp int_with_check |
372 | ||
373 | /* handle signals and tracing -- both require a full stack frame */ | |
374 | int_very_careful: | |
2601e64d | 375 | TRACE_IRQS_ON |
72fe4858 | 376 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 LT |
377 | SAVE_REST |
378 | /* Check for syscall exit trace */ | |
379 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edx | |
380 | jz int_signal | |
381 | pushq %rdi | |
7effaa88 | 382 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
383 | leaq 8(%rsp),%rdi # &ptregs -> arg1 |
384 | call syscall_trace_leave | |
385 | popq %rdi | |
7effaa88 | 386 | CFI_ADJUST_CFA_OFFSET -8 |
36c1104e | 387 | andl $~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edi |
1da177e4 LT |
388 | jmp int_restore_rest |
389 | ||
390 | int_signal: | |
8f4d37ec | 391 | testl $_TIF_DO_NOTIFY_MASK,%edx |
1da177e4 LT |
392 | jz 1f |
393 | movq %rsp,%rdi # &ptregs -> arg1 | |
394 | xorl %esi,%esi # oldset -> arg2 | |
395 | call do_notify_resume | |
396 | 1: movl $_TIF_NEED_RESCHED,%edi | |
397 | int_restore_rest: | |
398 | RESTORE_REST | |
72fe4858 | 399 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 400 | TRACE_IRQS_OFF |
1da177e4 LT |
401 | jmp int_with_check |
402 | CFI_ENDPROC | |
bcddc015 | 403 | END(system_call) |
1da177e4 LT |
404 | |
405 | /* | |
406 | * Certain special system calls that need to save a complete full stack frame. | |
407 | */ | |
408 | ||
409 | .macro PTREGSCALL label,func,arg | |
410 | .globl \label | |
411 | \label: | |
412 | leaq \func(%rip),%rax | |
413 | leaq -ARGOFFSET+8(%rsp),\arg /* 8 for return address */ | |
414 | jmp ptregscall_common | |
4b787e0b | 415 | END(\label) |
1da177e4 LT |
416 | .endm |
417 | ||
7effaa88 JB |
418 | CFI_STARTPROC |
419 | ||
1da177e4 LT |
420 | PTREGSCALL stub_clone, sys_clone, %r8 |
421 | PTREGSCALL stub_fork, sys_fork, %rdi | |
422 | PTREGSCALL stub_vfork, sys_vfork, %rdi | |
1da177e4 LT |
423 | PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx |
424 | PTREGSCALL stub_iopl, sys_iopl, %rsi | |
425 | ||
426 | ENTRY(ptregscall_common) | |
1da177e4 | 427 | popq %r11 |
7effaa88 JB |
428 | CFI_ADJUST_CFA_OFFSET -8 |
429 | CFI_REGISTER rip, r11 | |
1da177e4 LT |
430 | SAVE_REST |
431 | movq %r11, %r15 | |
7effaa88 | 432 | CFI_REGISTER rip, r15 |
1da177e4 LT |
433 | FIXUP_TOP_OF_STACK %r11 |
434 | call *%rax | |
435 | RESTORE_TOP_OF_STACK %r11 | |
436 | movq %r15, %r11 | |
7effaa88 | 437 | CFI_REGISTER rip, r11 |
1da177e4 LT |
438 | RESTORE_REST |
439 | pushq %r11 | |
7effaa88 JB |
440 | CFI_ADJUST_CFA_OFFSET 8 |
441 | CFI_REL_OFFSET rip, 0 | |
1da177e4 LT |
442 | ret |
443 | CFI_ENDPROC | |
4b787e0b | 444 | END(ptregscall_common) |
1da177e4 LT |
445 | |
446 | ENTRY(stub_execve) | |
447 | CFI_STARTPROC | |
448 | popq %r11 | |
7effaa88 JB |
449 | CFI_ADJUST_CFA_OFFSET -8 |
450 | CFI_REGISTER rip, r11 | |
1da177e4 | 451 | SAVE_REST |
1da177e4 | 452 | FIXUP_TOP_OF_STACK %r11 |
5d119b2c | 453 | movq %rsp, %rcx |
1da177e4 | 454 | call sys_execve |
1da177e4 | 455 | RESTORE_TOP_OF_STACK %r11 |
1da177e4 LT |
456 | movq %rax,RAX(%rsp) |
457 | RESTORE_REST | |
458 | jmp int_ret_from_sys_call | |
459 | CFI_ENDPROC | |
4b787e0b | 460 | END(stub_execve) |
1da177e4 LT |
461 | |
462 | /* | |
463 | * sigreturn is special because it needs to restore all registers on return. | |
464 | * This cannot be done with SYSRET, so use the IRET return path instead. | |
465 | */ | |
466 | ENTRY(stub_rt_sigreturn) | |
467 | CFI_STARTPROC | |
7effaa88 JB |
468 | addq $8, %rsp |
469 | CFI_ADJUST_CFA_OFFSET -8 | |
1da177e4 LT |
470 | SAVE_REST |
471 | movq %rsp,%rdi | |
472 | FIXUP_TOP_OF_STACK %r11 | |
473 | call sys_rt_sigreturn | |
474 | movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer | |
475 | RESTORE_REST | |
476 | jmp int_ret_from_sys_call | |
477 | CFI_ENDPROC | |
4b787e0b | 478 | END(stub_rt_sigreturn) |
1da177e4 | 479 | |
7effaa88 JB |
480 | /* |
481 | * initial frame state for interrupts and exceptions | |
482 | */ | |
483 | .macro _frame ref | |
484 | CFI_STARTPROC simple | |
adf14236 | 485 | CFI_SIGNAL_FRAME |
7effaa88 JB |
486 | CFI_DEF_CFA rsp,SS+8-\ref |
487 | /*CFI_REL_OFFSET ss,SS-\ref*/ | |
488 | CFI_REL_OFFSET rsp,RSP-\ref | |
489 | /*CFI_REL_OFFSET rflags,EFLAGS-\ref*/ | |
490 | /*CFI_REL_OFFSET cs,CS-\ref*/ | |
491 | CFI_REL_OFFSET rip,RIP-\ref | |
492 | .endm | |
493 | ||
494 | /* initial frame state for interrupts (and exceptions without error code) */ | |
495 | #define INTR_FRAME _frame RIP | |
496 | /* initial frame state for exceptions with error code (and interrupts with | |
497 | vector already pushed) */ | |
498 | #define XCPT_FRAME _frame ORIG_RAX | |
499 | ||
1da177e4 LT |
500 | /* |
501 | * Interrupt entry/exit. | |
502 | * | |
503 | * Interrupt entry points save only callee clobbered registers in fast path. | |
504 | * | |
505 | * Entry runs with interrupts off. | |
506 | */ | |
507 | ||
508 | /* 0(%rsp): interrupt number */ | |
509 | .macro interrupt func | |
1da177e4 | 510 | cld |
1da177e4 LT |
511 | SAVE_ARGS |
512 | leaq -ARGOFFSET(%rsp),%rdi # arg1 for handler | |
1de9c3f6 JB |
513 | pushq %rbp |
514 | CFI_ADJUST_CFA_OFFSET 8 | |
515 | CFI_REL_OFFSET rbp, 0 | |
516 | movq %rsp,%rbp | |
517 | CFI_DEF_CFA_REGISTER rbp | |
1da177e4 LT |
518 | testl $3,CS(%rdi) |
519 | je 1f | |
72fe4858 | 520 | SWAPGS |
96e54049 AK |
521 | /* irqcount is used to check if a CPU is already on an interrupt |
522 | stack or not. While this is essentially redundant with preempt_count | |
523 | it is a little cheaper to use a separate counter in the PDA | |
524 | (short of moving irq_enter into assembly, which would be too | |
525 | much work) */ | |
526 | 1: incl %gs:pda_irqcount | |
1de9c3f6 | 527 | cmoveq %gs:pda_irqstackptr,%rsp |
2699500b | 528 | push %rbp # backlink for old unwinder |
2601e64d IM |
529 | /* |
530 | * We entered an interrupt context - irqs are off: | |
531 | */ | |
532 | TRACE_IRQS_OFF | |
1da177e4 LT |
533 | call \func |
534 | .endm | |
535 | ||
536 | ENTRY(common_interrupt) | |
7effaa88 | 537 | XCPT_FRAME |
1da177e4 LT |
538 | interrupt do_IRQ |
539 | /* 0(%rsp): oldrsp-ARGOFFSET */ | |
7effaa88 | 540 | ret_from_intr: |
72fe4858 | 541 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 542 | TRACE_IRQS_OFF |
3829ee6b | 543 | decl %gs:pda_irqcount |
1de9c3f6 | 544 | leaveq |
7effaa88 | 545 | CFI_DEF_CFA_REGISTER rsp |
1de9c3f6 | 546 | CFI_ADJUST_CFA_OFFSET -8 |
7effaa88 | 547 | exit_intr: |
1da177e4 LT |
548 | GET_THREAD_INFO(%rcx) |
549 | testl $3,CS-ARGOFFSET(%rsp) | |
550 | je retint_kernel | |
551 | ||
552 | /* Interrupt came from user space */ | |
553 | /* | |
554 | * Has a correct top of stack, but a partial stack frame | |
555 | * %rcx: thread info. Interrupts off. | |
556 | */ | |
557 | retint_with_reschedule: | |
558 | movl $_TIF_WORK_MASK,%edi | |
7effaa88 | 559 | retint_check: |
10cd706d | 560 | LOCKDEP_SYS_EXIT_IRQ |
1da177e4 LT |
561 | movl threadinfo_flags(%rcx),%edx |
562 | andl %edi,%edx | |
7effaa88 | 563 | CFI_REMEMBER_STATE |
1da177e4 | 564 | jnz retint_careful |
10cd706d PZ |
565 | |
566 | retint_swapgs: /* return to user-space */ | |
2601e64d IM |
567 | /* |
568 | * The iretq could re-enable interrupts: | |
569 | */ | |
72fe4858 | 570 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 571 | TRACE_IRQS_IRETQ |
72fe4858 | 572 | SWAPGS |
2601e64d IM |
573 | jmp restore_args |
574 | ||
10cd706d | 575 | retint_restore_args: /* return to kernel space */ |
72fe4858 | 576 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
577 | /* |
578 | * The iretq could re-enable interrupts: | |
579 | */ | |
580 | TRACE_IRQS_IRETQ | |
581 | restore_args: | |
3701d863 IM |
582 | RESTORE_ARGS 0,8,0 |
583 | ||
f7f3d791 | 584 | irq_return: |
72fe4858 | 585 | INTERRUPT_RETURN |
3701d863 IM |
586 | |
587 | .section __ex_table, "a" | |
588 | .quad irq_return, bad_iret | |
589 | .previous | |
590 | ||
591 | #ifdef CONFIG_PARAVIRT | |
72fe4858 | 592 | ENTRY(native_iret) |
1da177e4 LT |
593 | iretq |
594 | ||
595 | .section __ex_table,"a" | |
72fe4858 | 596 | .quad native_iret, bad_iret |
1da177e4 | 597 | .previous |
3701d863 IM |
598 | #endif |
599 | ||
1da177e4 | 600 | .section .fixup,"ax" |
1da177e4 | 601 | bad_iret: |
3aa4b37d RM |
602 | /* |
603 | * The iret traps when the %cs or %ss being restored is bogus. | |
604 | * We've lost the original trap vector and error code. | |
605 | * #GPF is the most likely one to get for an invalid selector. | |
606 | * So pretend we completed the iret and took the #GPF in user mode. | |
607 | * | |
608 | * We are now running with the kernel GS after exception recovery. | |
609 | * But error_entry expects us to have user GS to match the user %cs, | |
610 | * so swap back. | |
611 | */ | |
612 | pushq $0 | |
613 | ||
614 | SWAPGS | |
615 | jmp general_protection | |
616 | ||
72fe4858 GOC |
617 | .previous |
618 | ||
7effaa88 | 619 | /* edi: workmask, edx: work */ |
1da177e4 | 620 | retint_careful: |
7effaa88 | 621 | CFI_RESTORE_STATE |
1da177e4 LT |
622 | bt $TIF_NEED_RESCHED,%edx |
623 | jnc retint_signal | |
2601e64d | 624 | TRACE_IRQS_ON |
72fe4858 | 625 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 626 | pushq %rdi |
7effaa88 | 627 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
628 | call schedule |
629 | popq %rdi | |
7effaa88 | 630 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 | 631 | GET_THREAD_INFO(%rcx) |
72fe4858 | 632 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 633 | TRACE_IRQS_OFF |
1da177e4 LT |
634 | jmp retint_check |
635 | ||
636 | retint_signal: | |
8f4d37ec | 637 | testl $_TIF_DO_NOTIFY_MASK,%edx |
10ffdbb8 | 638 | jz retint_swapgs |
2601e64d | 639 | TRACE_IRQS_ON |
72fe4858 | 640 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 LT |
641 | SAVE_REST |
642 | movq $-1,ORIG_RAX(%rsp) | |
3829ee6b | 643 | xorl %esi,%esi # oldset |
1da177e4 LT |
644 | movq %rsp,%rdi # &pt_regs |
645 | call do_notify_resume | |
646 | RESTORE_REST | |
72fe4858 | 647 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 648 | TRACE_IRQS_OFF |
10ffdbb8 | 649 | movl $_TIF_NEED_RESCHED,%edi |
be9e6870 | 650 | GET_THREAD_INFO(%rcx) |
1da177e4 LT |
651 | jmp retint_check |
652 | ||
653 | #ifdef CONFIG_PREEMPT | |
654 | /* Returning to kernel space. Check if we need preemption */ | |
655 | /* rcx: threadinfo. interrupts off. */ | |
b06babac | 656 | ENTRY(retint_kernel) |
1da177e4 LT |
657 | cmpl $0,threadinfo_preempt_count(%rcx) |
658 | jnz retint_restore_args | |
659 | bt $TIF_NEED_RESCHED,threadinfo_flags(%rcx) | |
660 | jnc retint_restore_args | |
661 | bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */ | |
662 | jnc retint_restore_args | |
663 | call preempt_schedule_irq | |
664 | jmp exit_intr | |
665 | #endif | |
4b787e0b | 666 | |
1da177e4 | 667 | CFI_ENDPROC |
4b787e0b | 668 | END(common_interrupt) |
1da177e4 LT |
669 | |
670 | /* | |
671 | * APIC interrupts. | |
672 | */ | |
673 | .macro apicinterrupt num,func | |
7effaa88 | 674 | INTR_FRAME |
19eadf98 | 675 | pushq $~(\num) |
7effaa88 | 676 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
677 | interrupt \func |
678 | jmp ret_from_intr | |
679 | CFI_ENDPROC | |
680 | .endm | |
681 | ||
682 | ENTRY(thermal_interrupt) | |
683 | apicinterrupt THERMAL_APIC_VECTOR,smp_thermal_interrupt | |
4b787e0b | 684 | END(thermal_interrupt) |
1da177e4 | 685 | |
89b831ef JS |
686 | ENTRY(threshold_interrupt) |
687 | apicinterrupt THRESHOLD_APIC_VECTOR,mce_threshold_interrupt | |
4b787e0b | 688 | END(threshold_interrupt) |
89b831ef | 689 | |
1da177e4 LT |
690 | #ifdef CONFIG_SMP |
691 | ENTRY(reschedule_interrupt) | |
692 | apicinterrupt RESCHEDULE_VECTOR,smp_reschedule_interrupt | |
4b787e0b | 693 | END(reschedule_interrupt) |
1da177e4 | 694 | |
e5bc8b6b AK |
695 | .macro INVALIDATE_ENTRY num |
696 | ENTRY(invalidate_interrupt\num) | |
697 | apicinterrupt INVALIDATE_TLB_VECTOR_START+\num,smp_invalidate_interrupt | |
4b787e0b | 698 | END(invalidate_interrupt\num) |
e5bc8b6b AK |
699 | .endm |
700 | ||
701 | INVALIDATE_ENTRY 0 | |
702 | INVALIDATE_ENTRY 1 | |
703 | INVALIDATE_ENTRY 2 | |
704 | INVALIDATE_ENTRY 3 | |
705 | INVALIDATE_ENTRY 4 | |
706 | INVALIDATE_ENTRY 5 | |
707 | INVALIDATE_ENTRY 6 | |
708 | INVALIDATE_ENTRY 7 | |
1da177e4 LT |
709 | |
710 | ENTRY(call_function_interrupt) | |
711 | apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt | |
4b787e0b | 712 | END(call_function_interrupt) |
61014292 EB |
713 | ENTRY(irq_move_cleanup_interrupt) |
714 | apicinterrupt IRQ_MOVE_CLEANUP_VECTOR,smp_irq_move_cleanup_interrupt | |
715 | END(irq_move_cleanup_interrupt) | |
1da177e4 LT |
716 | #endif |
717 | ||
1da177e4 LT |
718 | ENTRY(apic_timer_interrupt) |
719 | apicinterrupt LOCAL_TIMER_VECTOR,smp_apic_timer_interrupt | |
4b787e0b | 720 | END(apic_timer_interrupt) |
1da177e4 | 721 | |
1812924b CW |
722 | ENTRY(uv_bau_message_intr1) |
723 | apicinterrupt 220,uv_bau_message_interrupt | |
724 | END(uv_bau_message_intr1) | |
725 | ||
1da177e4 LT |
726 | ENTRY(error_interrupt) |
727 | apicinterrupt ERROR_APIC_VECTOR,smp_error_interrupt | |
4b787e0b | 728 | END(error_interrupt) |
1da177e4 LT |
729 | |
730 | ENTRY(spurious_interrupt) | |
731 | apicinterrupt SPURIOUS_APIC_VECTOR,smp_spurious_interrupt | |
4b787e0b | 732 | END(spurious_interrupt) |
1da177e4 LT |
733 | |
734 | /* | |
735 | * Exception entry points. | |
736 | */ | |
737 | .macro zeroentry sym | |
7effaa88 | 738 | INTR_FRAME |
1da177e4 | 739 | pushq $0 /* push error code/oldrax */ |
7effaa88 | 740 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 | 741 | pushq %rax /* push real oldrax to the rdi slot */ |
7effaa88 | 742 | CFI_ADJUST_CFA_OFFSET 8 |
37550907 | 743 | CFI_REL_OFFSET rax,0 |
1da177e4 LT |
744 | leaq \sym(%rip),%rax |
745 | jmp error_entry | |
7effaa88 | 746 | CFI_ENDPROC |
1da177e4 LT |
747 | .endm |
748 | ||
749 | .macro errorentry sym | |
7effaa88 | 750 | XCPT_FRAME |
1da177e4 | 751 | pushq %rax |
7effaa88 | 752 | CFI_ADJUST_CFA_OFFSET 8 |
37550907 | 753 | CFI_REL_OFFSET rax,0 |
1da177e4 LT |
754 | leaq \sym(%rip),%rax |
755 | jmp error_entry | |
7effaa88 | 756 | CFI_ENDPROC |
1da177e4 LT |
757 | .endm |
758 | ||
759 | /* error code is on the stack already */ | |
760 | /* handle NMI like exceptions that can happen everywhere */ | |
2601e64d | 761 | .macro paranoidentry sym, ist=0, irqtrace=1 |
1da177e4 LT |
762 | SAVE_ALL |
763 | cld | |
764 | movl $1,%ebx | |
765 | movl $MSR_GS_BASE,%ecx | |
766 | rdmsr | |
767 | testl %edx,%edx | |
768 | js 1f | |
72fe4858 | 769 | SWAPGS |
1da177e4 | 770 | xorl %ebx,%ebx |
b556b35e JB |
771 | 1: |
772 | .if \ist | |
773 | movq %gs:pda_data_offset, %rbp | |
774 | .endif | |
775 | movq %rsp,%rdi | |
1da177e4 LT |
776 | movq ORIG_RAX(%rsp),%rsi |
777 | movq $-1,ORIG_RAX(%rsp) | |
b556b35e | 778 | .if \ist |
5f8efbb9 | 779 | subq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) |
b556b35e | 780 | .endif |
1da177e4 | 781 | call \sym |
b556b35e | 782 | .if \ist |
5f8efbb9 | 783 | addq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) |
b556b35e | 784 | .endif |
72fe4858 | 785 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d IM |
786 | .if \irqtrace |
787 | TRACE_IRQS_OFF | |
788 | .endif | |
1da177e4 | 789 | .endm |
2601e64d IM |
790 | |
791 | /* | |
792 | * "Paranoid" exit path from exception stack. | |
793 | * Paranoid because this is used by NMIs and cannot take | |
794 | * any kernel state for granted. | |
795 | * We don't do kernel preemption checks here, because only | |
796 | * NMI should be common and it does not enable IRQs and | |
797 | * cannot get reschedule ticks. | |
798 | * | |
799 | * "trace" is 0 for the NMI handler only, because irq-tracing | |
800 | * is fundamentally NMI-unsafe. (we cannot change the soft and | |
801 | * hard flags at once, atomically) | |
802 | */ | |
803 | .macro paranoidexit trace=1 | |
804 | /* ebx: no swapgs flag */ | |
805 | paranoid_exit\trace: | |
806 | testl %ebx,%ebx /* swapgs needed? */ | |
807 | jnz paranoid_restore\trace | |
808 | testl $3,CS(%rsp) | |
809 | jnz paranoid_userspace\trace | |
810 | paranoid_swapgs\trace: | |
7a0a2dff | 811 | .if \trace |
2601e64d | 812 | TRACE_IRQS_IRETQ 0 |
7a0a2dff | 813 | .endif |
72fe4858 | 814 | SWAPGS_UNSAFE_STACK |
2601e64d IM |
815 | paranoid_restore\trace: |
816 | RESTORE_ALL 8 | |
3701d863 | 817 | jmp irq_return |
2601e64d IM |
818 | paranoid_userspace\trace: |
819 | GET_THREAD_INFO(%rcx) | |
820 | movl threadinfo_flags(%rcx),%ebx | |
821 | andl $_TIF_WORK_MASK,%ebx | |
822 | jz paranoid_swapgs\trace | |
823 | movq %rsp,%rdi /* &pt_regs */ | |
824 | call sync_regs | |
825 | movq %rax,%rsp /* switch stack for scheduling */ | |
826 | testl $_TIF_NEED_RESCHED,%ebx | |
827 | jnz paranoid_schedule\trace | |
828 | movl %ebx,%edx /* arg3: thread flags */ | |
829 | .if \trace | |
830 | TRACE_IRQS_ON | |
831 | .endif | |
72fe4858 | 832 | ENABLE_INTERRUPTS(CLBR_NONE) |
2601e64d IM |
833 | xorl %esi,%esi /* arg2: oldset */ |
834 | movq %rsp,%rdi /* arg1: &pt_regs */ | |
835 | call do_notify_resume | |
72fe4858 | 836 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d IM |
837 | .if \trace |
838 | TRACE_IRQS_OFF | |
839 | .endif | |
840 | jmp paranoid_userspace\trace | |
841 | paranoid_schedule\trace: | |
842 | .if \trace | |
843 | TRACE_IRQS_ON | |
844 | .endif | |
72fe4858 | 845 | ENABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 846 | call schedule |
72fe4858 | 847 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
848 | .if \trace |
849 | TRACE_IRQS_OFF | |
850 | .endif | |
851 | jmp paranoid_userspace\trace | |
852 | CFI_ENDPROC | |
853 | .endm | |
854 | ||
1da177e4 LT |
855 | /* |
856 | * Exception entry point. This expects an error code/orig_rax on the stack | |
857 | * and the exception handler in %rax. | |
858 | */ | |
d28c4393 | 859 | KPROBE_ENTRY(error_entry) |
7effaa88 | 860 | _frame RDI |
37550907 | 861 | CFI_REL_OFFSET rax,0 |
1da177e4 LT |
862 | /* rdi slot contains rax, oldrax contains error code */ |
863 | cld | |
864 | subq $14*8,%rsp | |
865 | CFI_ADJUST_CFA_OFFSET (14*8) | |
866 | movq %rsi,13*8(%rsp) | |
867 | CFI_REL_OFFSET rsi,RSI | |
868 | movq 14*8(%rsp),%rsi /* load rax from rdi slot */ | |
37550907 | 869 | CFI_REGISTER rax,rsi |
1da177e4 LT |
870 | movq %rdx,12*8(%rsp) |
871 | CFI_REL_OFFSET rdx,RDX | |
872 | movq %rcx,11*8(%rsp) | |
873 | CFI_REL_OFFSET rcx,RCX | |
874 | movq %rsi,10*8(%rsp) /* store rax */ | |
875 | CFI_REL_OFFSET rax,RAX | |
876 | movq %r8, 9*8(%rsp) | |
877 | CFI_REL_OFFSET r8,R8 | |
878 | movq %r9, 8*8(%rsp) | |
879 | CFI_REL_OFFSET r9,R9 | |
880 | movq %r10,7*8(%rsp) | |
881 | CFI_REL_OFFSET r10,R10 | |
882 | movq %r11,6*8(%rsp) | |
883 | CFI_REL_OFFSET r11,R11 | |
884 | movq %rbx,5*8(%rsp) | |
885 | CFI_REL_OFFSET rbx,RBX | |
886 | movq %rbp,4*8(%rsp) | |
887 | CFI_REL_OFFSET rbp,RBP | |
888 | movq %r12,3*8(%rsp) | |
889 | CFI_REL_OFFSET r12,R12 | |
890 | movq %r13,2*8(%rsp) | |
891 | CFI_REL_OFFSET r13,R13 | |
892 | movq %r14,1*8(%rsp) | |
893 | CFI_REL_OFFSET r14,R14 | |
894 | movq %r15,(%rsp) | |
895 | CFI_REL_OFFSET r15,R15 | |
896 | xorl %ebx,%ebx | |
897 | testl $3,CS(%rsp) | |
898 | je error_kernelspace | |
899 | error_swapgs: | |
72fe4858 | 900 | SWAPGS |
1da177e4 LT |
901 | error_sti: |
902 | movq %rdi,RDI(%rsp) | |
37550907 | 903 | CFI_REL_OFFSET rdi,RDI |
1da177e4 LT |
904 | movq %rsp,%rdi |
905 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
906 | movq $-1,ORIG_RAX(%rsp) | |
907 | call *%rax | |
10cd706d PZ |
908 | /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ |
909 | error_exit: | |
910 | movl %ebx,%eax | |
1da177e4 | 911 | RESTORE_REST |
72fe4858 | 912 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 913 | TRACE_IRQS_OFF |
1da177e4 LT |
914 | GET_THREAD_INFO(%rcx) |
915 | testl %eax,%eax | |
916 | jne retint_kernel | |
10cd706d | 917 | LOCKDEP_SYS_EXIT_IRQ |
1da177e4 LT |
918 | movl threadinfo_flags(%rcx),%edx |
919 | movl $_TIF_WORK_MASK,%edi | |
920 | andl %edi,%edx | |
921 | jnz retint_careful | |
10cd706d | 922 | jmp retint_swapgs |
1da177e4 LT |
923 | CFI_ENDPROC |
924 | ||
925 | error_kernelspace: | |
926 | incl %ebx | |
927 | /* There are two places in the kernel that can potentially fault with | |
928 | usergs. Handle them here. The exception handlers after | |
929 | iret run with kernel gs again, so don't set the user space flag. | |
930 | B stepping K8s sometimes report an truncated RIP for IRET | |
931 | exceptions returning to compat mode. Check for these here too. */ | |
9d8ad5d6 VN |
932 | leaq irq_return(%rip),%rcx |
933 | cmpq %rcx,RIP(%rsp) | |
1da177e4 | 934 | je error_swapgs |
9d8ad5d6 VN |
935 | movl %ecx,%ecx /* zero extend */ |
936 | cmpq %rcx,RIP(%rsp) | |
1da177e4 LT |
937 | je error_swapgs |
938 | cmpq $gs_change,RIP(%rsp) | |
939 | je error_swapgs | |
940 | jmp error_sti | |
d28c4393 | 941 | KPROBE_END(error_entry) |
1da177e4 LT |
942 | |
943 | /* Reload gs selector with exception handling */ | |
944 | /* edi: new selector */ | |
945 | ENTRY(load_gs_index) | |
7effaa88 | 946 | CFI_STARTPROC |
1da177e4 | 947 | pushf |
7effaa88 | 948 | CFI_ADJUST_CFA_OFFSET 8 |
72fe4858 GOC |
949 | DISABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI)) |
950 | SWAPGS | |
1da177e4 LT |
951 | gs_change: |
952 | movl %edi,%gs | |
953 | 2: mfence /* workaround */ | |
72fe4858 | 954 | SWAPGS |
1da177e4 | 955 | popf |
7effaa88 | 956 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 | 957 | ret |
7effaa88 | 958 | CFI_ENDPROC |
4b787e0b | 959 | ENDPROC(load_gs_index) |
1da177e4 LT |
960 | |
961 | .section __ex_table,"a" | |
962 | .align 8 | |
963 | .quad gs_change,bad_gs | |
964 | .previous | |
965 | .section .fixup,"ax" | |
966 | /* running with kernelgs */ | |
967 | bad_gs: | |
72fe4858 | 968 | SWAPGS /* switch back to user gs */ |
1da177e4 LT |
969 | xorl %eax,%eax |
970 | movl %eax,%gs | |
971 | jmp 2b | |
972 | .previous | |
973 | ||
974 | /* | |
975 | * Create a kernel thread. | |
976 | * | |
977 | * C extern interface: | |
978 | * extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
979 | * | |
980 | * asm input arguments: | |
981 | * rdi: fn, rsi: arg, rdx: flags | |
982 | */ | |
983 | ENTRY(kernel_thread) | |
984 | CFI_STARTPROC | |
985 | FAKE_STACK_FRAME $child_rip | |
986 | SAVE_ALL | |
987 | ||
988 | # rdi: flags, rsi: usp, rdx: will be &pt_regs | |
989 | movq %rdx,%rdi | |
990 | orq kernel_thread_flags(%rip),%rdi | |
991 | movq $-1, %rsi | |
992 | movq %rsp, %rdx | |
993 | ||
994 | xorl %r8d,%r8d | |
995 | xorl %r9d,%r9d | |
996 | ||
997 | # clone now | |
998 | call do_fork | |
999 | movq %rax,RAX(%rsp) | |
1000 | xorl %edi,%edi | |
1001 | ||
1002 | /* | |
1003 | * It isn't worth to check for reschedule here, | |
1004 | * so internally to the x86_64 port you can rely on kernel_thread() | |
1005 | * not to reschedule the child before returning, this avoids the need | |
1006 | * of hacks for example to fork off the per-CPU idle tasks. | |
1007 | * [Hopefully no generic code relies on the reschedule -AK] | |
1008 | */ | |
1009 | RESTORE_ALL | |
1010 | UNFAKE_STACK_FRAME | |
1011 | ret | |
1012 | CFI_ENDPROC | |
4b787e0b | 1013 | ENDPROC(kernel_thread) |
1da177e4 LT |
1014 | |
1015 | child_rip: | |
c05991ed AK |
1016 | pushq $0 # fake return address |
1017 | CFI_STARTPROC | |
1da177e4 LT |
1018 | /* |
1019 | * Here we are in the child and the registers are set as they were | |
1020 | * at kernel_thread() invocation in the parent. | |
1021 | */ | |
1022 | movq %rdi, %rax | |
1023 | movq %rsi, %rdi | |
1024 | call *%rax | |
1025 | # exit | |
1c5b5cfd | 1026 | mov %eax, %edi |
1da177e4 | 1027 | call do_exit |
c05991ed | 1028 | CFI_ENDPROC |
4b787e0b | 1029 | ENDPROC(child_rip) |
1da177e4 LT |
1030 | |
1031 | /* | |
1032 | * execve(). This function needs to use IRET, not SYSRET, to set up all state properly. | |
1033 | * | |
1034 | * C extern interface: | |
1035 | * extern long execve(char *name, char **argv, char **envp) | |
1036 | * | |
1037 | * asm input arguments: | |
1038 | * rdi: name, rsi: argv, rdx: envp | |
1039 | * | |
1040 | * We want to fallback into: | |
5d119b2c | 1041 | * extern long sys_execve(char *name, char **argv,char **envp, struct pt_regs *regs) |
1da177e4 LT |
1042 | * |
1043 | * do_sys_execve asm fallback arguments: | |
5d119b2c | 1044 | * rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack |
1da177e4 | 1045 | */ |
3db03b4a | 1046 | ENTRY(kernel_execve) |
1da177e4 LT |
1047 | CFI_STARTPROC |
1048 | FAKE_STACK_FRAME $0 | |
1049 | SAVE_ALL | |
5d119b2c | 1050 | movq %rsp,%rcx |
1da177e4 LT |
1051 | call sys_execve |
1052 | movq %rax, RAX(%rsp) | |
1053 | RESTORE_REST | |
1054 | testq %rax,%rax | |
1055 | je int_ret_from_sys_call | |
1056 | RESTORE_ARGS | |
1057 | UNFAKE_STACK_FRAME | |
1058 | ret | |
1059 | CFI_ENDPROC | |
3db03b4a | 1060 | ENDPROC(kernel_execve) |
1da177e4 | 1061 | |
0f2fbdcb | 1062 | KPROBE_ENTRY(page_fault) |
1da177e4 | 1063 | errorentry do_page_fault |
d28c4393 | 1064 | KPROBE_END(page_fault) |
1da177e4 LT |
1065 | |
1066 | ENTRY(coprocessor_error) | |
1067 | zeroentry do_coprocessor_error | |
4b787e0b | 1068 | END(coprocessor_error) |
1da177e4 LT |
1069 | |
1070 | ENTRY(simd_coprocessor_error) | |
1071 | zeroentry do_simd_coprocessor_error | |
4b787e0b | 1072 | END(simd_coprocessor_error) |
1da177e4 LT |
1073 | |
1074 | ENTRY(device_not_available) | |
1075 | zeroentry math_state_restore | |
4b787e0b | 1076 | END(device_not_available) |
1da177e4 LT |
1077 | |
1078 | /* runs on exception stack */ | |
0f2fbdcb | 1079 | KPROBE_ENTRY(debug) |
7effaa88 | 1080 | INTR_FRAME |
1da177e4 LT |
1081 | pushq $0 |
1082 | CFI_ADJUST_CFA_OFFSET 8 | |
5f8efbb9 | 1083 | paranoidentry do_debug, DEBUG_STACK |
2601e64d | 1084 | paranoidexit |
d28c4393 | 1085 | KPROBE_END(debug) |
1da177e4 LT |
1086 | |
1087 | /* runs on exception stack */ | |
eddb6fb9 | 1088 | KPROBE_ENTRY(nmi) |
7effaa88 | 1089 | INTR_FRAME |
1da177e4 | 1090 | pushq $-1 |
7effaa88 | 1091 | CFI_ADJUST_CFA_OFFSET 8 |
2601e64d IM |
1092 | paranoidentry do_nmi, 0, 0 |
1093 | #ifdef CONFIG_TRACE_IRQFLAGS | |
1094 | paranoidexit 0 | |
1095 | #else | |
1096 | jmp paranoid_exit1 | |
1097 | CFI_ENDPROC | |
1098 | #endif | |
d28c4393 | 1099 | KPROBE_END(nmi) |
6fefb0d1 | 1100 | |
0f2fbdcb | 1101 | KPROBE_ENTRY(int3) |
b556b35e JB |
1102 | INTR_FRAME |
1103 | pushq $0 | |
1104 | CFI_ADJUST_CFA_OFFSET 8 | |
5f8efbb9 | 1105 | paranoidentry do_int3, DEBUG_STACK |
2601e64d | 1106 | jmp paranoid_exit1 |
b556b35e | 1107 | CFI_ENDPROC |
d28c4393 | 1108 | KPROBE_END(int3) |
1da177e4 LT |
1109 | |
1110 | ENTRY(overflow) | |
1111 | zeroentry do_overflow | |
4b787e0b | 1112 | END(overflow) |
1da177e4 LT |
1113 | |
1114 | ENTRY(bounds) | |
1115 | zeroentry do_bounds | |
4b787e0b | 1116 | END(bounds) |
1da177e4 LT |
1117 | |
1118 | ENTRY(invalid_op) | |
1119 | zeroentry do_invalid_op | |
4b787e0b | 1120 | END(invalid_op) |
1da177e4 LT |
1121 | |
1122 | ENTRY(coprocessor_segment_overrun) | |
1123 | zeroentry do_coprocessor_segment_overrun | |
4b787e0b | 1124 | END(coprocessor_segment_overrun) |
1da177e4 | 1125 | |
1da177e4 LT |
1126 | /* runs on exception stack */ |
1127 | ENTRY(double_fault) | |
7effaa88 | 1128 | XCPT_FRAME |
1da177e4 | 1129 | paranoidentry do_double_fault |
2601e64d | 1130 | jmp paranoid_exit1 |
1da177e4 | 1131 | CFI_ENDPROC |
4b787e0b | 1132 | END(double_fault) |
1da177e4 LT |
1133 | |
1134 | ENTRY(invalid_TSS) | |
1135 | errorentry do_invalid_TSS | |
4b787e0b | 1136 | END(invalid_TSS) |
1da177e4 LT |
1137 | |
1138 | ENTRY(segment_not_present) | |
1139 | errorentry do_segment_not_present | |
4b787e0b | 1140 | END(segment_not_present) |
1da177e4 LT |
1141 | |
1142 | /* runs on exception stack */ | |
1143 | ENTRY(stack_segment) | |
7effaa88 | 1144 | XCPT_FRAME |
1da177e4 | 1145 | paranoidentry do_stack_segment |
2601e64d | 1146 | jmp paranoid_exit1 |
1da177e4 | 1147 | CFI_ENDPROC |
4b787e0b | 1148 | END(stack_segment) |
1da177e4 | 1149 | |
0f2fbdcb | 1150 | KPROBE_ENTRY(general_protection) |
1da177e4 | 1151 | errorentry do_general_protection |
d28c4393 | 1152 | KPROBE_END(general_protection) |
1da177e4 LT |
1153 | |
1154 | ENTRY(alignment_check) | |
1155 | errorentry do_alignment_check | |
4b787e0b | 1156 | END(alignment_check) |
1da177e4 LT |
1157 | |
1158 | ENTRY(divide_error) | |
1159 | zeroentry do_divide_error | |
4b787e0b | 1160 | END(divide_error) |
1da177e4 LT |
1161 | |
1162 | ENTRY(spurious_interrupt_bug) | |
1163 | zeroentry do_spurious_interrupt_bug | |
4b787e0b | 1164 | END(spurious_interrupt_bug) |
1da177e4 LT |
1165 | |
1166 | #ifdef CONFIG_X86_MCE | |
1167 | /* runs on exception stack */ | |
1168 | ENTRY(machine_check) | |
7effaa88 | 1169 | INTR_FRAME |
1da177e4 LT |
1170 | pushq $0 |
1171 | CFI_ADJUST_CFA_OFFSET 8 | |
1172 | paranoidentry do_machine_check | |
2601e64d | 1173 | jmp paranoid_exit1 |
1da177e4 | 1174 | CFI_ENDPROC |
4b787e0b | 1175 | END(machine_check) |
1da177e4 LT |
1176 | #endif |
1177 | ||
2699500b | 1178 | /* Call softirq on interrupt stack. Interrupts are off. */ |
ed6b676c | 1179 | ENTRY(call_softirq) |
7effaa88 | 1180 | CFI_STARTPROC |
2699500b AK |
1181 | push %rbp |
1182 | CFI_ADJUST_CFA_OFFSET 8 | |
1183 | CFI_REL_OFFSET rbp,0 | |
1184 | mov %rsp,%rbp | |
1185 | CFI_DEF_CFA_REGISTER rbp | |
ed6b676c | 1186 | incl %gs:pda_irqcount |
2699500b AK |
1187 | cmove %gs:pda_irqstackptr,%rsp |
1188 | push %rbp # backlink for old unwinder | |
ed6b676c | 1189 | call __do_softirq |
2699500b | 1190 | leaveq |
7effaa88 | 1191 | CFI_DEF_CFA_REGISTER rsp |
2699500b | 1192 | CFI_ADJUST_CFA_OFFSET -8 |
ed6b676c | 1193 | decl %gs:pda_irqcount |
ed6b676c | 1194 | ret |
7effaa88 | 1195 | CFI_ENDPROC |
4b787e0b | 1196 | ENDPROC(call_softirq) |
75154f40 AK |
1197 | |
1198 | KPROBE_ENTRY(ignore_sysret) | |
1199 | CFI_STARTPROC | |
1200 | mov $-ENOSYS,%eax | |
1201 | sysret | |
1202 | CFI_ENDPROC | |
1203 | ENDPROC(ignore_sysret) |